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					§ 2.05      Exclusive Rights
   The prerequisites for United States patent protection are not easy to satis-
   1
fy. Once they are satisfied, however, United States patents provide strong
           2
protection. Other countries provide for compulsory licensing or even revoca-
tion of patents that are not commercially exploited, but in the United States a
patentee has the legal right to refuse to license the patent and even to suppress
                                                  3
the invention during the limited patent term. Thus, a U.S. patent holder's
exclusive rights are strong indeed.

   [1]—Nature of Exclusive Rights
                                            4
   For almost two hundred years, the patentee's rights to exclude were an
immutable holy trinity: “the right to exclude others from making, using, or
                                                    5
selling the invention throughout the United States.” The theretofore invaria-
ble trinity, however, began to change under the Process Patents Amendments
               6
Act of 1988, which added the rights of process patent holders to exclude
others from using, selling or importing the products of their patented process-
   6.1
es. The Uruguay Round Agreements Act completed the transformation, as
                     6.2
of January 1, 1996, by adding the rights to control offers of sale in, and


   1
       See: §§ 2.03, 2.04 supra.
   2
      Indeed, patents provide the strongest protection of any type of intellectual property. See: §§
1.03[1], 2.01 supra.
    3
      See § 2.05[1][c] infra. For more thorough discussion of the right to refuse to license and to
suppress patents during their statutory terms, see Dratler, Licensing of Intellectual Property §
3.02[2], [4] (Law Journal Press 1994).
    4
      The Patent Act of 1790 gave each patentee “the sole and exclusive right and liberty of
making, constructing, using, and vending to others to be used, the said invention or discovery.”
Act of April 10, 1790, Ch. 7, § 1, 1 Stat. 109, 110.
    5
      See 35 U.S.C. § 154 (1986).
    6
      Omnibus Trade and Competitiveness Act of 1988, Title IX, Subtitle A, §§ 9001-9007,
Pub. L. No. 100-418, 102 Stat. 1107, 1563-1567 (Aug. 23, 1988), amending 35 U.S.C. §§ 154,
271, and 287 and adding 35 U.S.C. § 295, discussed in § 3.01 infra.
    6.1
        See 35 U.S.C. § 154, as amended by the Process Patent Amendments Act of 1988, Title
IX, Subtitle A, § 9002 of Omnibus Trade and Competitiveness Act of 1988, Pub. L. No. 100-
418, 102 Stat. 1107, 1563 (Aug. 23, 1988).
    6.2
        The changes to 35 U.S.C. § 154, like conforming changes to 35 U.S.C. § 271 (the defini-
tion of infringement) and other sections of the patent statute took effect “one year after the date
on which the WTO Agreement enter[ed] into force with respect to the United States.” Uruguay
Round Agreements Act § 534(a), Pub. L. No. 103-465, 108 Stat. 4809, 4990 (Dec. 8, 1994). See
also, Uruguay Round Agreements Act, supra, § 534(b)(2) (prescribing same effective date for
those portions of Section 532 amending 35 U.S.C. § 154(a)(1)). Since the WTO Agreement
entered into force both in general and for the United States on January 1, 1995, see: §§
1A.03[3], 1A.05[1] supra, the effective date of these amendments was January 1, 1996.

                                                                                        (Rel. 25)
                                                                                       6.3
importation of patent-protected products into, the United States.       These
changes were intended to bring the United States into compliance with the
                                        6.4
requirements of the TRIPS Agreement.
   As a result of these amendments, the statutory exclusive rights of patent
                                                            6.5
holders are more comprehensive than they were originally, but they are no
longer capable of such concise expression. A number of sections of the patent
        6.6                       6.7
statute, including Section 271, which defines infringement, mention the
patent holder's exclusive rights. But the exclusive rights as a whole are best
enumerated in Section 154(a)(1), which now reads in relevant part as follows:

   “Every patent shall contain . . . a grant to the patentee, his heirs or assigns,
   of the right to exclude others from making, using, offering for sale, or sell-
   ing the invention throughout the United States or importing the invention
   into the United States, and, if the invention is a process, of the right to ex-
   clude others from using, offering for sale, or selling throughout the United
   States, or importing into the United States, products made by that process.
        6.8
   . .”

                                       6.9
Correspondingly, Section 271 provides that the enumerated acts, if unau-
                                                                 6.10
thorized by the patentee, constitute infringement of the patent.

   6.3
         See Uruguay Round Agreements Act § 532(a)(1), 533, Pub. L. No. 103-465, 108 Stat.
4809, 4983-4984, 4988-4990 (Dec. 8, 1994), amending 35 U.S.C. §§ 41(c), 154, 252, 262, 271,
272, 287, 292(a), 295, and 307(b).
    6.4
         Article 28 of the TRIPS Agreement states that “[a] patent shall confer” certain enumerat-
ed rights, including the rights “to prevent third parties not having the owner's consent” from
“offering for sale, . . . or importing” a patented product or “at least the product obtained direct-
ly” by a patented process. Agreement on Trade-Related Aspects of Intellectual Property Rights,
Art. 28:1, Annex 1C to Agreement Establishing the World Trade Organization, reprinted in H.R.
Doc. 316, 103d Cong., 2d Sess. 1621, 1634 (Sept. 27, 1994). The primary motivation for the
amendment made by the Uruguay Round Agreements Act was to comply with these require-
ments. See Uruguay Round Agreements Act, Statement of Administrative Action 656, 1004,
1995 U.S. Code Cong. & Admin. News 4040, 4297 (“Section 533 of the bill amends section 154
of title 35 to conform to the requirements of [TRIPS Agreement] Article 28”).
    6.5
         See N.4 supra.
    6.6
         See N.6.3 supra.
    6.7
         35 U.S.C. § 271, as amended by Uruguay Round Agreements Act § 533(a), Pub. L. No.
103-465, 108 Stat. 4809, 4988 (Dec. 8, 1994).
    6.8
         35 U.S.C. § 154(a)(1), as amended by Uruguay Round Agreements Act § 532(a)(1), Pub.
L. No. 103-465, 108 Stat. 4809, 4983-4984 (Dec. 8, 1994).
    6.9
         35 U.S.C. § 271, as amended by Uruguay Round Agreements Act § 533(a), Pub. L. No.
103-465, 108 Stat. 4809, 4988 (Dec. 8, 1994).
    6.10
          See especially 35 U.S.C. § 271(a), (g), as amended by Uruguay Round Agreements Act
§ 533(a)(1), (4), Pub. L. No. 103-465, 108 Stat. 4809, 4988 (Dec. 8, 1994) (providing basic
definitions of infringement for product and process patents, respectively). For additional discus-
sion of Section 271, see: §§ 2.05[3], [4], 2.06 infra.

                                                                                        (Rel. 25)
    The statutory additions to the primordial trinity of making, using, and sell-
    6.11
ing      have considerable commercial importance. Process patentees' rights to
control the products of their patented processes, which are discussed else-
        6.12
where,        are vital in the pharmaceutical, biotechnology, and semiconductor
industries, in which important advances often take the form of new processes
                                                   6.13
for producing known or unpatentable products.
    While perhaps less important commercially than the rights of process pa-
tentees, the additional rights added by the Uruguay Round Agreements Act
                        6.14
are also significant.        Adding the rights to exclude others from offering a
patented invention for sale had two effects. First, it confirmed and strength-
ened precedent holding that offers of patented products for sale may consti-
                                                                        6.15
tute infringement if followed by substantial assembly and testing.           Under
the amended statute, any offer for sale of a patented product, or of a product
of a patented process, infringes the patent if the sale is unauthorized and is to
                                   6.16
occur during the patent's term.         Second, putting offers of sale in the class
of infringing acts helped insure that patentees would be free from serious un-
authorized competition with respect to their patented products during the en-
                    6.17
tire patent term.        It thus can be viewed, in essence, as a term-protection
         6.18
device.        The importation right, although perhaps less important, provided


   6.11
          See the text accompanying Ns.3-5 and Ns.4, 5 supra.
   6.12
          See generally, Chapter 3 infra.
   6.13
          These are the rights to use, offer for sale, sell, and import products of the patented pro-
cess. See the text at N.6.8 supra.
    6.14
          These are the rights to control offers of sale, as well as sales, and the right to control
importation. See the text accompanying Ns.6.1-6.3 supra.
    6.15
          See Paper Converting Machine Co. v. Magna-Graphics Corp., 745 F.2d 11, 14, 16, 19-
20 (Fed. Cir. 1984) (offer of sale, contract for delivery, and delivery of automatic paper rewinder
infringed patent, although machine was never fully assembled and operationally tested before
patent expired).
    6.16
          A definition of “offer for sale” added by the Uruguay Round Agreements Act limits the
concept of infringing offers to those directed toward pre-expiration sales. See 35 U.S.C. §
271(i), as added by Uruguay Round Agreements Act § 533(a)(5), Pub. L. No. 103-465, 108 Stat.
4809, 4988 (Dec. 8, 1994).
    6.17
          Although the motivation for the amendment was compliance with the TRIPS Agree-
ment, see N.6.4 supra, its effect was to draw a brighter line prohibiting marketing activity di-
rected toward infringing sales during the patent term, thereby avoiding the sorts of fine
distinctions made in Paper Converting Machine Co. v. Magna-Graphics Corp., 745 F.2d 11, 19-
20 (Fed. Cir. 1984). Cf., 745 F.2d 11, 26 (Fed. Cir. 1984) (opinion dissenting in part) (“A com-
petitor should be able to look to the patent claims and know whether his activity infringes or not.
Here, the majority provides no guidance to industry or the district courts”).
    6.18
          Cf., Paper Converting Machine Co. v. Magna-Graphics Corp., 745 F.2d 11, 16 (Fed.
Cir. 1984). (“With this case we are once again confronted with a situation which tests the tem-
poral limits of the American patent grant”), citing also Roche Products, Inc. v. Bolar Pharma-
ceutical Co., 733 F.2d 858 (Fed. Cir. 1984), which is discussed in § 2.05[1][b] infra.

                                                                                         (Rel. 25)
an explicit basis for excluding patented products from entry into the United
        6.19
States.
    Although the substance of a patentee's rights to exclude has thus changed
with time, two features of those rights remain fixed. First, no United States
patent gives any affirmative rights to practice an invention; the only rights it
                                                           6.20
provides are negative, i.e., the rights to exclude others.      This rule reflects
the fact that any patented technology may be dominated, and hence con-
trolled, by more fundamental underlying technology, for which patent rights
                                 7
may lie in third parties' hands.
    The second unchanged feature of a patentee's exclusive rights is their di-
visibility. A patentee may divide up the rights by grant or license in almost
any manner, and unauthorized performance of any one of the statutory activi-
                                     8
ties constitutes patent infringement. In the words of the Federal Circuit:

   “It is beyond argument that performance of only one of the three enumer-
   ated activities is patent infringement. It is well-established, in particular,
   that the use of a patented invention, without either manufacture or sale, is
   actionable. . . . Thus, the patentee does not need to have any evidence of
                                                          9
   damage or lost sales to bring an infringement action.”

There is no reason why the same conclusion should not apply to the expanded
list of exclusive rights provided by statutory amendment.

       [a]—The Power to Exclude and Its Strength



   6.19
          Even before the Uruguay Round amendment, patentees in the United States could ex-
clude patented products and the products of patented processes from unauthorized entry into the
United States by securing an exclusion order from a civil court or the International Trade Com-
mission. See § 13.02[1], [2] infra. The Uruguay Round Agreements Act provided no new gen-
eral authority for exclusion; rather, it served only to underscore the statutory authority for
existing procedure.
    6.20
          See 35 U.S.C. § 154(a)(1), as amended by Uruguay Round Agreements Act §
532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4983-4984 (Dec. 8, 1994), quoted in relevant
part in the text at N.6.8 supra. This was true before the 1988 and 1996 amendments as well. See
the text accompanying Ns.4-5 supra.
    7
      See § 2.05[1][a] infra.
    8
       See Extractol Process, Ltd. v. Hiram Walker & Sons, Inc., 153 F.2d 264, 266 (7th Cir.
1946) (dictum). The division of rights, of course, is subject to antitrust restraints.
    9
       Roche Products, Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858, 861 (Fed. Cir. 1984),
cert. denied 469 U.S. 856 (1984). (Emphasis in original.) Cf., Monsanto Co. v. McFarling, 302
F.3d 1291, 1293, 1298-1299 (Fed. Cir. 2002), cert. denied 123 S.Ct. 1357, 155 L.Ed.2d 196
(2003) (for purposes of preliminary injunction rejecting, as not likely to succeed, claims that
agreement for sale of patented, herbicide-resistant soybeans, requiring farmer not to save seed or
use grown seed for planting, constituted restraint of trade in violation of antitrust laws or misuse
of patent or was inconsistent with “exhaustion” or “first-sale” doctrine).

                                                                                        (Rel. 25)
   The statute's peculiar language of exclusion, referring to “the right to ex-
                                         10
clude others,” is a modern innovation. It reflects the fact that a patent does
                                                       11
not itself include the right to practice the invention. It is axiomatic, for ex-
ample, that an improvement patent is subject to the dominant patent; thus the
improvement patentee has no right to practice the improvement without a
license from the holder of the patent on the underlying invention being im-
        12
proved. Indeed, “a patent may be rendered quite useless, or 'blocked,' by
another unexpired patent which covers a vitally related feature of the manu-

   10
        The Patent Act of 1952 introduced this language for the sake of clarity. Compare Act of
July 19, 1952, Ch. 950, § 154, 66 Stat. 792, 804 (present language), with R.S. § 4884, based on
Act of May 23, 1930, Ch. 312, § 1, 46 Stat. 376 (“the exclusive right to make, use, and vend the
invention or discovery . . . throughout the United States”).
    11
        See Herman v. Youngstown Car Manufacturing Co., 191 F. 579, 584-585 (6th Cir. 1911)
(“A patent is not the grant of a right to make or use or sell. It does not, directly or indirectly,
imply any such right. It grants only the right to exclude others”).
    The inventor's right to practice the invention derives from the common law. See, e.g., Crown
Die & Tool Co. v. Nye Tool & Machine Works, 261 U.S. 24, 36-37, 43 S.Ct. 254, 67 L.Ed. 516
(1923) (under common law, inventor had right to make, use, and vend his inventions; patent law
makes that right exclusive); United States v. Line Material Co., 333 U.S. 287, 345, 68 S.Ct. 550,
92 L.Ed. 701 (1948) (dissenting opinion) (same). If another patent dominates the invention,
however, the dominant patentee's statutory rights of course displace the common law, and the
inventor must have the dominant patentee's permission to practice his invention. See N.12 infra.
    12
        See, e.g.:
    Supreme Court: United States v. Line Material Co., 333 U.S. 287, 290-291 & n.5, 295, 68
S.Ct. 550, 92 L.Ed. 701 (1948) (legally subservient improvement patent was economically dom-
inant because improvement provided manufacturing economy and enabled commercial success
of product).
    Third Circuit: Baldwin-Lima-Hamilton Corp. v. Tatnall Measuring Systems Co., 169 F.
Supp. 1, 9 (E.D. Pa. 1958), aff'd 268 F.2d 395 (3d Cir.), cert. denied 361 U.S. 894 (1959) (im-
provement in accused device does not avoid infringement, even where improvement is patented)
(Citations omitted.); Q-Tips, Inc. v. Johnson & Johnson, 207 F.2d 509, 511 (3d Cir. 1953), cert.
denied 347 U.S. 935 (1954) (dictum).
    Fifth Circuit: Ziegler v. Phillips Petroleum Co., 483 F.2d 858, 871 (5th Cir.), cert. denied
414 U.S. 1079 (1973) (“An improver cannot appropriate the basic patent of another, and an
unlicensed improver is an infringer”) (citing numerous authorities).
    Sixth Circuit: Herman v. Youngstown Car Manufacturing Co., 191 F. 579, 584-585 (6th Cir.
1911) (“a very considerable portion of the patents granted are in a field covered by a former
relatively generic or basic patent, are tributary to such earlier patent, and cannot be practiced
unless by license thereunder”).
    Eighth Circuit: Sbicca-Del Mac, Inc. v. Milius Shoe Co., 145 F.2d 389, 396-397 (8th Cir.
1944) (improvement on patented method was infringement).
    Ninth Circuit: Carpet Seaming Tape Licensing Corp. v. Best Seam Inc., 616 F.2d 1133,
1142 (9th Cir. 1980), cert. denied 464 U.S. 818 (1983) (“well-established law”).
    Tenth Circuit: McCullough Tool Co. v. Well Surveys, Inc., 343 F.2d 381, 402 (10th Cir.
1965), cert. denied 383 U.S. 933 (1966) (“mere fact that the accused device is more or less
efficient or performs additional functions” does not avoid infringement) (Citation omitted.)
    Federal Circuit: Water Technologies Corp. v. Calco, Ltd., 850 F.2d 660, 669 (Fed. Cir.),
cert. denied 488 U.S. 968 (1988) (“[i]t is elementary patent law that a patent may issue on an
improvement which infringes another's patent”); Atlas Powder Co. v. E.I. Du Pont de Nemours
& Co., 750 F.2d 1569, 1580-1581 (Fed. Cir. 1984) (patented improvement infringed dominant
patent under doctrine of equivalents).

                                                                                       (Rel. 25)
                        13
facturing process.” Thus, the fact that something accused of infringement
has been patented raises no presumption against a finding of infringement,
                                          13.1               14
whether under the doctrine of equivalents      or otherwise.

                                                          (Text continued on page 2-109)




   13
        Standard Oil Co. v. United States, 283 U.S. 163, 171 n.5, 51 S.Ct. 421, 75 L.Ed. 926
(1931).
    13.1
          See National Presto Industries, Inc. v. West Bend Co., 76 F.3d 1185, 1191-1192, 37
U.S.P.Q.2d (BNA) 1685 (Fed. Cir. 1996) (“The grant of a separate patent on the accused device
does not automatically avoid infringement, either literal or by equivalency. Improvements or
modifications may indeed be separately patentable if the requirements of patentability are met,
yet the device may or may not avoid infringement of the prior patent”). (Citations omitted.)
    Although not conclusive on the issue, the fact that an accused device has been granted a pa-
tent may be relevant when considering whether it infringes another patent under the doctrine of
equivalents, for that fact may implicate the substantiality of the differences between the accused
device and the patent's claims. See, e.g.: Zygo Corp. v. Wyko Corp., 79 F.3d 1563, 1570, 38
U.S.P.Q.2d (BNA) 1281 (Fed. Cir. 1996) (“The nonobviousness of the accused device, evi-
denced by the grant of a United States patent, is relevant to the issue of whether the change
therein is substantial” for purposes of doctrine of equivalents), citing Roton Barrier, Inc. v.
Stanley Works, 79 F.3d 1112, 1128, 37 U.S.P.Q.2d 1816 (Fed. Cir. 1996) (Nies, J., Additional
Views) (Other citations omitted.); National Presto Industries, Inc. v. West Bend Co., supra, 76
F.3d at 1192 (“The fact of separate patentability is relevant, and is entitled to due weight.”)
    14
        See, e.g.: Bio-Technology General Corp. v. Genentech, Inc., 80 F.3d 1553, 1559, 38
U.S.P.Q.2d (BNA) 1321 (Fed. Cir. 1996) (accused process fell within broadly worded claim
involving “isolating and purifying” human growth hormone, although it was allegedly unique
and indeed was patented, where defendant's new drug application characterized part of process
as “purification” step: “the existence of one's own patent does not constitute a defense to in-
fringement of someone else's patent”). (Citation omitted.); Hoechst Celanese Corp. v. BP Chem-
icals Ltd., 78 F.3d 1575, 1582, 38 U.S.P.Q.2d (BNA) 1126 (Fed. Cir. 1996), cert. denied 117
S.Ct. 275 (1996) (rejecting argument that patent on accused device required presumption of
noninfringement: “The fact of separate patentability presents no legal or evidentiary presumption
of noninfringement and, in this case, does not outweigh the substantial evidence supporting the
jury verdict of infringement”); Atlas Powder Co. v. E.I. Du Pont de Nemours & Co., 750 F.2d
1569, 1581 (Fed. Cir. 1984) (citing authorities).

                                                                                      (Rel. 25)
   The patent holder's rights to exclude others, however, provide tremendous
power over competition. A patentee may exclude from the marketplace even
                                                                           15
those who come upon the same invention innocently and independently.
Independent, original invention of the same subject matter is no defense to a
claim of infringement of a valid patent, unless the independent inventor has
          16
priority.

        [b]—The Elusive “Experimental Use” Exception
   By and large, any incursion on the patentee's exclusive rights to make, use,
and sell the patented invention constitutes infringement. There is, however, a
theoretical exception of minor practical importance. As a result of a line of
                              17                               18
early lower-court decisions, unauthorized experimental use of a patented
invention is not actionable if it is solely for such purposes as philosophical
                                                  19
inquiry, satisfaction of curiosity, or amusement.
   As construed by the courts, this judge-made “experimental use” exception
           20
is narrow; it does not cover experiments or testing for commercial purpos-


   15
        See: Kewanee Oil Co. v. Bicron Corp., 416 U.S. 470, 490, 94 S.Ct. 1879, 40 L.Ed.2d 315
(1974); § 2.01 supra.
    16
         A defendant may have priority of invention by being the first to conceive the invention
or, if the plaintiff was not diligent in reducing the invention to practice, by being the first to do
so. See: 35 U.S.C. §§ 102(a), 102(g); § 2.03[1][a], [c] supra.
    17
        “The standard for the experimental use exception to infringing uses grows from the judi-
cial origins of the exception.” Deuterium Corp. v. United States, 19 Cl. Ct. 624, 14 U.S.P.Q.2d
(BNA) 1636, 1643 (1990).
    18
        This exception is based on judicial construction of the concept of “use,” which the statute
does not define. See Roche Products, Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858, 861 (Fed.
Cir.), cert. denied 469 U.S. 856 (1984).
    19
         This principle was established as early as 1813 in Whittemore v. Cutter, 29 Fed. Cas.
1120, 1121 (C.C.D. Mass., 1813). There the court opined that “it could never have been the
intention of the legislature to punish a man who constructed [a patented] machine merely for
philosophical experiments or for the purpose of ascertaining the sufficiency of the machine to
produce its described effects.” A later circuit court decision held it “well-settled that an experi-
ment with a patented article for the sole purpose of gratifying a philosophical taste, or curiosity,
or for mere amusement is not an infringement of the rights of the patentee.” Peppenhausen v.
Falke, 19 Fed. Cas. 1048, 1049 (C.C.S.D.N.Y., 1861). See also, Roche Products, Inc. v. Bolar
Pharmaceutical Co., 733 F.2d 858, 863 (Fed. Cir. 1984), cert. denied 469 U.S. 856 (1984) (dis-
cussing precedent and concluding that use of patented drug for investigations relating to FDA
approval of generic version did not fall under experimental use exception because it was “solely
for business reasons and not for amusement, to satisfy idle curiosity, or for strictly philosophical
inquiry”).
    20
        See, e.g.:
    Federal Circuit: Roche Products, Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858, 862-863
(Fed. Cir. 1984) (“truly narrow”).
    Claims Court: Deuterium Corp. v. United States, 19 Cl. Ct. 624, 14 U.S.P.Q.2d (BNA)
1636, 1643 (1990).

                                                                                         (Rel. 25)
   21
es. Thus, for example, the exception does not apply to use of a patented
                                        22
drug for commercial testing purposes, even if the experiments are intended
                                                       23
to satisfy government-imposed testing requirements, even if they are ac-
                                               24
complished near the end of the patent's term, and even if the amounts used
           25
are small. For this reason Congress had to adopt a special statutory exemp-
tion to allow generic drug manufacturers to test patented drugs, before expira-
tion of the patents, for purposes of obtaining regulatory approval to market
                                                  26
generic versions after expiration of the patents.

    Cf., Douglas v. United States, 181 U.S.P.Q. (BNA) 170, 177 (Ct. Cl. 1974) (experimental
use doctrine is “an expression of the maxim de minimis non curat lex”), aff'd 510 F.2d 364, 370
(Ct. Cl.) (not reaching issue of experimental use), cert. denied 423 U.S. 825 (1975).
    See generally, Bee, Experimental Use as an Act of Patent Infringement, 39 J. Pat. & Trade-
mark Office Soc'y 357 (1957).
    21
        See, e.g.:
    Federal Circuit: Roche Products, Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858, 863 (Fed.
Cir.), cert. denied 469 U.S. 856 (1984) (tests, demonstrations and experiments which advance
user's legitimate business interests do not fall within experimental use exemption; there is no
exception for uses that have “definite, cognizable, and not insubstantial commercial purposes”).
    Claims Court: Deuterium Corp. v. United States, 19 Cl. Ct. 624, 14 U.S.P.Q.2d (BNA)
1636, 1643-1644 (1990) (exception did not apply to government-sponsored pilot project testing
process for cleansing geothermal steam, where “objective of the demonstration project was to
develop an economically feasible commercial application”) (dictum: no infringement was
found).
    Court of Claims: Pitcairn v. United States, 547 F.2d 1106, 1125-1126 (Ct. Cl. 1976), cert.
denied 434 U.S. 1051 (1978) (“Tests, demonstrations, and experiments” of helicopters for “lift-
ing ability, for the effect of vibration on installed equipment, flight speed and range, engine
efficiency, and numerous other factors . . . are intended uses of the infringing aircraft manufac-
tured for” the government and “are in keeping with the legitimate business of the using agency”)
(adopting opinion of district judge); Douglas v. United States, 181 U.S.P.Q.2d (BNA) 170, 177
(Ct. Cl. 1974), aff'd 510 F.2d 364, 370 (Ct. Cl.) (not reaching issue of experimental use), cert.
denied 423 U.S. 825 (1975) (dictum: evaluation testing of aircraft by Army, Navy and Air Force
was compensable use).
    The Federal Circuit has questioned the precedential value of Douglas, however, because the
Court of Claims did not affirm the portion of the trial judge's opinion dealing with experimental
use. See Roche Products, Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858, 863 (Fed. Cir.), cert.
denied 469 U.S. 856 (1984).
    22
        See Roche Products, Inc. v. Bolar Pharmaceutical Co., 733 F.2d 858, 860, 863 (Fed.
Cir.), cert. denied 469 U.S. 856 (1984) (use of patented drug for testing for FDA approval of
generic version before patent expired did not fall within experimental use exemption).
    23
        Id., 733 F.2d at 861. See also, 733 F.2d at 863-864 (refusing to hold that changes in FDA
approval procedures, increasing time required to obtain approval for generic version of patented
drug, impliedly modified statutory rules governing patent infringement, as “[r]epeals by implica-
tion are not favored”).
    24
        Id., 733 F.2d at 861 (accused use of patented drug came during last six months of patent
term).
    25
        Id., 733 F.2d at 860, 863, 866 (only five kilograms of patented drug, bought from foreign
manufacturer, were used; “[i]t is clear that the economic injury to [the patentee] is, or is threat-
ened to be, substantial, even though the amount of material used in the tests was small”).
    26
        See 35 U.S.C. § 271(e), discussed in § 2.06[7] infra.


                                                                                        (Rel. 25)
   The experimental use exception to infringement liability is not to be con-
fused with the experimental use exception to the “in public use or on sale” bar
                                              27
of Section 102(b) of the Patent Act of 1952. The two exceptions serve dif-
ferent purposes, and their respective scopes of application therefore differ. As
the Claims Court held:

   “The experimental use exception to a public use or sale protects an inven-
   tor's intellectual property for the period of development and testing prior to
   patent application. The experimental use exception to infringing uses, on
   the other hand, narrows the scope of intellectual property protection. . . .
   Thus,                                                                      the




   27
        35 U.S.C. § 102(b). See § 2.03[1][b][ii] supra.


                                                                       (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW


    broader objective standards developed to protect an inventor during ex-
   perimentation prior to patent application do not apply to experiments by a
                         28
   potential infringer.”

    Until recently, the courts had never addressed whether nonprofit university
                                                     29
research falls under the experimental use exception. The exception has been
                                                                        30
applied to experimental use that has no commercial consequences, and
some academic research is of that character. If the academic research in ques-
tion is supported by external funds, however, it may advance the funding par-
                                                                     31
ty's commercial interests and therefore fall outside the exception. This is
particularly so if the project involves applied research designed for the pur-
                                                             32
poses of making the invention work in commercial practice. Funding by the
government should not necessarily invoke the exception, for the government
                                                                         33
has agreed by statute to pay for unauthorized use of patented inventions. On


   28
        Deuterium Corp. v. United States, 19 Cl. Ct. 624, 14 U.S.P.Q.2d (BNA) 1636, 1643
(1990) (dictum).
    29
        Indeed, existing case law appears not to have probed the limits of the experimental use
exception very thoroughly. See Pitcairn v. United States, 547 F.2d 1106, 1125 (Ct. Cl. 1976),
cert. denied 434 U.S. 1051 (1978) (in suit for “reasonable and entire compensation” under 28
U.S.C. § 1498 for federal government's unauthorized use of patented helicopter inventions,
plaintiff did not claim compensation for use of static test mechanisms or for experimental heli-
copters developed under research and development contracts).
    30
        See, e.g.:
    Second Circuit: Dugan v. Lear Avia, Inc., 55 F. Supp. 223, 229 (S.D.N.Y. 1944) (finding no
infringement where it appeared “without contradiction by plaintiff, that defendant built [the
accused] device only experimentally and that it has neither manufactured it for sale nor sold
any”).
    Court of Claims: Chesterfield v. United States, 159 F. Supp. 371, 375 (Ct. Cl. 1958) (dic-
tum: if patent were valid, exception would have excused use of patented alloy “only for testing
and for experimental purposes”) (adopting opinion of trial commissioner).
    31
        As the Federal Circuit noted, “unlicensed experiments conducted with a view to the adap-
tion [sic] of the patented invention to the experimentor's business is [sic] a violation of the rights
of the patentee to exclude others from using his patented invention.” Roche Products, Inc. v.
Bolar Pharmaceutical Co., 733 F.2d 858, 863 (Fed. Cir. 1984), cert. denied 469 U.S. 856
(1984).
    32
        Cf., Deuterium Corp. v. United States, 19 Cl. Ct. 624, 14 U.S.P.Q.2d (BNA) 1636, 1637,
1643-1644 (1990) (dictum: pilot project, indirectly sponsored by United States government to
test process for cleansing geothermal steam, would not have qualified as experimental use be-
cause it examined “the economic feasibility and benefits” of the process and, if fully successful
“could have paved the way for broader commercial applications”).
    33
        See 28 U.S.C. § 1498:

   “Whenever an invention described in and covered by a patent of the United States is used or
   manufactured by or for the United States without license of the owner thereof or lawful right
   to use or manufacture the same, the owner's remedy shall be by action against the United

                                                                                          (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

the other hand, if the invention is used in the course of basic or other non-
applied research not directed toward commercial ends, and if it is funded in-
ternally by a nonprofit concern, by tax revenues in the case of a nonprofit
state institution, or perhaps even by the federal government, the experimental
use exception may apply. For example, it may be appropriate for courts to
allow basic, noncommercial biotechnology research in universities to proceed
without the threat of patent litigation, on the understanding that any practical
application to health care, or even applied research directed at commercial
                                         34
objectives, must be properly licensed.
    The Federal Circuit has refused to give significant scope to the defense of
                      34.1
“experimental use.”        Strong arguments have been made that the goals of
patent law would be furthered by sheltering some experimental use from in-
                     34.2
fringement claims.        However, the Federal Circuit has consistently held that
the experimental use defense is very narrow and limited to actions performed
"for amusement, to satisfy idle curiosity, or for strictly philosophical in-
        34.3
quiry."      Thus, a use will not qualify for the experimental use defense if it
                                                                           34.4
has "definite, cognizable, and not insubstantial commercial purposes."          So
a use will not be protected as experimental, even if it is done for such scien-
tific purposes as pharmaceutical research or even basic scientific research,
where there is some chance that the results of the research could lead to
commercial results. At a time when most major research universities make
efforts to capitalize on the results of research through tech-transfer offices and
other endeavors, the defense will rarely apply. Indeed, under the Federal Cir-

   States in the United States Claims Court for the recovery of his reasonable and entire com-
   pensation for such use and manufacture.”
   34
        In the Roche case, the defendant argued unsuccessfully that policies underlying the feder-
al Food, Drug and Cosmetic Act required that testing pursuant to the Act's regulatory require-
ments be exempt from patent infringement liability. See Roche Products, Inc. v. Bolar
Pharmaceutical Co., 733 F.2d 858, 863-865 (Fed. Cir.), cert. denied 469 U.S. 856 (1984). Yet
whether or not federal regulatory policies require such an exemption, the substantive statutory
and regulatory restraints on testing in patients and unapproved marketing certainly preclude
commercial exploitation of the results of experimentation without some sort of public notice.
These regulatory restraints help control experimental use of patented inventions in two ways.
First, by making sure that no one can exploit health care innovations commercially without
public notice, they help patentees police commercial exploitation of the results of experiments
using patented inventions. Second, they provide a relatively easy way to draw the line between
experimental use and commercial exploitation of health-related inventions. For example, courts
could define the commencement of commercial exploitation as the beginning of regulated clini-
cal testing.
    34.1
          See Madey v. Duke University, 307 F.3d 1351 (Fed. Cir. 2002).
    34.2
          See: Mueller, “No ‘Dilettante Affair’: Rethinking the Experimental Use Exception to
Patent Infringement for Biomedical Research Tools,” 76 Wash. L. Rev. 1, 17 (2001); O'Rourke,
Towards a Fair Use Defense in Patent Law, 100 Columbia L. Rev. 1177 (2000).
    34.3
          Madey v. Duke University, N.34.1 supra.
    34.4
          Id., 307 F.3d at 1362.


                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

cuit’s view, the business of a university is to conduct research, so its activities
will rarely qualify for the experimental use exception: “In short, regardless of
whether a particular institution or entity is engaged in an endeavor for com-
mercial gain, so long as the act is in furtherance of the alleged infringer's le-
gitimate business and is not solely for amusement, to satisfy idle curiosity, or
for strictly philosophical inquiry, the act does not qualify for the very narrow
and strictly limited experimental use defense. Moreover, the profit or non-
                                                  34.5
profit status of the user is not determinative.”       The defense is so narrow
that it would be strange for it to be successfully raised. It would be an odd
patent holder that sued for infringement against one who used the invention
simply “for amusement, to satisfy idle curiosity, or for strictly philosophical
inquiry.” Rather, the present rule reflects strong faith in the power of patents
to act as a spur to invention.

        [c]—Patent Suppression and Refusal to License
In the United States, a patent holder's exclusionary power is virtually abso-
lute. The patentee's failure to practice the invention, or delay in doing so, pro-
vides no excuse for infringement. In many foreign countries, compulsory
                                 35                                     36
licensing may be available,          or a patent may be revoked,           if the

   34.5
          Id., 307 F.3d 1363.
   35
        The Paris Convention allows each member nation to enact provisions for compulsory li-
censing if a patent is not worked in the nation that granted it for three years after issue. See
International Convention for the Protection of Industrial Property, done at Paris on March 20,
1883, 25 Stat. 1372, TS No. 379 (Paris Convention), as revised at Stockholm on July 14, 1967,
Arts. 5(A)(2), (4), 21 U.S.T. 1629, 1636-1637, TIAS 6923. A number of nations have imple-
mented this provision by domestic legislation. See, e.g.:
    People's Republic of China: Chinese Patent Law, March 12, 1984, Ch. VI, Arts. 52, 57, 58,
reprinted in English in 2C Sinnott, World Patent Law & Practice China 15 (1991) (“reasonable
exploitation fee” may be fixed by parties, but Patent Office may “adjudicate,” and patentee may
appeal to court).
    France: French Law on Patents of Invention, Jan. 2, 1968, as amended July 13, 1978, Arts.
32, 33, reprinted in English in 2D Sinnott, World Patent Law & Practice France 74-75 (1991)
(compulsory licenses are available three years after grant or four years after application upon
petition to court).
    Germany: German Patent Law of Jan. 2, 1968, as amended May 26, 1972, Art. 15(1) (com-
pulsory license is available without time limit where “indispensable in the public interest”); Art.
15(2) (patent may be cancelled two years after final grant of compulsory license if “exclusively
or mainly” exploited outside of West Germany), reprinted in English in 2D Sinnott, World Pa-
tent Law & Practice West Germany 13 (1990).
    Japan: Japanese Patent Law, Law No. 121, April 13, 1959, as amended through June 1,
1987, Art. 83 (three year time limit), Art. 86 (Director-General of Patent Office determines
scope of license, amount of consideration, and method and time of payment), reprinted in Eng-
lish in 2F Sinnott, World Patent Law and Practice Japan 37-39 (1991).
    United Kingdom: Patents Act 1977 (U.K.), as amended through 1988, § 37(1) (three year
time limit), § 37(3) (compulsory license is available for nonworking), reprinted in 2D Sinnott,
World Patent Law & Practice Great Britain 41-43 (1991).
    36
        The Paris Convention allows a patent to be cancelled if the owner's exclusive rights con-
tinue to be abused for two years after the grant of the first compulsory license. See International

                                                                                       (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW




Convention for the Protection of Industrial Property, done at Paris on March 20, 1883, 25 Stat.
1372, TS No. 379 (Paris Convention), as revised at Stockholm on July 14, 1967, Art. 5(A)(3),
(4), 21 U.S.T. 1629, 1637, TIAS 6923. See also, N.35 supra (Germany).

                                                                                    (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

invention is not practiced or “worked” domestically within a specified period
         37
of time. The United States, however, has no similar compulsory licensing or
                                   38
general “working” requirements.
   In the United States, a patentee is free to practice or to refuse to practice
the invention at will. Supreme Court precedent clearly permits patentees to
                                                                      39
suppress or refuse to license their patents during the patent term, and the
1988 patent misuse amendments codified these rights with unmistakable clari-
   40
ty. Thus, the holder of a United States patent is free to “exact royalties as
high as he can negotiate” in exchange for a license, or to refuse to grant any
                41
license at all.
   As these principles suggest, the United States' approach to patent protec-
tion is based on a firm belief in the free market. By giving the patentee a near-
absolute right to control the patented invention during the patent term, United
States law promotes voluntary free-market transactions in which the patent



   37
        See generally, Baxter and Sinnott, 2 World Patent Law and Practice Ch. 8 (1987).
   38
         The United States government has authority to compel licensing only under very limited
circumstances. See:
    Atomic Energy Act: 42 U.S.C. § 2183 (compulsory licensing of patents related to atomic en-
ergy and nuclear devices).
    Clean Air Act: 42 U.S.C. § 7608 (patent licenses needed to comply with government anti-
pollution orders and to avoid restriction of competition).
    In addition, courts in rare cases create the same effect as a compulsory license by awarding a
patent holder damages for infringement but denying injunctive relief. See, e.g.:
    Second Circuit: Foster v. American Machine Foundry Co., 492 F.2d 1317, 1319, 1324 (2d
Cir.), cert. denied 419 U.S. 833 (1974) (denying injunction and requiring compulsory license
where welding patent was owned by patent attorney who had never exploited it).
    Seventh Circuit: City of Milwaukee v. Activated Sludge, Inc., 69 F.2d 577, 593 (7th Cir.).,
cert. denied 293 U.S. 576 (1984) (granting damages but denying injunction where nonuse of
patented sewage disposal system would have caused pollution of Lake Michigan).
    Cases like these, however, are rare exceptions to the general rule.
    39
         See, e.g.: Dawson Chemical Co. v. Rohm & Haas Co., 448 U.S. 176, 214-215, 100 S.Ct.
2601, 65 L.Ed.2d 696 (1980) (where nonstaple chemical had no known use other than as herbi-
cide, patentee of method for using chemical as herbicide could control manufacture and sale of
chemical by others and could refuse to grant licenses in order to arrogate market for chemical to
itself); Special Equipment Co. v. Coe, 324 U.S. 370, 379-380, 65 S.Ct. 741, 89 L.Ed. 1006
(1945) (patent holder could enforce patent on subcombination of patented combination, even
though patent holder never had used or manufactured subcombination by itself); Continental
Paper Bag Co. v. Eastern Paper Bag Co., 210 U.S. 405, 428-429, 28 S.Ct. 748, 52 L.Ed. 1122
(1908) (where expense of modifying existing plant to practice patent would have been consider-
able even if old machines could have been altered, suppression of patent to preserve investment
in plant, which did not diminish supply or raise prices, was not unreasonable or unlawful, even
though use of invention might have produced better products).
    See also, Dratler, Licensing of Intellectual Property § 3.02[1] (Law Journal Press 1994)
(discussing cases and statutes generally permitting refusal to license and suppression of patents).
    40
        See § 2.06[4][c] infra.
    41
        Brulotte v. Thys Co., 379 U.S. 29, 33, 85 S.Ct. 176, 13 L.Ed.2d 99 (1964) (dictum).


                                                                                       (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                                                                              42
holder grants others ownership of, or rights in, the invention. In this respect
United States law seeks to exploit the paradox of the marketplace, by which
strong rules of private ownership, although in theory restricting the use of
property, in practice encourage its free exchange and effective use by making
it valuable.

   [2]—Duration of Exclusive Rights
                                                                         43
    Patents are the strongest form of intellectual property, but they operate
                           44                                               45
for strictly limited terms. Until the advent of the TRIPS Agreement, all
patents in the United States lasted for fixed terms of years—fourteen years for
                45.1                                                   45.2
design patents       and seventeen years for utility and plant patents —and
all terms were measured from the date of grant. As a result, patent terms, alt-
                                                45.3
hough subject to extension in certain cases,         were generally easy to com-
pute.
                                   45.4
    For utility and plant patents,      the TRIPS Agreement changed both the
length of the term and the manner of its computation. Article 33 of the TRIPS
Agreement requires all WTO Members to provide a minimum term of “twen-
                                          45.5
ty years counted from the filing date.”        Section 532 of the Uruguay Round
                  46
Agreements Act conformed the terms of utility and plant patents in the
                                     46.1
United States to this requirement.        The term for design patents, however,


   42
       See §§ 1.01[1], 1.08[1] supra. See generally, Dratler, Licensing of Intellectual Property §
3.02[2][a], [4] (Law Journal Press 1994) (discussing cases and statutes generally permitting
refusal to license and suppression of patents).
    43
       See: §§ 1.03[1], 1.08[1], 2.05[1][b] supra.
    44
       See: §§ 1.04, 1.08[1] supra.
    45
        Agreement on Trade-Related Aspects of Intellectual Property Rights, Annex 1C to
Agreement Establishing the World Trade Organization (TRIPS Agreement), reprinted in H.R.
Doc. 316, 103d Cong., 2d Sess. 1621 (Sept. 27, 1994). See generally, § 1A.01 supra.
    45.1
          See 35 U.S.C. § 173 (1994).
    45.2
          See: 35 U.S.C. §§ 154, 161 (1994).
    45.3
          See 35 U.S.C. § 156, discussed in § 2.05[2][b][ii] infra.
    45.4
          Utility patents are the most important kind of patent, and plant patents cover certain
asexually reproduced plants. See § 2.02[1][a], [c] supra. The only other kind of patent in the
United States is the design patent. See § 2.02[1][b] supra.
    45.5
          Agreement on Trade-Related Aspects of Intellectual Property Rights, Art. 33, Annex 1C
to Agreement Establishing the World Trade Organization, reprinted in H.R. Doc. 316, 103d
Cong., 2d Sess. 1621, 1636 (Sept. 27, 1994) (Footnote omitted.), discussed in § 1A.06[2][d]
supra.
    46
       Uruguay Round Agreements Act § 532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4983-
4985 (Dec. 8, 1994), amending 35 U.S.C. § 154.
    46.1
          See § 2.05[2][a][i] infra.


                                                                                      (Rel. 25)
2-05                    PATENTS              INTELLECTUAL PROPERTY LAW

remained unchanged; it is still fourteen years from the date of the patent's
       46.2
grant.
    At first glance, the rule for utility and plant patents seems simple: a patent's
                                                           46.3
term runs twenty years from the application date.               There are, however,
three sources of complexity. First, where a series of related applications is
filed for the same invention, special rules determine which application's date
                          46.4
begins the patent term.        Second, a patent's term may be subject to adjust-
                                              46.5
ment or extension for several reasons.             Effective June 8, 1995, amend-
ments made by the Uruguay Round Agreements Act added three additional
                                                                             46.6
grounds—not theretofore recognized—for patent term extension.                      The
                                         46.7
Patent Term Guarantee Act of 1999             added yet other grounds for adjusting
a patent’s term and clarified the possibility of negative adjustments (although
                                                                   46.8
not producing a net term decrease) for the patentee’s delay.             It also clari-
fied the procedure for adjusting patent terms and strongly implied that the
                                                                                   46.9
length of a patent’s term may be challenged in infringement litigation.
Previous legislation providing term extensions for regulated drug products,
medical devices, food additives and color additives—to compensate for time
                                                                   46.10
lost in pre-marketing regulatory review—remains in effect.                The adjust-
                                                                                  46.11
ments, but not the extensions, to apply to plant as well as utility patents.
Finally, transition rules for utility and plant patents created additional com-
plexity for patent terms expiring and patent applications filed during certain
                    46.12
transition periods.

       [a]—Basic Rules for Computing the Patent Term

   46.2
         See 35 U.S.C. § 173, as amended by Uruguay Round Agreements Act § 532(c)(3), Pub.
L. No. 103-465, 108 Stat. 4809, 4987 (Dec. 8, 1994) (“Patents for designs shall be granted for
the term of fourteen years from the date of grant”).
    46.3
         See § 2.05[2][a][i] infra.
    46.4
         See § 2.05[2][a][ii] infra.
    46.5
         See § 2.05[2][b] infra.
    46.6
         See § 2.05[2][b][i] infra.
    46.7
          Patent Term Guarantee Act of 1999, Subtitle D (Patent Term Guarantee) of Tit. IV
(American Inventors Protection Act of 1999), §§ 4401-4405, of Intellectual Property and Com-
munications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B, Appendix I
(S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-557 through 1501A-561 (Nov.
29, 1999), discussed in § 2.05[2][b][i] infra.
    46.8
         See § 2.05[2][b][i] infra.
    46.9
         See id.
    46.10
          See § 2.05[2][b][ii] infra.
    46.11
          See § 2.05[2][b][i], [ii] infra.
    46.12
          See § 2.05[2][c] infra.


                                                                                   (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

   The current basic rule for utility and plant patent terms is deceptively sim-
ple: in accordance with the TRIPS Agreement, each term runs for twenty
                                        46.13
years from the application filing date.       This basic rule, however, is subject
                                                                             46.14
to refinement for inventions involving more than one patent application,
                                                      46.15
as well as to patent term adjustment and extension          and certain transition
       46.16
rules.

            [i]—The Basic Rule
                                                        46.17
   The basic rule of the TRIPS Agreement,          as implemented in the United
                                                 46.18
States by the Uruguay Round Agreements Act,            is simple: utility and plant
             46.19
patent terms       run for a period of twenty years from the application filing
      46.20
date.       They are no longer measured, as they once were, from the date of
                        46.21
issuance of the patent.
   Where related applications cover the same invention, however, applying
this rule requires some refinement: one must choose which of the relevant
applications is the one whose filing date begins the patent term. In certain
cases, the filing date of a daughter application on which a patent is granted
relates back to the filing date of an earlier parent application for purposes of
                              46.22
computing the patent term.

            [ii]—Relation Back
   In several situations, one or more later-filed patent applications (“daugh-
ter” applications) may claim the priority of an earlier-filed patent application
(the “parent” application) disclosing (but not necessarily claiming) the same
           46.23
invention.       The four most common situations of this kind involve: (1)

   46.13
           See: § 2.05[2] (introduction) supra; 2.05[2][a][i] infra.
   46.14
           See § 2.05[2][a][ii] infra.
   46.15
           See § 2.05[2][b] infra.
   46.16
           See § 2.05[2][c] infra.
   46.17
           See the text accompanying Ns.45.4-45.5 and N.45.5 supra.
   46.18
            See Uruguay Round Agreements Act § 532(a)(1), Pub. L. No. 103-465, 108 Stat.
4809, 4983-4985 (Dec. 8, 1994), amending 35 U.S.C. § 154.
    46.19
           Design patent terms are unchanged; they still run fourteen years from the date of pa-
tent grant. See § 2.05[2] (introduction) supra.
    46.20
           See 35 U.S.C. § 154(a)(2), as added by Uruguay Round Agreements Act § 532(a)(1),
Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994), quoted in § 2.05[2][a][ii] infra.
    46.21
           See § 2.05[2] (introduction) supra.
    46.22
           See § 2.05[2][a][ii] infra.
    46.23
           The terms “parent” and “daughter” applications are given very broad meanings in this
subsection. A parent application is one whose priority is claimed by a later application for an

                                                                                     (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                           46.24
continuations and continuations-in-part under Section 120;         (2) divisional
                                  46.25
applications under Section 121,         (3) continuations, continuations-in-part
                                                   46.26
and divisional applications under Section 365(c);        and (4) foreign-priority
              46.27
applications.       In each of these situations, a patent issued on a daughter
application may claim the priority of the parent application. Which applica-



invention disclosed (although not necessarily claimed) in the earlier parent application. A
daughter application is any later application so claiming the priority of the parent application. A
single parent application may have more than one daughter application, for example, when a
parent application disclosing more than one distinct invention is divided into separate divisional
applications for each invention. See 35 U.S.C. § 121 (governing such divisional applications),
outlined in N.46.25 infra.
    46.24
           35 U.S.C. § 120 (providing for priority of second application based on filing of first
application disclosing same invention by same inventors and specifically referenced in second
application, as long as second application is “filed before the patenting or abandonment of or
termination of proceedings on the first application or on an application similarly entitled to the
benefit of the filing date of the first application”).
    The scope of Section 120 is not limited to continuations and continuations-in-part of United
States applications. It provides the basic rule for relation back in all cases not involving foreign
priority. See also: 35 U.S.C. § 121 (requiring “compli[ance] with the requirements of section
120” for divisional applications in United States); 35 U.S.C. § 365(c) (providing rules for con-
tinuations, continuations-in-part, and divisions as between international applications designating
United States and United States applications), outlined in N.46.26 infra.
    46.25
           35 U.S.C. § 121 (providing for priority of divisional application, i.e., application re-
stricted at request of Patent and Trademark Office to one of “two or more independent and dis-
tinct inventions . . . claimed in one [earlier] application,” based upon filing date of earlier
application, as long as requirements of Section 120 are met, see N.46.24 supra).
    46.26
           35 U.S.C. § 365(c) (providing for relation back of international application designat-
ing United States to earlier United States application or to earlier international application des-
ignating United States, as well as relation back of United States application to earlier
international application designating United States, all “[i]n accordance with the conditions and
requirements of section 120”).
    No foreign priority is involved under Section 365(c) because an international application
designating the United States is equivalent to a United States application. See: 35 U.S.C. §§
102(e), 363, discussed in § 2.08 infra.
    46.27
            See: 35 U.S.C. § 119(a)-(d), as redesignated by Uruguay Round Agreements Act §
532(b) (1)(B), Pub. L. No. 103-465, 108 Stat. 4809, 4985 (Dec. 8, 1994) (priority of United
States application based upon previously filed foreign application); 35 U.S.C. § 365(a) (priority
of United States application based upon previously filed international application designating at
least one country other than United States); 35 U.S.C. § 365(b) (priority of international applica-
tion designating United States based upon previously filed foreign application or previously
filed international application designating at least one country other than United States).
    Just as Section 120 provides the basic rules for relation back in situations not involving for-
eign priority, Section 119 provides certain basic rules for relation back in cases involving for-
eign priority. See: 35 U.S.C. § 365(a), as amended by Uruguay Round Agreements Act § 532(c)
(4)(A), Pub. L. No. 103-465, 108 Stat. 4809, 4987 (Dec. 8, 1994) (providing for priority “[i]n
accordance with the conditions and requirements of subsections (a) through (d) of section 119”);
35 U.S.C. § 365(b), as amended by Uruguay Round Agreements Act § 532(c)(4)(B), Pub. L. No.
103-465, 108 Stat. 4809, 4987 (Dec. 8, 1994) (providing for priority “[i]n accordance with the
conditions and requirements of section 119(a)”).

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

tion's filing date then determines the beginning of the twenty-year term of
                     46.28
patent protection?
                               46.29
   The Patent Act of 1952,           as amended by the Uruguay Round Agree-
             46.30
ments Act,         provides an answer to this question. If the patent is granted on
a continuation, continuation-in-part, or divisional application under Sections
120, 121, or 365(c), and if that application is filed on or after January 1,
       46.31
1996,        the filing date for patent-term purposes relates back to the date of
                                                         46.32
the earliest specifically referenced parent application.
   The rule for relation back in cases of foreign priority, however, is to the
contrary. In the case of a claim of foreign priority (whether based upon a pre-
viously filed foreign application or a previously filed international applica-
tion), only the later United States filing is considered in computing the patent
      46.33
term.         That is, the daughter application's filing date, and not the
          46.34
parent's,       begins the patent term. This rule is required by the Paris Con-
vention, which demands that patent terms be independent of any claim of in-
                       46.35
ternational priority.        Similarly, since a provisional patent application is

   46.28
           See § 2.05[2][a][i] supra.
   46.29
           Act of July 19, 1952, Ch. 950, 66 Stat. 800, codified as amended at 35 U.S.C. §§ 1-
376.
   46.30
          Uruguay Round Agreements Act, Pub. L. No. 103-465, 108 Stat. 4809 (Dec. 8, 1994).
See generally, § 1A.10 supra.
    46.31
          This additional condition appears as part of the transition rules of the Uruguay Round
Agreements Act. See Uruguay Round Agreements Act § 534(b)(3), Pub. L. No. 103-465, 108
Stat. 4809, 4990 (Dec. 8, 1994), discussed in § 2.05[2][c][ii] infra.
    46.32
          See 35 U.S.C. § 154(a)(2), as added by Uruguay Round Agreements Act § 532(a)(1),
Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994):
   “(2) TERM—Subject to the payment of fees under this title, [the patent] grant shall be for a
   term beginning on the date on which the patent issues and ending 20 years from the date on
   which the application for patent was filed in the United States or, if the application contains
   a specific reference to an earlier filed application or applications under section 120, 121, or
   365(c) of this title [35 U.S.C.], from the date on which the earliest such application was
   filed.”
    The requirement that the daughter application contain “a specific reference” to the parent
application is also a general requirement under Section 120, see 35 U.S.C. § 120, outlined in
N.46.24 supra, whose rules govern relation back in all these cases. See N.46.24 supra.
    46.33
           See 35 U.S.C. § 154(a)(3), as added by Uruguay Round Agreements Act § 532(a)(1),
Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994) (“Priority under Section 119, 365(a),
or 365(b) of this title shall not be taken into account in determining the term of a patent”). For
outlines of the cited sections, see N.46.27 supra.
    46.34
           See N.46.23 supra.
    46.35
           See International Convention for the Protection of Industrial Property, done at Paris on
March 20, 1883, 25 Stat. 1372, TS No. 379, as revised at Stockholm on July 14, 1967, 21
U.S.T. 1629, TIAS 6923 (Stockholm text), Art. 4 bis(5) (“Patents obtained with the benefit of
priority shall, in the various countries of the Union, have a duration equal to that which they

                                                                                       (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW

                                                                                          46.36
not an examinable application and serves only to preserve a priority date,
its filing date does not begin the patent term; the term begins only upon the
                                                                       46.37
filing, if any, of a formal patent application for the same invention.
    The rule for relation back in computing the patent term thus depends upon
whether foreign priority is claimed. If it is not, the term for a patent issued on
a daughter application (whether a continuation, continuation-in-part, or divi-
sional application) begins upon the filing date of the earliest specifically ref-
                              46.38
erenced parent application.         If it is, only the filing date of the daughter
                      46.39
application counts.
    In any event, relation back requires that the daughter application make a
                                                  46.40
“specific reference” to the parent application.         This requirement opens the
door to a certain kind of strategic planning by patent applicants. Since rela-
tion back shortens the effective patent term by beginning the fixed twenty-
year duration at an earlier date, applicants can secure a longer time by declin-
ing to claim the priority of a parent application not involving foreign priority,
even if such a parent application exists. They can do so simply by declining to
make specific reference in the daughter application to the parent.
    Doing so, of course, would forfeit the priority of the parent applica-
      46.41
tion.       It therefore would create a risk that the daughter application would
be rejected or any patent issued on it later invalidated for lack of novelty or
nonobviousness, based on developments in the state of the art in the inter-




would have, had they been applied for or granted without the benefit of priority”). See also,
Uruguay Round Agreements Act, Statement of Administrative Action 656, 1002, 1995 U.S.
Code Cong. & Admin. News 4040, 4296 (“This provision is necessary to comply with the re-
quirements of Article 4bis(5) of the Paris Convention for the Protection of Industrial Property
[sic] under which countries must exclude from their measurement of patent term any periods for
which an applicant has based a claim of priority to an earlier foreign-filed application”).
    46.36
          See § 1.06[1] supra.
    46.37
           See Uruguay Round Agreements Act, Statement of Administrative Action 656, 1004,
1995 U.S. Code Cong. & Admin. News 4040, 4297 (new section 119(e), providing for relation
back of daughter formal applications to their parent provisional applications, “will provide ap-
plicants who take advantage of this section a period of up to 12 months in which to file the
formal application but claim priority based on the provisional application filed in the United
States, which period will not be included in the calculation of patent term”). This Statement of
Administrative Action is, by law, an authoritative interpretation of the statute. See § 1A.04
supra.
    46.38
          See the text accompanying Ns.46.30-46.32 supra.
    46.39
          See the text accompanying Ns.46.32-46.37 supra.
    46.40
           35 U.S.C. §§ 120, 154(a)(2). This general requirement of Section 120, see N.46.24
supra, is repeated in the provision for the patent term. See 35 U.S.C. § 154(a)(2), as added by
Uruguay Round Agreements Act § 532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec.
8, 1994), quoted in N.46.32 supra.
    46.41
          See 35 U.S.C. §§ 120, 121, 365(c), outlined in Ns.46.24-46.26 supra.


                                                                                     (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    46.42
im.      If the patent applicant believes this risk is low, however, and if the
period of time involved in the relation back is sufficiently long, the applicant
may wish to take the risk of invalidation resulting from loss of the priority of
the parent application in order to extend the patent term.
   Obviously this strategic decision cannot be made in the abstract. It depends
upon the facts of each case, including the nature of the invention, the exten-
sion of the effective patent term to be achieved, the state of the art, the rate of
progress in the art, whether competitors are working on parallel lines of re-
search, and the extent to which knowledge of others' research and develop-
ment (including their still-secret patent applications) is available to the
applicant. In most cases, uncertainty with regard to the risk of invalidation
will compel rejection of this risk and assertion of a claim of priority, but in
some cases the risk may be worth taking in order to lengthen the effective
patent term.

       [b]—Patent Term Adjustment and Extension
    Not only does the term of a utility or plant patent depend on the time of fil-
                                  46.43                                   46.44
ing of a particular application;        it also is subject to adjustment        and
           46.45
extension        for various reasons. As a result, the term (duration) of any utili-
                    46.46
ty or plant patent        may vary from the applicable statutory norm: twenty
                                                            46.47
years after the earliest relevant application filing date.        In order to deter-
mine the adjusted or extended term, an interested party must consult the pa-
tent certificate itself or the records of the Patent and Trademark Office in
                            46.48
Washington, D.C. (PTO).
    A byproduct of this statutory scheme is that the length of the patent term,
i.e., the duration of patent protection, is subject to legal challenge for non-
                                                  46.49
compliance with the relevant statutory norms.            In other words, a patent’s
term is just one more thing that an accused infringer or perhaps a licensee

   46.42
           See generally, § 2.03[1], [3] (discussing requirements of novelty and nonobviousness
under United States law).
    46.43
           See § 2.05[2][a][ii] supra.
    46.44
           See § 2.05[2][b][i] infra.
    46.45
           See § 2.05[2][b][ii] infra.
    46.46
           Regulations of the Patent and Trademark Office (PTO) purport to exclude both reissue
and design patents from term adjustments. See § 2.05[2][b][i] infra. The exclusion of design
patents appears consistent with common sense (because design patents have fixed terms meas-
ured from their issue dates) and with statutory authority, although the relevant provisions are far
from models of clarity. See id. The exclusion for reissue patents seems reasonable, because
reissue is entirely at the patentee’s initiative. See § 2.03[1][d][iii] supra.
    46.47
           See § 2.05[2][a][i] supra.
    46.48
           See § 2.05[2][b][i], [ii] infra.
    46.49
           Id.


                                                                                       (Rel. 25)
2-05                      PATENTS            INTELLECTUAL PROPERTY LAW

may challenge by way of defense or declaratory judgment action in patent
litigation.
    The terms “adjustment” and “extension” reflect similar concepts but dif-
ferent reasons for changing a patent’s term under different statutory sections.
Both refer to increases in a patent’s term designed to compensate for delay
                                          46.50
not attributable to the patentee’s fault.       The term “adjustment” comprises
changes in the patent term to compensate for delays in patent prosecu-
      46.51
tion,       while the term “extension” comprises changes to compensate for
federal regulatory review—unrelated to patent prosecution—on which mar-
                                                         46.52
keting of related products or processes is conditioned.
                                                                          46.53
    Adjustments arise under Section 154(b) of the Patent Act of 1952,           as
                                                          46.54
amended by the Patent Term Guarantee Act of 1999.               This section per-
mits increases in the patent’s term to compensate for delays in prosecuting the
patent application due to: (1) patent interference proceedings, (2) secrecy
orders for national security purposes, (3) judicial review of administrative
decisions adverse to patentability, and (4) certain specified types of delay
                           46.55
attributable to the PTO.          Effective June 8, 1995, the Uruguay Round
Agreements Act recognized the first three types of delay as reasons for in-
creasing the patent’s term; the Patent Term Guarantee Act of 1999, part of the
                                                 46.56
American Inventors Protection Act of 1999,             added the fourth category
                                         46.57
and clarified the rules and procedures.
    Both acts of legislation recognized, and consequently current Section
154(b) recognizes, the patentee’s own unreasonable delay as reason for de-
                              46.58
creasing the patent’s term.         Negative adjustments due to the patentee’s
delay, however, may never exceed positive adjustments for other reasons;
                                                                    46.59
thus adjustments, if made, always increase the patent’s term.             Section
154(b) also guarantees that delay not attributable to the patentee will not re-

   46.50
           Id.
   46.51
           See § 2.05[2][b][i] infra.
   46.52
           See § 2.05[2][b][ii] infra.
   46.53
           35 U.S.C. § 154(b).
   46.54
          Patent Term Guarantee Act of 1999, Subtitle D (Patent Term Guarantee) of Tit. IV
(American Inventors Protection Act of 1999), § 4402(a), of Intellectual Property and Communi-
cations Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B, Appendix I (S.1948),
106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-557 through 1501A-560 (Nov. 29, 1999),
amending 35 U.S.C. § 154(b).
    46.55
          See § 2.05[2][b][i] infra.
    46.56
          See N.46.54 supra.
    46.57
          See § 2.05[2][b][i] infra.
    46.58
          See 35 U.S.C. § 154(b)(2)(C), discussed in § 2.05[2][b][i] infra.
    46.59
          See § 2.05[2][b][i] infra.


                                                                                  (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

duce the patent term below the seventeen years after issuance that would have
                                                46.60
applied under the pre-TRIPs statutory scheme.
    In contrast to “adjustment,” “extension” refers to increases in a patent’s
term that have nothing directly to do with the patent prosecution process. Ex-
tensions are term increases designed to compensate for federal pre-marketing
regulatory review of patentable subject matter under the federal Food, Drug
and Cosmetic Act or similar regulatory statutes intended to insure the safety
and/or efficacy of medical (including veterinary) health care products, cos-
                    46.61
metics and food.
    Three separate sections of the patent statute provide extensions. Two—
                46.62          46.63
Sections 155           and 155A      —provide extensions for patents that were
subject to specific types of regulatory action during the period 1976 to 1981.
Most of these patents (unless extended by considerable margins) by now
should have expired. The most widely applicable provision—Section
     46.64
156        —sets forth generally applicable rules for patent term extensions to
compensate for federal regulatory review. The rules for these extensions are
                                                         46.65
extremely complex and subject to complex limitations.          Perhaps the most
important limitations are procedural: the patentee must apply for term exten-
sions and must do so within sixty days of having received relevant pre-
                                                                 46.66
marketing regulatory approval for a related product or process.        Although
a patentee who misses this deadline apparently cannot request extension lat-
    46.67
er,       the fact and length of an extension apparently may be challenged for
noncompliance with statutory norms by any interested party with standing,
                                          46.68
such as an accused infringer or licensee.

            [i]—Patent Term Adjustment


   46.60
           See 35 U.S.C. § 154(b)(1)(B), discussed in § 2.05[2][b][i] infra.
   46.61
           See § 2.05[2][b][ii] infra. The specific statutory categories are drug products, as de-
fined (including antibiotic drugs, animal drugs, and human or animal biological products), med-
ical devices, food additives and color additives. See 35 U.S.C. § 156(f)(1), discussed in §
2.05[2][b][ii] infra.
    46.62
          35 U.S.C. § 155.
    46.63
          35 U.S.C. § 155A.
    46.64
          35 U.S.C. § 156, discussed in § 2.05[2][b][ii] infra.
    46.65
          See id.
    46.66
          See 35 U.S.C. § 154(d)(1), discussed in § 2.05[2][b][ii] infra.
    There is an exception for early submission of requests to extend patents that are about to ex-
pire during the regulatory review period. See 35 U.S.C. § 156(d)(5), noted in § 2.05[2][b][ii]
infra.
    46.67
          See § 2.05[2][b][ii] infra.
    46.68
          See id.


                                                                                      (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

                                                               46.69
   Patent term “adjustments” under Section 154(b)           attempt to ameliorate
the effects of delays in patent prosecution. Most of the adjustments are posi-
tive, i.e., increases in the patent term, intended to compensate for delays
caused by the PTO, other federal agencies, or the courts. However, Section
154(b) also accounts for delays attributable to the patentee’s lack of due dili-
gence; those delays may be subtracted from the positive adjustments, but the
                                         46.70
net adjustment can never be negative.
   Section 154(b) lists the reasons for adjustments in four categories. First, it
                                       46.71
provides day-for-day compensation            for the pendency of interference pro-
           46.72                 46.73
ceedings,        secrecy orders,        and favorable administrative or federal
                                                                             46.74
judicial review of adverse administrative determinations of patentability.

   46.69
           35 U.S.C. § 154(b), as added by the Uruguay Round Agreements Act § 532(a)(1),
Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994), and as amended by the Patent Term
Guarantee Act of 1999, Subtitle D (Patent Term Guarantee) of Tit. IV (American Inventors
Protection Act of 1999), § 4402(a), of Intellectual Property and Communications Omnibus
Reform Act of 1999, Pub. L. No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st
Sess., 113 Stat. 1501A-521, 1501A-557 through 1501A-560 (Nov. 29, 1999).
    46.70
           See the text accompanying Ns.46.106-46.108 and N.46.107 infra.
    46.71
            See 35 U.S.C. § 154(b)(1)(C), as amended by the Patent Term Guarantee Act of
1999, Subtitle D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of
1999), § 4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999,
Pub. L. No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-
521, 1501A-558 through 1501A-559 (Nov. 29, 1999) (postamble: “the term of the patent shall
be extended 1 day for each day of the pendency of the proceeding, order, or review, as the case
may be”).
    46.72
           The statute refers to “a proceeding under section 135(a)[;]” 35 U.S.C. § 135(a). 35
U.S.C. § 154(b)(1)(C)(i), as amended by the Patent Term Guarantee Act of 1999, Subtitle D
(Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), § 4402(a), of
Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113,
Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-558
(Nov. 29, 1999). Such a proceeding, known as an “interference,” is called to determine which of
two or more applicants for a patent on the same invention has priority and therefore should
receive the patent. See generally: §§ 1.06[1], 2.03[1][a], [c][v] supra.
    46.73
           The statute refers to “the imposition of an order under section 181,” 35 U.S.C. § 181.
35 U.S.C. § 154(b)(1)(B)(ii), as amended by the Patent Term Guarantee Act of 1999, Subtitle D
(Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), § 4402(a), of
Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113,
Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-558
(Nov. 29, 1999). So-called “secrecy orders” under Section 181 allow the federal government to
sequester inventions whose disclosure might be detrimental to the national security—such as
those with military or intelligence applications—and temporarily to preclude their patenting. See
§ 2.09[2] infra. Secrecy orders have a maximum term of one year, except during wartime, but
they may be renewed indefinitely. See: 35 U.S.C. § 181; § 2.09[2] infra.
    46.74
           The statute refers to “appellate review by the Board of Patent Appeals and Interfer-
ences or by a Federal court in a case in which the patent was issued under a decision in the re-
view reversing an adverse determination of patentability[.]” 35 U.S.C. § 154(b)(1)(C)(iii), as
amended by the Patent Term Guarantee Act of 1999, Subtitle D (Patent Term Guarantee) of Tit.
IV (American Inventors Protection Act of 1999), § 4402(a), of Intellectual Property and Com-

                                                                                     (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

These same reasons for adjustments (then called “extensions”) had been in-
                                                      46.75
troduced by the Uruguay Round Agreements Act                 effective June 8,
      46.76
1995;       the 1999 amendments clarified them and introduced both the new
                                                      46.77
term “adjustment” and the day-for-day compensation.
                                                                    46.78
   Second, Section 154(b) provides for day-for-day compensation           for de-
                                                                          46.79
lays of the PTO in patent prosecution in excess of specified time limits        in

munications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B, Appendix I
(S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-558 (Nov. 29, 1999).
    The patent statute provides for review by either of two federal courts, the United States Court
of Appeals for the Federal Circuit or the United States District Court for the District of Colum-
bia. See: 35 U.S.C. §§ 141, 145, 146. Although the adjustment provision speaks of “appellate
review” and its title speaks of “appeals,” which words appear to contemplate only the appellate
court, other language (“a Federal court”) appears to contemplate either possibility. The 1999
amendments muddied the water in this regard by deleting statutory language determining the
precise period of delay, which referred to “the date on which an appeal is filed under section 134
or 141 of this title, or on which an action is commenced under section 145 of this title . . .” 35
U.S.C. § 154(b)(3), as added by the Uruguay Round Agreements Act § 532(a)(1), Pub. L. No.
103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994). The apparent purpose of deleting this language,
however, appears to have been simply to substitute the clearer “day for day” language quote in
N.46.71 supra, and not to undermine the generality of the reference to “a Federal court.” Ac-
cordingly, the statute should be interpreted as covering delays due to review by either the district
court or the court of appeals.
    Unlike the time period for PTO delays in responding to appeals, see Ns.46.79, 46.82 infra,
the delay due to appeals is measured from the date of filing the notice of appeal, not the appeal
brief. See 65 Fed. Reg. 56366, 56369-56370 (Sept. 18, 2000). The supplementary information to
the PTO’s regulations contains helpful examples of the types of “final decision” that meet the
statutory requirement for reversing adverse determinations of patentability. See 65 Fed. Reg.
56366, 56370 (Sept. 18, 2000).
    46.75
            See 35 U.S.C. § 154(b)(1), (2) (1996), as added by the Uruguay Round Agreements
Act § 532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994).
    46.76
            This was the date on which the provisions for patent term extension of the Uruguay
Round Agreements Act generally became effective. See: Uruguay Round Agreements Act §
534(b), Pub. L. No. 103-465, 108 Stat. 4809, 4990 (Dec. 8, 1994) (generally making provisions
of Uruguay Round Agreements Act § 532, except for those amending 35 U.S.C. § 154(a)(1),
effective six months after date of enactment, i.e., on June 8, 1995); Uruguay Round Agreements
Act § 532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994) (adding 35 U.S.C. §
154(b), which provided for term extension). But see, § 2.05[2][c][ii] infra (discussing different,
special effective date for relation-back provisions of term-computation rules).
    46.77
            See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 125, 127 (Nov. 9, 1999) (Confer-
ence Report).
    46.78
           See 35 U.S.C. § 154(b)(1)(A), as amended by the Patent Term Guarantee Act of 1999,
Subtitle D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), §
4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L.
No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521,
1501A-557 through 1501A-558 (Nov. 29, 1999) (postamble).
    46.79
           The specified time limits are as follows: (1) fourteen months for providing the first no-
tice of rejection, objection or requirement (i.e., the first Office Action), or a notice of allowance,
after the filing of a U.S. application or the fulfillment of statutory requirements for advancing an
international application to the national stage, see 35 U.S.C. § 154(b)(1)(A)(i), N.46.78 supra
(referring, in the case of international applications, to “the requirements of section 371[,]” 35

                                                                                          (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                                                           46.80
issuing Office actions or notices of allowance    in response to applications,
                                                        46.81
in responding to applicants’ replies to Office actions,       in responding to
applicants’ appeals to the Board of Patent Appeals and Interferences
        46.82                                                   46.83
(BPAI),       in responding to review by the BPAI or a court,         or in issu-

U.S.C. § 371); (2) four months for responding to a reply to a notice of rejection, objection or
requirement (i.e., a reply to an Office action) or to an appeal to the Board of Patent Appeals and
Interferences, see 35 U.S.C. § 154(b)(1)(A)(ii), N.46.78 supra; (3) four months to act on a deci-
sion of the Board of Patent Appeals and Interferences or a federal court “in a case in which
allowable claims remain in the application[,]” 35 U.S.C. § 154(b)(1)(A)(iii), N.46.78 supra; and
(4) four months to issue a patent “after the date on which the issue fee [is] paid . . . and all out-
standing requirements [are] satisfied,” 35 U.S.C. § 154(b)(1)(A)(iv), N.46.78 supra. See also,
37 C.F.R. § 1.702(a), as added by 65 Fed. Reg. 56366, 56391-56392 (Sept. 18, 2000).
     Regulations of the PTO specify in some detail exactly how these time limits are to be calcu-
lated. See 37 C.F.R. § 1.703(a), as added by 65 Fed. Reg. 56366, 56392 (Sept. 18, 2000).
Among other things, the four-month period for appeals begins with the filing of the appeal brief,
not the notice of appeal. See: 37 C.F.R. § 1.703(a)(4), as added by 65 Fed. Reg. 56366, 56392
(Sept. 18, 2000); 65 Fed. Reg. at 56368.
     46.80
           The statute, 35 U.S.C. § 154(b)(1)(A)(i) (preamble), N.46.78 supra, uses the term “no-
tification[] under section 132[,]” 35 U.S.C. § 132, which by its terms governs notices of “rejec-
tion, or objection or requirement” when the PTO decides not to issue a notice of allowance.
Practitioners refer to these notices loosely as “Office actions.” The statute also refers, see 35
U.S.C. § 154(b)(1)(A)(i) (preamble), N.46.78 supra, to “a notice of allowance under section
151[,]” 35 U.S.C. § 151, which by its terms refers to a “written notice of allowance of the appli-
cation[.]” (Emphasis added.) The clear implication is that, in order to avoid a term adjustment,
an Office action must not only meet the fourteen-month deadline but must dispose of all claims
in the application by allowance, rejection, objection or requirement. An Office action that fails
to address all claims, or that merely provides information with respect to a particular claim but
no allowance, rejection, objection or requirement with respect to that claim, does not stop the
clock for purposes of term adjustments.
     Supplementary information to regulations of the PTO adds the following to the list of notifi-
cations under Section 132 that stop the clock: “[a] written restriction requirement, a written
election of species requirement, a requirement for information under [37 C.F.R.] § 1.105, an
action under Ex parte Quayle, 1935 Comm’r Dec. 11 (1935), and a notice of allowability
(PTOL-37)[.]” 65 Fed. Reg. 56366, 56368 (Sept. 18, 2000). The same supplementary infor-
mation also contains examples of preexamination processing notifications that do not stop the
clock. See id.
     46.81
           See 35 U.S.C. § 154(b)(1)(A)(ii), N.46.78 supra. Again, the statute refers to section
132, cf., N.46.80 supra, suggesting that the applicant’s reply must respond to a rejection, objec-
tion or requirement of the PTO. The PTO’s regulations state that the applicant’s reply must
comply with 37 C.F.R. § 1.111 to start the clock. See 37 C.F.R. § 1.703(a)(2), as added by 65
Fed. Reg. 56366, 56392 (Sept. 18, 2000). Correspondence from the applicant that merely re-
quests information or that otherwise does not provide such a substantive response should not do
so.
     46.82
            See 35 U.S.C. § 154(b)(1)(A)(ii), N.46.78 supra. Here the statute refers to “an appeal
taken under section 134[,]” 35 U.S.C. § 134. As amended in 1999, section 134 allows appeals
not only by the applicant from a second or subsequent rejection, but also by the applicant or by
a third party requester from a reexamination proceeding. See 35 U.S.C. § 134, especially (b)
and (c), as amended by Optional Inter Partes Reexamination Procedure Act of 1999, Subtitle F
(Optional Inter Partes Reexamination Procedure) of Tit. IV (American Inventors Protection Act
of 1999), § 4605(b), of Intellectual Property and Communications Omnibus Reform Act of
1999, Pub. L. No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat.
1501A-521, 1501A-570 through 1501A-571 (Nov. 29, 1999). See also, § 1.06[1] supra, dis-

                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                          46.84
ing patents once fees are paid and requirements satisfied.       These specific
reasons for adjustment, including the specific time limitations and day-for-day
                                                      46.85
compensation, were new with the 1999 amendments.
   Third, as a “backup” to the day-for-day compensation for excessive PTO
delays, it extends the patent term, on a day-for-day basis, to compensate for
                                                    46.86
PTO delays aggregating greater than three years,           thereby guaranteeing

cussing inter-partes reexamination proceedings. As a result of these statutory provisions, the
PTO’s delay in responding to an appeal from a reexamination proceeding may result in a term
adjustment, whether the reexamination is requested by the applicant, brought sua sponte by the
PTO, or requested by a third party.
    With respect to appeals, the time period is measured from the filing of the appeal brief, not
the notice of appeal. See: 37 C.F.R. § 1.703(a)(4), as added by 65 Fed. Reg. 56366, 56392
(Sept. 18, 2000); 65 Fed. Reg. at 56368.
    46.83
           See 35 U.S.C. § 154(b)(1)(A)(iii), N.46.78 supra. This reason for a term adjustment
applies only if “allowable claims remain in the application” after the appeal. Id. For regulatory
gloss on this requirement, along with helpful examples, see 65 Fed. Reg. 56366, 56369 (Sept.
18, 2000).
    In order to start the clock, a BPAI decision must sustain or reverse one or more claim rejec-
tions or decide the patentability of one or more claims or priority of invention; a remand or other
administrative order does not start the clock. See 65 Fed. Reg. 56366, 56368 (Sept. 18, 2000). In
addition, a decision of the BPAI or a court must be a “final decision[,]” 37 C.F.R. § 1.703(a)(5),
as added by 65 Fed. Reg. 56366, 56392 (Sept. 18, 2000), which the PTO defines in 65 Fed. Reg.
56366, 56369 (Sept. 18, 2000).
    46.84
           The statute measures this delay from the date on which “the issue fee was paid under
section 151 and all outstanding requirements were satisfied[.]” 35 U.S.C. § 154(b)(1)(A)(iv),
N.46.78 supra. Section 151, 35 U.S.C. § 151, refers to the fee specified in the notice of allow-
ance, which must be paid within three months after the notice is given or mailed to the appli-
cant. If prosecution is reopened after allowance, the clock is stopped until a new notice of
allowance issues. See 65 Fed. Reg. 56366, 56369 (Sept. 18, 2000).
    46.85
           There was no counterpart to Section 154(b)(1)(A) under the Uruguay Round Amend-
ments. See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 125 (Nov. 9, 1999) (Conference
Report) (“Not only are [the Uruguay Round] adjustments too short in some cases, but no ad-
justments were provided for administrative delays caused by the USPTO that were beyond the
control of the applicant. Accordingly, [the 1999 bill] . . . adds a new provision to compensate
applicants fully for USPTO-caused administrative delays”).
    46.86
           See 35 U.S.C. § 154(b)(1)(B) (in part), as added by Patent Term Guarantee Act of
1999, Subtitle D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of
1999), § 4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999,
Pub. L. No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-
521, 1501A-558 (Nov. 29, 1999):
    “[Subject to certain limitations and exclusions,] if the issue of an original patent is delayed
   due to the failure of the United States Patent and Trademark Office to issue a patent within 3
   years after the actual filing date of the application in the United States, . . . the term of the
   patent shall be extended 1 day for each day after the end of that 3-year period until the patent
   is issued.”
    The statute explicitly excludes three types of delay from the three-year period: (1) continued
examination of the application at the applicant’s request, see 35 U.S.C. § 154(b)(1)(B)(i), supra,
referring to 35 U.S.C. § 132(b), as added by Patent Term Guarantee Act of 1999, Subtitle D
(Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), § 4403, of
Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113,

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

that the patent prosecution process will cut no more than three years from the
time between the patent’s issuance and the end of the patent’s term. This
guarantee assures the patentee of at least seventeen years of patent term after
issuance, as was the case before the TRIPs Agreement changes took ef-
      46.87
fect.        This term “guarantee” was also new with the 1999 amend-
        46.88
ments.
   Finally, Section 154(b)(2)(C) explicitly requires subtracting from any term
increase any period during which the applicant failed to act with due dili-
        46.89
gence.        The statute defines this as “the period of time during which the


Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-560
(Nov. 29, 1999); (2) unexcused applicant-requested delay, see 35 U.S.C. § 154(b)(1)(B)(iii),
supra; and (3) delay for which adjustment may be made under Section 154(b)(1)(C), i.e., delay
due to interferences, secrecy orders, and appeals, see the text accompanying Ns.46.70-46.74 and
N.46.71 supra. The applicant-requested continued examination to which the statute refers is that
under PTO regulations authorized by statute in 1999, see 35 U.S.C. § 132(b), supra, which
appear at 37 C.F.R. § §§ 1.103(c), 1.114, 1.313(a), as amended by 65 Fed. Reg. 50092, 50104-
50105 (Aug. 16, 2000). Excuses for applicant-caused delay are governed by Section
154(b)(3)(C), 35 U.S.C. § 154(b)(3)(C), quoted in N.46.105 infra. As for the last exclusion, for
Uruguay-Round delays, it appears unnecessary in light of a general rule against double-counting
of periods of delay, see 35 U.S.C. § 154(b)(2)(A), as added by Patent Term Guarantee Act of
1999, Subtitle D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of
1999), § 4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999,
Pub. L. No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-
521, 1501A-559 (Nov. 29, 1999), quoted in N.46.116 infra. Nevertheless, it makes double clear
that Uruguay-Round delays are not to be double counted.
     The words “actual filing date of the application in the United States” are intended to exclude
filings under the Patent Cooperation Treaty (PCT). See H.R. Rep. No. 106-464, 106th Cong., 1st
Sess. 126 (Nov. 9, 1999) (Conference Report). “Otherwise, an applicant could obtain up to a 30-
month extension of a U.S. patent merely by filing under PCT, rather than directly in the USPTO,
gaining an unfair advantage in contrast to strictly domestic applicants.” Id. For a discussion of
how the PCT gives applicants up to thirty months before committing to prosecute applications at
the national stage, see § 2.08 infra.
       46.87
              This indeed was the purpose of the three-year guarantee. See H.R. Rep. No. 106-
   464, 106th Cong., 1st Sess. 125 (Nov. 9, 1999) (Conference Report) (Footnote omitted.):
   “[F]or good measure, [the 1999 act] includes a new provision guaranteeing diligent appli-
   cants at least a 17-year term by extending the term of any patent not granted within three
   years of filing. Thus, no patent applicant diligently seeking to obtain a patent will receive a
   term of less than the 17 years as provided under the pre-GATT standard; in fact, most will
   receive considerably more. Only those who purposely manipulate the system to delay the is-
   suance of their patents will be penalized . . ., a result that the Conferees believe entirely ap-
   propriate.”
   46.88
           See Ns.46.86, 46.87 supra.
   46.89
          See 35 U.S.C. § 154(b)(2)(C), as added by Patent Term Guarantee Act of 1999, Subti-
tle D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), §
4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L.
No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521,
1501A-559 (Nov. 29, 1999) (in full):
       “(C) Reduction of period of adjustment.—

                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

applicant failed to engage in reasonable efforts to conclude prosecution of the
              46.90
application.”        For purposes of applying the term guarantee of Section
               46.91
154(b)(1)(B),        the statute defines such a period as including any appli-
cant’s delay over three months in responding to any Office action “making
                                                       46.92
any rejection, objection, argument, or other request.”
   The statute gives the PTO general rule-making authority to define circum-
stances constituting a failure on the applicant’s part to act with due dili-
       46.93                                        46.94
gence.       The PTO has issued such regulations,         and the supplementary
information to them provide extensive background information and helpful
examples of circumstances that, in the PTO’s view, do and do not constitute
               46.95
due diligence.
   Although buried in fine print in the Federal Register, these rules of dili-
gence have great importance for patent attorneys and their clients. They de-
                                       46.96
termine with considerable specificity        what action (or inaction) by patent
attorneys and their clients may, by reducing positive term adjustments, de-
                                                       46.97
crease the term that a patent otherwise might have.          Unless justified and


       “(i) The period of adjustment of the term of a patent under paragraph (1) shall be reduced
   by a period equal to the period of time during which the applicant failed to engage in reason-
   able efforts to conclude prosecution of the application.
       “(ii) With respect to adjustments to patent term made under the authority of paragraph
   (1)(B), an applicant shall be deemed to have failed to engage in reasonable efforts to con-
   clude processing or examination of an application for the cumulative total of any periods of
   time in excess of 3 months that are taken to respond to a notice from the Office making any
   rejection, objection, argument, or other request, measuring such 3-month period from the
   date the notice was given or mailed to the applicant.”(iii) The Director [PTO] shall prescribe
   regulations establishing the circumstances that constitute a failure of an applicant to engage
   in reasonable efforts to conclude processing or examination of an application.”
    The “paragraph (1)” referred to in clause (i) of this excerpt includes all of the basic rules for
term adjustment under Section 154(b). See Ns.46.71, 46.78, 46.86 supra. It is thus a general
rule for subtracting periods for which the applicant was not diligent. Clause (ii) is more specific:
it applies only to guaranteed maximum of three years of PTO delay under Section 154(b)(1)(B),
see N.46.86 supra, so its three-month limitation on an applicant’s response applies only in con-
nection with the “guarantee.”
    46.90
           35 U.S.C. § 154(b)(2)(C)(i), N.46.89 supra.
    46.91
           See N.46.86 supra.
    46.92
           35 U.S.C. § 154(b)(2)(C)(ii), N.46.89 supra.
    46.93
           See 35 U.S.C. § 154(b)(2)(C)(iii), N.46.89 supra.
    46.94
           See 37 C.F.R. § 1.704, as added by 65 Fed. Reg. 56366, 56393-56394 (Sept. 18,
2000).
    46.95
           See 65 Fed. Reg. 56366, 56370-56373 (Sept. 18, 2000).
    46.96
           See id.
    46.97
           These rules do not apply if the applicant is not eligible for any adjustment, since the
negative diligence adjustments apply only to the extent there are positive adjustments from
which to subtract them. See the text accompanying Ns.46.106-46.108 infra. However, determin-

                                                                                         (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW

carefully explained to clients, resulting reductions in patent terms may be
perceived by clients as their attorneys’ responsibility, leading to clients’ dis-
satisfaction or even claims of malpractice.
    Consequently, in a very practical sense the PTO’s detailed rules for dili-
gence represent a comprehensive code of conduct for patent attorneys, alt-
hough probably not intended as such. Among many other things, the rules
require close written communication between patent attorneys and their cli-
ents at many stages in the patent prosecution process. Many patent attorneys
may wish to create a portfolio of form letters to clients, informing them of
their responsibility to provide information and assistance at all these stages, as
outlined in the PTO’s extensive rules occupying some three pages in the Fed-
eral Register. This is a formidable task.
    Because of the burden that the PTO’s rules place on patent attorneys and
their clients, it is a matter of some interest whether those rules are fully con-
sistent with the statutory authority under which they were promulgated. De-
tailed rule-by-rule analysis is beyond the scope of this book, but there may be
certain general respects in which the PTO’s diligence rules may fall short of
full compliance with statutory authority. Those rules are generally based on
the assumption that the PTO’s determination of patent term adjustments must
                                                 46.98
be automated, using the PTO’s PALM system.             Indeed, the PTO professes
an inability to accommodate the statutory requirement for individual adjust-
                                                               46.99
ments of every patent’s term without the aid of automation.          Accordingly,
certain of the rules of diligence are designed specifically to avoid judgment
calls and case-by-case determinations and to provide a mechanical system that
                             46.100
lends itself to automation.         To the extent the rules are motivated by the


ing whether such positive adjustments exist in every case may be a task equally difficult to, or
more difficult than, complying with the diligence rules in the first place.
    46.98
           The PTO “must make its patent term adjustment determinations by a computer pro-
gram that uses information recorded in Office’s automated patent application information sys-
tem (the Patent Application Location and Monitoring System or PALM System).” 65 Fed. Reg.
56366, 56370 (Sept. 18, 2000).
    46.99
           See 65 Fed. Reg. at 56373-56374 (“Since the Office now issues over 160,000 patents
each year, the only practical way to make the [*56374] patent term adjustment determinations
required by 35 U.S.C. § 154(b)(3)(B)(i) [including “any patent term adjustment under this sub-
section”] is by a computer program that uses the information (dates of receipt and nature of
application correspondence and of the dates of mailing and nature of Office actions or notices)
recorded in the PALM system”).
    46.100
            See, e.g.: 65 Fed. Reg. 56366, 56376 (Sept. 18, 2000) (Response to Comment 10, re-
jecting commenter’s request that periods for diligence in responding to Office actions be com-
puted based on certificates of mailing of responses to PTO because “[t]he certificate of mailing
date is not recorded in the Office’s PALM system” and only date of receipt is available to auto-
mated system); 65 Fed. Reg. at 56377 (Responses to Comments 11 and 12, respectively reject-
ing for similar reasons complaint that PTO’s notices are dated as of their mailing while
applicants’ responses are dated on receipt, and opining that applicants should “use a postcard
receipt to establish when a paper is received by the Office”). Cf., 65 Fed. Reg. at 54680 (Re-
sponse to Comment 24, advising applicants to check PALM records on line at

                                                                                     (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

                                                           46.101
PTO’s convenience and its need for automation,           rather than the statutory
purpose of providing fair adjustments of patent terms to compensate patentees
                                      46.102
for delays not attributable to them,          the rules may be subject to legal
challenge for inconsistency with the statute or its purpose. This fact lends
additional uncertainty to the already great uncertainty of patent terms subject
                                    46.103
to numerous statutory adjustments.
                                     46.104
   In contesting a term adjustment           or the denial of one, the applicant
can argue excuses for failing to respond within each three-month dead-
      46.105
line.        However, the applicant may only do so before the patent issues,
and in any event the statute precludes allowing more than an additional three
                              46.106
months in each such instance.



http://pair.uspto.gov to avoid delay adjustments for failure to petition to avoid abandonment
within two months of notice of mailing date of Notice of Abandonment).
     It should be noted, however, that measuring the timing of applicants’ responses based on the
dates of mailing of notices to applicants is a statutory requirement. See 35 U.S.C. §
154(b)(2)(C)(ii), N.46.89 supra.
     46.101
             See Ns.46.99, 46.100 supra.
     The PTO has taken the position that an applicant may lack due diligence, and therefore may
have her patent term adjustments “docked” for unreasonable delay, despite full compliance with
the rules of patent practice. In other words, the PTO has ruled that taking full advantage of all
the delay built into the rules of practice may sometimes demonstrate lack of due diligence. See
65 Fed. Reg. 56366, 56377-56379 (Sept. 18, 2000) (extensive response to Comment 17, justify-
ing this position); 65 Fed. Reg. at 56379 (concluding that “[the fact] that conduct is permitted
by the patent statute and rules of practice does not imply that such conduct is not a failure to
engage in reasonable efforts to conclude processing or examination of an application”).
     While some of these rules may seem harsh, they may constitute a valid exercise of the PTO’s
regulatory authority, see N.46.89 supra, if they are reasonably related to the statutes’ apparent
purposes, namely, encouraging expedition in patent prosecution and avoiding unreasonable
delay. They may be invalid however, if they are based solely or primarily on the PTO’s adminis-
trative convenience.
     46.102
             See: § 2.05[2][b] (introduction) supra; H.R. Rep. No. 106-464, 106th Cong., 1st
Sess. 125 (Nov. 9, 1999) (Conference Report).
     46.103
             See the text accompanying Ns.46.108-46.118 infra.
     46.104
             See the text accompanying Ns.46.119-46.121 infra.
     46.105
             See 35 U.S.C. § 154(b)(3)(C), as added by Patent Term Guarantee Act of 1999, Sub-
title D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), §
4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L.
No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521,
1501A-559 (Nov. 29, 1999) (in full):
       “(C) The [PTO] shall reinstate all or part of the cumulative period of time of an adjust-
   ment under paragraph (2)(C) [quoted in N.46.89 supra] if the applicant, prior to the issuance
   of the patent, makes a showing that, in spite of all due care, the applicant was unable to re-
   spond within the 3-month period, but in no case shall more than three additional months for
   each such response beyond the original 3-month period be reinstated.”
   46.106
            Id.


                                                                                     (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    The statutory language makes clear that an applicant’s failure to be diligent
can never reduce the patent term below the term that would apply in the ab-
sence of adjustments made to increase it; such failure can only reduce or elim-
                      46.107
inate the increases.         Thus, failure to be diligent can never decrease the
patent term below the nominal twenty years from the relevant application
      46.108
date.
                                 46.109
    Apart from the “guarantee,”          Section 154(b) contains no overall limi-
tation on the patent term or on the adjustments that can be made to it. It did
contain such limitations as originally enacted by the Uruguay Round Agree-
             46.110                                            46.111
ments Act,          but the 1999 amendments removed them.             Rather than
limit the adjustments, Congress apparently wanted to guarantee the patentee a



   46.107
             See 35 U.S.C. § 154(b)(2)(C)(i), N.46.89 supra (“period of adjustment” under Sec-
tion 154(b)(1) “shall be reduced” by period during which applicant was not diligent).
    In this respect the Conference Report’s implication that nondiligent applicants “will be pe-
nalized,” see N.46.87 supra, is misleading. They will be penalized only to the extent that, in the
absence of their inexcusable delay, they would have been entitled to adjustments that would
have extended the terms of their patents further.
    46.108
            See § 2.05[2][a][i] supra.
    46.109
             See the text accompanying Ns.46.85-46.88 supra   .
    46.110
            The extension provisions under the Uruguay Round Agreements Act contained three
separate five-year limitations, two for two of the three reasons for delay, and one overall. See 35
U.S.C. § 154(b)(1), (2), (4), as added by Uruguay Round Agreements Act § 532(a)(1), Pub. L.
No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994). These limitations required coordination with
a similar five-year limitation on term extensions for reasons of regulatory review. See: §
2.05[2][b][ii] infra (discussing regulatory-review term extensions); Uruguay Round Agreements
Act, Statement of Administrative Action 656, 1003, 1995 U. S. Code Cong. & Admin. News
4040, 4296 (noting both limitations); 60 Fed. Reg. 3398, 3398 (Jan. 17, 1995) (PTO notice of
public hearing and request for comment, opining that two type of limits were independent and
cumulative); Merck & Co. v. Kessler, 80 F.3d 1543, 1551, 38 U.S.P.Q.2d (BNA) 1347 (Fed.
Cir. 1996), cert. denied sub nom. Organon, Inc. v. Kessler, 117 S.Ct. 788 (1997) (dictum: term
extension due to delays in appellate review of patent prosecution could be added to term exten-
sion due to delays in regulatory review of drug or medical product). Elimination of the maxi-
mum limitation on delay-based adjustments also eliminated the need for coordination with the
regulatory-review extensions in this regard.
    46.111
             Earlier bills had proposed extending the original five-year limitations, see N.46.110
supra, to ten, but the 1999 amendments removed the limitations entirely. See H.R. Rep. No.
106-464, 106th Cong., 1st Sess. 125 (Nov. 9, 1999) (Conference Report):

       “The provisions that were initially included in the term adjustment provisions of patent
   bills in the 105th Congress only provided adjustments for up to 10 years for secrecy orders,
   interferences, and successful appeals. Not only are these adjustments too short in some cases,
   but no adjustments were provided for administrative delays caused by the USPTO that were
   beyond the control of the applicant. Accordingly, [the 1999 act] removes the 10 year caps
   from the existing provisions[.]”
The last sentence of this excerpt is simply in error. It should refer to the existing bill, not the
existing provisions, as the ten-year caps were never enacted into law.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                   46.112
minimum term            matching the old term of seventeen years after issu-
      46.113
ance.        As a result, term adjustments can extend indefinitely. For exam-
ple, a term adjustment for a government-imposed secrecy order might extend
                                                                           46.114
as long as the secrecy order is in effect, which could be decades.
Whether the patent will have any practical or commercial value after such
delay is of course another matter, but the law does provide means for patent-
ees to seek compensation for commercial value lost due to secrecy or-
      46.115
ders.
   There are only two overall limitations on the adjustments that may be
made under Section 154(b) to increase a patent’s term. First, where different
                                                                           46.116
causes of delay overlap temporally, only a single adjustment is made;
this rule reflects the universal remedial principle that prohibits double count-
     46.117
ing.        Second, no adjustment can extend a patent’s expiration date beyond
                                   46.118
the date of a terminal disclaimer.


   46.112
            See N.46.87 and the text accompanying Ns.46.85-46.88 supra      .
   46.113
            See: N.46.87 supra; § 2.05[2][a][i] supra.
   46.114
             Secrecy orders, although limited to one year except in wartime, can be renewed in-
definitely. See: N.46.73 supra; § 2.09[2] infra. Indeed, there are litigated cases of secrecy orders
extending many years. See § 2.09[2] infra.
     46.115
            See § 2.09[2] infra.
     46.116
             See 35 U.S.C. § 154(b)(2)(A), as added by Patent Term Guarantee Act of 1999, Sub-
title D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), §
4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L.
No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521,
1501A-559 (Nov. 29, 1999) (in full):”(2) Limitations.—”(A) In general.—To the extent that
periods of delay attributable to grounds specified in paragraph (1) overlap, the period of any
adjustment granted under this subsection shall not exceed the actual number of days the issu-
ance of the patent was delayed.”
     46.117
            See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 127 (Nov. 9, 1999) (Conference
Report):

       “To the extent that there are multiple grounds for extending the term of a patent that may
   exist simultaneously (e.g., delay due to a secrecy order under section 181 and administrative
   delay under section 154(b)(1)(A)), the term should not be extended for each ground of delay
   but only for the actual number of days that the issuance of a patent was delayed.”
   46.118
            See 35 U.S.C. § 154(b)(2)(B), as added by Patent Term Guarantee Act of 1999, Sub-
title D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), §
4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L.
No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521,
1501A-559 (Nov. 29, 1999) (in full):”The term of any patent which has been disclaimed beyond
a date certain may not receive an adjustment beyond the expiration date specified in the dis-
claimer.”
     A terminal disclaimer is a disclaimer of the remainder of a patent term beyond a specified
date or time. See 35 U.S.C. § 253 (last ¶: ““[a]ny patentee or applicant may disclaim or dedicate
to the public the entire term, or any terminal part of the term, of the patent granted or to be

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    In addition to the substance of patent term adjustments, Section 154(b) al-
                                                  46.119
so prescribes the procedure for making them.             The PTO must determine
the length of the adjustment, notify the applicant along with the notice of al-
lowance, and give the applicant a single opportunity to request reconsidera-
      46.120
tion.        The statute strongly implies that the applicant may argue due
                                               46.121
diligence at any time until the patent issues.        The applicant also may con-
test the PTO’s determination by filing an action in federal district court within
                                       46.122
180 days after the patent’s issuance.         The patentee’s right to contest the
length of adjustments is thus time-limited.
    Third parties, on the other hand, have no time limit on their ability to chal-
lenge the length of the patent term, as adjusted. The statute provides explicitly
that “The determination of a patent term adjustment under this subsection
shall not be subject to appeal or challenge by a third party prior to the grant
                46.123
of the patent.”        Thus third parties may not bring premature challenges,


granted”). It is often made for the purpose of validating a patent that, without such a disclaimer,
would be invalid, as in the case of double patenting. See § 2.04[3][a] supra.
    46.119
             See 35 U.S.C. § 154(b)(3), (4), as added by Patent Term Guarantee Act of 1999,
Subtitle D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), §
4402(a), of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L.
No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521,
1501A-559 through 1501A-560 (Nov. 29, 1999).
    46.120
            See id., § 154(b)(3)(B).
    46.121
            See: id., § 154(b)(3)(C), quoted in full in N.46.105 supra; id., § 154(b)(3)(D) (in
full):
      “(D) The [PTO] shall proceed to grant the patent after completion of the [PTO’s] deter-
   mination of a patent term adjustment under the procedures established under this subsection,
   notwithstanding any appeal taken by the applicant of such determination.”
   46.122
             See 35 U.S.C. § 154(b)(4), as added by Patent Term Guarantee Act of 1999, Subtitle
D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), § 4402(a),
of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-
113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-560
(Nov. 29, 1999) (in full):
       “(4) Appeal of patent term adjustment determination.—
           “(A) An applicant dissatisfied with a determination made by the [PTO] under para-
       graph (3) shall have remedy by a civil action against the [PTO] filed in the United States
       District Court for the District of Columbia within 180 days after the grant of the patent.
       Chapter 7 of title 5, United States Code, shall apply to such action. Any final judgment
       resulting in a change to the period of adjustment of the patent term shall be served on the
       [PTO], and the [PTO] shall thereafter alter the term of the patent to reflect such change.”
           “(B) The determination of a patent term adjustment under this subsection shall not be
       subject to appeal or challenge by a third party prior to the grant of the patent.”
    (The bracketed references to the PTO are to the “Director” or PTO Commissioner.)
    46.123
             35 U.S.C. § 154(b)(4)(B), as added by Patent Term Guarantee Act of 1999, Subtitle
D (Patent Term Guarantee) of Tit. IV (American Inventors Protection Act of 1999), § 4402(a),
of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

but they may challenge the length of the patent term at any time after the pa-
             46.124
tent issues.        As a result of this provision, legal challenges to the determi-
nation of patent-term adjustments, including (where appropriate) the
                        46.125
applicant’s diligence,         are likely to become a common feature of patent
litigation, along with such questions as patent validity, infringement, and
proper subject matter.
There is no question that Section 154(b)’s term-adjustment provisions apply
                                    46.126
to both utility and plant patents.         They do not, however, appear to apply
to design patents, which have a fixed term measured from their issue date, not
                        46.127
their application date.        Because delays in prosecution cannot affect their
fixed terms, design patents do not require and therefore appear not to be eli-
gible for term adjustments, although the provisions of the PTO’s regula-
      46.128                                                  46.129
tions         and the statute’s effective date provision             purporting to
                                                46.130
exclude them are hardly models of clarity.             The PTO’s regulations also

113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-560
(Nov. 29, 1999) (in full), quoted in context in N.46.122 supra. (Emphasis added.)
    46.124
           See also, H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 127 (Nov. 9, 1999) (Confer-
ence Report) (“Paragraph (4)(B) precludes a third party from challenging the determination of a
patent term prior to patent grant”).
    46.125
             See the text accompanying Ns.46.88-46.103 supra    .
    46.126
             See § 2.02[1] supra (discussing three types of patents: utility, plant, and design).
    46.127
             See § 2.05[2][a][i] supra.
    46.128
             See: 37 C.F.R. § 1.701(e), as added by 65 Fed. Reg. 56366, 56391 (Sept. 18, 2000)
(“The provisions of this section [regarding Uruguay Round term adjustments, see the text ac-
companying Ns.46.70-46.77 supra] apply only to original patents, except for design patents,
issued on applications filed on or after June 8, 1995, and before May 29, 2000”) (Emphasis
added.); 37 C.F.R. § 1.702(f), as added by 65 Fed. Reg. 56366, 56392 (Sept. 18, 2000) (“The
provisions of this section and §§ 1.703 through 1.705 apply only to original applications, except
applications for a design patent, filed on or after May 29, 2000, and patents issued on such
applications”). See also, N.46.131 infra.
    46.129
             See Patent Term Guarantee Act of 1999, Subtitle D (Patent Term Guarantee) of Tit.
IV (American Inventors Protection Act of 1999), § 4405(a), of Intellectual Property and Com-
munications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B, Appendix I
(S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-560 (Nov. 29, 1999) (amend-
ments made, inter alia, by Section 4402, which revised Section 154(b), “shall take effect on the
date that is 6 months after the date of the enactment of this Act and, except for a design patent
application filed under chapter 16 of title 35, United States Code, shall apply to any application
filed on or after the date that is 6 months after the date of the enactment of this Act”). (Emphasis
added.)
    46.130
             No explicit exclusion for design patents appears in the substantive language of Sec-
tion 154(b), and the regulations and the effective date provisions each contain the same textual
ambiguity: whether design patents are excluded categorically, or whether they are excluded only
from the effective date provisions that depend on the time of filing of the relevant application.
See Ns.46.128, 46.129 supra.
    Apparently in trying to explain the reason for the exclusion, the Conference Report only ex-
acerbated the ambiguity. See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 128 (Nov. 9, 1999)
(Conference Report) (In part; emphasis added.):

                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                                              46.131
purport to exclude reissue patents,                    and the exclusion seems reasona-
     46.132
ble.

            [ii]—Extension to Compensate for Federal Regulatory Review
    Since 1984, the patent statute has provided for the extension of patent
terms for certain regulated drugs and medical products and the methods for
                                47
manufacturing and using them. The purpose of this statutory term extension
is to compensate for commercial exploitation time lost during the process of
federal regulatory review of products that cannot lawfully be marketed in the
United States without government approval under food, drug, and similar
      47.1
laws.      By extending the patent term by the amount of post-issuance time
lost to federal regulatory review, Congress hoped to maintain the incentive for
innovation in medicine despite the high costs of product development and the
                                                            48
equally high cost of obtaining federal regulatory approval.
    Congress enacted patent term extension in two stages. In 1984, it passed
                                                               49
the Drug Price Competition and Patent Term Restoration Act. This amend-
ment covered human drug products (including antibiotics and biologicals),
human medical devices, human food additives, and human color additives
that are subject to regulation under the Federal Food, Drug and Cosmetic


       “The effective date for the amendments in section 4402 . . . [which amended Section
   154(b)] is six months after the date of enactment and, with the exception of design applica-
   tions (the terms of which are not measured from filing), applies to any application filed on
   or after such date.”
   46.131
             See: sources cited in N.46.128 supra, referring to “original patents” and “original
applications[;]” 65 Fed. Reg. 56366, 56367-56368 (Sept. 18, 2000) (referring to “applications
(other than for a reissue or [*56368] design patent)” and to “original (i.e., non-reissue) applica-
tions, except applications for a design patent”).
    46.132
             Whether to apply for a reissue patent is entirely within the patentee’s control, and re-
issue, if granted, is the result of the patentee’s nondeceptive error. See: 35 U.S.C. § 251 (statuto-
ry provisions governing reissue); § 2.03[1][d][iii] supra (discussing reissue generally). Thus it
makes sense to exclude reissue patents from adjustments designed to compensate patentees for
term decreases that are not their responsibility. See § 2.05[2][b] (introduction) supra.
    47
        See generally: Lourie, A Review of Recent Patent Term Extension Data, 71 J. Pat. &
Trademark Office Soc'y 171 (1989).
    47.1
          The patent term extension was a legislative quid pro quo for changes in regulatory law
that allowed generic drug manufacturers to rely on safety and efficacy data submitted by prior
applicants for regulatory approval (usually patent owners), thus speeding generic follow-on
products to market. See Merck & Co. v. Kessler, 80 F.3d 1543, 1546, 38 U.S.P.Q.2d (BNA)
1347 (Fed. Cir. 1996), cert. denied sub nom. Organon, Inc. v. Kessler, 519 U.S. 1101 (1997).
    48
        See: H. R. Rep. No. 972(I), 100th Cong., 2d Sess. 3 (Sept. 23, 1988); H. R. Rep. No.
972(II), 100th Cong., 2d Sess. 16 (Sept. 29, 1988), reprinted in 1988 U.S. Code Cong. & Ad-
min. News 5659, 5661, 5669-5670. See also, § 2.02[2][b][iv][F] supra (reporting cost figures).
    49
        Pub. L. No. 98-417, Tit. II, 98 Stat. 1585, 1598-1603 (Sept. 24, 1984), codified in part in
35 U.S.C. §§ 156, 271(e).

                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

     50                                                                      51
Act, as well as methods for manufacturing or using them. In 1988, Con-
                                                                             52
gress passed the Generic Animal Drug and Patent Term Restoration Act,
which covered animal drugs and veterinary biological products and the meth-
                                       53
ods of manufacturing and using them.
   There is one important difference between the 1984 and 1988 amend-
ments. Unlike the 1984 amendments, the 1988 amendments exclude products
                                                   54
made using certain genetic engineering techniques. Consequently, the scope
of patent term extension for veterinary products and processes is more limited
than that for products and processes used in human health care.
   The substance of both amendments appears in Section 156 of the Patent
Act of 1952. Under that section, utility patents for products and processes
                               55                                56
may be extended once only for a period of up to five years, in order to
compensate for the post-issuance period of pre-marketing federal regulatory
       57
review. The restoration extension is added to the patent term, even if the
patent term itself was “extended” beyond seventeen years after the patent's
           57.1                                                 57.2
issue date      by virtue of the Uruguay Round Agreements Act,       unless the


   50
        Act of June 25, 1938, Ch. 675, 52 Stat. 1040, as amended, codified in primary part at 21
U.S.C. §§ 301-392.
    51
        See 35 U.S.C. § 156(a), (f)(1), (f)(2)(A).
    52
        Pub. L. No. 100-670, Tit. II, 102 Stat. 3971, 3984-3989 (Nov. 16, 1988), codified in part
in 35 U.S.C. §§ 156, 271(e).
    53
        See 35 U.S.C. § 156(a), (f)(2)(B). The term “new animal drug or veterinary biological
product” is defined in the Federal Food, Drug, and Cosmetic Act, see N.50 supra, and the Virus-
Serum-Toxin Act, Act of March 4, 1913, Ch. 145, 37 Stat. 832, as amended, codified in primary
part at 21 U.S.C. §§ 151-159.
    54
        The 1988 amendments cover only new animal drugs and veterinary products (and related
processes) that are “not primarily manufactured using recombinant DNA, recombinant RNA,
hybridoma technology, or other processes involving site specific genetic manipulation tech-
niques[.]” 35 U.S.C. § 156(f)(2)(B). This limiting language does not apply to products for hu-
man health care covered by the 1984 Amendments. See H.R. Rep. No. 972(II), 100th Cong., 2d
Sess. 17 (Sept. 29, 1988), reprinted in 1988 U.S. Code Cong. & Admin. News 5659, 5667,
5671.
    55
        See 35 U.S.C. § 156(a)(2).
    56
        See 35 U.S.C. § 156(g)(6). The five-year limit is an overall upper limit. Determining the
actual length of the extension in each case may require a complex calculation depending on a
number of variables. See: 35 U.S.C. §§ 156(c)(2), 156(g)(1)(B)(i), (2)(B)(i), (3)(B)(i), (4)(B) (i),
(5)(B)(i).
    57
        See 35 U.S.C. § 156(c) (preamble). The regulatory review period is defined specifically
for each type of product, see 35 U.S.C. § 156(g)(1)-(5), and is subject to certain limitations, see:
35 U.S.C. § 156(g)(6); N.56 supra.
    57.1
         See N.57.3 infra.
    57.2
          The Uruguay Round Agreements Act extended the terms of certain transition-period pa-
tents. See § 2.05[2][c] infra. For patents in force on June 8, 1995, and those resulting from
applications filed before that date, the patent term is the longer of (1) seventeen years after the

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

patent was in force on June 8, 1995, only because of such a restoration exten-
      57.3
sion.      When the patent term is extended, the PTO issues a certificate to that
                                                         57.4
effect, which is treated as part of the original patent.      In order to extend the
                                                                     58
patent term, the patent's owner of record (or the owner's agent) must submit
an application for extension to the Commissioner of Patents and Trademarks
within sixty days after the product first receives regulatory approval for com-
                             59
mercial marketing or use. Accordingly, the patent holder cannot wait to
apply for extension until near the end of the patent term, but must apply at the
beginning of the relevant product's commercial life.
   As extended, the patent covers only approved uses of products and ap-
                                                                       60
proved methods of using and manufacturing approved products. Moreover,
extension is permitted only for the first approved use of each product or man-
                     61
ufacturing method, and only one patent may be extended for each period of
                    62
regulatory review. Thus, a patent owner with a portfolio of patents related
to a particular field of human or veterinary medicine must determine not only
which patents in the portfolio are eligible for extension, but also which of the
permissible extensions will produce the greatest benefit as a business matter.
The statutory provisions are sufficiently complicated that both of these deci-
sions require careful consideration.


issue date or (2) twenty years after the relevant application date, subject to any terminal dis-
claimers. See § 2.05[2][c][i] infra.
    57.3
         See Merck & Co. v. Kessler, 80 F.3d 1543, 1553, 38 U.S.P.Q.2d (BNA) 1347 (Fed.
Cir. 1996), cert. denied sub nom. Organon, Inc. v. Kessler, 117 S.Ct. 788 (1997):
   “[P]atents that were in force on June 8, 1995, only because of a [Section 156 term-
   restoration] extension are not entitled to reapply a restoration extension to a 20-year from fil-
   ing term. Except for those patents, a patent in force on June 8, 1995, is entitled to have a res-
   toration extension, whenever granted, added to the longer term of either 17 years from
   issuance or 20 years from filing.”

   See also: 80 F.3d at 1550, 1551 (to same effect); 80 F.3d at 1548 (government and private
   parties agreed “that a patent issued after June 8, 1995, on a transition application is entitled
   to any applicable restoration extension to be added to its term which is 17 years from issu-
   ance or 20 years from filing whichever is longer”).
   57.4
          See: 35 U.S.C. § 156(e)(1); 37 C.F.R. § 1.780.
   58
        See 35 U.S.C. § 156(a)(3).
   59
        See 35 U.S.C. § 156(d)(1).
   60
        See 35 U.S.C. § 156(b).
   61
       See 35 U.S.C. § 156(a)(5)(A). The owner of a patent for a veterinary drug or biological,
however, may elect extension based on the first approved use for food-producing or non-food-
producing animals. See: 35 U.S.C. § 156(a)(5)(C); H. R. Rep. No. 972(II), 100th Cong., 2d
Sess. 20 (Sept. 29, 1988), reprinted in 1988 U.S. Code Cong. & Admin. News 5659, 5667,
5674.
   62
       See 35 U.S.C. § 156(c)(4).


                                                                                        (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

       [c]—Effective Dates and Transition Rules
                                          62.1
    For utility and plant patents,      the Uruguay Round Agreements Act in-
                                                              62.2
troduced three new rules for determining the patent term.          First it changed
the based patent term from seventeen years after the date of grant to twenty
                                     62.3                                       62.4
years after the application date.         Second, for daughter applications
claiming the priority of parent applications based on something other than
foreign priority, it measures the patent term from the “relation-back” date,
i.e., from the date of the earliest-filed specifically referenced parent applica-
      62.5
tion.       Finally, it provides three new reasons for extension of the patent
       62.6
term.       Each of these rules is governed by specific effective-date and transi-
tion provisions.

           [i]—Term Computation
                                                                     62.7
   The current rule for computing the patent term           is effective June 8,
1995, and applies to all patent applications filed in the United States on and
                 62.8
after that date.      A special rule, however, applies to patents that were in
force, or that issue on applications filed, before that date. For those patents,
the patent term is the greater of twenty-years from the application date or sev-
                                                                          62.9
enteen years from the date of grant, subject to any terminal disclaimers.



   62.1
         The term of design patents remains the same as before the Uruguay Round Agreements.
See § 2.05[2] (introduction) supra.
    62.2
         See § 2.05[2][a], [b] supra.
    62.3
         See § 2.05[2][a] supra.
    62.4
         For the meaning of this term, see § 2.05[2][a][ii] supra.
    62.5
         See § 2.05[2][a][ii] supra.
    62.6
         See § 2.05[2][b][i] supra.
    62.7
         See § 2.05[2][a][i] supra.
    62.8
         See Uruguay Round Agreements Act § 534(b)(1), Pub. L. No. 103-465, 108 Stat. 4809,
4990 (Dec. 8, 1994) (“amendments made by section 532 [except for those amending 35 U.S.C.
§ 154(a)(1)] take effect on the date that is 6 months after the date of enactment of this Act and
shall apply to all patent applications filed in the United States on or after the effective date”); 35
U.S.C. § 154(a)(2), (3), as amended by Uruguay Round Agreements Act § 532(a)(1), Pub. L.
No. 103-465, 108 Stat. 4809, 4984 (Dec. 8, 1994) (specifying current rules for patent term),
discussed in § 2.05[2][a] supra.
    62.9
         See 35 U.S.C. § 154(c)(1), as added by Uruguay Round Agreements Act § 532(a)(1),
Pub. L. No. 103-465, 108 Stat. 4809, 4984-4985 (Dec. 8, 1994):
   “The term of a patent that is in force on or that results from an application filed before the
   date that is six months after the date of enactment of the Uruguay Round Agreements Act
   shall be the greater of the 20-year term as provided in subsection (a), or 17 years from the
   date of grant, subject to any terminal disclaimers.”


                                                                                          (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

   According to the executive branch's Statement of Administrative Action,
                                                              62.10
this transition rule was required by the TRIPS Agreement.           Although this
                                      62.11
assertion seems correct in general,         the transition date that the TRIPS
                                                              62.12
Agreement requires is January 1, 1996, not June 8, 1995.            Nevertheless,
since the Uruguay Round Agreements are not self-executing, it is the statute,
                                   62.13
not the Agreements, that controls.
   This transition rule makes it useful to divide patents into four different cat-
egories. Those that expired prior to June 8, 1995, are in the public domain



   For the relevant substance of referenced subsection (a), i.e., 35 U.S.C. § 154(a), as amended
by Uruguay Round Agreements Act § 532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4983-
4984 (Dec. 8, 1994), see § 2.05[2][a] supra.
   62.10
         See Uruguay Round Agreements Act, Statement of Administrative Action 656, 1003,
1995 U.S. Code Cong. & Admin. News 4040, 4296:
   “A further change in U.S. law incident to the change in how patent term is measured is re-
   quired by virtue of the operation of Articles 33, 70.2 and 70.4 [sic] of the TRIPs [sic]
   Agreement. Specifically, section 532(a) of the implementing bill amends section 154 to pro-
   vide that the term of a patent in force on, or that results from an application filed before,
   [June 8, 1995,] will be the greater of 17 years from the date of patent grant or 20 years from
   the date of filing of the application leading to the patent.”

   Of the provisions of the TRIPS Agreement that this passage cites, Article 70:2 is the most
   relevant. See N.62.11 infra. Article 33 merely states the patent term requirement, see §
   2.05[2] (introduction) supra, and Article 70:4 permits, but does not require, the sort of limi-
   tation of remedies and equitable remuneration that the United States statute provides, see the
   text accompanying Ns.62.18-62.25 infra, for acts that become infringing as a result of exten-
   sion of terms of existing and certain pending patents. See Agreement on Trade-Related As-
   pects of Intellectual Property Rights, Arts. 33, 70:4, Annex 1C to Agreement Establishing
   the World Trade Organization, reprinted in H.R. Doc. 316, 103d Cong., 2d Sess. 1621,
   1636, 1651-1652 (Sept. 27, 1994), discussed, respectively, in § 1A.06[2][d], [9][b] supra.
   62.11
           The crux of the matter is Article 70:2 of the TRIPS Agreement, which imposes “obli-
gations in respect of all subject matter existing at the date of application of this Agreement for
the Member in question, and which is protected in that Member on the said date, or which meets
or comes subsequently to meet the criteria for protection under the terms of this Agreement.”
Agreement on Trade-Related Aspects of Intellectual Property Rights, Art. 70:2, Annex 1C to
Agreement Establishing the World Trade Organization, reprinted in H.R. Doc. 316, 103d Cong.,
2d Sess. 1621, 1651 (Sept. 27, 1994).
    By its terms, this provision appears to require that the mandatory minimum patent term un-
der Article 33, see § 2.05[2] (introduction) supra, apply to patents issued and pending on the
“date of application” of the TRIPS Agreement for the United States. Congress no doubt provided
the longer of the two terms to avoid disturbing business expectations—and consequent constitu-
tional questions—in cases in which the new term—twenty years from the application date—
would provide a shorter term than the old one—seventeen years from the date of grant.
    62.12
           Article 70:2 of the TRIPS Agreement protects matter existing on the “date of applica-
tion” of the TRIPS Agreement for the United States. See N.62.11 supra. Although the fact is not
immediately apparent from the text of the TRIPS Agreement, that “date of application” is Janu-
ary 1, 1996. See § 1A.06[9][a] supra.
    62.13
           See § 1A.04 supra.


                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                               62.14
and are not resurrected.        Those still in force on June 8, 1995, have the
benefit of the longer term: their terms are extended automatically to the extent
(if any) that the current patent term (twenty years after the relevant applica-
            62.15
tion date)        exceeds the old one (seventeen years after the date of
        62.16
grant).       Patents pending, but not yet issued, on June 8, 1995, also have the
                            62.17
benefit of the longer term.       Patents issued on applications filed on or after
June 8, 1995, however, are limited to the current patent term (twenty years
                                      62.18
after the relevant application date).
    The automatic extension of certain patent terms under these transition
     62.19
rules       has the potential to affect adversely the interests of third parties
who may have relied upon an expectation of earlier expiration under the orig-
inal patent term. To reduce this adverse effect, the Uruguay Round Agree-
ments Act limits the remedies available for acts that become infringing by
                                  62.20
virtue of these transition rules.       In particular, it precludes liability for in-
                                                                       62.21
junctive relief, damages, reasonable royalties, or attorneys' fees           for any
such acts that “were commenced or for which substantial investment was
                              62.22
made” before June 8, 1995.           Such acts are allowed to continue subject to
payment of “equitable remuneration” determined in an action for patent in-




   62.14
            Since the transition rule affects only patents in force or pending on June 8, 1995, see
the text accompanying Ns.62.8-62.9 and N.62.9 supra, it cannot affect those that have already
expired by that date. See also, Agreement on Trade-Related Aspects of Intellectual Property
Rights, Art. 70:3, Annex 1C to Agreement Establishing the World Trade Organization, reprinted
in H.R. Doc. 316, 103d Cong., 2d Sess. 1621, 1651 (Sept. 27, 1994) (“There shall be no obliga-
tion to restore protection to subject matter which on the date of application of this Agreement for
the Member in question has fallen into the public domain”), discussed in § 1A.06[9][b], [c]
supra.
     62.15
            See § 2.05[2][a] supra.
     62.16
            See the text accompanying Ns.62.8-62.9 and N.62.9 supra.
     62.17
            See the text accompanying Ns.62.8-62.9 and N.62.9 supra.
     62.18
            See the text accompanying Ns.62.7-62.8 and N.62.8 supra.
     62.19
            See the text accompanying Ns.62.14-62.17 supra.
     62.20
             See 35 U.S.C. § 154(c)(2)(B), as added by Uruguay Round Agreements Act §
532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4985 (Dec. 8, 1994) (referring to acts that “be-
came infringing by reason of paragraph (1),” i.e., 35 U.S.C. § 154(c)(1), which established rule
of longer term for transitional patents and applications, see N.62.9 supra).
     62.21
            The statute refers by number to the “remedies of sections 283, 284, and 285 of this ti-
tle,” i.e., to 35 U.S.C. § 283, 284, 285, which provide for these remedies. 35 U.S.C. §
154(c)(2)(preamble), as added by Uruguay Round Agreements Act § 532(a)(1), Pub. L. No.
103-465, 108 Stat. 4809, 4985 (Dec. 8, 1994).
     62.22
            35 U.S.C. § 154(c)(2) & (2)(A), as added by Uruguay Round Agreements Act §
532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4985 (Dec. 8, 1994).

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

              62.23
fringement.       These rules apply even to acts commenced and investments
                                                    62.24
made while the relevant patents were still pending,       although it is hard to
see how an adverse party could rely on any particular expectation of a limited
                          62.25
patent term in that case.

           [ii]—Relation Back
    Another special transition rule applies to the second change effected by the
                                     62.26
Uruguay Round Agreements Act               —the principle that application dates
for daughter applications not based on foreign priority relate back to the filing
dates of the earliest-filed parent applications specifically referenced in
       62.27
them.        A special transition provision applies that principle only to daugh-
    62.28                                                     62.29
ter       applications filed on or after January 1, 1996.           Accordingly,

   62.23
         See 35 U.S.C. § 154(c)(3), as added by Uruguay Round Agreements Act § 532(a)(1),
Pub. L. No. 103-465, 108 Stat. 4809, 4985 (Dec. 8, 1994):
   “(3) REMUNERATION.—The acts referred to in paragraph (2) may be continued only upon the
   payment of an equitable remuneration to the patentee that is determined in an action brought
   under chapter 28 and chapter 29 (other than those provisions excluded by paragraph (2)) of
   this title.”

   The referenced provisions of Chapters 28 and 29 are 35 U.S.C. §§ 271-296, except for 35
   U.S.C. §§ 283-285 (the excluded remedies). They: define infringement (35 U.S.C. §§ 271-
   272), provide for jurisdiction of civil actions and interferences (35 U.S.C. § 281 and 291),
   impose a presumption of patent validity and define defenses (35 U.S.C. § 282), fix limita-
   tions of actions and remedies (35 U.S.C. § 286-288), require notice of lawsuits to the Com-
   missioner of Patents and Trademarks (35 U.S.C. § 290), prohibit false patent marking (35
   U.S.C. § 292), provide for substituted service upon nonresidents (35 U.S.C. § 293), provide
   for voluntary arbitration by agreement (35 U.S.C. § 294), impose a presumption regarding
   the use of patented processes (35 U.S.C. § 295), and affirm the liability of state and local
   governments and their instrumentalities (35 U.S.C. § 296). Section 289, which provides a
   profits remedy for infringement of design patents, see 35 U.S.C. § 289, does not appear rele-
   vant, since design patent terms are not affected by the Uruguay Round Agreements Act, see
   § 2.05[2] (introduction), [a] supra.
   62.24
           The rule of the longer term applies to patents pending, as well as patents in force, on
June 8, 1995. See: the text accompanying Ns.62.8-62.9 and N.62.9 supra; the text accompany-
ing Ns.62.16-62.17 supra.
    62.25
           Pending patent applications are required by statute to be kept secret. See 35 U.S.C. §
122, discussed in § 4.06[1] supra. Consequently, a party not related to the patent applicant
would have no way of knowing, in general, that a patent affecting his acts or investment was
about to issue. Under these circumstances, the risk that such a patent's term might be longer than
otherwise might be expected appears irrelevant to any concerns of fairness or equity; that risk
only increases an unknown and unknowable uncertainty.
    62.26
           See § 2.05[2][c] (introduction) supra.
    62.27
           See § 2.05[2][a][ii] supra.
    62.28
           The statute refers to “a patent granted on an application that is filed on or after” the
transition date. See N.62.29 infra. The application referred to is thus the one on which the patent
is granted, i.e., the daughter application.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                                              62.30
daughter applications filed in the interregnum—on or after June 8, 1995,
but before January 1, 1996—produce patents with the current term—twenty
                                  62.31
years after the application date        —but the twenty years are measured from
the filing date of the applications themselves, not their parent applications;
                                 62.32
i.e., there is no relation back.       This rule provides a longer term for these
patents than otherwise would be the case.

           [iii]—New Reasons for Term Extension
   A final transition rule applies to the new reasons for patent term extension
                                                       62.33
introduced by the Uruguay Round Agreements Act.              Like the rest of the
                                                                 62.34
patent term provisions, except for the relation-back principle,         these new
                                                                   62.35
reasons apply to applications filed on and after June 8, 1995.             That is,
applications filed on and after that date are eligible for term extension on the
new grounds, and those filed earlier are not. In applying this rule, it is the date



   62.29
         See Uruguay Round Agreements Act § 534(b)(3), Pub. L. No. 103-465, 108 Stat.
4809, 4990 (Dec. 8, 1994):
   “The term of a patent granted on an application that is filed on or after the effective date de-
   scribed in subsection (a) and that contains a specific reference to an earlier application filed
   under the provisions of section 120, 121, or 365(c) of title 35, United States Code, shall be
   measured from the filing date of the earliest filed application.”

   The referenced subsection (a) reads: “Subject to subsection (b), the amendments made by
   this subtitle take effect on the date that is one year after the date on which the WTO Agree-
   ment enters into force with respect to the United States.” Id., § 532(a). Since the date of en-
   try into force of the WTO Agreement is January 1, 1995, both in general and for the United
   States, see: §§ 1A.03[3], 1A.05[1] supra, the general effective date of the subtitle relating to
   patents, as provided in Section 534(a) of the Uruguay Round Agreements Act, is January 1,
   1996.
   62.30
           This date is a significant transitional date for both calculation of the term, see §
2.05[2] [c][i] supra, and term extension, see § 2.05[2][c][iii] infra.
    62.31
           See § 2.05[2][c][i] supra.
    62.32
           Although the statute does not say this specifically, the negative implication from the
special transition rule, see N.62.29 supra, is irresistible. If the relation-back rules applied to
patent applications filed on and after June 8, 1995, there would be no need for the special rule,
since all applications filed after January 1, 1996, a fortiori would be covered.
    62.33
           See § 2.05[2][b][i] supra.
    62.34
           See § 2.05[2][c][ii] supra. The special transition rule for relation back is an exception
to the general rule for the patent term, see § 2.05[2][c][ii] supra, which itself is an exception to
the general rule for the patent provisions of the Uruguay Round Agreements Act, see Uruguay
Round Agreements Act § 534(a), Pub. L. No. 103-465, 108 Stat. 4809, 4990 (Dec. 8, 1994),
quoted in N.62.29 supra.
    62.35
           See Uruguay Round Agreements Act § 534(b)(1), Pub. L. No. 103-465, 108 Stat.
4809, 4990 (Dec. 8, 1994), quoted in N.62.8 and discussed in § 2.05[2][c][i] supra.

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

of the daughter application on which the patent issues that counts, not the date
                           62.36
of any parent application.

           [iv]—Table of Transition Rules
   The foregoing transition rules can be summarized in the following table:
Type of Patent                           Applicable Term and Rules

Patent expiring before 6/8/95            17 years from grant no exten-
                                         sion on new grounds

Patent in force on 6/8/95                longer term no relation back
                                         no extension on new grounds

Patent on application filed              longer term no relation back
before 6/8/95                            no extension on new grounds

Patent on application filed on           20 years from application
or after 6/8/95 but before               date no relation back exten-
1/1/96                                   sion on new grounds

Patent on application filed on      20 years from application
or after 1/1/96                     relation back extension on
                                    new grounds
In this table: (1) the “longer term” means the last to expire of seventeen years
after the date of grant or twenty years after the filing date of the relevant ap-
           62.37
plication;       (2) “no relation back” means that the filing date of a daughter
application not claiming foreign priority does not relate back to the filing date
                           62.38
of the parent application        (the filing date of a daughter application never
relates back to a foreign-priority parent application for term-computation pur-
        62.39
poses);        and (3) “extension on new grounds” means that patent term ex-
tension is available to compensate for delay due to interference proceedings,




   62.36
          The relation-back rule does not change the date of application; it just changes the date
used to calculate the beginning of the patent term. See 35 U.S.C. § 154(b)(2), as added by Uru-
guay Round Agreements Act § 532(a)(1), Pub. L. No. 103-465, 108 Stat. 4809, 4984 (Dec. 8,
1994), discussed and quoted in § 2.05[2][a][ii] supra. Therefore the application date for other
purposes is the date of the application on which the patent issues, i.e., the daughter application.
   62.37
          See § 2.05[2][c][i] supra.
   62.38
          This is contrary to the normal rules that prevail after the transition is complete, see §
2.05[2][a][ii] supra, but it applies during a transitional period, see § 2.05[2][c][ii] supra.
   62.39
          See § 2.05[2][a][ii] supra.


                                                                                       (Rel. 25)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

 secrecy orders, or review of adverse decisions on patentability in the Board
                                                   62.40
of Patent Appeals and Interferences or the courts.

   [3]—Scope of Exclusive Rights
    Among all the fields of intellectual property, infringement analysis in the
                                         62.41
field of utility patents is unique.             Assessing infringement of copy-
        62.42               62.43                                        62.44
rights,       mask works,         and (to a lesser extent) trade symbols       re-
quires comparing a physical embodiment of the intellectual property with the
subject matter that allegedly infringes it. In order to determine whether intel-
lectual property of these sorts is infringed, the trier of fact compares one tan-
gible object embodying the intellectual property with another embodying the
                        62.45
alleged infringement.          Even design patent litigation has much the same
            62.46
character.        In contrast, utility patent law requires comparing the physical

   62.40
           See § 2.05[2][b][i], [c][iii] supra.
   62.41
           See § 1.07[2] supra.
   62.42
            See § 5.01[3] infra (discussing standards and procedure for assessing copyright in-
fringement).
    62.43
            See: §§ 8.04[1][b], 8.05[1][b], [c] infra (discussing standards and procedure for as-
sess mask work infringement in general, and when reverse-engineering defense is raised).
    62.44
            See 10.01[3][b], [c], [d], [e] (discussing similarity of marks, products or services,
channels of trade and advertising and promotional methods as important but nonexclusive fac-
tors to be considering in assessing near-universal standard of likelihood of confusion in cases of
alleged trade symbol infringement and unfair competition).
    62.45
           Copyright law requires comparing the copyrighted work with the allegedly infringing
work for “substantial similarity.” See § 5.01[3] infra. A work is copyrighted only if it is “fixed”
in a tangible medium of expression, see: 17 U.S.C. § 102(a); § 5.03[1] infra, and the process of
comparison necessarily relies on a tangible “copy” or “phonorecord,” see § 6.01[1] infra, in
which the copyrighted work is fixed. In semiconductor chip protection cases, the allegedly in-
fringing mask work is compared for “substantial similarity,” see: § 8.04[1][b], 8.05[1][c] infra,
or (if a prima facie case of reverse engineering is made) for “substantial identity,” see §
8.05[1][b] infra, with the protected mask work. Although the process of comparison may in-
volve more than the plaintiff’s chip, protection requires, and the process of comparison pre-
sumes, that the mask work, which in any event controls the physical configuration of the
plaintiff’s chip, see § 8.01[3], [4] infra, has been fixed in a semiconductor chip. See § 8.03[2]
infra. While the comparison process may involve copyright-like fixations of the mask work
other than the chip itself (for example, magnified representations of the masks), all those fixa-
tions must represent the actual physical configuration of a protected chip, and therefore they can
be analogized to copyright-infringement comparisons as comparing physical embodiments of
the infringing work with the protected one. In trade symbol cases, the law is even clearer: it is
black- letter law that accused and protected trade symbols must be compared as they appear in
the marketplace, in use with actual products or services, and not singly or in the abstract. See §
10.01[3][b] infra.
    62.46
           In design-patent infringement litigation, courts or juries compare the allegedly infring-
ing design with the patented one for substantial sameness in the eyes of an ordinary observer.
See § 2.05[3][b][ii] infra. Whether they compare the allegedly infringing design with the draw-
ing that must be attached to the single pro forma patent claim, see § 2.02[1][b] supra, or with an
actual product containing the patented design makes little difference because industrial design

                                                                                        (Rel. 25)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

embodiment of the alleged infringement with an abstract, verbal description
                                                                    62.47
of the patented invention set forth in a series of patent “claims.”
   In other words, while assessing infringement of other intellectual property
requires comparing a thing with a thing, patent law requires comparing a
thing with a description in words. The trier of fact must compare the thing
alleged to infringe—in patent parlance, the “accused device” or “accused
process”—with the abstract verbal description of the patented invention in the
                 62.48
patent’s claims.       Moreover, since the law treats each patent claim as the
                                       62.49
description of a separate invention,         the trier of fact must compare the
accused thing with each of the claims allegedly infringed.
   The importance of this simple fact is hard to overestimate. Words, not a
tangible thing, determine the scope of patent protection. Like all words with
                                                                   62.50
legal effect, the words of patent claims require interpretation.          The need


necessarily involves a blend of form and function, see § 5.02[3][a] infra, and therefore the draw-
ing of the design must show how the design relates to the product. See § 2.02[1][b] supra.
    62.47
           See generally, § 2.05[3][a] infra.
    62.48
           See id.
    62.49
           See § 2.05[3][a][ii] infra. This point is so basic that it is difficult to find specific mod-
ern authority. See Donnelly Corp. v. Gentex Corp., 1996 U.S. App. LEXIS 20868 at *7-*8
(Fed. Cir. Aug. 19, 1996) (unpublished) (noting that “each claim of a patent is distinct, and
infringement of any one of the claims is still infringement of [*8] the patent” on way to refusing,
under circumstances, to accept jurisdiction of appeal based on alleged partial final judgment
involving only some, but not all, of disputed claims of patents in issue). Cf., 35 U.S.C. § 282
(each claim of patent, whether independent or dependent, is separately presumed valid).
    62.50
           See, e.g.:
    Supreme Court: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122
S.Ct. 1831, 1837, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting Autogiro Co.
of America v. United States, 384 F.2d 391, 397, 181 Ct. Cl. 55 (1967):
   “Unfortunately, the nature of language makes it impossible to capture the essence of a thing
   in a patent application. The inventor who chooses to patent an invention and disclose it to
   the public, rather than exploit it in secret, bears the risk that others will devote their efforts
   toward exploiting the limits of the patent’s language:

         ‘An invention exists most importantly as a tangible structure or a series of drawings. A
         verbal portrayal is usually an afterthought written to satisfy the requirements of patent
         law. This conversion of machine to words allows for unintended idea gaps which can-
         not be satisfactorily filled. Often the invention is novel and words do not exist to de-
         scribe it. The dictionary does not always keep abreast of the inventor. It cannot.
         Things are not made for the sake of words, but words for things.’”
   Federal Circuit: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558,
621-622, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (opinion by
Judge Linn, joined by Judge Rader, dissenting in part) (Citations omitted.):
   “Due to the inherent limitations of language, the fit between the description [in the claims]
   and the [inventive] concept is almost always inexact. . . . [*622] . . . In addition to the inex-
   act fit caused by the inherent limitations of language, the language itself may not be ade-

                                                                                            (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

for interpretation raises five important questions. First, who interprets patent
claims? In particular, does the judge or the jury (when either party demands
one) do so? Second, what substantive rules and canons of interpretation apply
in construing patent claims? Third, what evidence is relevant to claim inter-
pretation? Is there an analog to the parol evidence rule in contract law that
favors the written word over other evidence? Fourth, once interpreted, how
are claims applied to the accused thing to assess infringement? And finally,
what procedures apply to the interpretation and application of claims and to
review     of     that    interpretation  and     application     on    appeal?




   quately developed at the early stages when patent applications typically are filed, particularly
   in rapidly evolving research fields.”


                                                                                       (Rel. 25)
2-05                      PATENTS               INTELLECTUAL PROPERTY LAW


    Although patent law has existed in the United States since late in the eight-
                62.51
eenth century,        these apparently basic questions were not resolved—even
in broad outline—until the end of the twentieth and the dawn of the twenty-
first. A principal achievement of the Federal Circuit, newly established in
1982 in part for the purpose of clarifying patent law and procedure and mak-
                       62.52
ing it more uniform,         has been, with the aid and occasionally the correc-
tive supervision of the Supreme Court, to sketch answers to these vital
questions. More than in any other area of patent law, the Federal Circuit’s
decisionmaking on infringement has revolutionized patent practice. It is there-
fore worthwhile to outline the crucial decisions, that changed the face of pa-
tent infringement practice forever.
    The celebrated Markman v. Westview Instruments, Inc. decision, rendered
                                             62.53
en banc in 1992 by the Federal Circuit             and affirmed by the Supreme
       62.54
Court,       answered the first question definitively. Under Markman, judges,
                                     62.55
not juries, construe patent claims.        Although the Supreme Court’s deci-
sion involved all of the historical intricacies of Seventh Amendment jurispru-
       62.56
dence,        it ultimately turned on policy: judges construe patent claims
because they are better at it than juries and because their legal training prom-
                                         62.57
ises greater certainty and uniformity.         The Markman decision might be
said to constitute the first revolution in patent law wrought by the Federal
Circuit.
    With respect to the second question, regarding canons of claim construc-
tion, the Federal Circuit has been less revolutionary. It adopted and clarified a
number of principles of claim construction established by its predecessor
courts and the Supreme Court over nearly two centuries of patent prac-

   62.51
           See Act of April 10, 1790, 1 Stat. 109.
   62.52
           See § 2.01 supra.
   62.53
           Markman v. Westview Instruments, Inc., 52 F.3d 967, 34 U.S.P.Q.2d (BNA) 1321
(Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38 U.S.P.Q.2d
(BNA) 1461 (1996).
    62.54
            See Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S.Ct. 1384, 134
L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996), aff’g 52 F.3d 967, 34 U.S.P.Q.2d (BNA) 1321
(Fed. Cir. 1995) (en banc).
    62.55
           Id., 517 U.S. at 372 (unanimous opinion) (“We hold that the construction of a patent,
including terms of art within its claim, is exclusively within the province of the court”), dis-
cussed in § 2.05[3][a][iv] infra.
    62.56
           See id., 517 U.S. at 376-389 (reviewing precedent and treatises from Founding to pre-
sent and concluding that “history and precedent provide no clear answers”). Because the Sev-
enth Amendment states that the right of trial by jury in certain actions “shall be preserved[,]”
U.S. Const., Amend. 7, courts must first look at law and practice when the Seventh Amendment
was adopted in order to determine whether jury trials, if demanded, are constitutionally required
under specified circumstances. See 517 U.S. at 376.
    62.57
           Id., 517 U.S. at 388-391, discussed in § 2.05[3][a][iv] infra.


                                                                                     (Rel. 24)
2-05                      PATENTS               INTELLECTUAL PROPERTY LAW

     62.58
tice.     It also highlighted the importance of patent claims by confirming
that anything disclosed but not claimed in a patent application is ipso facto
                         62.59
dedicated to the public.       Beyond clarification, the Federal Circuit empha-
sized the importance of claim limitations and the corresponding elements of
                                                              62.60
inventions as the basic matter on which legal rules operate.        (The Federal
Circuit tried to make revolutionary changes in the doctrine of prosecution
history estoppel, but its most revolutionary proposal—the “complete bar”
                                                                  62.61
rule—was rejected by the Supreme Court, as discussed below.)
   With respect to the third question—relevant evidence—the Federal Circuit
                                                                            62.62
wrought a second revolution in patent practice. In a panel decision,
                                                       62.63
which a later en banc decision appeared to confirm,          the court ruled that

   62.58
           See § 2.05[3][a][ii] infra.
   62.59
           See Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1106-1107, 39 U.S.P.Q.2d (BNA) 1001
(Fed. Cir. 1996), cert. denied 520 U.S. 1115 (1997) (applying “well-established rule that ‘sub-
ject matter disclosed but not claimed in a patent application is dedicated to the public’” to obvi-
ate infringements under doctrine of equivalents), quoting Unique Concepts, Inc. v. Brown, 939
F.2d 1558, 1562-1563, 19 U.S.P.Q.2d (BNA) 1500 (Fed. Cir. 1991).
    62.60
           See § 2.05[3][a][ii] infra.
    62.61
           See: the text accompanying Ns.62.85-62.100 infra; § 2.05[3][b][i][B] infra. See also,
§ 2.06[2] infra.
    62.62
           See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583, 39 U.S.P.Q.2d (BNA)
1573 (Fed. Cir. 1996) (Citations omitted.):
   “The claims, specification, and file history, rather than extrinsic evidence, constitute the
   public record of the patentee’s claim, a record on which the public is entitled to rely. In other
   words, competitors are entitled to review the public record, apply the established rules of
   claim construction, ascertain the scope of the patentee's claimed invention and, thus, design
   around the claimed invention. . . . Allowing the public record to be altered or changed by ex-
   trinsic evidence introduced at trial, such as expert testimony, would make this right mean-
   ingless.”
    62.63
           See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1455-1456, 46
U.S.P.Q.2d (BNA) 1169 (Fed. Cir. 1998), discussed in § 2.05[3][a][iii] infra.
    The issue in Cybor was procedural, not evidentiary. The Federal Circuit decided, en banc,
that claim construction is purely a matter of law for the judge, not the jury, and is subject to de
novo review upon appeal. See 138 F.3d at 1456. To reach that conclusion, however, the court
had to reject the views of certain judges that claim construction necessarily involves assessing
matters of fact, including the definitions of terms, with the aid of expert witnesses and conse-
quent credibility assessments. See 138 F.3d at 1481 (“additional views” of Judges Mayer and
Newman) (Emphasis added and citation omitted.):
   “Of course the primary source of information concerning the claimed invention is the patent
   documents. But such documents are directed to persons knowledgeable in the field; addi-
   tional evidence and expert testimony as to their meaning should be the rule, not the excep-
   tion. So-called ‘extrinsic’ evidence—the evidence of expert witnesses and of
   experimentation, exhibits, demonstrations, and explanation—should be treated like any other
   evidence, and received and given weight and value as appropriate. Our broad constraint on
   resort to such evidence is an unnecessary bar to enlightenment. It is also an incursion into
   the authority of the trial court.”


                                                                                        (Rel. 24)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

“intrinsic” evidence in the public record is favored, and “extrinsic” evidence
like the testimony of inventors and experts is disfavored and to be admitted
                                            62.64
only when intrinsic evidence is ambiguous.




The Cybor majority, by a vote of 9-3, soundly and completely rejected this line of reasoning.
See 138 F.3d at 1456 (majority opinion) (Citations to disapproved decisions omitted.):
    “[W]e . . . reaffirm that, as a purely legal question, we review claim construction de novo on
    appeal including any allegedly fact-based questions relating to claim construction. Accord-
    ingly, we today disavow any language in previous opinions of this court that holds, purports
    to hold, states, or suggests anything to the contrary[.]”
See also, § 2.05[3][a][iii] infra (discussing Cybor in more depth).
    62.64
            See: Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582, 39 U.S.P.Q.2d (BNA)
1573 (Fed. Cir. 1996) (“It is well-settled that, in interpreting an asserted claim, the court should
look first to the intrinsic evidence of record, i.e., the patent itself, including the claims, the speci-
fication and, if in evidence, the prosecution history”); 90 F.3d at 1583 (“[i]n most situations, an
analysis of the intrinsic evidence alone will resolve any ambiguity in a disputed claim term. In
such circumstances, it is improper to rely on extrinsic evidence”). (Citations omitted.)
    The Federal Circuit earlier had defined “extrinsic” evidence as “all evidence external to the
patent and prosecution history, including expert and inventor testimony, dictionaries, and
learned treatises.” Markman v. Westview Instruments, Inc., 52 F.3d 967, 980, 34 U.S.P.Q.2d
(BNA) 1321 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577,
38 U.S.P.Q.2d (BNA) 1461 (1996).

                                                                                            (Rel. 24)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

     These decisions to some extent startled the patent bar, which had become
accustomed to relying heavily on oral testimony by inventors and experts in
patent litigation. In making claim construction depend on written evidence in
the public record where unambiguous, the Federal Circuit highlighted the
importance of the “public notice” function of patents and their prosecution
           62.65
histories.       It also emphasized an objective theory of patent claim interpre-
tation, in which the intentions of the various parties such as the inventor, the
patent attorney, and the patent examiner are irrelevant, except as reflected in
the written record, and what matters is objective interpretation by a hypothet-
                                            62.66
ical person of reasonable skill in the art.       The court thus went far beyond
even the parol evidence rule of contract law in repudiating after-the-fact oral
            62.67
testimony.
    In answering the fourth question—how claims once construed are ap-
plied—the Federal Circuit continued a long tradition of patent law but in
some respects revolutionized it. Under that tradition, applying construed
claims to an accused device or process requires two steps: (1) assessing so-

   62.65
           The Federal Circuit’s emphasis on the “public notice” function of patents and their
prosecution histories perhaps reached its apex in the year 2000, when the court relied in part on
that policy to declare, en banc, that claim elements amended for reasons related to patentability,
as well as those amended without explanation of reasons, cannot enjoy the benefits of the doc-
trine of equivalents and therefore are entitled to protection only against literal infringement. See
Ns.62.90-62.93 infra.
    See generally: §§ 2.05[3][b][i][B] infra, 2.06[2] infra (discussing prosecution history estop-
pel and effect of Festo decision on it).
    62.66
           See Markman v. Westview Instruments, Inc., 52 F.3d 967, 985-986, 34 U.S.P.Q.2d
(BNA) 1321 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577,
38 U.S.P.Q.2d (BNA) 1461 (1996):
   “No inquiry as to the subjective intent of the applicant or PTO is appropriate or even possi-
   ble in the context of a patent infringement suit. The subjective intent of the inventor when he
   used a particular term is of little or no probative weight in determining the scope of a claim
   (except as documented in the prosecution history). * * * [*986] * * *
   “Thus the focus in construing disputed terms in claim language is not the subjective intent of
   the parties to the patent contract when they used a particular term. Rather the focus is on the
   objective test of what one of ordinary skill in the art at the time of the invention would have
   understood the term to mean.”
See generally, 52 F.3d at 985-987 (rejecting analogy of patent interpretation to contract interpre-
tation in favor of analogy to statutory interpretation).
    62.67
           See id., 52 F.3d at 985 (Citation omitted.):

   “Questions of fact may arise in construing contracts, deeds, or wills in two contexts. First,
   the document may not reflect the agreement between, or the intent of, the two parties. Thus,
   unless the document is fully integrated and the parol evidence rule (or its equivalent in the
   other areas of law) applies, extrinsic evidence may be offered to demonstrate different or ad-
   ditional terms. There is no parol evidence rule in patent law for obvious reasons. It is axio-
   matic that the invention protected by the patent must be covered by the claims, otherwise it
   is lost. . . . Parol or other extrinsic evidence cannot add, subtract, or vary the limitations of
   the claims.”


                                                                                        (Rel. 25)
2-05                      PATENTS                  INTELLECTUAL PROPERTY LAW

                                        62.68
called “literal” infringement,       and (2) for those claim elements that merit
    62.69                                                62.70
it,       analyzing “equivalents” of what is claimed.          In the first step, the
decisionmaker, in patent parlance, “reads” the construed claims “on” the ac-
cused device or process in order to determine whether those claims describe
    62.71
it.       This process is called assessing “literal” infringement because it in-
volves comparing the claim language, as construed, to the asserted infringe-
        62.72
ment.         Yet, because of the nature of claim interpretation, this process is
                                                62.73
hardly as “literal” as its name might suggest.
     In the second step, the decisionmaker assesses whether what appears in the
accused device is “equivalent” to features of the claimed invention although
                                      62.74
not “literally” stated in the claims.       This second step, which relies on the
so-called “doctrine of equivalents,” is designed, in essence, to insure that a
copyist cannot escape liability for infringement simply by exploiting the limi-
tations of language and making insubstantial differences from the invention
                           62.75
described in the claims.         Both this step and its underlying doctrine reflect
the perennial battle of substance over form.
     The Federal Circuit’s revolution in applying construed claims was based
on the notion of claim “limitations” and corresponding “elements” of accused
                        62.76
devices or processes.         A claim limitation is a word, phrase, or clause that
                                                62.77
adds an element to the claimed invention              and therefore increases the

   62.68
           See generally, § 2.05[3][a] infra.
   62.69
           See § 2.05[3][b][i][B] infra.
   62.70
           See generally, § 2.05[3][b][i] infra.
   62.71
           See § 2.05[3][a][i] infra.
   62.72
           Id.
   62.73
           Id.
   62.74
           See § 2.05[3][b][i][A] infra.
   62.75
           Id.
   62.76
         Although addressed to complementary concepts, the two terms are often confused. See
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 563 n.1, 56 U.S.P.Q.2d
(BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground 535 U.S.
722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), citing Lemelson v.
United States, 752 F.2d 1538, 1551, 224 U.S.P.Q. (BNA) 526, 533 (Fed. Cir. 1985) (using
“element”); Sextant Avionique, S.A. v. Analog Devices, Inc., 172 F.3d 817, 826-827, 49
U.S.P.Q.2d (BNA) 1865, 1870-71 (Fed. Cir. 1999) (using “limitation”):
   “In our prior cases, we have used both the term ‘element’ and the term ‘limitation’ to refer to
   words in a claim. It is preferable to use the term ‘limitation’ when referring to claim lan-
   guage and the term ‘element’ when referring to the accused device. See Dawn Equipment
   Co. v. Kentucky Farms, Inc., 140 F.3d 1009, 1014 n.1, 46 U.S.P.Q.2d [(BNA)]1109, 1112
   n.1 (Fed. Cir. 1998). However, because the en banc questions use the term ‘element,’ we use
   that term [for claim limitation] in this opinion.”
   62.77
           See N.62.76 supra.


                                                                                      (Rel. 25)
2-05                      PATENTS               INTELLECTUAL PROPERTY LAW

specificity of the invention claimed and narrows the scope of the claim. The
notion of inventive elements and corresponding claim limitations had been
well established before the advent of the Federal Circuit, for infringement had
long required satisfaction of every limitation of a claim, and therefore the
                                                          62.78
presence of every claim element in the accused thing.
    The Federal Circuit’s revolutionary contribution consisted not just of
adopting this established rule, but in clarifying and strengthening the rule by
                                                62.79
applying it to the doctrine of equivalents.           The court refused to assess
equivalence broadly with regard to a whole invention, but confined the doc-
trine of equivalents to each element of the invention separately, on an ele-
                          62.80
ment-by-element basis.          In order to infringe, ruled the court, the accused
device or process must have an element that corresponds to each and every
element of the claimed invention (and therefore each and every claim limita-
                                                                62.81
tion), either directly or under the doctrine of equivalents.          That is, every
element of the claimed invention (corresponding to every claim limitation) or
its equivalent must appear in the accused device or process in order for in-
                       62.82                                            62.83
fringement to occur.          The Supreme Court affirmed this rule,           which
                                                    62.84
has become known as the “all elements” rule.              Its precise impact in as-
                                                           62.85
sessing equivalents, however, is still not entirely clear.




   62.78
           See § 2.05[3][a][i] infra.
   62.79
           See § 2.05[3][b][i][A] infra.
   62.80
           Id.
   62.81
           See Pennwalt Corp. v. Durand-Wayland Inc., 833 F.2d 931, 936-939, 4 U.S.P.Q.2d
(BNA) 1737, 1741 (Fed. Cir. 1987) (en banc), cert. denied 485 U.S. 1009 (1988), discussed in
§ 2.05[3][b][i][A] infra.
    62.82
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 598-599,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (opinion by Judges Michel and Rader, concurring
in part and dissenting in part) (“The all-elements rule provides that every limitation of a claim is
material, and that an accused device lacking a corresponding element, [*599] or an equivalent
thereof, for every limitation cannot infringe the claim, even under the doctrine of equivalents”),
citing Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 937, 4 U.S.P.Q.2d (BNA) 1737,
1741 (Fed. Cir. 1987) (en banc) (“device that does not satisfy [a claim limitation] at least equiv-
alently does not function in substantially the same way as the claimed invention,” and thus can-
not infringe under the doctrine of equivalents).
    62.83
           See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997) (“Each element contained in a patent claim is deemed
material to defining the scope of the patented invention, and thus the doctrine of equivalents
must be applied to individual elements of the claim, not to the invention as a whole”), discussed
in § 2.05[3][b][i][A] infra.
    62.84
           See N.62.81 supra.
    62.85
           See § 2.05[3][b][i] infra.


                                                                                        (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

   A second phase in the revolution in applying the doctrine of equivalents
                                                 62.86
began with the Federal Circuit’s maniFesto             on the subject in the year
2000. In that case, the Federal Circuit, sitting en banc, established four prin-
ciples of so-called “prosecution history estoppel”62.87 by claim amendment.
First, it ruled that any claim amendment relating to any statutory requirement
for patentability creates an estoppel, whether the amendment relates to pa-
tentable subject matter, novelty, utility, nonobviousness, proper disclosure, or
any other requirement of the patent statute for a valid patent.62.88 The Supreme
Court affirmed the decision on this point, but in less absolute terms, ruling
that a claim amendment relating to any statutory requirement for patentability
may give rise to an estoppel62.89 if there are reasons why the claim amendment




   62.86
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 563, 566-
579, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (posing five important questions
regarding application of doctrine of equivalents to amended claim limitations and answering
four of them), discussed in § 2.05[3][b][i][B] infra.
    62.87
           “Prosecution history estoppel” is a doctrine under which a patentee cannot claim as an
infringement matter surrendered in patent prosecution, whether by statement, argument to the
patent examiner, or claim amendments. See: §§ 2.05[3][b][i][B], 2.06[3] infra.
    The Supreme Court has summarized the doctrine, as applied to claim amendments and limit-
ing the doctrine of equivalents, in the following terms:
   “In some cases the Patent and Trademark Office (PTO) may have rejected an earlier version
   of the patent application on the ground that a claim does not meet a statutory requirement for
   patentability. 35 U.S.C. § 132. . . . When the patentee [as applicant] responds to the rejection
   by narrowing his claims, this prosecution history estops him from later arguing that the sub-
   ject matter covered by the original, broader claim was nothing more than an equivalent.
   Competitors may rely on the estoppel to ensure that their own devices will not be found to
   infringe by equivalence.”
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct. 1831, 1835,
152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002).
    62.88
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 563, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), aff’d on this point and vacated and re-
manded on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d
(BNA) 1705 (2002), quoting Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17,
33, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (Footnote omitted.):
   “[W]e hold that ‘a substantial reason related to patentability’ is not limited to overcoming
   prior art, but includes other reasons related to the statutory requirements for a patent. There-
   fore, an amendment that narrows the scope of a claim for any reason related to the statutory
   requirements for a patent will give rise to prosecution history estoppel with respect to the
   amended claim element.”
   62.89
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1839, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“We agree with the Court of
Appeals that a narrowing amendment made to satisfy any requirement of the Patent Act may
give rise to an estoppel”). (Emphasis added.) See also id., 122 S.Ct. at 1839-1840 (specifically
citing requirements for novelty, utility, nonobviousness, written description, enablement, and
best mode). For further discussion of this point, see § 2.05[3][b][i][B] infra.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

should preclude the range of equivalents for which the patentee is arguing.62.90
Second, the Federal Circuit ruled that prosecution history estoppel by claim
amendment applies whether the amendment is made in response to an exam-
iner’s objection or is “voluntary” on the part of the patent applicant.62.91 The
Supreme Court did not address this issue.62.92 Third, the Federal Circuit, fol-
lowing strong dictum in the Supreme Court’s decision in Warner-
Jenkinson,62.93 ruled that unexplained claim amendments create an estoppel

   62.90
         The Court’s opinion struck an especially cautionary note with respect to the disclosure
requirements under 35 U.S.C. § 112, discussed in § 2.04[1] supra. See Festo Corp. v. Shoketsu
Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct. 1831, 1840, 152 L.Ed.2d 944, 62
U.S.P.Q.2d (BNA) 1705 (2002) (Emphasis added.):
   “Estoppel arises when an amendment is made to secure the patent and the amendment nar-
   rows the patent’s scope. If a § 112 amendment is truly cosmetic, then it would not narrow
   the patent’s scope or raise an estoppel. On the other hand, if a § 112 amendment is necessary
   and narrows the patent’s scope—even if only for the purpose of better description—estoppel
   may apply. A patentee who narrows a claim as a condition for obtaining a patent disavows
   his claim to the broader subject matter, whether the amendment was made to avoid the prior
   art or to comply with § 112. We must regard the patentee as having conceded an inability to
   claim the broader subject matter or at least as having abandoned his right to appeal a rejec-
   tion. In either case estoppel may apply.”
   62.91
         See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 563-564,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc):
   “[W]e hold that ‘voluntary’ claim amendments are treated the same as other claim amend-
   ments; therefore, any voluntary amendment that narrows the scope of a claim for a reason re-
   lated to the statutory requirements for a patent will give rise [*564] to prosecution history
   estoppel with respect to the amended claim element.”
   62.92
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1835, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (certiorari was granted to
address two questions only: whether prosecution history estoppel applies to claim amendments
made for reasons other than avoiding prior art and whether the complete-bar rule applies). Por-
tions of the Supreme Court’s opinion can be read as focusing on amendments to address exam-
iners’ requirements, while others appear to contemplate a broader range of amendments,
including voluntary amendments. Compare, 122 S.Ct. at 1838-1839 (“A rejection indicates that
the patent examiner does not believe the original claim could be patented. While the patentee
has the right to appeal, his decision to forgo an appeal and submit an amended claim is taken as
a concession that the invention as patented does not reach as far as the original claim”) (Empha-
sis added.), with 122 S.Ct. at 1839 (“Where the original application once embraced the purport-
ed equivalent but the patentee narrowed his claims to obtain the patent or to protect its
validity, the patentee cannot assert that he lacked the words to describe the subject matter in
question”). (Emphasis added.)
     62.93
           See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997) (“where no explanation [for a claim amendment] is established, .
. . the court should presume that the patent applicant had a substantial reason related to patenta-
bility for including the limiting element added by the amendment” and therefore “prosecution
history estoppel would bar the application of the doctrine of equivalents as to that element”).
     This statement is dictum because the Court remanded the case for an assessment of the rea-
sons for the claim amendment at issue. See 520 U.S. at 34 (“Because respondent has not prof-
fered in this Court a reason for the addition of [the claim limitation], it is impossible to tell
whether the reason for that addition could properly avoid an estoppel. Whether a reason in fact

                                                                                       (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

because they are presumed to be made for substantial reasons related to pa-
tentability.62.94 The Supreme Court agreed that unexplained amendments cre-
ate an estoppel that amounts to a complete bar to the doctrine of
equivalents.62.95 Finally, the Federal Circuit ruled that, in determining whether

exists, but simply was not adequately developed, we cannot say. On remand, the Federal Circuit
can consider whether reasons for that portion of the amendment were offered or not and whether
further opportunity to establish such reasons would be proper”).
    62.94
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 564, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), aff’d on this point and vacated and re-
manded on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d
(BNA) 1705 (2002) (reversing judgments of infringement under doctrine of equivalents based
on two different patents because of unexplained amendments added in prosecution of one and
re-examination of other, which required complete bar to applying doctrine of equivalents to
those elements).
    Whether or not there is a presumption, the patentee bears the burden of proving the reason
for a claim amendment. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S.
722, 122 S.Ct. 1831, 1841-1842, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (reaf-
firming that burden is “on the patentee to show that an amendment was not for purposes of
patentability”), citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33,
117 S.Ct. 1040, 137 L.Ed.2d 146 (1997). The patentee also bears the burden of proving that
coverage of any particular equivalent survives an estoppel. See 122 S.Ct. 1842 (“Just as Warner-
Jenkinson held that the patentee bears the burden of proving that an amendment was not made
for a reason that would give rise to estoppel, we hold here that the patentee should bear the bur-
den of showing that the amendment does not surrender the particular equivalent in question”),
referring to Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997).
    62.95
           The Federal Circuit had ruled that any amendment of a claim element creates a com-
plete bar to applying the doctrine of equivalents to that element. See § 2.05[3][b][i][B] infra.
Consistent with that decision, it also ruled that an unexplained amendment creates an estoppel
that completely bars application of the doctrine of equivalents as to the amended claim element.
See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 576, 56 U.S.P.Q.2d
(BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded 535 U.S. 722, 122 S.Ct. 1831,
152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002):
   “A complete bar . . . serves the definitional and notice functions when explained amend-
   ments give rise to prosecution history estoppel. Regardless of whether the amendment is ex-
   plained or unexplained, if the amendment narrows the scope of the claim for a reason related
   to patentability, a complete bar to the doctrine of equivalents provides the public and the pa-
   tentee with definite notice as to the scope of the claimed invention.”
While reversing the Federal Circuit’s decision applying the complete bar generally, the Supreme
Court agreed with the Federal Circuit that a complete bar to applying the doctrine of equivalents
is appropriate with respect to a claim amendment whose purpose is unexplained. See Festo
Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct. 1831, 1842, 152
L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting and explaining Warner-Jenkinson Co.
v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997):
   “When the patentee is unable to explain the reason for amendment, estoppel not only applies
   but also ‘bars the application of the doctrine of equivalents as to that element.’ . . . These
   words do not mandate a complete bar; they are limited to the circumstance where ‘no expla-
   nation is established.’ They do provide, however, that when the court is unable to determine
   the purpose underlying a narrowing amendment—and hence a rationale for limiting the es-
   toppel to the surrender of particular equivalents—the court should presume that the patentee
   surrendered all subject matter between the broader and the narrower language.”


                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

a claim amendment is explained (and, if so, whether the explanation relates to
a substantial question of patentability), a court may consider only evidence
from the written public records, including the patent and its prosecution histo-
ry, and not oral evidence that is unavailable to the public. 62.96 The Supreme
Court did not address this issue.
Although these four principles constrained the growing use of the doctrine of
equivalents, the Supreme Court rejected the most revolutionary ruling in the
                                                                       62.97
Federal Circuit’s decision in Festo. Over the dissents of four judges,       the

   62.96
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 586, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (Footnote omitted.), vacated and remanded
on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705
(2002), referring to Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117
S.Ct. 1040, 137 L.Ed.2d 146 (1997) (placing burden of explaining reasons for claim amend-
ments on patentee “gives proper deference to the role of claims in defining an invention and
providing public notice”) (Footnote omitted.):
   “In order to give due deference to public notice considerations under the Warner-Jenkinson
   framework, a patent holder seeking to establish the reason for an amendment must base his
   arguments solely upon the public record of the patent’s prosecution, i.e., the patent’s prose-
   cution history. To hold otherwise—that is, to allow a patent holder to rely on evidence not in
   the public record to establish a reason for an amendment—would undermine the public no-
   tice function of the patent record. If the reasons for the amendment do not appear in the pub-
   lic record of the patent’s prosecution, the reasons in most cases will be known only to the
   patent holder. We therefore hold that a narrowing amendment will give rise to prosecution
   history estoppel unless the prosecution history of the patent reveals that the amendment was
   made for a purpose unrelated to patentability concerns.”
   62.97
             See id., 234 F.3d at 598 (opinion of Judge Michel, joined by Judge Rader, dissenting
with regard to complete-bar rule) (“I am convinced . . . that the majority’s new ‘complete bar
rule,’ . . . contravenes consistent Supreme Court authority. Not only does the majority’s new rule
directly contradict one Supreme Court holding, but it undermines the legal standard that the
Supreme Court has consistently articulated in seven other cases for determining the scope of
such estoppel. . . . The majority’s new rule [also] constitutes a rejection of the policy advanced
by the Supreme Court in Warner-Jenkinson that the all-elements rule and prosecution history
estoppel are sufficient to balance the competing needs of granting meaningful protection to
patentees and of notifying the public of the effective scope of a patentee’s claims”), referring to
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct. 1040, 137
L.Ed.2d 146 (1997) (“Each element contained in a patent claim is deemed material to defining
the scope of the patented invention, and thus the doctrine of equivalents must be applied to
individual elements of the claim, not to the invention as a whole”), discussed in § 2.05[3][b][i]
infra; 234 F.3d at 627 (opinion of Judge Linn, joined by Judge Rader, dissenting with regard to
complete-bar rule) (“the majority’s new rule hands the unscrupulous copyist a free ride on po-
tentially valuable patented technology, as long as the copyist merely follows the prosecution
history road map and makes a change, no matter how trivial or insubstantial, to an element oth-
erwise covered by such a narrowed claim limitation. Every other detail of the patented invention
may be imitated with impunity”); 234 F.3d at 641-642 (opinion of Judge Newman, dissenting
with regard to complete bar) (“ The doctrine of equivalents has not been deemed superfluous as
an instrument as justice, and not until today has it been [*642] deemed ‘unworkable’ by this
court. The Federal Circuit's sua sponte change in this law is a change in industrial policy that
requires public discussion in advance of, not after, the law has been changed. This court's initia-
tive flows uncomfortably as a ruling that affects myriad vested rights, on a novel legal theory,
without briefing or argument”). (Footnote omitted.)
    See also, 122 S.Ct. 1836-1837 (Supreme Court’s discussion of dissenting opinions below).

                                                                                       (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

en banc Federal Circuit had approved a “complete bar” to applying the doc-
trine of equivalents to any claim element that was amended in the course of
                                                           62.98
patent prosecution for a reason relating to patentability.        In other words,
the Federal Circuit had ruled that amending a claim element for any reason
relating to the claim’s patentability ipso facto precludes applying the doctrine
of equivalents to that element, even if the reason for the amendment does not
                                                 62.99
appear to preclude coverage of an equivalent.           The Supreme Court va-
                                                                    62.100
cated and remanded the Federal Circuit’s decision on this point,            hold-
                                                        62.101
ing that a complete bar is inappropriate in general.             In the Supreme

   62.98
          See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 563, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on this point 535
U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“an amend-
ment that narrows the scope of a claim for any reason related to the statutory requirements for a
patent will give rise to prosecution history estoppel with respect to the amended claim ele-
ment”); 234 F.3d at 569 (“When a claim amendment creates prosecution history estoppel with
regard to a claim element, there is no range of equivalents available for the amended claim ele-
ment. Application of the doctrine of equivalents to the claim element is completely barred (a
‘complete bar’)”).
    62.99
          The Federal Circuit recognized that it was overruling its own precedent. See id., 234
F.3d at 574-575, referring to Hughes Aircraft Co. v. United States, 717 F.2d 1351, 1363, 219
U.S.P.Q. (BNA) 473 (Fed. Cir. 1983):
   “Today, we revisit the question we first addressed in Hughes I and come to a different con-
   clusion as to the proper scope of equivalents that is available when prosecution history es-
   toppel applies than we did in that case. We hold that prosecution history estoppel acts as a
   complete bar to the application of the doctrine of equivalents when an amendment has nar-
   rowed the scope of a claim for a reason related to patentability. Our decision to reject the
   flexible bar approach adopted in Hughes I comes after nearly twenty years of experience in
   performing our role as the [*575] sole court of appeals for patent matters. In those years, the
   notice function of patent claims has become paramount, and the need for certainty as to the
   scope of patent protection has been emphasized.”
The Federal Circuit reached this conclusion because it felt that the “flexible bar” rule had be-
come unworkable. See 234 F.3d at 575 (“We believe that the current state of the law regarding
the scope of equivalents that is available when prosecution history estoppel applies is ‘unworka-
ble’”), quoting United States v. IBM Corp., 517 U.S. 843, 856, 116 S.Ct. 1793, 135 L.Ed. 2d
124 (1996) (noting that Supreme Court itself has overruled precedent that is “unworkable” or
“badly reasoned”). (Citations omitted.)
    62.100
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., ____ U.S. ____, 122
S.Ct. 1831, 1843, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (vacating and reman d-
ing).
    62.101
            See id., 122 S.Ct. at 1840 (“we disagree with the decision to adopt the complete
bar”). See also, 122 S.Ct. at 1841:
   “[A] narrowing amendment may demonstrate what the claim is not; but it may still fail to
   capture precisely what the claim is. There is no reason why a narrowing amendment should
   be deemed to relinquish equivalents unforeseeable at the time of the amendment and beyond
   a fair interpretation of what was surrendered. Nor is there any call to foreclose claims of
   equivalence for aspects of the invention that have only a peripheral relation to the reason the
   amendment was submitted. The amendment does not show that the inventor suddenly had
   more foresight in the drafting of claims than an inventor whose application was granted

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

Court’s view, a court must determine the scope of equivalents covered by
amended claim language based on the reasons for the amendment(s) and the
                                62.102
details of the amended claim.           The Court repudiated the Federal Cir-
cuit’s favoring certainty in claim construction over protecting the patent from
nonliteral, insubstantial copying, pointing out that the Supreme Court had
twice previously chosen protecting the patent over the countervailing value of
                                    62.103
certainty, despite strong dissents.        It also feared the adverse effect that
                                                                62.104
a complete bar—as a new rule of patent claim construction              —would



   without amendments having been submitted. It shows only that he was familiar with the
   broader text and with the difference between the two. As a result, there is no more reason for
   holding the patentee to the literal terms of an amended claim than there is for abolishing the
   doctrine of equivalents altogether and holding every patentee to the literal terms of the pa-
   tent.”
   62.102
            See id., 122 S.Ct. at 1842:

   “There are some cases . . . where the amendment cannot reasonably be viewed as surrender-
   ing a particular equivalent. The equivalent may have been unforeseeable at the time of the
   application; the rationale underlying the amendment may bear no more than a tangential re-
   lation to the equivalent in question; or there may be some other reason suggesting that the
   patentee could not reasonably be expected to have described the insubstantial substitute in
   question. In those cases the patentee can overcome the presumption that prosecution history
   estoppel bars a finding of equivalence.”
   62.103
            See id., 122 S.Ct. at 1837-1838:

   “It is true that the doctrine of equivalents renders the scope of patents less certain. It may be
   difficult to determine what is, or is not, an equivalent to a particular element of an invention.
   If competitors cannot be certain about a patent’s extent, they may be deterred from engaging
   in legitimate manufactures outside its limits, or they may invest by mistake in competing
   products that the patent secures. In addition the uncertainty may lead to wasteful litigation
   between competitors, suits that a rule of literalism might avoid. These concerns with the doc-
   trine of equivalents, however, are not new. Each time the [*1838] Court has considered the
   doctrine, it has acknowledged this uncertainty as the price of ensuring the appropriate incen-
   tives for innovation, and it has affirmed the doctrine over dissents that urged a more certain
   rule.”
For discussion of the precedents referred to in this excerpt, see: N.62.129 infra; § 2.05[3][b][i]
infra.
    62.104
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1836-1837, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), referring to Warner-
Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146
(1997) (Citations to opinion below omitted.):
   “The [Federal Circuit in its en banc decision below] acknowledged that its own prior case
   law did not go so far [as to create a complete bar]. Previous decisions had held that prosecu-
   tion history estoppel constituted a flexible bar, foreclosing some, but not all, claims of
   equivalence, depending on the purpose of the amendment and the alterations in the text. . . .
   [*1837] . . . Four judges dissented from the decision to adopt a complete bar. . . . In four
   separate opinions, the dissenters argued that the majority’s decision to overrule precedent
   was contrary to Warner-Jenkinson and would unsettle the expectations of many existing pa-
   tentees. Judge Michel, in his dissent, described in detail how the complete bar required the

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

have on the settled expectations of holders of existing patents issued under the
          62.105
old rule.
   Of the four principles that the Federal Circuit established in Festo, and that
survived the Supreme court’s review, all appeared implicit in, or consistent
with, earlier decisions of the Supreme Court, the Federal Circuit, or both. The
complete bar rule, however, would have been truly revolutionary. For the
custom and practice of the patent bar had been to file broad claims initially
and to refine and narrow them in the course of patent prosecution, often in
response to examiners’ objections and often without careful explanation of
                                         62.106
the reasons for making amendments.                Since the complete bar rule
would have precluded resort to equivalents for every claim element that had
been amended for reasons of patentability, and since such reasons are pre-
sumed if an amendment is unexplained, a complete bar would have encour-
aged, if not dictated, a drastic change in this common prosecution practice. In
rejecting the complete bar rule in favor a flexible bar, the Supreme Court, in
effect, validated the common practice of filing broad patent claims and nar-
rowing them by amendment in the course of patent prosecution.
   The Federal Circuit also has had a dramatic impact on the fifth and final
general question of patent infringement practice—the procedure for constru-
ing and applying patent claims. Part of the effect of the Federal Circuit’s and

   Court of Appeals to disregard 8 older decisions of this Court, as well as more than 50 of its
   own cases.”
   62.105
            See id., 122 S.Ct. at 1841:

   “Inventors who amended their claims under the previous regime had no reason to believe
   they were conceding all equivalents. If they had known, they might have appealed the rejec-
   tion instead. There is no justification for applying a new and more robust estoppel to those
   who relied on prior doctrine.”
   62.106
             See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 638, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (opinion of Judge Newman, dissenting in part) (Foot-
note omitted.), citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 41-42,
117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (concurring opinion, warning of unfairness of retroac-
tive effect of presumption that unexplained amendments are made for reasons of patentability):
   “It has been routine practice for patent solicitors to initially present broad claims to an inven-
   tion, in the expectation of honing the claims in interaction with the examiner. As very few
   patent applications traverse the PTO without amendment or argument, few issued patents
   will be free of the consequences of these changes in the law, for the majority has declined to
   act on the warnings against derogation of vested rights and expectancies, and has declined to
   make this decision applicable only prospectively.”
    See also, 234 F.3d at 618 (opinion by Judges Michel and Rader, concurring on all but com-
plete-bar rule). (Citation omitted.):
   “The vast majority of patent applications contain claims that are initially rejected in view of
   the prior art, and are only allowed after being amended. Patent prosecution is an iterative
   process in which the applicant typically submits claims that are thought to be allowable, the
   examiner rejects the claims in view of the prior art, and the applicant then amends the claims
   to traverse the examiner’s patentability rejections.”


                                                                                         (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW
                                                         62.107
the Supreme Court’s decisions in Markman               was procedural. As a re-
sult of Markman’s holding that judges, not juries, construe patent
        62.108
claims,           claim interpretation often proceeds in separate hearings,
                                                                  62.109
known as Markman hearings, before or in lieu of a full trial.             When
claim construction appears decisive, the parties may avoid a full trial alto-
gether by stipulating to infringement vel non, depending upon the construc-
tion of the relevant claims, and then submitting the issue of claim construction
for trial by the judge or for summary judgment.
                                        62.110
    The Warner-Jenkinson decision                and its progeny, including
       62.111
Festo,          are likely to have equally dramatic effects on patent litigation
procedure. Since these decisions make the availability of the doctrine of
equivalents turn on whether a particular claim limitation has been amended
and, if so, whether the amendment was unexplained or made for a substantial
reason of patentability, the parties may wish to try these issues separately, or
in the Markman hearing, at least in cases in which the absence of literal in-
fringement is undisputed and the only possibility of a finding of infringement
is under the doctrine of equivalents. Since the existence, purpose, and estop-
                                                                     62.112
pel effect of claim amendments are issues for the court, not a jury,        they

   62.107
            Markman v. Westview Instruments, Inc., 517 U.S. 370, 372, 116 S.Ct. 1384, 1387,
134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (“We hold that the
construction of a patent, including terms of art within its claim, is exclusively within the prov-
ince of the court”), discussed in § 2.05[3][a] infra.
     62.108
            See id.
     62.109
            See § 2.05[3][a][iv] infra.
     62.110
             Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997) (“Each element contained in a patent claim is deemed material to
defining the scope of the patented invention, and thus the doctrine of equivalents must be ap-
plied to individual elements of the claim, not to the invention as a whole”), discussed in §§
2.05[3][b][i][B], [C], 2.06[3] infra.
     62.111
             Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) aff’d in part and vacated and remanded in
part 535 U.S. 722, 122 S.Ct. 1831, 1839-1840, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705
(2002).
     62.112
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 585, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), rev’d and remanded on other grounds 535
U.S. 722, 122 S.Ct. 1831, 1839-1840, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002)
(“Prosecution history estoppel is a legal question that is subject to de novo review by this court. .
. . Thus, when reviewing the jury verdict, we will independently decide the legal question of the
application of prosecution history estoppel . . . .”), (citing LaBounty Manufacturing, Inc. v.
United States International Trade Commission, 867 F.2d 1572, 1576, 9 U.S.P.Q.2d (BNA)
1995, 1998 (Fed. Cir. 1989)). See also, 234 F.3d at 586 (Citations omitted.):
   “The first legal limitation a court should consider is prosecution history estoppel . . . . The
   first step in a prosecution history estoppel analysis is to determine which claim elements are
   alleged to be met by equivalents. Then, the court must determine whether the elements at is-
   sue were amended during prosecution of the patent. If they were not, amendment-based es-
   toppel will not bar the application of the doctrine of equivalents. However, the court still

                                                                                         (Rel. 25)
2-05                      PATENTS               INTELLECTUAL PROPERTY LAW
                                                                                     62.113
can be determined by summary judgment or in a Markman hearing.               To
the extent that claim construction and estoppel are decided separately by the
judge, the only issues remaining for a jury would be literal infringement, the
extent of any range of equivalents not constrained by estoppel, and infringe-
ment of equivalents within that range.
   Two general themes underlie the revolutionary changes that the Federal
Circuit, with the Supreme Court’s partial approval, has wrought. The first is
the perennial battle between certainty and justice. The function of patent
claims is to define a patented invention precisely, so that the public may know
                                      62.114
what is protected and what is not.            This function is particularly im-
portant in an innovative society that encourages “inventing around” patents
                          62.115
without infringing them.          If what constitutes infringement is not clear,
the lack of certainty can discourage legitimate “inventing around” and im-
provement, in addition to increasing the cost of litigation and the cost of un-
                                    62.116
certainty for business planning.            Lack of clarity in infringement

   may need to consider whether statements made during prosecution give rise to argument-
   based estoppel.”
   62.113
           See id., 234 F.3d at 586, citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co.,
520 U.S. 17, 39 n.8, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997):
   “When infringement is alleged to occur under the doctrine of equivalents, two primary legal
   limitations on the doctrine ‘are to be determined by the court, either on a dispositive pretrial
   motion or on a motion for judgment as a matter of law at the close of evidence and after the
   jury verdict.’. . . Those legal limitations are prosecution history estoppel and the ‘all ele-
   ments’ rule.”
   62.114
            See § 2.05[3][a][i] infra.
   62.115
            See id. See also, e.g.: Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583, 39
U.S.P.Q.2d (BNA) 1573 (Fed. Cir. 1996) (Citations omitted.); Hilton Davis Chemical Co. v.
Warner-Jenkinson Co., 62 F.3d 1512, 1520, 35 U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995), rev’d
on other grounds 520 U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (“The ability of the
public successfully to design around—to use the patent disclosure to design a product or process
that does not infringe, but like the claimed invention, is an improvement over the prior art—is
one of the important public benefits that justify awarding the patent owner exclusive rights to his
invention”), quoting State Industries, Inc. v. A.O. Smith Corp., infra, 751 F.2d at 1236; State
Industries, Inc. v. A.O. Smith Corp., 751 F.2d 1226, 1235, 224 U.S.P.Q. (BNA) 418 (Fed. Cir.
1985):
   “Conduct such as [the alleged infringer’s] involving keeping track of a competitor's products
   and designing new and possibly better or [*1236] cheaper functional equivalents is the stuff
   of which competition is made and is supposed to benefit the consumer. One of the benefits
   of a patent system is its so-called ‘negative incentive’ to ‘design around’ a competitor’s
   products, even when they are patented, thus bringing a steady flow of innovations to the
   marketplace.”
   62.116
            See, e.g.: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122
S.Ct. 1831, 1837-1838, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (dictum: “[i]f
competitors cannot be certain about a patent’s extent, they may be deterred from engaging in
legitimate manufactures outside its limits, or they may invest by mistake in competing products
that the patent secures. In addition the uncertainty may lead to wasteful litigation between com-

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

doctrine thus may reduce the incentive to invest in further innovation at the
                                           62.117
margins of previous inventive activity.              On the other hand, an overly
literalistic interpretation of patent claims may allow infringers to appropriate
the essence of primary inventions through insubstantial variations, thereby
devaluing patents generally and decreasing the flow of risk capital into prima-
                        62.118
ry inventive activity.          Indeed, this is the reason for having a doctrine of
                                62.119
equivalents in the first place.


petitors, suits that a rule of literalism might avoid”); Markman v. Westview Instruments, Inc.,
517 U.S. 370, 390, 116 S.Ct. 1384, 1387, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996)
(unanimous opinion), quoting General Electric Co. v. Wabash Appliance Corp., 304 U.S. 364,
369, 58 S.Ct. 899, 82 L Ed. 1402 (1938) (“the limits of a patent must be known for the protec-
tion of the patentee, the encouragement of the inventive genius of others and the assurance that
the subject of the patent will be dedicated ultimately to the public”); United Carbon Co. v.
Binney & Smith Co., 317 U.S. 228, 236, 63 S.Ct. 165, 87 L.Ed. 232 (1942), quoted in Markman
v. Westview Instruments, Inc., supra, 517 U.S. at 390:
   “The statutory requirement of particularity and distinctness in claims is met only when they
   clearly distinguish what is claimed from what went before in the art and clearly circumscribe
   what is foreclosed from future enterprise. A zone of uncertainty which enterprise and exper-
   imentation may enter only at the risk of infringement claims would discourage invention on-
   ly a little less than unequivocal foreclosure of the field. Moreover, the claims must be
   reasonably clear-cut to enable courts to determine whether novelty and invention are genu-
   ine.”
   62.117
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1837, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), citing Bonito Boats, Inc. v.
Thunder Craft Boats, Inc., 489 U.S. 141, 150, 109 S.Ct. 971, 103 L.Ed.2d 118 (1989):
   “The patent laws ‘promote the Progress of Science and useful Arts’ by rewarding innovation
   with a temporary monopoly. U.S. Const., Art. I, § 8, cl. 8. The monopoly is a property right;
   and like any property right, its boundaries should be clear. This clarity is essential to pro-
   mote progress, because it enables efficient investment in innovation. A patent holder should
   know what he owns, and the public should know what he does not. For this reason, the pa-
   tent laws require inventors to describe their work in ‘full, clear, concise, and exact terms,’ 35
   U.S.C. § 112, as part of the delicate balance the law attempts to maintain between inventors,
   who rely on the promise of the law to bring the invention forth, and the public, which should
   be encouraged to pursue innovations, creations, and new ideas beyond the inventor’s exclu-
   sive rights.”
   62.118
           See id., 122 S.Ct. at 1837, citing Winans v. Denmead, 56 U.S. (15 How.) 330, 347,
14 L.Ed. 717 (1854) (seminal decision on doctrine of equivalents):
   “The language in the patent claims may not capture every nuance of the invention or de-
   scribe with complete precision the range of its novelty. If patents were always interpreted by
   their literal terms, their value would be greatly diminished. Unimportant and insubstantial
   substitutes for certain elements could defeat the patent, and its value to inventors could be
   destroyed by simple acts of copying. For this reason, the clearest rule of patent interpretation,
   literalism, may conserve judicial resources but is not necessarily the most efficient rule. The
   scope of a patent is not limited to its literal terms but instead embraces all equivalents to the
   claims described.”
   62.119
           See id. See also, Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339
U.S. 605, 607, 700 S.Ct. 854, 94 L.Ed. 1097 (1950):

                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

   In attempting to make prosecution history estoppel by claim amendment a
complete bar, rather than a flexible bar, to applying the doctrine of equiva-
       62.120
lents,         the en banc majority of the Federal Circuit tried to adjust the
                                                              62.121
balance between certainty and justice in favor of certainty.          The Su-
preme Court’s repudiation of this aspect of the Federal Circuit’s decision in
        62.122                                                          62.123
Festo,          however, leaves little room for any such adjustment.
Indeed, the Supreme Court suggested that flexibility in applying the doctrine
of equivalents, in order to balance certainty and justice, is sufficiently en-
trenched in its own precedent so as to require congressional action in order to




   “[C]ourts have . . . recognized that to permit imitation of a patented invention which does
   not copy every literal detail would be to convert the protection of the patent grant into a hol-
   low and useless thing. Such a limitation would leave room for—indeed encourage—the un-
   scrupulous copyist to make unimportant and insubstantial changes and substitutions in the
   patent which, though adding nothing, would be enough to take the copied matter outside the
   claim, and hence outside the reach of law. One who seeks to pirate an invention, like one
   who seeks to pirate a copyrighted book or play, may be expected to introduce minor varia-
   tions to conceal and shelter the piracy. Outright and forthright duplication is a dull and very
   rare type of infringement. To prohibit no other would place the inventor at the mercy of ver-
   balism and would be subordinating substance to form. It would deprive him of the benefit of
   his invention and would foster concealment rather than disclosure of inventions, which is
   one of the primary purposes of the patent system.”
See generally, § 2.05[3][b][i][A] infra.
     62.120
            See: the text accompanying Ns.62.96- 62.105 supra; § 2.05[3][b][i][B] infra.
     62.121
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 575, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (“We . . . believe that the flexible bar ap-
proach poses a direct obstacle to the realization of important objectives. . . . These objectives
include giving effect, when prosecution history estoppel arises, to a narrowing amendment's
operation as a disclaimer of subject matter, . . . preserving the notice function of patent claims, .
. . and promoting certainty in patent law . . . . The realization of these objectives cannot help but
be frustrated by the uncertainty inherent in the flexible bar approach”). (Citations and internal
quotation marks omitted.)
     62.122
            See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122
S.Ct. 1831, 1837, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), citing Winans v.
Denmead, 56 U.S. (15 How.) 330, 347, 14 L.Ed. 717 (1854) (seminal decision on doctrine of
equivalents):
   “If patents were always interpreted by their literal terms, their value would be greatly dimin-
   ished. Unimportant and insubstantial substitutes for certain elements could defeat the patent,
   and its value to inventors could be destroyed by simple acts of copying. For this reason, the
   clearest rule of patent interpretation, literalism, may conserve judicial resources but is not
   necessarily the most efficient rule.”
   62.123
            See id., 122 S.Ct. at 1837 (“It is true that the doctrine of equivalents renders the
scope of patents less certain. . . . These concerns with the doctrine of equivalents, however, are
not new. Each time the [*1838] Court has considered the doctrine, it has acknowledged this
uncertainty as the price of ensuring the appropriate incentives for innovation, and it has affirmed
the doctrine over dissents that urged a more certain rule”).

                                                                                         (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW
                                          62.124
make any substantial adjustment.              Therefore, the question how many
equivalents a claim amendment bars through estoppel will continue to be one
of the chief battlegrounds on which litigants fight the perennial war between
certainty and justice.
    The second theme that runs throughout the Federal Circuit’s revolutionary
changes in patent law and procedure is its emphasis on the “public notice”
                             62.125
function of patent claims.           In limiting what evidence a judge may con-
                                          62.126
sider both in construing patent claims            and in deciding whether a claim
                                                                      62.127
amendment has been made for substantial reasons of patentability,             that
court emphasized public records—especially the patent itself and its prosecu-
tion history—and disfavored other evidence, such as oral testimony, that may
be inaccessible before patent litigation arises and may represent afterthoughts
in litigation. The purpose of this emphasis is obvious and salubrious: to make
the results of litigation after a dispute arises turn on evidence available to the
public beforehand and therefore to increase the possibility and certainty of
realistic business planning as well as productive settlement discussions. If
successful, this new emphasis should decrease the frequency and duration of
patent litigation by allowing both potential infringers and patentees to assess
more accurately what the patent covers before a dispute arises. If litigation
nevertheless ensues, the same emphasis should decrease its complexity, and
therefore its expense and duration, by encouraging more realistic settlement
discussions and limiting the scope of relevant evidence largely to what the
patentee has provided in advance.
    It is worth noting that these two general themes are quite separate and dis-
tinct. The struggle between certainty and justice, literalism and flexibility,
                                    62.128
form and substance never ends.              There is no final solution to the ten-


   62.124
            See id., 122 S.Ct. at 1838 (“Most recently, in Warner-Jenkinson, the Court reaf-
firmed that equivalents remain a firmly entrenched part of the settled rights protected by the
patent. A unanimous opinion concluded that if the doctrine is to be discarded, it is Congress and
not the Court that should do so”), citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co.,
520 U.S. 17, 28, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997).
    62.125
            See § 2.05[3][a][i], [iii] infra.
    62.126
            See § 2.05[3][a][iii] infra.
    62.127
            See: the text accompanying Ns.62.95-62.96 supra; § 2.05[3][b][i][B] infra.
    62.128
            Perhaps for this reason, a minority of judges on the Federal Circuit would prefer to
abandon any attempt at developing precise legal standards for the doctrine of equivalents and
simply have district courts assess, as a matter of equity, whether an alleged infringer has taken
the substance of an invention without taking its form. See: Festo Corp. v. Shoketsu Kinzoku
Kogyo Kabushiki Co., 234 F.3d 558, 593-594, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000),
vacated and remanded on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62
U.S.P.Q.2d (BNA) 1705 (2002). (concurring opinion by Plager, J.) (arguing that equitable ap-
proach, with deference to trial judges’ equitable discretion, could eventually develop coherent
body of law governing piracy of inventions in substance without taking their form, while “the
notion of ‘insubstantial differences’ between a particular claim and a particular product, viewed
as the governing principle, can never be anything other than an ad hoc judgment, dependent on

                                                                                     (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW
                                                                                         62.129
sions between those pairs of values, and there probably never will be.
As long as patent coverage depends on human language, with all its vague-

the eye of the beholder in the individual case”), referring to standard for equivalence articulated
by Federal Circuit and accepted with lukewarm approval by Supreme Court in Warner-
Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 40, 117 S.Ct. 1040, 137 L.Ed.2d 146
(1997); 234 F.3d at 617 (opinion by Judges Michel and Rader, concurring on all but complete-
bar rule) (“The complete bar eliminates the flexibility that equity demands. Without this flexibil-
ity, courts are precluded from protecting patentees from copyists”).
     Both the Supreme Court and the Federal Circuit, however, have rejected the notion of a doc-
trine of equivalents based upon unfettered equity. See:
     Supreme Court: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 35-36,
117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (rejecting claim that doctrine is equitable in favor of
approach based upon demonstration of objective equivalence):
   “If the essential predicate of the doctrine of equivalents is the notion of identity between a
   patented invention and its equivalent, there is no basis for treating an infringing equivalent
   any differently than a device that infringes the express terms of the patent. Application of the
   doctrine of equivalents, therefore, is akin to determining literal infringement, and neither re-
   quires proof of intent.”
   Federal Circuit: Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1521,
35 U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995), rev’d on other grounds 520 U.S. 17, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997), referring to Graver Tank & Manufacturing Co. v. Linde Air
Products Co., 339 U.S. 605, 700 S.Ct. 854, 94 L.Ed. 1097 (1950) (Other citation omitted.):
   “By referring to the doctrine [of equivalents] as a doctrine of fairness, neither the Supreme
   Court nor this court has invoked the myriad implications of an alternative to legal remedies.
   In addition, neither the Supreme Court nor this court has invoked equity in the technical
   sense of a set of principles originating in England to compensate for the historically harsh
   rules of common law. Graver Tank does not discuss any of the principles commonly attend-
   ing the chancellor’s invocation of equitable power, such as the ‘clean hands’ doctrine, the el-
   evated burden of proof, the abuse of discretion standard of review, or the mandatory
   balancing of the equities. Indeed, the Supreme Court has more than once stated that every
   patent owner is entitled to invoke the doctrine of equivalents—a proposition inimical to the
   hypothesis that the doctrine is equitable.”
   62.129
            Indeed, as the Supreme Court recognized in both Festo and Warner-Jenkinson, the
debate has raged already for nearly 150 years. See: Festo Corp. v. Shoketsu Kinzoku Kogyo
Kabushiki Co., 535 U.S. 722, 122 S.Ct. 1831, 1837-1838, 152 L.Ed.2d 944, 62 U.S.P.Q.2d
(BNA) 1705 (2002); Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 26 n.3,
117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (noting vigorous dissents to holdings of infringement
under doctrine of equivalents in both Winans v. Denmead and Graver Tank—decisions from
1854 and 1950, respectively—both in part on ground that application of doctrine undermines
public notice function of claims), referring to: Winans v. Denmead, 56 U.S. (15 How.) 330, 347,
14 L.Ed. 717 (1854) (dissenting opinion of Campbell, J.) (“Fulness, clearness, exactness, pre-
ciseness, and particularity, in the description of the invention, its principle, and of the matter
claimed to be invented, will alone fulfil the demands of Congress or the wants of the country.
Nothing, in the administration of this law, will be more mischievous, more productive of oppres-
sive and costly litigation, of exorbitant and unjust pretensions and vexatious demands, more
injurious to labor, than a relaxation of these wise and salutary requisitions of the act of Con-
gress”) and Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 617,
700 S.Ct. 854, 94 L.Ed. 1097 (1950) (dissenting opinion of Justices Black and Douglas) (“The
Court’s ruling today sets the stage for more patent ‘fraud’ and ‘piracy’ against business than
could be expected from faithful observance of the congressionally enacted plan to protect busi-
ness against judicial expansion of precise patent claims. Hereafter a manufacturer cannot rely on
what the language of a patent claims. He must be able, at the peril of heavy infringement dam-

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

ness, ambiguity, and intrinsic redundancy, the debate between those who fa-
vor strict construction for reasons of certainty and those who favor flexible
construction for purposes of justice will continue. The Supreme Court has
ruled that case-by-case flexibility in balancing these two values will remain
                                                62.130
the rule, unless Congress decrees otherwise.
   From an historical perspective, the controversy over the complete bar for
amended claims can be viewed as just another step in the long evolution of
claiming practice in the United States. As the nineteenth century began, pa-
tentees used so-called “central claiming,” by which they described their in-
ventions centrally and generally, without identifying new and inventive
components, and courts assessed infringement by determining how closely the
                                                  62.131
accused thing fell to the center of their claims.        Later during that centu-
ry, “central claiming” evolved into so-called “peripheral claiming,” in which
claims serve as a “fence” around patented inventions, marking precisely
                                                                          62.132
where the inventor’s novel contribution begins and prior art leaves off.
Peripheral claiming’s attempt to mark the precise boundary between protected
and unprotected matter tended toward literalism, and that tendency necessitat-
ed further development of the doctrine of equivalents after the end of the
nineteenth century in order to soften the harshness of literal interpretation of
peripheral claims. During the twentieth century, however, the doctrine of
equivalents became a more and more common feature of patent litigation,
                                               62.133
until it reared its head in nearly every case.


ages, to forecast how far a court relatively unversed in a particular technological field will ex-
pand the claim’s language after considering the testimony of technical experts in that field. To
burden business enterprise on the assumption that men possess such a prescience bodes ill for
the kind of competitive economy that is our professed goal”).
    62.130
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1838, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“Most recently, in Warner-
Jenkinson, the Court reaffirmed that equivalents remain a firmly entrenched part of the settled
rights protected by the patent. A unanimous opinion concluded that if the doctrine is to be dis-
carded, it is Congress and not the Court that should do so”), citing Warner-Jenkinson Co. v.
Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997).
    62.131
            For discussion of the evolution of claiming practice from “central claiming” to “pe-
ripheral claiming” and the relationship of that evolution to the doctrine of equivalents, see, e.g.:
Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1563-1571, 35 U.S.P.Q.2d
(BNA) 1641 (Fed. Cir. 1995), aff’d 520 U.S. 17, 29, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997)
(dissenting opinion of the late Judge Nies).
    62.132
            This practice was codified in the Patent Act of 1870, which contained the first statu-
tory requirement that the inventor distinctly point out what about her invention was new and
inventive. See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1566 & n.18,
35 U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995), aff’d 520 U.S. 17, 29, 117 S.Ct. 1040, 137
L.Ed.2d 146 (1997) (dissenting opinion of the late Judge Nies).
    62.133
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 28-29, 117
S.Ct. 1040, 137 L.Ed.2d 146 (1997) (“We do . . . share the concern of the dissenters below that
the doctrine of equivalents, as it has come to be applied since Graver Tank, has taken on a life
of its own, unbounded by the patent claims. There can be no denying that the doctrine of equiva-

                                                                                        (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

    This evolution in law to some extent contravened parallel developments in
technology, in which the technology became both more complex and more
various and many fields became crowded with patentable minor improve-
        62.134
ments.           Just as evolution in technology and patent law in the nineteenth
century called for a transition from central to peripheral claiming, so similar
developments in the twentieth century called for a retrenchment of the doc-
trine of equivalents, lest every minor incremental improvement receive the
same uncertain, complex, and expansive treatment as a major pioneering dis-
covery. The Federal Circuit has led that retrenchment, principally through its
                                                                       62.135
application of the “all elements” rule to the doctrine of equivalents         and
its maniFesto strengthening prosecution history estoppel as applied to amend-
                      62.136
ed claim elements.            By repudiating the complete bar in Festo, the Su-
preme Court limited the retrenchment, in effect decreeing that the doctrine of
equivalents will remain a robust bastion of justice for patentees, even in mod-
ern technological fields of crowded art, regardless of the inevitable uncertain-
ty that it creates.
    The second theme of public notice, however, is another matter. Unlike the
controversy over certainty, the need for public notice does not reflect any
fundamental and perpetual tension between opposing but equally important
values. The entire edifice of patent law is build upon adequate public disclo-
      62.137
sure,          and efficiency in both the courtroom and the marketplace de-
mands evidence accessible to the public. Moreover, efficiency in the
marketplace requires evidence that is available before a dispute arises, so that
affected parties can, by accessing that evidence and predicting the results of
litigation, avoid it or reduce its expense and duration.
    There is therefore little, if any, justification in policy for allowing patent
attorneys to omit critical clarifying material from patent applications and
prosecution histories and later seek to make up for those omissions by adduc-
ing oral testimony of inventors or experts after a dispute has arisen. Doing so
reduces the certainty and reliability of patent enforcement, thereby reducing
the incentive for investment in both primary innovation and incremental im-

lents, when applied broadly, conflicts with the definitional and public-notice functions of the
statutory claiming requirement”).
    62.134
            See id., 520 U.S. at 27 n.4 (“change in claiming practice [from central to peripheral
claiming] predate[d] Graver Tank, is not of statutory origin, and seems merely to reflect narrow-
er inventions in more crowded arts”), referring to Graver Tank & Manufacturing Co. v. Linde
Air Products Co., 339 U.S. 605, 700 S.Ct. 854, 94 L.Ed. 1097 (1950).
    62.135
            See id., 520 U.S. at 29 (“Each element contained in a patent claim is deemed materi-
al to defining the scope of the patented invention, and thus the doctrine of equivalents must be
applied to individual elements of the claim, not to the invention as a whole”), discussed in §
2.05[3][b][i] infra.
    62.136
            See the text accompanying Ns.62.85-62.105 supra.
    62.137
            See: § 2.01 supra (discussing disclosure of innovations in exchange for temporary
protection as fundamental quid pro quo of patents from policy perspective); § 2.04 supra (dis-
cussing details of statutory disclosure requirements).

                                                                                     (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

provements, increasing the expense and duration of patent litigation and the
workload of federal judges, and giving patent litigation much the same
“game-of-chance” character that motivated adoption of the liberal discovery
provisions of the Federal Rules of Civil Procedure. Thus, wherever the fine
line between literalism and justice may wander from case to case, the Federal
Circuit’s healthy emphasis on evidence in the public record before the fact is
likely to remain. As a result of this emphasis, litigators may lose work depos-
ing and cross-examining witnesses, and patent prosecutors may gain work
making patent claims more precise, but innovative industries and our com-
petitive economy will be much the better for the effort to confine relevant
evidence in patent disputes to recorded evidence available to all, before the
fact, from written records.
    On remand from the Supreme Court, the Federal Circuit provided some
                                                                62.138
further guidance on applying the principles set out in Festo.          First, the en
banc court held that it was a question of law whether a party had rebutted the
presumption that a narrowing amendment to a patent claim surrenders all
equivalents. Accordingly, the issue would be appropriately decided by the
judge, rather than a jury. Second, the court declined to enumerate specific
factors in analyzing the three rebuttal criteria set forth by the Supreme Court.
Rather, the court left such factors to be developed on a case-by-case basis. It
did, however, offer some general guidance. As to the first criterion,
unforeseeability, the court stated that in “determining whether an alleged
equivalent would have been unforeseeable, a district court may hear expert
testimony and consider other extrinsic evidence relating to the relevant factual
            62.139
inquiries.”        The second criterion, showing that the rationale for the
amendment was not directly related to the equivalent at issue, “is for the court
to determine from the prosecution history record without the introduction of
additional evidence, except, when necessary, testimony from those skilled in
                                                  62.140
the art as to the interpretation of that record.”        Determination of the third
criterion, requiring “some other reason suggesting that the patentee could not
reasonably be expected to have described the insubstantial substitute in ques-
tion," should generally be limited to the prosecution history record, but the
court did not foreclose extrinsic evidence in an appropriate case.

       [a]—Claim Interpretation and “Literal” Infringement
                                                              62.141
   Although just part of the patent specification,       a patent’s claims are
the most important part, for they define the patented invention and the scope

   62.138
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 344 F.3d 1359 (Fed.
Cir. 2003) (en banc).
    62.139
            Id., 344 F.3d at 1369.
    62.140
            Id., 344 F.3d at 1370.
    62.141
            The patent statute defines the patent specification as including both a narrative de-
scription of the invention and the patent claims. See 35 U.S.C. § 112, ¶¶ 1, 2 (Emphasis added.):

                                                                                     (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

                                62.142
of legal protection of it.         Accordingly, determining whether a patent
claim has been infringed requires, among other things, “reading” the claim
“on” the accused device or process in order to assess whether there has been
                        62.143
“literal” infringement.        Before this can happen, however, the meaning of
the claims must be determined—a process that involves the application of
                                                          62.144
various substantive rules and “canons” of interpretation.        The process of
                                                              62.145
claim interpretation is subject to special rules of evidence         and proce-
     62.146
dure        which derive from seminal decisions of the Federal Circuit and the
Supreme Court in the 1990s.

          [i]—The Importance of Patent Claims
   The claims are the heart of every patent. They express in stylized but pre-
cise language exactly what aspects of the patented invention meet the statuto-
                                                      63
ry standards of novelty, utility, and nonobviousness. Because the claims

   “The specification shall contain a written description of the invention, and of the manner and
   process of making and using it, in such full, clear, concise, and exact terms as to enable any
   person skilled in the art to which it pertains, or with which it is most nearly connected, to
   make and use the same, and shall set forth the best mode contemplated by the inventor of
   carrying out his invention.

   “The specification shall conclude with one or more claims particularly pointing out and dis-
   tinctly claiming the subject matter which the applicant regards as his invention.”
Nevertheless, in common parlance the claims and specification are normally considered distinct.
See Markman v. Westview Instruments, Inc., 517 U.S. 370, 373, 116 S.Ct. 1384, 1387, 134
L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (Citations to treatises
omitted.):
   “[The patent document first] contains a specification describing the invention ‘in such full,
   clear, concise, and exact terms as to enable any person skilled in the art . . . to make and use
   the same.’ 35 U.S.C. § 112 . . . . Second, a patent includes one or more ‘claims,’ which ‘par-
   ticularly poin[t] out and distinctly clai[m] the subject matter which the applicant regards as
   his invention.’ 35 U.S.C. § 112.”
   For discussion of the disclosure requirements implicit in Section 112, see § 2.04[1] supra.
   62.142
           See § 2.05[3][a][i] infra.
   62.143
           Id.
   62.144
           See § 2.05[3][a][ii] infra.
   62.145
           See § 2.05[3][a][iii] infra.
   62.146
           See § 2.05[3][a][iv] infra.
   63
      See Motion Picture Patents Co. v. Universal Film Manufacturing Co., 243 U.S. 502, 510,
37 S.Ct. 416, 61 L.Ed. 871 (1917):
   “The scope of every patent is limited to the invention described in the claims contained in it,
   read in the light of the specification. These so mark where the progress claimed by the patent
   begins and where it ends that they have been aptly likened to the description in a deed,
   which sets the bounds to the grant which it contains.”


                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

determine the scope of the patent holder's rights to exclude others, they define
               64
the invention. Infringement of a patent thus consists of making, using, sell-
ing, offering for sale, or importing something (or a product of a process) that
                                                   65
is covered by one or more of the patent's claims, whether literally or under
                              66
the doctrine of equivalents. Since infringement depends on applying the
claims to the accused device or process, the alleged infringer's intent is irrele-




   64
       See, e.g.:
    Supreme Court: Markman v. Westview Instruments, Inc., 517 U.S. 370, 372, 116 S.Ct.
1384, 1387, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (de-
scribing patent claims as “the portion of the patent document that defines the scope of the pa-
tentee’s rights”); Aro Manufacturing Co. v. Convertible Top Replacement Co., 365 U.S. 336,
339, 81 S.Ct. 599, 5 L.Ed.2d 592 (1961) (claims of patent are sole measure of patent grant);
Mercoid Corp. v. Mid-Continent Investment Co., 320 U.S. 661, 665, 64 S.Ct. 268, 88 L.Ed. 376
(1944) (limits of patent “are narrowly and strictly confined to the precise terms of the grant”);
Continental Paper Bag Co. v. Eastern Paper Bag Co., 210 U.S. 405, 419, 28 S.Ct. 748, 52 L.Ed.
1122 (1908) (“[T]he claims measure the invention. They may be explained and illustrated by the
description. They cannot be enlarged by it”). (Citation omitted.).
    Fourth Circuit: AB Iro v. Otex, Inc., 566 F. Supp. 419, 457 (D.S.C. 1983) (“the claims of a
patent define the patentee's invention”) (citing many authorities).
    Tenth Circuit: McCullough Tool Co. v. Well Surveys, Inc., 343 F.2d 381, 402-403 (10th
Cir. 1965), cert. denied 383 U.S. 933 (1966).
    Federal Circuit: Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *12-13 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (Other citations omit-
ted.):
   “Both the Supreme Court and this court have adhered to the fundamental principle that
   claims define the scope of patent protection. . . . [*13] . . . The claims thus give notice of the
   scope of patent protection. See, e.g., Mahn v. Harwood, 112 U.S. 354, 361, 28 L. Ed. 665, 5
   S. Ct. 174 (1884) (‘The public is notified and informed by the most solemn act on the part of
   the patentee, that his claim to invention is for such and such an element or combination, and
   for nothing more.’). The claims give notice both to the examiner at the U.S. Patent and
   Trademark Office during prosecution, and to the public at large, including potential competi-
   tors, after the patent has issued.”
Atlantic Thermoplastics Co. v. Faytex Corp., 974 F.2d 1299, 1300, 24 U.S.P.Q.2d (BNA) 1138,
1139-1140 (Fed. Cir. 1992) (“The claims alone define the patent right”); Corning Glass Works
v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1257 (Fed. Cir. 1989) (“A claim in a patent
provides the metes and bounds of the right which the patent confers on the patentee to exclude
others from making, using, or selling the protected invention”); Uniroyal Inc. v. Rudkin-Wiley
Corp., 837 F.2d 1044, 1053, 5 U.S.P.Q.2d 1434, 1440 (Fed. Cir.), cert. denied 488 U.S. 825
(1988) (“it is the claims which define the invention”) (Citation omitted.); Loctite Corp. v.
Ultraseal Ltd., 781 F.2d 861, 865 (Fed. Cir. 1985) (additional components do not avoid in-
fringement if “the claims otherwise read on the accused product or process”); SRI International
v. Matsushita Electric. Corp., 775 F.2d 1107, 1121, 227 U.S.P.Q. (BNA) 577, 585 (Fed. Cir.
1985) (“It is the claims that measure the invention”).
    65
       See 35 U.S.C. §§ 154(a)(1), 271(a), (g), as discussed in: § 2.05[1] (introduction) supra;
§§ 2.05[4][c], 3.01 infra.
    66
       For a discussion of the doctrine of equivalents, see § 2.05[3][b] infra.


                                                                                         (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                                            67                                                   68
vant to the issue of infringement, although it may bear on the remedy.
                                                            68.1
Whether infringement has occurred is a question of fact.
   The first step in assessing infringement is literal application of the patent's
        69
claims. Courts look for “literal infringement” by examining whether the
                                                               70
patent's claims “read on” the accused device or process. Literal infringe-
ment, however, occurs only where every limitation of a patent claim is found
                                    70.1
in the accused device or process.        If there is no claim of which all limita-
tions read on the accused item, there is no literal infringement. Conversely,

   67
        See § 1.07[2][a] supra.
   68
         See: §§ 12.03[1][a] (reasonable royalties), 12.05[1][a] (damage augmentation), and
12.06[3][b][i], [iii], [c][i] (attorneys' fees) infra. See generally, § 1.07[2][a] supra.
    68.1
          See Bowers v. Baystate Technologies, Inc., 320 F.3d 1317, 1323 (Fed. Cir. 2003) (“In-
fringement, whether literal or under the doctrine of equivalents, is a question of fact”), citing:
Optical Disc Corp. v. Del Mar Avionics, Inc., 208 F.3d 1324, 1333-1334, 54 U.S.P.Q.2d (BNA)
1289, 1294-1295 (Fed. Cir. 2000) and Bai v. L & L Wings, Inc., 160 F.3d 1350, 1353, 48
U.S.P.Q.2d (BNA) 1674, 1676 (Fed. Cir. 1998).
    69
        See, e.g.:
    Supreme Court: Motion Picture Patents Co. v. Universal Film Manufacturing Co., 243 U.S.
502, 510, 37 S.Ct. 416, 61 L.Ed. 871 (1917).
    Fifth Circuit: Ziegler v. Phillips Petroleum Co., 483 F.2d 858, 868 (5th Cir.), cert. denied
414 U.S. 1079 (1973) (citing authorities).
    The second step is applying the doctrine of equivalents. See Smithkline Diagnostics, Inc. v.
Helena Laboratories Corp., 859 F.2d 878, 889 (Fed. Cir. 1988) (discussing two-step approach to
assessing infringement). See also, § 2.05[3][b] infra.
    70
        See Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1257 (Fed.
Cir. 1989), quoted in N.73 infra.
    70.1
          See, e.g.:
    Tenth Circuit: McCullough Tool Co. v. Well Surveys, Inc., 343 F.2d 381, 401-402 (10th
Cir. 1965), cert. denied 383 U.S. 933 (1966) (every element of combination patent is “conclu-
sively presumed” to be essential, and there is no infringement unless every element or its func-
tional equivalent is found in accused device). (Citations omitted.)
    Federal Circuit: Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *10
(Fed. Cir. Sept. 10, 1998) (“To prove literal infringement, the patentee must show that the ac-
cused device contains every limitation in the asserted claims. . . . If even one limitation is miss-
ing or not met as claimed, there is no literal infringement”), citing: Cybor Corp. v. FAS
Technologies, Inc., 138 F.3d 1448, 1467, 46 U.S.P.Q.2d (BNA) 1169, 1184 (Fed. Cir. 1998) (en
banc), in turn citing Dolly, Inc. v. Spalding & Evenflo Companies, 16 F.3d 394, 397, 29
U.S.P.Q.2d (BNA) 1767, 1769 (Fed. Cir. 1994), and Pennwalt Corp. v. Durand-Wayland, Inc.,
833 F.2d 931, 934, 4 U.S.P.Q.2d (BNA) 1737, 1751 (Fed. Cir. 1987) (en banc); Pennwalt Corp.
v. Durand-Wayland, Inc., 833 F.2d 931, 934 (Fed. Cir. 1987), cert. denied 485 U.S. 961 (1988)
(where claim is expressed as means for performing stated function, “the court must compare the
accused structure with the disclosed structure, and must find equivalent structure as well as
identity of claimed function for that structure”) (en banc) (Emphasis in original.); Mannesmann
Demag Corp. v. Engineered Metal Products Co., 793 F.2d 1279, 1282-1283 (Fed. Cir. 1986)
(there was no infringement where accused device did not satisfy claim limitation that elements
of smelting furnace be “in a contacting relation” with each other); Builders Concrete, Inc. v.
Bremerton Concrete Products Co., 757 F.2d 255, 257 (Fed. Cir. 1985) (two claim limitations did
not read on accused device).
    For the relationship between “elements” and “limitations,” see N.62.76 supra.

                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

only literal infringement is required. For example, where a defendant uses a
patented process, there may be infringement, even if the defendant used the
process for a different purpose than the inventor, or even if use of the process
                                              71
was not necessary for defendant’s purposes.
   A patent’s claims have always been important, but it is now also important
that amendments of them during the patent prosecution process be ex-
         71.1                                                            71.2
plained.      In Warner-Jenkinson Co. v. Hilton Davis Chemical Co.,           the
Supreme Court ruled that unexplained amendments of any claim limitation
preclude applying the doctrine of equivalents to the element of the accused
device or process corresponding to that claim limitation.
   In this respect, the Supreme Court affirmed the decision of the Federal
                                                   71.3
Circuit, in its seminal en banc decision in Festo,      that any claim limitation
narrowed by amendment for unexplained reasons cannot enjoy protection
                                          71.4
under the doctrine of equivalents at all.




   71
        Dow Chemical Co. v. Mee Industries, Inc., 341 F.3d 1370, 1380-1381 (Fed. Cir. 2003).
    71.1
           During the patent prosecution process, the patent examiner often rejects one or more
proposed claims in an application for patent. See § 1.06[1] supra (outlining patent application
procedure). Although a rejection may be based on any statutory requirement for patentability, as
well as on formal requirements, the most common reasons for rejection are that a claim is not
novel in light of prior art, see § 2.03[1] supra (discussing statutory requirement for novelty), that
a claim is obvious in light of prior art, see § 2.03[3] supra (discussing statutory requirement for
nonobviousness), and that a claim is not adequately supported by matter disclosed in the specifi-
cation, see § 2.04[1] supra (discussing four separate disclosure requirements for valid patent). If
the examiner rejects a particular claim, the applicant has three options: (1) to withdraw the
claim, (2) to amend it, or (3) to argue with the examiner and, if the examiner persists in the
rejection, to appeal the examiner’s rejection within the Patent and Trademark Office and then to
the courts. See § 1.06[1] supra.
    71.2
          Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040,
137 L.Ed.2d 146 (1997) (“Where no explanation [for amending a claim limitation] is estab-
lished, . . . the court should presume that the PTO had a substantial reason related to patentabil-
ity for including the limiting element added by amendment. In those circumstances, prosecution
history estoppel would bar the application of the doctrine of equivalents as to that element”),
discussed in: § 2.05[3] (introduction) supra; § 2.05[3][b][i][B] infra.
    71.3
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1842, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting and explaining
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997) (“When the patentee is unable to explain the reason for amendment,
estoppel not only applies but also ‘bars the application of the doctrine of equivalents as to [the
amended claim] element’”).
    71.4
          See id., aff’ing Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), discussed in § 2.05[3] (introduction)
supra; § 2.05[3][b][i][B] infra. See also, id. (“[W]hen the court is unable to determine the pur-
pose underlying a narrowing amendment—and hence a rationale for limiting the estoppel to the
surrender of particular equivalents—the court should presume that the patentee surrendered all
subject matter between the broader and the narrower language”).

                                                                                         (Rel. 25)
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     This was the only respect in which the Supreme Court, although refusing
                  71.5
to use that term,       in effect upheld the Federal Circuit’s en banc applica-
                                                            71.6
tion of the “complete bar” to amended claim elements.             Where claim
amendments are explained and relate to patentability, their estoppel effect
depends on a detailed analysis of the relationship between what the narrowing
                                                                      71.7
amendment surrendered and the equivalents asserted by the patentee.
     The Supreme Court did help cabin the doctrine of equivalents as applied to
amended claim elements by recognizing two important presumptions allocat-
ing burdens of proof. First, any claim amendment is presumed to relate to
patentability, and the patentee bears the burden of proving other reasons for
    71.8
it.       Second, if the patentee fails to bear this burden (and therefore the

   71.5
         See id. (“These words do not mandate a complete bar; they are limited to the circum-
stance where ‘no explanation is established’”), quoting Warner-Jenkinson Co. v. Hilton Davis
Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997).
    71.6
         In Festo the Supreme Court rejected the rule that any narrowing claim amendment for
reasons of patentability creates a complete bar to applying the doctrine of equivalents to amend-
ed claim elements. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722,
122 S.Ct. 1831, 1840, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“we disagree with
the decision [below] to adopt the complete bar”); 122 S.Ct. at 1843, vacating and remanding
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 574, 56 U.S.P.Q.2D
(BNA) 1865 (Fed. Cir. 2000) (en banc) (“We hold that prosecution history estoppel acts as a
complete bar to the application of the doctrine of equivalents when an amendment has narrowed
the scope of a claim for a reason related to patentability”). See generally, § 2.05[3] (introduc-
tion) supra.
    71.7
         See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1840-1841, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002):
   “Though prosecution history estoppel can bar challenges to a wide range of equivalents, its
   reach requires an examination of the subject matter surrendered by the narrowing amend-
   ment. The complete bar avoids this inquiry by establishing a per se rule; but that approach is
   inconsistent with the purpose of applying the estoppel in the first place—to hold the inventor
   to the representations made during the application process and to the inferences that may
   reasonably be drawn from the amendment. By amending the application, the inventor is
   deemed to concede that the patent does not extend as far as the original claim. It does not
   follow, however, that the amended claim becomes so perfect in its description that no one
   [*1841] could devise an equivalent. After amendment, as before, language remains an im-
   perfect fit for invention. The narrowing amendment may demonstrate what the claim is not;
   but it may still fail to capture precisely what the claim is. There is no reason why a narrow-
   ing amendment should be deemed to relinquish equivalents unforeseeable at the time of the
   amendment and beyond a fair interpretation of what was surrendered. Nor is there any call to
   foreclose claims of equivalence for aspects of the invention that have only a peripheral rela-
   tion to the reason the amendment was submitted. The amendment does not show that the in-
   ventor suddenly had more foresight in the drafting of claims than an inventor whose
   application was granted without amendments having been submitted. It shows only that he
   was familiar with the broader text and with the difference between the two. As a result, there
   is no more reason for holding the patentee to the literal terms of an amended claim than there
   is for abolishing the doctrine of equivalents altogether and holding every patentee to the lit-
   eral terms of the patent.”
   71.8
       See: N.71.2 supra; Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S.
722, 739, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (reaffirming

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

claim amendment is presumed to relate to patentability), the doctrine of
                                        71.9
equivalents is presumed inapplicable,          and the patentee must bear the
burden of proving the extent of any equivalents remaining despite the claim
                               71.10                                        71.11
amendment’s estoppel effect.          This presumption may be rebutted
by showing that the alleged equivalent was “unforeseeable at the time of the
application[,]” that “the rationale underlying the amendment . . . bear[s] no
more than a tangential relation to the equivalent in question[,]” or “some oth-
er reason suggesting that the patentee could not reasonably be expected to
                                                           71.12
have described the insubstantial substitute in question.”         If the patentee
does not bear the burden of proving the reason for a narrowing claim amend-
ment or the extent of its estoppel effect, then the doctrine of equivalents does
not apply to amended claim elements.
                                                                      71.13
   Whether or not amended, patent claims are the most vital part            of the
patent specification insofar as inventors are concerned. The reason is simple:
anything disclosed in the patent specification, but not specifically claimed, is


that burden is “on the patentee to show that an amendment was not for purposes of patentabil-
ity”), citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997).
    An amendment made to satisfy any requirement of the patent statute relates to patentability
in this sense. See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., supra, 122 S.Ct. at
1839 (“We agree with the Court of Appeals that a narrowing amendment made to satisfy any
requirement of the Patent Act may give rise to an estoppel”); 535 U.S. at 736 (specifically citing
requirements for novelty, utility, nonobviousness, written description, enablement, and best
mode). But cf., 535 U.S. at 736 (giving as examples of amendments not related to patentability
those made “to clarify an ambiguous term, to improve the translation of a foreign word, or to
rewrite a dependent claim as an independent one”).
    71.9
          See id., 535 U.S. at 740:

   “The patentee, as the author of the claim language, may be expected to draft claims encom-
   passing readily known equivalents. A patentee’s decision to narrow his claims through
   amendment may be presumed to be a general disclaimer of the territory between the original
   claim and the amended claim.
   71.10
           See id., 535 U.S. at 741:“This presumption is not . . . just the complete bar by another
name. Rather, it reflects the fact that the interpretation of the patent must begin with its literal
claims, and the prosecution history is relevant to construing those claims. When the patentee has
chosen to narrow a claim, courts may presume the amended text was composed with awareness
of this rule and that the territory surrendered is not an equivalent of the territory claimed.
    71.11
           See: id. (“[T]the patentee still might rebut the presumption that estoppel bars a claim
of equivalence. The patentee must show that at the time of the amendment one skilled in the art
could not reasonably be expected to have drafted a claim that would have literally encompassed
the alleged equivalent”); id. (“There are some cases, . . . where the amendment cannot reasona-
bly be viewed as surrendering a particular equivalent. . . . In those cases the patentee can over-
come the presumption that prosecution history estoppel bars a finding of equivalence”).
    71.12
           Id.
    71.13
           Although common parlance treats them as separate, the claims are technically part of
the patent specification, which includes the narrative description outside the claims. See
N.62.136 supra.

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                                71.14
dedicated to the public,         subject to the possibility of broadening the
                                             71.15
claims in reissue for a period of two years.       Thus failure to draft and pros-
ecute claims broadly enough to cover all matter disclosed in the specification
precludes infringement by disclosed but unclaimed matter, whether literal-
  71.16                                         71.17
ly      or under the doctrine of equivalents,         so that only that which is
claimed is protected.
   This dedication rule applies only to the patent disclosing but failing to
claim the matter in question. It does not undermine coverage of the same mat-
ter in another issued patent. For example, an improvement patent, in the
course of explaining the improvement, may disclose but fail to claim matter

   71.14
            See, e.g.:
     Supreme Court: Miller v. Bridgeport Brass Co., 104 U.S. 350, 352, 26 L.Ed. 783 (1881)
(“The claim of a specific device or combination, and an omission to claim other devices or com-
binations apparent on the face of the patent, are, in law, a dedication to the public of that which
is not claimed”).
     Federal Circuit: Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *20 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (“when a patent drafter
discloses but declines to claim subject matter, as in this case, this action dedicates that un-
claimed subject matter to the public”); Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1106-1107, 39
U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996) (discussing rule and applying it to limit extension of
literal claim language under doctrine of equivalents); Unique Concepts, Inc. v. Brown, 939 F.2d
1558, 1562-1563, 19 U.S.P.Q.2d (BNA) 1500 (Fed. Cir. 1991) (“subject matter disclosed but
not claimed in a patent application is dedicated to the public”), quoted in Maxwell v. Baker,
Inc., 86 F.3d 1098, 1106, 39 U.S.P.Q.2d (BNA) 1001, 1006 (Fed. Cir. 1996).
     See also, Novo Nordisk of North America, Inc. v. Genentech, Inc., 77 F.3d 1364, 1369, 37
U.S.P.Q.2d (BNA) 1773 (Fed. Cir. 1996) (“What is not claimed, even though disclosed as part
of the ‘invention,’ cannot be enjoined”). (Cross-reference omitted.)
     71.15
            See 35 U.S.C. § 251 (in part):

   “Whenever any patent is, through error without any deceptive intention, deemed wholly or
   partly inoperative or invalid, by reason of a defective specification or drawing, or by reason
   of the patentee claiming more or less than he had a right to claim in the patent, the [PTO]
   shall, on the surrender of such patent and the payment of the fee required by law, reissue the
   patent for the invention disclosed in the original patent, and in accordance with a new and
   amended application, for the unexpired part of the term of the original patent. No new matter
   shall be introduced into the application for reissue.

   “* * *

   “No reissued patent shall be granted enlarging the scope of the claims of the original patent
   unless applied for within two years from the grant of the original patent.”
    See also, Maxwell v. Baker, Inc., 86 F.3d 1098, 1107 & n.2, 39 U.S.P.Q.2d (BNA) 1001
(Fed. Cir. 1996) (noting that rule dedicating disclosed but unclaimed matter to public is subject
to broadening of claims in reissue for two years).
    71.16
           See Maxwell v. Baker, Inc., 86 F.3d 1098, 1107, 39 U.S.P.Q.2d (BNA) 1001 (Fed.
Cir. 1996) (describing as “frequently applied” rule prohibiting “finding of literal infringement
when an accused infringer practices disclosed but unclaimed subject matter”). (Citations omit-
ted.)
    71.17
          See § 2.05[3][b][i][A] infra.


                                                                                       (Rel. 25)
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                                                       71.18
covered by an underlying dominant patent,       but that failure does not affect
the scope or validity of the dominant patent. Consequently, the “dedication”
rule does not simplify patent searches as much as may at first appear. It is not
the case that anyone may freely use technology disclosed but not claimed in a
single patent, for the same technology may be covered by other patents.

               [ii]—Patent Claim Construction
    Because assessing patent infringement requires comparing the accused de-
vice or process with the verbal description of the patented invention in the
        71.19
claims,       the first step in that assessment is determining what the claims
      71.20
mean.        That step must come even before assessing so-called “literal” in-
             71.21
fringement,        for in this context the word “literal” is a misnomer. The
                                                72
claims of a patent are not read in a vacuum; they must be properly inter-
       73                                                               74
preted. Patent law “allows the inventor to be his own lexicographer” and


   71.18
          For discussion of the relationship between improvement and dominant patents, see §
2.05[1][a] supra.
   71.19
          See § 2.05[3] (introduction) supra.
   71.20
          See Markman v. Westview Instruments, Inc., 52 F.3d 967, 976, 34 U.S.P.Q.2d (BNA)
1321 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38
U.S.P.Q.2d (BNA) 1461 (1996) (Citation omitted.):
   “An infringement analysis entails two steps. The first step is determining the meaning and
   scope of the patent claims asserted to be infringed. . . . The second step is comparing the
   properly construed claims to the device accused of infringing. . . . It is the first step [that is]
   commonly known as claim construction or interpretation[.]”
See also, N.73 infra.
    71.21
           See § 2.05[3] (introduction) supra.
    72
        See SRI International v. Matsushita Electric Corp., 775 F.2d 1107, 1118 (Fed. Cir. 1985)
(determination of actual infringement is not “limited to literalism[;]” accused infringer may
argue that claim language, “as properly interpreted, does not actually read on his device”).
    73
        See: Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1257 (Fed.
Cir. 1989) (“the words of the claim must first be interpreted, . . . and, as properly interpreted,
they must be 'read on' the accused structure to determine whether each of the limitations recited
in the claim is present in the accused structure”) (Citations omitted.); Moeller v. Ionetics, Inc.,
794 F.2d 653, 656 (Fed. Cir. 1986) (“The first step in determining infringement is to construe
the claims”); SRI International v. Matsushita Electric Corp., 775 F.2d 1107, 1118 (Fed. Cir.
1985) (“A claim is construed in the light of the claim language, the other claims, the prior art,
the prosecution history, and the specification, not in light of the accused device. . . . It is only
after the claims have been construed without reference to the accused device that the claims, as
so construed, are applied to the accused device to determine infringement”) (Emphasis in origi-
nal; citation omitted.); 775 F.2d at 1132 (dissenting opinion) (“Under our precedent, literal
infringement cannot be determined without first determining what a claim means in light of the
specification, the prosecution history, and the prior art”) (citing authorities).
    74
        Loctite Corp. v. Ultraseal, Ltd., 781 F.2d 861, 867 (Fed. Cir. 1985), quoting Autogiro Co.
v. United States, 384 F.2d 391, 397 (Ct. Cl. 1976), quoted more fully in N.77.1 infra.

                                                                                          (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                         74.1
indeed encourages him to do so.          Therefore the reader often cannot deci-
                                                           74.2
pher terms used in the claims without resort to the rest        of the patent speci-
fication.
    An issue that frequently arises is whether the preamble to a claim should
be read as a limitation. Thus, if a claim reads: “I claim a water bottle compris-
ing . . . .”, the question might arise as to whether the claim reads only on de-
vices that are used as water bottles or whether a soda bottle might also fall
within the scope of the claim. As the Federal Circuit has formed the analysis,
“a preamble limits the invention if it recites essential structure or steps, or if it
is necessary to give life, meaning, and vitality to the claim. Conversely, a pre-
amble is not limiting where a patentee defines a structurally complete inven-
tion in the claim body and uses the preamble only to state a purpose or
                                  74.3
intended use for the invention."
    A similar issue is whether the transition phrase is interpreted to be “open”
or “closed.” For example, a method claim might read, “A process comprising
steps A, B, and C” or “A process consisting of steps A, B, and C.” When the
term “comprising” is used, the claim is usually read as open, meaning it
would be infringed by any process using those steps, even if there were addi-
tional steps. If the term “consisting of” was used, then it would be infringed
                                                                      74.4
only by a process using exactly those three steps and no others.           These are
only general guidelines. A claim might be interpreted differently in context.
Moreover, applicants have formulated numerous variants on those transitional
phrases, such as “consisting essentially of,” which may require more nuanced
interpretation.
    The drawings and the narrative description of the invention and its signifi-
                                                                     75
cance are particularly useful guides to interpreting the claims. In addition,


    74.1
          The rules for interpreting words in patent claims differ from the normal “plain mean-
ing” rules for interpreting statutes and other legal writings. Specialized meanings known to those
skilled in the art take priority over common dictionary definitions. See Hoechst Celanese Corp.
v. BP Chemicals Ltd., 78 F.3d 1575, 1580, 38 U.S.P.Q.2d (BNA) 1126 (Fed. Cir. 1996), cert.
denied 117 S.Ct. 275 (1996) (“a general dictionary definition is secondary to the specific mean-
ing of a technical term as it is used and understood in a particular technical field”). (Citations
omitted.) Yet even commonly understood technical definitions yield to the inventor's own lexi-
cography, as disclosed in the patent specification. See 78 F.3d at 1578 (“A technical term used
in a patent document is interpreted as having the meaning that it would be given by persons
experienced in the field of the invention, unless it is apparent from the patent and the prosecu-
tion history that the inventor used the term with a different meaning”). (Emphasis added; cita-
tions omitted.)
    74.2
          See N.62.136 supra.
    74.3
          Catalina Marketing International Inc. v. Coolsavings.com, 289 F.3d 801, 808 (Fed. Cir.
2002). (Citations and quotation marks omitted.)
    74.4
          See, e.g., Invitrogen Corp. v. Biocrest Manufacturing, L.P., 327 F.3d 1364, 1368-1369
(Fed. Cir. 2003).
    75
       See, e.g.:


                                                                                      (Rel. 25)
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other claims and the patent prosecution history may serve as aids in claim
              76
construction.
   The other claims, the rest of the specification, and the patent’s prosecution
                                                          77
history are thus the raw materials for claim construction. Over the years, the
federal courts have developed several rules or “canons” of claim construction
to rationalize to some extent how those raw materials are to be used. The pro-
cess is far from mechanical, for the purpose of claim construction is to do
justice both to the patent attorney’s handiwork and to the advances in tech-
                          77.1
nology that it describes.      As a result, wooden application of supposed can-
ons of claim construction may interfere with, rather than assist, the

    Eighth Circuit: Priebe & Sons Co. v. Hunt, 188 F.2d 880, 881 (8th Cir.), cert. dismissed 342
U.S. 801 (1951) (refusing to read “hollow finger” limitation into claims for chicken-plucking
machine where some claims read directly on solid fingers, and solid fingers were mentioned as
alternative embodiment in specifications).
    Federal Circuit: Perini America Inc. v. Paper Converting Machine Co., 832 F.2d 581, 584
(Fed. Cir. 1987).
    76
        See, e.g.:
    Fourth Circuit: Baker-Cammack Hosiery Mills, Inc. v. Davis Co., 181 F.2d 550, 563 (4th
Cir.), cert. denied 340 U.S. 824 (1950) (limiting claims in hosiery patent to full-fashion hosiery
by reference to patent specification and prosecution history).
    Federal Circuit: Perini America Inc. v. Paper Converting Machine Co., 832 F.2d 581, 584
(Fed. Cir. 1987) (specification and prosecution history); Townsend Engineering Co. v. HiTec
Co. Ltd., 829 F.2d 1086, 1090-1092 (Fed. Cir. 1987) (prosecution history); Moeller v. Ionetics,
Inc., 794 F.2d 653, 656 (Fed. Cir. 1986) (resort to certain evidence such as specification, prose-
cution history, and other claims, is “always necessary to interpret disputed claims”); Loctite
Corp. v. Ultraseal Ltd., 781 F.2d 861, 867-869 (Fed. Cir. 1985) (interpreting same word in two
patents differently based on different prosecution histories); SRI International v. Matsushita
Electric Corp., 775 F.2d 1107, 1118 (Fed. Cir. 1985), quoted in N.73 supra.
    For more on evidence relevant to claim construction, see § 2.05[3][a][iii] infra.
    77
        See, e.g., Markman v. Westview Instruments, Inc., 52 F.3d 967, 34 U.S.P.Q.2d (BNA)
1321 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38
U.S.P.Q.2d (BNA) 1461 (1996) (“To ascertain the meaning of claims, we consider three
sources: The claims, the specification, and the prosecution history”), quoting Unique Concepts,
Inc. v. Brown, 939 F.2d 1558, 1561 (Fed. Cir. 1991) and citing Autogiro Company of America,
Inc. v. United States, 384 F.2d 391, 155 U.S.P.Q. (BNA) 697 (Ct. Cl. 1967) (“In deriving the
meaning of a claim, we inspect all useful documents and reach what Justice Holmes called the
‘felt meaning’ of the claim. In seeking this goal, we make use of three parts of the patent: the
specification, the drawings, and the file wrapper”), citing United States v. Johnson, 221 U.S.
488, 496, 31 S.Ct. 627, 55 L.Ed. 823 (1911) (“although the meaning of a sentence is to be felt
rather than to be proved, generally and here the impression may be strengthened by argument, as
we shall try to show”).
    Interpretive materials are generally limited to these three sources, unless they are ambiguous.
See § 2.05[3][a][iii] infra.
    77.1
          See Autogiro Company of America, Inc. v. United States, 384 F.2d 391, 397, 155
U.S.P.Q. (BNA) 697 (Ct. Cl. 1967) (Citations omitted.):
   “Often the invention is novel and words do not exist to describe it. The dictionary does not
   always keep abreast of the inventor. It cannot. Things are not made for the sake of words, but
   words for things. To overcome this lag, patent law allows the inventor to be his own lexi-
   cographer.”


                                                                                       (Rel. 25)
2-05                      PATENTS               INTELLECTUAL PROPERTY LAW

                           77.2
interpretive process.      Nevertheless, the canons of claim construction do
provide a useful guide to the interpretive process, and the Federal Circuit has
continued the tradition of refining and relying on them.
    Some canons of interpretation relate to the claims themselves. Just like
words in a statute, every claim is supposed to have independent meaning, and
                                                                    77.3
therefore two different claims are not supposed to be read alike.        This can-
                                                         77.4
on is known as the doctrine of “claim differentiation.”        The Federal Circuit
                                     77.5
has applied it to dependent claims,       but has refused to be bound rigidly by
it in addressing independent claims, thinking it more significant whether the
                                                          77.6
specification supports the claim construction asserted.        The doctrine, how-
ever, has a corollary more often applied by the Federal Circuit: that limita-
                                                       77.7
tions are not to be read from one claim into another.

   77.2
          Id., 384 F.2d at 397:

   “Patent law is replete with major canons of construction of minor value which have seldom
   provided useful guidance in the unraveling of complex claims. Instead, these canons have
   only added confusion to the problem of claim interpretation.”
   77.3
          Id., 384 F.2d at 404:

   “[T]he concept of claim differentiation . . . states that claims should be presumed to cover
   different inventions. This means that an interpretation of a claim should be avoided if it
   would make the claim read like another one. Claim differentiation is a guide, not a rigid rule.
   If a claim will bear only one interpretation, similarity will have to be tolerated.”
   77.4
          See N.77.3 supra.
   77.5
         See: Rambus Inc. v. Infineon Technologies, AG, 318 F.3d 1081, 1093 (Fed. Cir. 2003)
(noting that court “disfavors” construction of claims that “would render claim language in de-
pendent claims . . . meaningless”), citing Comark Communications, Inc. v. Harris Corp., 156
F.3d 1182, 1187, 48 U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1998), and Wright Medical Technology,
Inc. v. Osteonics Corp., 122 F.3d 1440, 1445, 43 U.S.P.Q.2d (BNA) 1837, 1841 (Fed. Cir.
1997); United States v. Telectronics, Inc., 857 F.2d 778, 784, 8 U.S.P.Q.2d (BNA) 1217 (Fed.
Cir. 1988), cert. denied 490 U.S. 1046 (1989) (refusing to import into independent claim limita-
tion in dependent claim that depended on it). See also, N.77.7 infra.
    77.6
          See, e.g.: ATD Corp. v. Lydall, Inc., 159 F.3d 534, 541, 48 U.S.P.Q.2d (BNA) 1321
(Fed. Cir. 1998) (“[t]he doctrine of claim differentiation can not broaden claims beyond the
scope that is supported by the specification”) (Citations omitted.); Laitram Corp. v. Morehouse
Industries, Inc., 143 F.3d 1456, 1462, 46 U.S.P.Q.2d (BNA) 1609 (Fed. Cir. 1998) (refusing to
apply doctrine where specification would not support differentiation of claims); Tandon Corp. v.
U.S. International Trade Commission, 831 F.2d 1017, 1023- 1024, 4 U.S.P.Q.2d (BNA) 1283
(Fed. Cir. 1987) (affirming ITC’s decision that, despite doctrine of claim differentiation, specifi-
cation did not support claim construction asserted by patentee).
    77.7
         See, e.g., SRI International, Inc. v. Matsushita Electric Corp., 775 F.2d 1107, 1122, 227
U.S.P.Q. (BNA) 577 (Fed. Cir. 1985) (“It is settled law that when a patent claim does not con-
tain a certain limitation and another claim does, that limitation cannot be read into the former
claim in determining either validity or infringement”) (Citations omitted.); 775 F.2d at 1122
(where narrower claim was specifically drawn to structure in drawing, reading broader claims as
drawn to same structure or its method of operation would render them superfluous); Palumbo v.
Don-Joy Co., 762 F.2d 969, 977, 226 U.S.P.Q. (BNA) 5 (Fed. Cir. 1985).

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    Other canons of claim construction reflect the relationship between the
claims and the specification. The claims and the rest of the specification have
an intimate relationship because the rest of the specification must support
                                           77.8
each claim with four kinds of disclosure.       Yet just as it is improper to read
limitations from one claim into another, it is improper to read extraneous limi-
                                                         77.9
tations into a claim from the rest of the specification,      for the scope of the
claims is not restricted to the preferred embodiments shown in the specifica-
     77.10                  77.11
tion       or the drawings.       Even a specification that seems to teach away
from a claim's literal language may not preclude giving that language its full,




     (“This court has recognized that ‘it is improper for courts to read into an independent claim a
limitation explicitly set forth in another claim’”), quoting Environmental Designs, Ltd. v. Union
Oil of California, 713 F.2d 693, 699, 218 U.S.P.Q. (BNA) 865, 871 (Fed. Cir. 1983), cert. de-
nied 464 U.S.1043 (1984). (Other citations omitted.)
     77.8
          See: 35 U.S.C. § 112; § 2.04[1] supra.
     77.9
           See, e.g.: Toro Co. v. White Consolidated Industries, Inc., 2001 U.S. App. LEXIS
20915 at *8-9 (Fed. Cir. Sept. 24, 2001) (refusing to import into claim for unitary restriction
ring and cover in vacuum blower function of automatically restricting airflow where claim did
not mention such function, and noting that court “did not and could not import into the claim a
function from the specification, particularly when the claim recites only purely structural limita-
tions”); 2001 U.S. App. LEXIS 20915 at *10 (specified functions “do not become part of the
claimed structure unless claimed as such”); Exxon Research & Engineering Co. v. United States,
2001 U.S. App. LEXIS 20590 at *27-30 (Fed. Cir. Sept. 19, 2001) (two conditions describing
operating parameters of fluidized catalyst reactor were not, as found by district court, “fatally
inconsistent” where one described “sufficient” fluidization and other “excellent” fluidization and
only former was claimed; trial court “improperly imported the ‘excellent’ fluidization condition
into the claims, thereby creating an apparent inconsistency”); E. I. du Pont de Nemours & Co. v.
Phillips Petroleum Co., 849 F.2d 1430, 1433 (Fed. Cir.), cert. denied 488 U.S. 986 (1988) (“It is
entirely proper to use the specification to interpret what the Patentee meant by a word or phrase
in the claim. . . . But this is not to be confused with adding an extraneous limitation appearing in
the specification, which is improper”) (Citation omitted.); SRI International v. Matsushita Elec-
tric Corp., 775 F.2d 1107, 1121 (Fed. Cir. 1985) (“claims are infringed, not specifications”).
     77.10
            See, e.g.:
     Fifth Circuit: Ziegler v. Phillips Petroleum Co., 483 F.2d 858, 869, 876-877 (5th Cir.), cert.
denied 414 U.S. 1079 (1973) (patent on polymerization catalyst and related process covered
production of polypropylene from propylene, although specification described production of
polyethylene from ethylene).
     Seventh Circuit: Binks Manufacturing Co. v. Ransburg Electro-Coating Corp., 281 F.2d
252, 258 (7th Cir. 1960), cert. denied 366 U.S. 211 (1961) (neither method nor apparatus patent
is limited to specific embodiment of apparatus disclosed).
     Federal Circuit: SRI International v. Matsushita Electric Corp., 775 F.2d 1107, 1121 (Fed.
Cir. 1985) (“If everything in the specification were required to be read into the claims, or if
structural claims were to be limited to devices operated precisely as a specification-described
embodiment is operated, there would be no need for claims”).
     See also, § 2.04[1][b] infra.
     77.11
            See Binks Manufacturing Co. v. Ransburg Electro-Coating Corp., 281 F.2d 252, 256
(7th Cir. 1960), cert. denied 366 U.S. 211 (1961) (“the claims not the drawings define the in-
vention”).

                                                                                        (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                77.12
literal scope.     On the other hand, the rest of the specification may, in ef-
fect, help expand the scope of a claim; a court would not reach, for example,
to interpret a claim so narrowly as to exclude the preferred embodiment dis-
                             77.13
closed in the specification.
    Actual expansion of claims, however, is prohibited by the rule that matter
                                                                           77.14
disclosed in the specification but not claimed is dedicated to the public.
If, for example, the specification discloses a range or genus of alternative
embodiments of the invention, of which the claims clearly describe only a
subset, the remaining embodiments not covered by the claims are dedicated to


   77.12
            See PPG Industries, Inc. v. Guardian Industries Corp., 75 F.3d 1558, 1561-1562, 37
U.S.P.Q.2d (BNA) 1618 (Fed. Cir. 1996) (patent specification for glass with reduced ultraviolet
transmission, which had been based upon use of flawed testing software and which therefore
had overestimated difficulty of making glass to meet claim limitations without cerium, did not
preclude reading clear claims on accused glass, although it contained no cerium).
    77.13
             See Hoechst Celanese Corp. v. BP Chemicals Ltd., 78 F.3d 1575, 1581, 38
U.S.P.Q.2d (BNA) 1126 (Fed. Cir. 1996), cert. denied 117 S.Ct. 275 (1996) (choosing interpre-
tation of claim that would include inventor's preferred embodiment, rather than one that would
not: “it is unlikely that an inventor would define the invention in a way that excluded the pre-
ferred embodiment, or that persons of skill in this field would read the specification in such a
way”). (Citation omitted.)
    77.14
           See, e.g.:
    Supreme Court: Milcor Steel Co. v. George A. Fuller Co., 316 U.S. 143, 146, 62 S.Ct. 969,
86 L.Ed. 1332 (1942) (“Out of all the possible permutations of elements which can be made
from the specifications, [the patentee] reserves for himself only those contained in the claims”)
(Citation to opinion below and internal quotation marks omitted.); Mahn v. Harwood, 112 U.S.
354, 361, 5 S.Ct. 174, 28 L.Ed. 665 (1884) (“The public is notified and informed by the most
solemn act on the part of the patentee, that his claim to invention is for such and such an ele-
ment or combination, and for nothing more. Of course, what is not claimed is public property”);
Miller v. Bridgeport Brass Co., 104 U.S. (14 Otto) 350, 352, 35, 26 L.Ed. 783, (1882) (“The
claim of a specific device or combination, and an omission to claim other devices or combina-
tions apparent on the face of the patent, are, in law, a dedication to the public of that which is
not claimed”).
    Federal Circuit: Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *20 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (“when a patent drafter
discloses but declines to claim subject matter, as in this case, this action dedicates that un-
claimed subject matter to the public”), overruling YBM Magnex, Inc. v. International Trade
Commission, 145 F.3d 1317, 1320, 46 U.S.P.Q.2d (BNA)1843 (Fed. Cir. 1998); Maxwell v. J.
Baker, Inc., 86 F.3d 1098, 1106, 39 U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996); Unique Con-
cepts, Inc. v. Brown, 939 F.2d 1558, 1562-1563, 19 U.S.P.Q.2d (BNA) 1500 (Fed. Cir. 1991)
(“subject matter disclosed but not claimed in a patent application is dedicated to the public”).
    For a brief discussion of how Johnson & Johnston Associates overruled YBM Magnex,
which attempted to limit the dedication rule, see § 2.05[3][b][i][A] infra.
    This dedication rule applies only to the patent disclosing but failing to claim the matter in
question. It does not undermine any coverage of the same matter in another issued patent. For
example, an improvement patent, in the course of explaining the improvement, may disclose but
fail to claim matter covered by the underlying dominant patent; but that failure does not affect
the scope or validity of the dominant patent. See § 2.05[1][a] supra. Thus the “dedication” rule
does not wholly simplify patent searches. It is simply not the case that anyone may freely use
technology disclosed but not claimed in a single patent, for the same technology may be covered
by other patents.

                                                                                      (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW
             77.15
the public.      This rule is a necessary consequence of the principle that the
                                                                 77.16
claims, not the rest of the specification, define the invention.        It also
prevents an inventor from avoiding examination of the full breadth of her
alleged discovery by submitting narrow claims and then later arguing for a

    77.15
           The paradigmatic case is Unique Concepts, Inc. v. Brown, 939 F.2d 1558, 1563, 19
U.S.P.Q.2d (BNA) 1500 (Fed. Cir. 1991). The invention was a wall-mounted frame for in-
stalling fabric wall coverings, with slots in which to stuff excess material. See 939 F.2d at 1559-
1560. The patent claimed “right angle corner border pieces,” which the specification indicated
were pre-formed, but the accused device was an improvised, composite corner piece formed by
mitering (accurately sawing at 45% angles) and joining two straight pieces. See 939 F.2d at
1560-1561. Since the patent specification had mentioned mitered corner pieces but the claims
did not cover them, the court found no literal infringement. See 939 F.2d at 1562-1563.
    Although Unique Concepts did not apply the dedication rule to infringement under the doc-
trine of equivalents, that application of the rule is also well-established. See 2.05[3][b][i][A]
infra. Indeed, the cases applying the dedication rule to infringement by equivalents further cor-
roborates the basic rule. In Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1106, 39 U.S.P.Q.2d (BNA)
1001 (Fed. Cir. 1996), the patent claimed fastening tabs used to join mated pairs of shoes, which
were stitched between the shoes’ inner and outer soles; it disclosed, but did not claim, fastening
tabs stitched into the shoes’ lining seams. See 86 F.3d at 1102-1103. The Federal Circuit held
that the dedication rule prohibited applying the doctrine of equivalents to the lining-seam fas-
teners. See 86 F.3d at 1106-1107.
    Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App. LEXIS 5171 at
*20 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) was an even clearer case. There the patent
claimed a removable substrate for handling printed circuit boards made of “a sheet of alumi-
num[,]” while the specification disclosed, but did not claim, substrates made of “other metals,
such as stainless steel or nickel alloys[.]” 2002 U.S. App. LEXIS 5171 at *22. The court held, as
a matter of law, that the claims could not encompass steel substrates under the doctrine of
equivalents. See 2002 U.S. App. LEXIS 5171 at *22-24.
    Applying the dedication doctrine to infringement by equivalents, however, may involve
some special nuances. See § 2.05[3][b][i][A] infra.
    77.16
           See, e.g.:
    Supreme Court: Milcor Steel Co. v. George A. Fuller Co., 316 U.S. 143, 146, 62 S.Ct. 969,
86 L.Ed. 1332 (1942) (“Out of all the possible permutations of elements which can be made
from the specifications, [the patentee] reserves for himself only those contained in the claims”)
(Citation to opinion below and internal quotation marks omitted.); Continental Paper Bag Co. v.
Eastern Paper Bag Co., 210 U.S.405, 419, 28 S.Ct. 748, 52 L.Ed. 1122 (1908) (“The invention,
of course, must be described and the mode of putting it to practical use, but the claims measure
the invention”); McClain v. Ortmayer, 141 U.S. 419, 424, 12 S.Ct. 76, 35 L.Ed. 800 (1891)
(“The claim is the measure of his right to relief, and while the specification may be referred to to
limit the claim, it can never be made available to expand it.").
    Federal Circuit: Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *13 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (“Consistent with its scope
definition and notice functions, the claim requirement presupposes that a patent applicant de-
fines his invention in the claims, not in the specification. After all, the claims, not the specifica-
tion, provide the measure of the patentee’s right to exclude”) ((Citations omitted.); SRI
International v. Matsushita Electric. Corp., 775 F.2d 1107, 1121 n.14, 227 U.S.P.Q. (BNA) 577
(Fed. Cir. 1985) (“Specifications teach. Claims claim”).
    See also, Johnson & Johnston Associates, Inc., supra, 2002 U.S. App. LEXIS 5171 at *14-
15 (“the law of infringement compares the accused product with the claims as construed by the
court. Infringement, either literally or under the doctrine of equivalents, does not arise by com-
paring the accused product ‘with a preferred embodiment described in the specification, or with
[*15] a commercialized embodiment of the patentee’”), quoting SRI International, supra, 775
F.2d at 1121.

                                                                                          (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

broader interpretation of those claims, based on the specification, in litiga-
      77.17
tion.
   Although courts cannot cite the rest of the specification to read limitations
                                                                      77.18
into claims in order to avoid their invalidation for overbreadth,           courts
may look outside the claims to save a claim from invalidation on grounds of
                77.19
indefiniteness.       In any event, the character of the invention affects “lit-
eral” interpretation of the claims just as it affects application of the doctrine




   77.17
           See Unique Concepts, Inc. v. Brown, 939 F.2d 1558, 1563, 19 U.S.P.Q.2d (BNA)
1500, 1504 (Fed. Cir. 1991)) (“If Unique intended to claim mitered linear border pieces as an
alternative to its right angle corner border pieces, it had to persuade the examiner to issue such a
claim”).
    This rationale is perhaps better established in applying the dedication rule to limit the doc-
trine of equivalents. See Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S.
App. LEXIS 5171 at *21-22 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam), citing Maxwell v.
J. Baker, Inc., 86 F.3d 1098, 1107, 39 U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996) (Internal cita-
tions omitted.):
       “[A] patentee cannot narrowly claim an invention to avoid prosecution scrutiny by the
   PTO, and then, after patent issuance, use the doctrine of equivalents to establish infringe-
   ment because the specification discloses equivalents. ‘Such a result would merely encourage
   a patent applicant to present a broad disclosure in the specification of the application and file
   narrow claims, avoiding examination of broader claims that the applicant could have filed
   consistent with the specification.’ . . . By enforcing the Maxwell rule, the courts avoid the
   problem of extending the coverage of an exclusive right to encompass more than that proper-
   ly examined by the PTO. Keystone Bridge Co. v. Phoenix Iron Co., 95 U.S. 274, 278, 24
   L.Ed. 344 (1877) [*22] (‘The courts have no right to enlarge a patent beyond the scope of its
   claim as allowed by the Patent Office, or the appellate tribunal to which contested applica-
   tions are referred.’).”
   See also, Sage Products, Inc. v. Devon Industries, Inc., 126 F.3d 1420, 1421, 44 U.S.P.Q.2d
(BNA) 1103 (Fed. Cir. 1997):
        “If Sage desired broad patent protection for any container that performed a function simi-
   lar to its claimed container, it could have sought claims with fewer structural encumbrances.
   Had Sage done so, then the Patent and Trademark Office (PTO) could have fulfilled its
   statutory role in helping to ensure that exclusive rights issue only to those who have, in fact,
   contributed something new, useful, and unobvious. Instead, Sage left the PTO with manifest-
   ly limited claims that it now seeks to expand through the doctrine of equivalents. However,
   as between the patentee who had a clear opportunity to negotiate broader claims but did not
   do so, and the public at large, it is the patentee who must bear the cost of its failure to seek
   protection for this foreseeable alteration of its claimed structure.”
    For discussion of the “foreseeability” test suggested by the last sentence of this excerpt, see §
2.05[3][b][i][A] infra.
    77.18
           See the text accompanying Ns.77.8-77.12 supra.
    77.19
           See Cutter Laboratories, Inc. v. Lyophile-Cryochem Corp., 179 F.2d 80, 87 (9th Cir.
1949) (prosecution history established meaning of term “substantially instantaneous freezing” as
“referring to an old rather than an inventive step” and thereby avoided indefiniteness).

                                                                                         (Rel. 25)
2-05                       PATENTS             INTELLECTUAL PROPERTY LAW

                   77.20
of equivalents;       claims to a pioneering invention are interpreted more lib-
                                                                77.21
erally than those to a minor improvement in a crowded art.
    While interpretive aids are helpful, they must be applied with care. If the
literal language of the claims is clear, the rest of the specification cannot mod-
ify that language, for example, to invalidate the claims in light of prior
     77.22
art.       Moreover, in litigation courts must consider the validity of each
                                                                   77.23
claim separately and determine infringement claim by claim.              The statute
                         77.24
requires this approach,        for it declares that every claim, whether depend-
ent or independent, is separately presumed valid, independently of every other
        77.25                                                                  77.26
claim.        Thus each claim has some of the aspects of a separate patent,
although a dependent claim cannot be infringed without infringing the inde-
                                       77.27
pendent claim on which it depends.
    Although not strictly speaking a “canon” of interpretation, the Federal Cir-
                                                        77.28
cuit’s emphasis on the “notice function” of patents           also may affect claim
construction. For example, where two interpretations of a claim are equally




   77.20
           See § 2.05[3][b][i][A] infra.
   77.21
          See, e.g.:
    Supreme Court: Smith v. Snow, 294 U.S. 1, 14, 55 S.Ct. 279, 79 L.Ed. 721 (1935) (dictum).
    Ninth Circuit: Cutter Laboratories, Inc. v. Lyophile-Cryochem Corp., 179 F.2d 80, 86 (9th
Cir. 1949).
    77.22
           See Uniroyal Inc. v. Rudkin-Wiley Corp., 837 F.2d 1044, 1053 (Fed. Cir.), cert. de-
nied 488 U.S. 825 (1988) (court below erred in comparing prior art with limitations in specifica-
tion and drawings not appearing in claims).
    77.23
          See, e.g.: Uniroyal Inc. v. Rudkin-Wiley Corp., 837 F.2d 1044, 1054-1055 (Fed. Cir.),
cert. denied 488 U.S. 825 (1988) (it is error to read claims together as if they have the same
limitations); D.M.I., Inc. v. Deere & Co., 755 F.2d 1570, 1574 (Fed. Cir. 1985) (limitations of
narrow claims cannot be read into broad claims); W.L. Gore & Associates, Inc. v. Garlock, Inc.,
721 F.2d 1540, 1550 (Fed. Cir. 1983), cert. denied 469 U.S. 851 (1984).
    77.24
          See 35 U.S.C. § 282.
    77.25
          See: 35 U.S.C. § 282; § 2.04[4] supra.
    77.26
          See, e.g.:
    Second Circuit: Medeco Security Locks, Inc. v. Lock Technology Corp., 199 U.S.P.Q.
(BNA) 519, 523 (S.D.N.Y. 1976).
    Seventh Circuit: Hunt v. Armour & Co., 185 F.2d 722, 729 (7th Cir. 1950).
    77.27
          See, e.g.:
    Fourth Circuit: AB Iro v. Otex, Inc., 566 F. Supp. 419, 456 (D.S.C. 1983) (citing authori-
ties).
    Federal Circuit: Wahpeton Canvas Co. v. Frontier, Inc., 870 F.2d 1546, 1552, 1554 (Fed.
Cir. 1989) (proper jury verdict of noninfringement of independent claims required judgment of
noninfringement of all dependent claims depending on them); 870 F.2d at 1553.
    77.28
          See § 2.05[3] (introduction) supra.


                                                                                     (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

plausible, the function of claims in providing public notice of the limits of a
                                                                   78
patent’s protection requires adopting the narrower interpretation.
    The Federal Circuit has consistently held that there is a “heavy presump-
tion” in favor of reading claim language according to its ordinary and cus-
                   78.1
tomary meaning.         The court has stated that a court may depart from such
ordinary meaning in four cases: “First, the claim term will not receive its or-
dinary meaning if the patentee acted as his own lexicographer and clearly set
forth a definition of the disputed claim term in either the specification or
prosecution history. Second, a claim term will not carry its ordinary meaning
if the intrinsic evidence shows that the patentee distinguished that term from
prior art on the basis of a particular embodiment, expressly disclaimed subject
matter, or described a particular embodiment as important to the invention
Third, and most relevant to this case, a claim term also will not have its ordi-
nary meaning if the term chosen by the patentee so deprives the claim of clari-
ty as to require resort to the other intrinsic evidence for a definite meaning.
Last, as a matter of statutory authority, a claim term will cover nothing more
than the corresponding structure or step disclosed in the specification, as well
as equivalents thereto, if the patentee phrased the claim in step- or means-
                        78.2
plus-function format.”

           [iii]—Evidence Used in Construing Claims
                                                                                79
   One of the major revolutions wrought by the Federal Circuit has been in
the nature of the evidence used for construing claims. Until the Federal Cir-
                                  79.1
cuit’s 1995 decision in Markman,       oral testimony of inventors and experts
had been routine in patent cases and had often been used as a basis for con-
                79.2
struing claims.      In Markman, however, the Federal Circuit, sitting en banc,

   78
        See Athletic Alternatives, Inc. v. Prince Manufacturing, Inc., 73 F.3d 1573, 1581, 37
U.S.P.Q.2d (BNA) 1365 (Fed. Cir. 1996) (where facts present equal choice between broad and
narrow construction, and specification supports at least narrower construction, notice function is
best served by narrower interpretation).
    78.1
         See, e.g., Sunrace Roots Enterprises Co., LTD v. SRAM Corp., 336 F.3d 1298, 1303
(Fed. Cir. 2003).
    78.2
         CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366-1367 (Fed. Cir. 2002).
(Quotation marks and citations omitted.)
    79
       For general discussion of this and other revolutions, see § 2.05[3] (introduction) supra.
    79.1
          Markman v. Westview Instruments, Inc., 52 F.3d 967, 34 U.S.P.Q.2d (BNA) 1321
(Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38 U.S.P.Q.2d
(BNA) 1461 (1996), discussed in: § 2.05[3] (introduction) supra; § 2.05[3][a][iv] infra.
    79.2
         See, e.g., Whittaker Corp. v. UNR Industries, Inc., 911 F.2d 709, 711 15 U.S.P.Q.2d
(BNA) 1742 (Fed. Cir. 1990) (noting use of expert testimony “where appropriate” in construing
claims and citing authorities); Smithkline Diagnostics, Inc. v. Helena Laboratories Corp., 859
F.2d 878, 882-885, 8 U.S.P.Q.2d (BNA) 1468 (Fed. Cir. 1988) (relying in part on expert testi-
mony); McGill, Inc. v. John Zink Co., 736 F.2d 666, 672- 675, 221 U.S.P.Q. (BNA) 944 (Fed.
Cir. 1984), cert. denied 469 U.S. 1037 (1984) (same).

                                                                                      (Rel. 25)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

                                                                                      79.3
hinted that such oral testimony and other “extrinsic” evidence            would be
                          79.4
given a restricted role.       One year later, in Vitronics Corp. v. Conveptronic,
      79.5
Inc.,      a panel of the court ruled that extrinsic evidence is disfavored in
claim construction and to be used only when other evidence cannot resolve
              79.6
ambiguities.       That ruling and its rationale are sufficiently important to mer-
it detailed discussion.
    In Vitronics,79.7 the Federal Circuit emphasized the importance of “intrin-
sic” evidence in the public record over “extrinsic” evidence, such as expert
testimony, in construing patent claims. The primary sources of intrinsic evi-
dence are the claims themselves, the rest of the patent specification, and the
                 79.8                                 79.9
“file wrapper”        or patent prosecution history.       In most cases, questions


    79.3
          The Markman court defined as “extrinsic evidence” “all evidence external to the patent
and prosecution history, including expert and inventor testimony, dictionaries, and learned trea-
tises.” Markman v. Westview Instruments, Inc., 52 F.3d 967, 980, 34 U.S.P.Q.2d (BNA) 1321
(Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38 U.S.P.Q.2d
(BNA) 1461 (1996).
    79.4
          See id., 52 F.3d at 980-981 (court “may, in its discretion, receive extrinsic evidence in
order to aid the court in coming to a correct conclusion as to the true meaning of the language
employed in the patent[,]” but “[e]xtrinsic evidence is to be used for the court’s understanding
of the patent, not for the purpose of varying or contradicting the terms of the claims”). (Cita-
tions and internal quotation marks omitted.)
    79.5
          Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 39 U.S.P.Q.2d (BNA) 1573 (Fed.
Cir. 1996).
    79.6
          See: N62.64 supra; N.79.21 infra. This does not mean that extrinsic evidence is neces-
sarily inadmissible. See AFG Industries, Inc. v. Cardinal IG Co., 239 F.3d 1239, 1249, 57
U.S.P.Q.2d (BNA) 1776 (Fed. Cir. 2001) (to extent specification was vague or ambiguous, trial
court construing claim “should have considered” expert’s “essentially undisputed” testimony
that those skilled in art distinguished between “layers” and “interlayers”); 239 F.3d at 1249
(“This case presents a good example of how extrinsic evidence can and should be used to inform
a court's claim construction and how failure to take into account the testimony of persons of
ordinary skill in the art may constitute reversible error”).
    79.7
          Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1578, 1584-1585, 39 U.S.P.Q.2d
(BNA) 1573 (Fed. Cir. 1996) (reversing and remanding judgment of noninfringement that had
been based in part on extrinsic evidence); id., 90 F.3d at 1584-1585 (where patent specification
unambiguously defined disputed term, district court's reliance on extrinsic evidence, including
expert testimony and paper by former company employee, was “unnecessary and legally incor-
rect”). See also, N.79.21 infra.
    A court may use expert testimony as an aid to understanding the technology, rather than as a
basis for construing the patent claims, and doing so is not reversible error. See id., 90 F.3d at
1585.
    79.8
          See § 2.05[3][b][i][B] infra.
    79.9
          See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582, 39 U.S.P.Q.2d (BNA)
1573 (Fed. Cir. 1996) (“It is well settled that, in interpreting an asserted claim, the court should
look first to the intrinsic evidence of record, i.e., the patent itself, including the claims, the speci-
fication, and, if in evidence, the prosecution history”), citing Markman v. Westview Instru-
ments, Inc., 52 F.3d 967, 979, 34 U.S.P.Q.2d (BNA) 1321, 1329 (Fed. Cir. 1995) (en banc),
aff'd 517 U.S. 370, 116 S.Ct. 1384, 1387, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996).

                                                                                             (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

of claim interpretation can be resolved by examining and analyzing these
documentary records, without resort to expert testimony or other extrinsic
          79.10
evidence.       Only if examination and analysis fail to resolve an ambiguity in
                                        79.11             79.12
a claim is resort to extrinsic evidence       permitted.        Even if such an
ambiguity exists, other forms of extrinsic evidence, such as the prior art, are
                                               79.13
preferred as the basis for claim construction.       According to the Vitronics
panel, instances in which expert testimony is needed for claim construction
                79.14
should be rare.


   79.10
           Even within the broad category of intrinsic evidence, the Vitronics court sought to es-
tablish a hierarchy. The starting point is the claims themselves, including both asserted and
unasserted claims; claim language takes its ordinary meaning unless the specification or prose-
cution history clearly states a special meaning. See id., 90 F.3d at 1582. Next is the specifica-
tion, which must always be reviewed “to determine whether the inventor has used any terms in a
manner inconsistent with their ordinary meaning.” Id. The specification normally “is dispositive,
[because] it is the single best guide to the meaning of a disputed term.” Id. Only if an ambiguity
remains after the claims and specification have been examined and analyzed should the court
resort to the prosecution history, if it has been placed in evidence. See 90 F.3d at 1582, 1584-
1585.
    79.11
           “Extrinsic evidence is that evidence which is external to the patent and file history,
such as expert testimony, inventor testimony, dictionaries, and technical treatises and articles.”
(Footnote omitted.) Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1584, 39 U.S.P.Q.2d
(BNA) 1573 (Fed. Cir. 1996).
    79.12
           See id., 90 F.3d at 1584 (Fed. Cir. 1996) (“Only if there were still some genuine am-
biguity in the claims, after consideration of all available intrinsic evidence, should the trial court
have resorted to extrinsic evidence, such as expert testimony”). See also, 90 F.3d at 1584 (Cita-
tions omitted.):
   “[E]xtrinsic evidence in general, and expert testimony in particular, may be used only to help
   the court come to the proper understanding of the claims; it may not be used to vary or con-
   tradict the claim language. . . . Nor may it contradict the import of other parts of the specifi-
   cation. Indeed, where the patent documents are unambiguous, expert testimony regarding the
   meaning of a claim is entitled to no weight.”
See also, Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1367 (Fed. Cir. 2003) (refusing
to address extrinsic evidence in determining whether means-plus-function claim was indefinite
where it was not indefinite as construed using intrinsic evidence: “[w]hen an analysis of intrinsic
evidence resolves any ambiguity in a disputed claim term, it is improper to rely on extrinsic
evidence to contradict the meaning so ascertained”), citing Vitronics Corp. v. Conceptronic,
Inc., 90 F.3d 1576, 1583, 1584 (Fed. Cir. 1996) (“Only if there were still some genuine ambigui-
ty in the claims, after consideration of all available intrinsic evidence, should the trial court have
resorted to extrinsic evidence, such as expert testimony, in order to construe claim 1").
    79.13
           See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1584-1584 (Fed. Cir. 1996)
(where extrinsic evidence is necessary, prior art is preferable to expert testimony, as it “can often
help to demonstrate how a disputed term is used by those skilled in the art” and does not merely
“indicate[] what a particular expert believes a term means[;]” in comparison, expert testimony is
“no better than opinion testimony on the meaning of statutory terms”). (Citation omitted.)
    79.14
           See id., 90 F.3d at 1585 (unlike expert testimony to help court understand technology,
expert testimony on proper construction of disputed claim is needed only when patent docu-
ments, as whole, are insufficient to enable court to construe claim; “[s]uch instances will rarely,
if ever, occur”).

                                                                                          (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

   Even within the preferred category of intrinsic evidence, there is a hierar-
     79.14a
chy.        The language of the claims themselves is the most favored evi-
dence, with the specification and prosecution history following in that order.
Another Federal Circuit panel reaffirmed that hierarchy in 2002 in the follow-
ing terms:

   “All intrinsic evidence is not equal . . . .


   “First, we look to the claim language. . . . Then we look to the rest of the
   intrinsic evidence, beginning with the specification and concluding with
   the prosecution history, if in evidence. . . .


   “If the claim language is clear on its face, then our consideration of the rest
   of the intrinsic evidence is restricted to determining if a deviation from the
   clear language of the claims is specified. A deviation may be necessary if
   ‘a patentee [has chosen] to be his own lexicographer and use terms in a
   manner other than their ordinary meaning.’ . . . A deviation may also be
   necessary if a patentee has ‘relinquished [a] potential claim construction in
   an amendment to the claim or in an argument to overcome or distinguish a
   reference.’ . . . If, however, the claim language is not clear on its face, then
   our consideration of the rest of the intrinsic evidence is directed to resolv-
                                           79.14b
   ing, if possible, the lack of clarity.”

Thus Vitronics and its progeny have prescribed a highly structured eviden-
tiary approach to claim interpretation by courts.
              79.15
    Vitronics       was only a panel decision, not an en banc decision, and its
conclusion was not entirely congruent with precedent approving the use of
                                                         79.16
expert testimony for purposes of patent construction.          Nevertheless, its

   79.14a
            See N.79.10 supra.
   79.14b
            Banyan Licensing, L.C. v. Orthosupport International, Inc., 2002 U.S. App. LEXIS
4983 at *3-4 (Fed. Cir. Mar. 21, 2002) (reaffirming Vitronics’ hierarchy of intrinsic evidence),
citing and quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582, 39 U.S.P.Q.2d
(BNA) 1573 (Fed. Cir. 1996), and quoting Elkay Manufacturing Co. v. Ebco Manufacturing
Co., 192 F.3d 973, 979, 52 U.S.P.Q.2d (BNA) 1109, 1113 (Fed. Cir. 1999). (Other citations
omitted.)
    79.15
          Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 39 U.S.P.Q.2d (BNA) 1573 (Fed.
Cir. 1996).
    79.16
          See N.79.2 supra.
    Indeed, there seems to be some disagreement among the judges on the Federal Circuit re-
garding the proper role of expert testimony in claim construction. Compare Bell & Howell Doc-
ument Management Products Co. v. Altek Systems, 1997 U.S. App. LEXIS 34253 at *19, 45
U.S.P.Q.2d (BNA) 1034 (Fed. Cir. 1997) (where intrinsic evidence from claims, patent specifi-
cation and file wrapper were unambiguous, it was error for district court to base claim construc-

                                                                                     (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

basic thrust is unlikely to be averted, for three reasons. First, the evidentiary
rule it established is entirely consistent with the central rationale of Markman:
that judges should have the job of construing claims because they are more
expert than juries in interpreting written documents and so can render more
                        79.17
predictable decisions.        That job is similar to construing written contracts
or statutory provisions; the judge is supposed to be an expert in construing the
written word and may rely on others' testimony only to resolve ineluctable
        79.18
doubt.        Second, the Vitronics approach reflects the fact that patents are
                                                       79.19
public documents, affected with a public interest,            the goal of which—
notwithstanding the doctrine of equivalents—is to delineate precisely the
                                                           79.20
metes and bounds of the patentee's exclusive rights.             Relying more on
“intrinsic” evidence contained in the public record, and less on after-the-fact
expert testimony the import of which can only be guessed in advance, in-
creases the public transparency and public orientation of the patent system, as
                                                          79.21
well as the economic efficiency of business planning.           Finally, by empha-


tion on expert testimony) (citing Vitronics), with Fromson v. Anitec Printing Plates, Inc., 132
F.3d 1437, 45 U.S.P.Q.2d (BNA) 1269, 1997 U.S. App. LEXIS 36412 at *15-19 (Fed. Cir.
1997) (affirming district court's construction of term “anodization” based on expert testimony
and other extrinsic evidence of purpose and effect of anodization process in context of patent,
without citing Vitronics or Bell and Howell). See also, Fromson, supra, 1997 U.S. App. LEXIS
36412 at *28-31 (Fed. Cir. 1997) (concurring opinion) (arguing that construction of claims
requires factual inquiry, which justifies use of expert testimony and other extrinsic evidence not
just to educate judge, but also to determine disputed issues of fact).
    79.17
           See: § 2.05[3] (introduction) supra; § 2.05[3][a][iv] infra.
    79.18
           See Markman v. Westview Instruments, Inc. 517 U.S. 370, 116 S.Ct. 1384, 1387, 134
L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (likening patent claim
construction to interpretation of contracts and statutes).
    79.19
           See Precision Instrument Manufacturing Co. v. Automotive Maintenance Machinery
Co., 324 U.S. 806, 816, 65 S.Ct. 993, 89 L.Ed. 1381 (1945):
   “A patent by its very nature is affected with a public interest. As recognized by the Constitu-
   tion, it is a special privilege designed to serve the public purpose of promoting the 'Progress
   of Science and useful Arts.’”
   79.20
           See: § 2.05[3] (introduction), [a][i] supra; § 2.05[3][b] infra.
   79.21
         See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583, 39 U.S.P.Q.2d (BNA)
1573 (Fed. Cir. 1996) (Citation omitted.):
   “In those cases where the public record unambiguously describes the scope of the patented
   invention, reliance on any extrinsic evidence is improper. The claims, specification, and file
   history, rather than extrinsic evidence, constitute the public record of the patentee's claim, a
   record on which the public is entitled to rely. In other words, competitors are entitled to re-
   view the public record, apply the established rules of claim construction, ascertain the scope
   of the patentee's claimed invention and, thus, design around the claimed invention. . . . Al-
   lowing the public record to be altered or changed by extrinsic evidence introduced at trial,
   such as expert testimony, would make this right meaningless.”
    A 2002 panel decision of the Federal Circuit provides a good example of the Vitronics rule’s
salubrious economic and practical effect. The panel affirmed the district court’s refusal to con-

                                                                                       (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

sizing documentary evidence and de-emphasizing expert testimony, at least in
the Markman phase of patent litigation, the Vitronics approach may reduce
the cost, time, and effort involved in patent litigation. For all these reasons,
the evidentiary philosophy expressed in Vitronics is unlikely to go away, and
intrinsic evidence is likely to increase in importance in patent litigation. Since
intrinsic evidence lies within the patent applicant's control, Markman and its
progeny have considerably increased the pressure on the patent applicant and
the patent attorney to anticipate problems in claim construction before the
fact, instead of attempting to gloss them over with expert testimony later, in
litigation.
                                                        79.22
    A 1998 en banc decision of the Federal Circuit            both confirmed the
                                           79.23
relative importance of intrinsic evidence        and tied up a loose end in claim
                                                                          79.24
construction procedure. In Cybor Corp. v. FAS Technologies, Inc.,               the
                                                                  79.25
court, by the vote of nine of the twelve judges participating,          ruled that
claim construction, as a question of law, must be reviewed de novo upon ap-
      79.26
peal.       It rejected the notion that factual predicates in claim construction

sider handwritten notes in the patent attorney’s private files in construing a patent’s claims. See
Banyan Licensing, L.C. v. Orthosupport International, Inc., 2002 U.S. App. LEXIS 4983 at *3-4
(Fed. Cir. Mar. 21, 2002) (“Because the claim language here is susceptible to a reasonable inter-
pretation consistent with the intrinsic record, the district court properly did not consider the
extrinsic evidence”), citing Key Pharmaceuticals, Inc. v. Hercon Laboratories Corp., 161 F.3d
709, 716, 48 U.S.P.Q.2d (BNA) 1911, 1917 (Fed. Cir. 1998). Notes of that sort generally would
not be available to the public without the coercion of the discovery process in litigation, and—if
unfavorable to the patentee—without overcoming objections on grounds of attorney-client and
work-product privileges. Therefore, a contrary decision in this case would have required anyone
interested in skirting the patent’s periphery to incur the expense of filing a lawsuit, and likely the
further expense of extended discovery battles, just to find out what the patent covers. It would be
hard to imagine a result more at war with the goals of reducing transaction costs and making
patent protection transparent.
    79.22
           Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1451, 46 U.S.P.Q.2d (BNA)
1169 (Fed. Cir. 1998) (en banc).
    79.23
            Although the decision itself addressed another issue, see the text accompanying
Ns.79.24-79.26 and N.79.26 infra, those judges urging a greater role for extrinsic evidence
recognized the decision's influence in this regard. See id., 138 F.3d at 1480 (additional views of
Judges Newman and Mayer) (“I add to my concerns the position of the Federal Circuit, here
reaffirmed, that extrinsic evidence is of strictly limited availability in claim interpretation. Such
evidence should be encouraged, not restrained, if summary disposition is at hand”); 138 F.3d at
1480 (“The Federal Circuit's ruling that extrinsic evidence must be restricted unless there is a
facial ambiguity in the meaning of the claim is an unnecessary restraint on potentially useful
evidence”). (Citation omitted.) Cf., N.79.28 infra.
    79.24
           Cybor Corp. v. FAS Technologies, Inc., N.79.22 supra, 138 F.3d at 1451.
    79.25
           See id., 138 F.3d at 1451 (summarizing positions taken in various opinions).
    79.26
            See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1451, 1456, 46
U.S.P.Q.2d (BNA) 1169 (Fed. Cir. 1998) (en banc) (“we conclude that the Supreme Court's
unanimous affirmance in Markman . . . of our in banc judgment in that case fully supports our
conclusion that claim construction, as a purely legal issue, is subject to de novo review on ap-
peal”), referring, respectively, to: Markman v. Westview Instruments, Inc., 517 U.S. 370, 116
S.Ct. 1384, 134 L.Ed.2d 577 (1996) (Markman II) and Markman v. Westview Instruments, Inc.,

                                                                                          (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

(such as the meaning of terms or the level of ordinary skill in the art) present
                   79.27                                                79.28
factual questions,       to be reviewed on appeal for clear error only.       In so
doing, it disapproved a number of earlier panel decisions applying or suggest-
                                                  80
ing that notion, including the Fromson decision.

52 F.3d 967, 979, 34 U.S.P.Q.2d (BNA) 1321, 1329 (Fed. Cir. 1995) (en banc) (Markman I),
aff'd Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577
(1996) (Markman II).
    The court based its decision upon its own prior en banc decision in Markman, which, the
court reasoned, the Supreme Court had not modified on this point. See Cybor Corp. v. FAS
Technologies, Inc., supra, 138 F.3d at 1456:
   “Because the [Supreme] Court [in Markman II] did not discuss the appellate standard of re-
   view, Markman II can be read as addressing solely the respective roles of the judge and jury
   at the trial level and not the relationship between the district courts and this court. Although
   [sic: because] our conclusion in Markman I that claim construction is a matter of law was af-
   firmed in all respects, even this narrower view of Markman II leaves Markman I as the con-
   trolling authority regarding our standard of review.”
The court recognized, however, that the standard of appellate review is distinct from the precise
issue decided by the Supreme Court in Markman II—whether the judge or jury should construe
patent claims. See 138 F.3d at 1454 (“Although the law is clear that the judge, and not the jury,
is to construe the claims, this case presents the issue of the proper role of this court in reviewing
the district court's claim construction”).
     79.27
            See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1454, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (Citation omitted.):
   “[In] construing claims by, among other things, using certain extrinsic evidence that the
   court finds helpful and rejecting other evidence as unhelpful, and resolving disputes en route
   to pronouncing the meaning of claim language as a matter of law based on the patent docu-
   ments themselves, the court is not crediting certain evidence over other evidence or making
   factual evidentiary findings. Rather, the court is looking to the extrinsic evidence to assist in
   its construction of the written document, a task it is required to perform.”
   79.28
           Id., 138 F.3d at 1451 (rejecting view—and precedent espousing view—that “clearly
erroneous” standard applies “to findings considered to be factual in nature that are incident to
the judge's construction of patent claims”) (Citations to disapproved decision omitted.); 138
F.3d at 1455 (“the [Supreme Court in Markman II] held that the totality of claim construction is
a legal question to be decided by the judge[, not the jury]. Nothing in the Supreme Court's opin-
ion supports the view that the Court endorsed a silent, third option—that claim construction may
involve subsidiary or underlying questions of fact”).
    Instead, the court ruled that any subsidiary factual questions would and should be submerged
in its plenary review of the claim construction as a matter of law. See 138 F.3d at 1455 (“The
Supreme Court in effect confirmed this when it stated that the credibility determinations among
experts 'will be subsumed within the necessarily sophisticated analysis of the whole
document'“), quoting Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S.Ct. 1384,
1395, 134 L.Ed.2d 577 (1996) (Markman II).
    80
        See N.79.16 supra. See also, Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448,
1456, 46 U.S.P.Q.2d (BNA) 1169 (Fed. Cir. 1998) (en banc) (“[W]e today disavow any lan-
guage in previous opinions of this court that holds, purports to hold, states, or suggests any-
thing” contradicting blanket rule of de novo review on appeal), citing, inter alia, Fromson v.
Anitec Printing Plates, Inc., 132 F.3d 1437, 1444, 45 U.S.P.Q.2d (BNA) 1269, 1274 (Fed. Cir.
1997) (“The district court's findings of scientific/technological fact were material to the issue of
construction of the term 'anodizing'“); 138 F.3d at 1454 n.5, (“It is difficult to reconcile the
language and reasoning in this court's recent opinion in Fromson . . . with Markman I, although

                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

   Judges Newman and Mayer bemoaned both the plenary standard of review
                                                 81
and the subordination of extrinsic evidence, arguing that “[t]he value of
extrinsic evidence in claim interpretation is not surprising, because patent
documents are written by and for persons in the field of the invention, not for
         82                                      83
judges.” Judge Rader agreed on this point. Yet, in practice, patents are
hardly written by or for scientists, engineers, or other inventors. Some inven-
tors may prepare the first drafts of patent disclosures, but even those drafts
are seldom, if ever, submitted without considerable lawyerly review and revi-
sion. Indeed, given the complexity and confusion in patent law today, any
inventor who drafted his own patent for an invention of significant potential
importance would have the proverbial fool for a client. In practice, patents are
written by lawyers, who are well aware that their ultimate audiences are judg-
es and juries. In light of these realities, holding lawyers to a higher standard
by requiring them to “get it right” in drafting specifications and correspond-
ence, rather than attempting to correct drafting errors and omissions later
through extrinsic testimony in litigation, seems appropriate. After all, lawyers'
very expertise and added value is communication—the ability to convey diffi-
cult concepts and distinctions in simple terms and to penetrate to the heart of
a matter. Forcing them to apply these skills to patents and prosecution records
more diligently may well help simplify and streamline patent practice, as well
as make patents more transparent to the public. In any event, concurring opin-


the opinion purports to do so”). See also, 138 F.2d at 1455 (disapproving “opinions in some of
our cases suggesting that there should be deference to what are asserted to be factual underpin-
nings of claim construction”).
    81
       See N.79.23 supra.
    82
        Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1480, 46 U.S.P.Q.2d (BNA)
1169 (Fed. Cir. 1998) (en banc) (additional views of Judges Newman and Mayer). See also, 138
F.3d at 1480 (additional views of Judges Newman and Mayer) (Citations omitted.):
   “Of course the primary source of information concerning the claimed invention is the patent
   documents. But such documents are directed to persons knowledgeable in the field; addi-
   tional evidence and expert testimony as to their meaning should be the rule, not the excep-
   tion. So-called 'extrinsic' evidence—the evidence of expert witnesses and of
   experimentation, exhibits, demonstrations, and explanation—should be treated like any other
   evidence, and received and given weight and value as appropriate.”
   83
       See id., 138 F.3d at 1475 (dissenting opinion of Judges Rader and Newman) (Citations
omitted.):
   “The objective of claim interpretation is to discern the meaning of the claim terms to one of
   ordinary skill in the art at the time of invention. . . . Of course this relevant testimony must
   not conflict with or attempt to trump contemporaneous intrinsic evidence from the patent
   document itself, see Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582-1583, 39
   U.S.P.Q.2d (BNA) 1573, 1576-77 (Fed. Cir. 1996), but . . . . it seems a contradiction to bar
   those of skill in the art at the time of invention from a search for the meaning of terms to one
   of skill in the art at the time of the invention. In effect, the en banc opinion has sub silentio
   redefined the claim construction inquiry as 'how a lawyer or judge would interpret the
   term.’”


                                                                                        (Rel. 25)
2-05                       PATENTS               INTELLECTUAL PROPERTY LAW

ions stressed that the de novo review standard is not intended to preclude def-
                                       84
erence to decisions of district courts, and Judge Plager implied that it is in
some sense experimental and may be subject to change if it does not in fact
                             85
produce the desired results. Yet another Federal Circuit panel reinforced the
                                           85.1
preference for intrinsic evidence in 2003.

             [iv]—Procedure for Claim Construction
   One of the most significant revolutions in patent law wrought by the Fed-
                                                 86
eral Circuit, with the Supreme Court’s approval, involves the procedure by


   84
         See id., 138 F.3d at 1462 (concurring opinion of Judge Plager):

   “Though we review . . . [the record below] 'de novo,' meaning without applying a formally
   deferential standard of review, common sense dictates that the trial judge's view will carry
   weight. That weight may vary depending on the care, as shown in the record, with which that
   view was developed, and the information on which it is based. . . . [J]ust as three minds are
   deemed better than one in deciding appeals, four minds may often be better than three when
   a complex claim construction is at issue.”

   See also, 138 F.3d at 1463 (concurring opinion of Judge Bryson):

   “While I join the opinion of the court without reservation, I think it important to note that
   our adoption of the rule that claim construction is an issue of law does not mean that we in-
   tend to disregard the work done by district courts in claim construction or that we will give
   no weight to a district court's conclusion as to claim construction, no matter how the court
   may have reached that conclusion. Simply because a particular issue is denominated a ques-
   tion of law does not mean that the reviewing court will attach no weight to the conclusion
   reached by the tribunal it reviews.”
    Cf., 138 F.3d at 1477 (dissenting opinion of Judges Rader and Newman) (suggesting flexible
“functional approach” to review, in which Federal Circuit would defer “when it appears that the
district court is 'better positioned' than the appellate court to decide the issue in question or that
probing appellate scrutiny will not contribute to the clarity of legal doctrine”), quoting Salve
Regina College v. Russell, 499 U.S. 225, 233, 111 S.Ct. 1217, 113 L.Ed.2d 190 (1991).
    85
        See id., 138 F.3d at 1463 (concurring opinion of Judge Plager) (“Our purpose is to im-
prove the process of patent infringement litigation for the benefit of patentees and their competi-
tors, and ultimately the public. Whether this approach to patent litigation will in the long run
prove beneficial remains to be seen”).
    85.1
           See Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1367 (Fed. Cir. 2003) (re-
fusing to address extrinsic evidence in determining whether means-plus-function claim was
indefinite where it was not indefinite as construed using intrinsic evidence: “[w]hen an analysis
of intrinsic evidence resolves any ambiguity in a disputed claim term, it is improper to rely on
extrinsic evidence to contradict the meaning so ascertained”), citing Vitronics Corp. v.
Conceptronic, Inc., 90 F.3d 1576, 1583, 1584 (Fed. Cir. 1996) (“Only if there were still some
genuine ambiguity in the claims, after consideration of all available intrinsic evidence, should
the trial court have resorted to extrinsic evidence, such as expert testimony, in order to construe
claim 1").

   86
         For discussion of the history and nature of these revolutions, see § 2.05[3] (introduction)
supra.

                                                                                          (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

which claims are construed in patent litigation. The two courts’ revolution in
claim-construction procedure, which is still ongoing, has had three phases so
far.
                                                                        87
    The first phase came with the two rulings in the Markman case that
judges, not juries, construe patent claims. By virtue of these decisions, the
construction of patent claims, including any terms of art used in them, is a
                                              87.1
question of law exclusively for the court.         The trial judge, not a jury, must
                                                    87.2
construe both patent claims and terms of art.            Accordingly, the Federal
Circuit reviews claim construction de novo, without deference to the trial
                  87.3
court's decision.
                                                                            87.4
    Juries do not participate in the literal construction of patent claims       not-
                                                                                 87.5
withstanding the Seventh Amendment to the United States Constitution,
which preserves the right to jury trials in civil cases as it existed under Eng-
                                                                     87.6
lish common law upon ratification of the Constitution in 1791.            There was
no established practice of having jury trials on issues of patent construction at



   87
        See: Markman v. Westview Instruments, Inc., 52 F.3d 967, 979, 34 U.S.P.Q.2d (BNA)
1321 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38
U.S.P.Q.2d (BNA) 1461 (1996) (“the court has the power and obligation to construe as a matter
of law the meaning of language used in the patent claim”); Markman v. Westview Instruments,
Inc., 517 U.S. 370, 372, 116 S.Ct. 1384, 1387, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461
(1996) (unanimous opinion) (“We hold that the construction of a patent, including terms of art
within its claim, is exclusively within the province of the court”), discussed also in § 2.05[3]
(introduction) supra.
    87.1
         See Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S.Ct. 1384, 1387, 134
L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (“We hold that the con-
struction of a patent, including terms of art within its claim, is exclusively within the province of
the court”), aff'ing 52 F.3d 967, 34 U.S.P.Q.2d (BNA) 1321 (Fed. Cir. 1995) (en banc).
    87.2
         Id., 517 U.S. at 398-391 (allocating “all issues of construction to the court”; upholding
directed verdict reversing jury's interpretation of word “inventory” in claim for patent on inven-
tory control system for dry-cleaning business).
    87.3
          See § 2.05[3][a][iii] supra. See also, e.g.: Mas-Hamilton Group v. LaGard, Inc., 1998
U.S. App. LEXIS 22116 at *8-9 (Fed. Cir. Sept. 10, 1998) (“Claim construction is a question of
law, reviewed non-deferentially on appeal”) (Citation omitted.); Cybor Corp. v. FAS Technolo-
gies, Inc., 138 F.3d 1448, 1456, 46 U.S.P.Q.2d (BNA) 1169, 1174 (Fed. Cir. 1998) (en banc)
(“we review claim construction de novo on appeal”).
    87.4
         See Markman v. Westview Instruments, Inc., N.87.1 supra, 517 U.S. at 372, 288-291.
    87.5
         U.S. Const., Amend. VII:

   “In Suits at common law, where the value in controversy shall exceed twenty dollars, the
   right of trial by jury shall be preserved, and no fact tried by a jury shall be otherwise re-
   examined in any Court of the United States, than according to the rules of the common law.”
   87.6
        See Markman v. Westview Instruments, Inc., N.87.1 supra, 517 U.S. at 376, citing: Tull
v. United States, 481 U.S. 412, 417, 107 S.Ct. 1831, 95 L.Ed.2d 365 (1987), and Baltimore &
Carolina Line, Inc. v. Redman, 295 U.S. 654, 657, 55 S.Ct. 890, 79 L.Ed. 1636 (1935).

                                                                                         (Rel. 25)
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            87.7                                                                                87.8
that time,      nor was such a practice later established in the United States.
Moreover, because of their training and experience, judges are better suited
                                          87.9
than juries to construe patent claims,         for in patent cases questions of ab-
stract consistency and internal coherence weigh more heavily than issues of
credibility among contending expert witnesses or other questions that juries
                        87.10
might better resolve.         In addition, construction of claims by judges should
provide greater uniformity and reliability in patent litigation, at least in those
cases for which issue preclusion and the existence of a single appeals court
                                                             87.11
(the Court of Appeals for the Federal Circuit) does not.            For all these rea-
sons, the Seventh Amendment's guarantee of the right to trial by jury does not
require juries to become enmeshed in questions of patent claim construc-
      87.12
tion.
   Although having the exclusive power to interpret patent claims as a matter
         87.13
of law,        the trial judge is not required to do so conclusively at a prelimi-
                            87.14                             87.15
nary injunction hearing           or at any particular time.        Rather, the trial
judge has “discretion to interpret the claims at a time when the parties have
                                                                     87.16
presented a full picture of the claimed invention and prior art.”
                                      87.17
   Since the Markman decisions,             district courts have generally taken to
deciding disputed issues of claim construction before trial, in a preliminary


   87.7
          See id., 517 U.S. at 378-383 (unanimous opinion).
   87.8
          See id., 517 U.S. at 383-387.
   87.9
        See id., 517 U.S. at 388-389.
   87.10
         See id., 517 U.S. at 389-390 (Citations omitted.):

        “[I]n these cases a jury's capabilities to evaluate demeanor, . . . to sense the 'mainsprings
   of human conduct,' . . . or to reflect community standards . . . are much less significant than
   a trained ability to evaluate the testimony in relation to the overall structure of the patent.
   The decisionmaker vested with the task of construing the patent is in the better position to
   ascertain whether an expert's proposed definition [of a term of art] fully comports with the
   specification and claims and so will preserve the patent's internal coherence. We accordingly
   think there is sufficient reason to treat construction of terms of art like many other responsi-
   bilities that we cede to a judge in the normal course of trial, notwithstanding its evidentiary
   underpinnings.”
   87.11
           See id., 517 U.S. at 390-391.
   87.12
           See id., 517 U.S. at 372, 390-391.
   87.13
           See the text accompanying Ns.86-87.3 supra.
   87.14
          See Sofamor Danek Group, Inc. v. Depuy-Motech, Inc., 74 F.3d 1216, 1221, 37
U.S.P.Q.2d (BNA) 1529 (Fed. Cir. 1996) ('[T]he trial court has no obligation to interpret claims
1 conclusively and finally during a preliminary injunction proceeding”).
    87.15
          See: id.; Ns.87.19, 87.20 infra.
    87.16
          Sofamor Danek Group, Inc. v. Depuy-Motech, Inc., N.87.14 supra, 74 F.3d at 1221.
    87.17
          See:


                                                                                         (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

                                                87.18
hearing known as a Markman hearing.           A Markman hearing may simplify
patent litigation considerably in those cases in which claim construction is
          87.19                                  87.20
decisive.       It may take place at any time          and need not necessarily
                                 87.21
await completion of discovery.
   Where claim construction is not decisive by itself, however, the Federal
Circuit in its discretion has so far declined to take interlocutory, certified ap-
peals of district courts’ decisions in Markman hearings, preferring to wait

    Supreme Court: Markman v. Westview Instruments, Inc., 517 U.S. 370, 372, 116 S.Ct.
1384, 1387, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (“We
hold that the construction of a patent, including terms of art within its claim, is exclusively
within the province of the court”), discussed also in § 2.05[3] (introduction) supra.
    Federal Circuit: Markman v. Westview Instruments, Inc., 52 F.3d 967, 979, 34 U.S.P.Q.2d
(BNA) 1321 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577,
38 U.S.P.Q.2d (BNA) 1461 (1996) (“the court has the power and obligation to construe as a
matter of law the meaning of language used in the patent claim”).
    87.18
            See EMI Group of North America, Inc. v. Intel Corp., 157 F.3d 887, 891-892, 48
U.S.P.Q.2d (BNA) 1181 (Fed. Cir. 1998), cert. denied 526 U.S. 1112 (1999) (“Construction of
the claims by the trial court is often conducted upon a preliminary [*892] evidentiary hearing,
called a Markman hearing in homage to the decision . . . that established that this step must be
performed by the judge, not the jury. This case illustrates the resolution of most of a complex
infringement case with no more trial than a two-day Markman hearing”).
    87.19
           See, e.g.: EMI Group of North America, Inc. v. Intel Corp., 157 F.3d 887, 889, 891-
892, 48 U.S.P.Q.2d (BNA) 1181, 1182 (Fed. Cir. 1998), cert. denied 526 U.S. 1112 (1999),
quoted also in N.87.18 supra (affirming district court’s decision that resolved both literal in-
fringement and doctrine of equivalents “with no more trial than a two-day Markman hearing”);
Alpine Lace Brands, Inc. v. Kraft Foods, Inc., 1998 U.S. App. LEXIS 27642 at *5-6, 15-16,
27643, 51 U.S.P.Q.2d (BNA) 1157 (Fed. Cir. 1998) (upholding district court’s claim construc-
tion from Markman hearing despite its refusal to admit extrinsic evidence or allow discovery on
claim construction) (unpublished).
    Since Markman hearings may occur before discovery is complete, see N.87.21 infra, where
decisive they may simplify procedure by eliminating some or all discovery. See, e.g.: Vivid
Technologies, Inc. v. American Science & Engineering, Inc., 200 F.3d 795, 803-804, 53
U.S.P.Q.2d (BNA) 1289 (Fed. Cir. 1999) (affirming district court’s discretionary refusal to
allow discovery of allegedly infringing machines before Markman hearing where “the parties
and the court knew with reasonable certainty which claim terms were at issue with respect to
infringement; discovery was not needed for this purpose[;]” patent claims are “construed objec-
tively and without reference to the accused device, [so] only those terms need be construed that
are in controversy, and only to the extent necessary to resolve the controversy”) (Citation omit-
ted.); Alpine Lace Brands, Inc. v. Kraft Foods, Inc., supra.
    87.20
           See Firegear, Inc. v. Morning Pride Manufacturing., Inc., 1999 U.S. App. LEXIS
14812 * (Fed. Cir. June 30, 1999) (unpublished) (rejecting argument that Markman hearing
should have been held before trial, where “ argument [was] raised for the first time on appeal,
there is no legal requirement that the Markman hearing be held prior to trial, and [the moving
party had] only made vague allegations of harm because of the timing of this hearing”). See also,
the text accompanying Ns.87.12-87.16 supra.
    87.21
           See Vivid Technologies., Inc. v. American Science & Engineering, Inc., 200 F.3d 795,
803, 53 U.S.P.Q.2d (BNA) 1289 (Fed. Cir. 1999) (refusing to adopt uniform rule “that claim
construction should be done no earlier than the end of discovery” because “the stage at which
the claims are construed may vary with the issues, their complexity, the potentially dispositive
nature of the construction, and other considerations of the particular case”). See also, sources
cited in N.87.19 supra.

                                                                                     (Rel. 25)
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                                                                                               87.22
until the end of trial or until a decision on a preliminary injunction.
Sometimes this has motivated even patentees to stipulate to noninfringement
under the district court’s claim construction in order to obtain an immediate
        87.23
appeal.
   The second phase in the Federal Circuit’s procedural revolution followed
                                    87.24
directly from the first. In Cybor,         the en banc Federal Circuit ruled that
claim construction is a matter of law, subject to de novo review on appeal,
                                                        87.25
without special deference to the trial judge’s views.         This ruling followed
                                   87.26
from the decisions in Markman             that claim construction, including con-
struction of terms of art, is a matter for judges, not juries, to decide, based on
interpretation of written documents with a view toward predictability, certain-
                    87.27
ty and uniformity.        Like the first phase, this one encourages resort to
Markman hearings before a full trial and early appeals on questions of claim
                                           87.28
construction where it appears decisive.

   87.22
            See, e.g.: Microchip Technology, Inc. v. Scenix Semiconductor, Inc., 173 F.3d 432,
1998 U.S. App. LEXIS 23856 (Fed. Cir. 1998) (unpublished) (refusing in discretion to take
interlocutory appeal on issue of claim construction from Markman hearing pursuant to district
court’s certification under 28 U.S.C. § 1292(b), (c)(1), but preferring “to review the district
court’s pretrial claim construction decision in the context of any appeal of a preliminary injunc-
tion”); ArthroCare Corp. v. Ethicon, Inc., 1998 U.S. App. LEXIS 21835 at *1-2 (Fed. Cir. Aug.
20, 1998) (unpublished) (to same effect).See generally, Cybor Corp. v. FAS Technologies, Inc.,
138 F.3d 1448, 1479, 46 U.S.P.Q.2d (BNA) 1169, 1174 (Fed. Cir. 1998) (“additional views” of
Judges Newman and Meyer) (“Although the district courts have extended themselves, and so-
called ‘Markman hearings’ are common, this has not been accompanied by interlocutory review
of the trial judge’s claim interpretation. The Federal Circuit has thus far declined all such certi-
fied questions”).
    87.23
           See Schering Corp. v. Amgen Inc., 222 F.3d 1347, 1349, 1356, 55 U.S.P.Q.2d (BNA)
1650 (Fed. Cir. 2000) (after receiving unfavorably narrow construction of its claim in Markman
hearing, patentee moved for summary judgment of noninfringement, which district court grant-
ed, permitting immediate appeal, in which Federal Circuit affirmed).
    87.24
            Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1455-1456, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998), discussed also in § 2.05[3] (introduction), [a][iii] supra.
    87.25
            See id., 138 F.3d at 1456 (“we review claim construction de novo on appeal”), dis-
cussed also in § 2.05[3][a][iii] supra. See also, e.g., Schering Corp. v. Amgen Inc., 222 F.3d
1347, 1351, 55 U.S.P.Q.2d (BNA) 1650 (Fed. Cir. 2000) (“This court reviews the central ques-
tion of claim interpretation without deference. . . . Therefore, notwithstanding the district court’s
exhaustive and well-reasoned fifty-five page opinion, this court undertakes an independent ex-
amination of the claim limitations”); Mas-Hamilton Group v. LaGard, Inc., 156 F.3d 1206,
1211, 48 U.S.P.Q.2d (BNA) 1010 (Fed. Cir. 1998) (“Claim construction is a question of law,
reviewed non-deferentially on appeal”).
    87.26
           See N.87.17 supra.
    87.27
           See also, § 2.05[3] (introduction), [a][iii] supra.
    87.28
           Where claim construction is decisive, the de novo review standard for claim construc-
tion means that the parties can have the Federal Circuit review the decision in their case from
scratch, after the Markman hearing alone, as long as they can get that court to take the appeal.
The opportunity to shortcut other phases of the litigation, often including some discovery, see
N.87.19, 87.21 supra, may motivate parties to stipulate to infringement or noninfringement

                                                                                         (Rel. 25)
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    The Cybor decision was in part a pragmatic one, based upon the complexi-
ty, confusion and opportunities for strategic behavior on the part of litigants
which likely would result from subjecting different aspects of claim construc-
                                       87.29
tion to differing standards of review.        Concurring and dissenting opinions
complained that the decision would disrupt and complicate trial proce-
      87.30                         87.31                       87.32
dure,       deprive juries' verdicts       or trials in general       of practical
              87.33                       87.34                              87.35
significance,       increase uncertainty,       discourage early settlement,

under the district court’s claim construction in order to provide a final judgment to appeal. Cf.,
N.87.22 supra.
   87.29
           See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1462-1463, 46
U.S.P.Q.2d (BNA) 1169 (Fed. Cir. 1998) (en banc) (concurring opinion of Judge Plager):
   “This court's decision in Markman I, reaffirmed today, simply means that we do not spend
   our and appellate counsels' time debating whether the trial court's information base consti-
   tutes findings of 'fact' or conclusions of 'law,' with verbally different standards of review. In-
   stead both they and we can focus on the question that the trial court addressed, the question
   that counts: what do [*1463] the claims mean?”
   87.30
            Id., 138 F.3d 1448, 1466, 46 U.S.P.Q.2d (BNA) 1169 (Fed. Cir. 1998) (en banc)
(concurring opinion of Judges Mayer and Newman) (“indiscriminate and conclusive review
deprives the parties of important substantive and procedural mechanisms provided in the trial
courts, where interpretation can be informed by additional discovery and expert testimony, and
where it can be checked by appellate review as a matter of right”); 138 F.3d at 1474-1475 n.14
(dissenting opinion of Judges Rader and Newman) (providing “incomplete list of procedural
deviations” from “the normal procedural course for litigation” required by Markman I).
    87.31
           Id., 138 F.3d at 1471-1472 (concurring opinion of Judges Mayer and Newman) (“we
will affirm a finding of infringement as long as the district court avoids articulating its construc-
tion of the claims—which coincidentally leaves us free to arrive at our own constructions—and
as long as we can presume that the jury used [*1472] our constructions to arrive at that finding
of infringement”).
    87.32
           Id., 138 F.3d at 1473-1474 (dissenting opinion of Judges Rader and Newman) (“To
my eyes, this rejection of the trial process as the 'main event' will undermine, if not destroy, the
values of certainty and predictability sought by Markman I”). (Citations omitted.)
    87.33
           Id., 138 F.3d at 1476 (dissenting opinion of Judges Rader and Newman) (Footnote de-
scribing, but not citing, survey omitted.):
   “The Federal Circuit, according to its own official 1997 statistics, reversed in whole or in
   part 53% of the cases from district courts (27% fully reversed; 26% reversed-in-part). Grant-
   ed this figure deals with all issues in cases with many issues. Nonetheless, one study shows
   that the plenary standard of review has produced reversal, in whole or in part, of almost 40%
   of all claim constructions since Markman I.”
    See also, 138 F.3d at 1477 (dissenting opinion of Judges Rader and Newman) (“Because pa-
tent trial practitioners understand the distinct prospect of overturning trial court results on ap-
peal, the trial arena loses some of its luster as the center stage of the dispute resolution drama.
Instead the trial court becomes a ticket to the real center stage, the Court of Appeals for the
Federal Circuit”).
    87.34
           Id., 138 F.3d at 1478 (additional views of Judges Newman and Mayer) (“The expecta-
tion of greater stability in the application of patent law—thus enhancing consistency in result,
reducing the cost of litigation, and indeed reducing litigation by diminishing the uncertainties of
jury trials—has not been well achieved”); 138 F.3d at 1479 (additional views of Judges Newman

                                                                                         (Rel. 25)
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and increase the Federal Circuit's workload by permitting little deference to
                                                          87.36
district courts' decisions regarding claim construction.
   While some of these disadvantages may indeed accrue in the short run, in
the long run the decision may have beneficial effects. By emphasizing appel-
late review on a strictly legal basis and concentrating on the patent specifica-
tion and the written record, the Cybor decision encourages patent attorneys to
do a good job of drafting both patent specifications and prosecution corre-
spondence, with the rules of claim construction and prosecution history es-
                  87.37
toppel in mind.         If this goad has its probable effect, it may well result in
cleaner, clearer, and better patents and prosecution histories, which will make
the job of all courts, including the Federal Circuit, easier. In addition, the rule
of plenary review may ultimately promote uniformity of patent construc-
    87.38                                                                  87.39
tion      —a goal of the Supreme Court's decision in Markman as well.

and Mayer) (“The possibility of early finality to claim interpretation has not materialized”); 138
F.3d at 1476-1477 (dissenting opinion of Judges Rader and Newman) (outlining cases in which
Federal Circuit imposed claim interpretations not argued by parties or witnesses and one in
which Federal Circuit reached two different interpretations of same claim of same patent); 138
F.3d at 1479 (additional views of Judges Newman and Mayer):
   “The second area of disappointed expectations has flowed from the unexpectedly creative de
   novo claim interpretations that the Federal Circuit has issued in a few cases. This unpredict-
   ability in administration of the law of patent claiming has added a sporting element to our
   bench. It has not only released appellants' imaginations on appeal, but it will surely add
   complexity to future trials, as lawyers attempt to guard against the judicial imagination.”
   87.35
           Id., 138 F.3d at 1475-1476 (dissenting opinion of Judges Rader and Newman) (argu-
ing that plenary review of claim construction on appeal, without deference to preliminary factual
findings of district courts, removes putative benefits of Markman by reducing certainty of claim
construction at trials and thereby discourages settlement at claim construction phase of case):
   “The meaning of a claim is not certain (and the parties are not prepared to settle) until nearly
   the last step in the process—decision by the Court of Appeals for the Federal Circuit. To get
   a certain claim interpretation, parties must go past the district court's Markman I proceeding,
   past the entirety of discovery, past the entire trial on the merits, past post trial motions, past
   briefing and argument to the Federal Circuit—indeed past every step in the entire course of
   federal litigation, except Supreme Court review.”
   87.36
           Id., 138 F.3d at 1463 (concurring opinion of Judges Mayer and Newman, concurring
in result but arguing that failure to recognize, and review under clear error standard, factual
issues in claim construction “profoundly misapprehends” Supreme Court's decision in
Markman). See also, Ns.79.31-79.32 supra.
    87.37
           See: § 2.05[3] (introduction) supra; § 2.05[3][b][i][B] infra.
    87.38
           See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1455, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (in Markman, “the Supreme Court endorsed this court's
role in providing national uniformity to the construction of a patent claim, a role that would be
impeded if we were bound to give deference to a trial judge's asserted factual determinations
incident to claim construction”). Cf., Cybor Corp. v. FAS Technologies, Inc., supra, 138 F.3d at
1456 (analyzing Supreme Court's reasoning in Markman and concluding that Court anticipated
that evaluation of expert testimony in patent case, including credibility of expert witnesses,
would “be subsumed within the necessarily sophisticated analysis of the whole document, [as]
required by the standard construction rule that a term can be defined only in a way that comports

                                                                                         (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

   By and large, district courts’ claim construction in Markman hearings has
                                                          87.40             87.41
followed the evidentiary rules laid down in Vitronics           and Cybor,
which permit resort to extrinsic evidence such as expert testimony only when
                                                  87.42
intrinsic testimony fails to resolve ambiguities.       There has been a bit of
“guerilla warfare” on the part of some Federal Circuit judges who believe
                                                                  87.43
passionately in the value of expert testimony in patent cases,          but they

with the instrument as a whole”), quoting Markman v. Westview Instruments, Inc., 517 U.S.
370, 116 S.Ct. 1384, 1395, 134 L.Ed.2d 577 (1996) (Markman II).
   87.39
          See the text accompanying Ns.87.8-87.12 supra. But cf., N.87.34 supra (reporting un-
impressive record in this regard since Federal Circuit's decision in Markman I).
   87.40
          Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583, 39 U.S.P.Q.2d (BNA)
1573 (Fed. Cir. 1996) (Citations omitted.), discussed also in § 2.05[3] (introduction), [a][iii]
supra:
   “The claims, specification, and file history, rather than extrinsic evidence, constitute the
   public record of the patentee’s claim, a record on which the public is entitled to rely. In other
   words, competitors are entitled to review the public record, apply the established rules of
   claim construction, ascertain the scope of the patentee's claimed invention and, thus, design
   around the claimed invention . . . . Allowing the public record to be altered or changed by
   extrinsic evidence introduced at trial, such as expert testimony, would make this right mean-
   ingless.”
   87.41
          Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1455-1456, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998), discussed also in § 2.05[3] (introduction), [a][iii] supra.
   See also, EMI Group of North America, Inc. v. Intel Corp., 157 F.3d 887, 892, 48
U.S.P.Q.2d (BNA) 1181 (Fed. Cir. 1998), cert. denied 526 U.S. 1112 (1999), citing Markman
v. Westview Instruments, Inc., 52 F.3d 967, 983, 34 U.S.P.Q.2d (BNA) 1321, 1133 (Fed. Cir.
1995) (en banc), aff’d, 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA)
1461 (1996), and referring to and quoting Cybor Corp. v. FAS Technologies, Inc., 138 F.3d
1448, 1454 n.3, 1455-1456, 46 U.S.P.Q.2d (BNA) 1169, 1173 n.3, 1174 (Fed. Cir. 1998), dis-
cussed in § 2.05[3][a][iii] supra:
   “The Federal Circuit has admonished that claims should preferably be interpreted without
   recourse to extrinsic evidence such as expert testimony, other than perhaps dictionaries or
   reference books, and that expert testimony should be received only for the purpose of educat-
   ing the judge. . . . In Cybor the court reaffirmed that extrinsic evidence including expert tes-
   timony is not to be relied upon for purposes of claim interpretation, other than to aid the
   judge in understanding the technology; such evidence is only ‘an aid to the court in coming
   to a correct conclusion as to the true meaning of the language employed in the patent.’”
   87.42
           See § 2.05[3][a][iii] supra.
    In reviewing decisions to admit or exclude evidence, the Federal Circuit applies the eviden-
tiary standard of the appropriate regional circuit. See: Schering Corp. v. Amgen Inc., 222 F.3d
1347, 1354, 55 U.S.P.Q.2d (BNA) 1650 (Fed. Cir. 2000) (“This court interprets a claim without
deference to the district court’s interpretive efforts, solely on the basis of the record on re-
view[,]” but interprets district court’s decision to exclude evidence “according to the evidentiary
standards set by our sister circuit,” in this case Third Circuit) (Citations omitted.); id., 222 F.3d
at 1354-1355 (affirming district court’s decision not to reopen Markman hearing to consider
additional evidence where subject matter had been in patentee’s possession for eighteen years
but had not been analyzed).
    87.43
            See EMI Group of North America, Inc. v. Intel Corp., 157 F.3d 887, 892, 48
U.S.P.Q.2d (BNA) 1181 (Fed. Cir. 1998), cert. denied 526 U.S. 1112 (1999) (court’s opinion by

                                                                                         (Rel. 25)
2-05                       PATENTS                 INTELLECTUAL PROPERTY LAW

have generally covered their reliance on that testimony by giving some obei-
                                           87.44
sance to the rules of Vitronics and Cybor.       Thus, the rule of Markman for
judicial construction of claims, which now occurs often in Markman hearings,
has laid the groundwork for the other phases of the procedural revolution by
emphasizing judges’ training and expertise in the exegesis of written docu-
ments, the public notice function of written records (as distinguished from
expert testimony), and the importance of uniformity and certainty in claim
              87.45
construction.
   The third and currently final phase of the procedural revolution in patent
practice was the courts’ attempts to constrain the doctrine of equivalents and
                                                    87.46
reduce the number of cases in which it is invoked.         The main confining
attempts relied on refinements to the “all elements” rule for infringe-



Judge Newman) (while acknowledging Federal Circuit’s disapproval of expert testimony, noting
district court’s and Federal Circuit’s reliance on “extensive testimony from the technical ex-
perts” in this case); 157 F.3d at 895 (applying in essence prosecution history estopped to one
claim limitation in dispute by noting that “[i]t was not incorrect for the district court to construe
the claims as requiring at least the relative thickness [of the oxide layer] that was invoked to
distinguish the [patented] method from the prior art[,]” but with respect to two other limitations
affirming district court’s construction relying heavily on expert testimony).
     Among the judges of the Federal Circuit, Judge Newman is perhaps the truest believer in the
indispensability of expert testimony to educate judges and jurors. See § 2.05[3][a][iii] supra.
     Cf., American Imaging Services, Inc. v. Intergraph Corp., 2000 U.S. App. LEXIS 13949 at
*21 (Fed. Cir. June 12, 2000), cert. denied 121 S.Ct. 761, 148 L.Ed.2d 663 (2001) (un-
published) (finding no error in district court’s consideration of expert testimony in Markman
hearing “only to educate itself on the technology. The district court has the discretion to consider
factual or appropriate extrinsic evidence, such as expert testimony, for purposes of a tutorial or
for background information in the technical area at issue”).
     87.44
            See: EMI Group of North America, Inc. v. Intel Corp., 157 F.3d 887, 892, 48
U.S.P.Q.2d (BNA) 1181 (Fed. Cir. 1998), cert. denied 526 U.S. 1112 (1999) (court’s opinion by
Judge Newman), outlined and quoted in N.87.43 supra; Mantech Environmental Corp. v. Hud-
son Environmental Services, Inc., 152 F.3d 1368, 1373, 47 U.S.P.Q.2d (BNA) 1732 (Fed. Cir.
1998) (upholding claim construction in Markman hearing where district court, after admitting
extrinsic expert testimony “as background in the relevant technology,” held that “the written
description and the claims were not ambiguous” and that meaning of relevant claim term was
clear, thereby “correctly follow[ing] the guidance set forth in Vitronics for limiting reliance on
contrary extrinsic evidence[;]” and rejecting, as inconsistent with Vitronics, argument that dis-
trict court “should have relied on expert testimony which, we hold, contradicts the plain mean-
ing of the specification”); 152 F.3d at 1373 (Citations and internal quotation marks omitted.):
   “[T]he district court was legally correct both in admitting and accepting the testimony of the
   parties’ expert witnesses for the purpose of background in the technical area at issue, and
   then basing its claim construction solely upon intrinsic evidence. Although this information
   always may be admitted by the trial court to educate itself about the patent and the relevant
   technology, the claims and the written description remain the primary and more authoritative
   sources of claim construction. Thus, they always must be considered and where clear must
   be followed.”
   87.45
           See also, § 2.05[3] (introduction), [a][ii], [iii] supra.
   87.46
           See also, § 2.05[3][b][i][B] infra.


                                                                                         (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

       87.47                                                          87.48
ment      —applying it to the doctrine of equivalents        —and to the doc-
                                       87.49
trine of prosecution history estoppel.       The Federal Circuit’s en banc deci-
                     87.50
sion in Pennwalt           expanded the “all elements” rule to require an
                                                  87.51
“element-by-element” approach to equivalents,           and the Supreme Court
                                                     87.52
later approved that approach in Warner-Jenkinson.
    The second attempt to confine the doctrine of equivalents involved
                                                              87.53
strengthening the doctrine of prosecution history estoppel.          Under that
doctrine, ground given up by a patent applicant in prosecuting the patent ap-
                                                           87.54
plication cannot be recovered in infringement litigation.          Although the
Supreme Court has addressed the doctrine only with regard to narrowing
                                                                          87.55
claim amendments made in response to patent examiners’ objections,

   87.47
           See § 2.05[3] (introduction), [a][i] supra.
   87.48
           See: § 2.05[3] (introduction) supra; 2.05[3][b][i][A] infra.
   87.49
           See: § 2.05[3][b][i][B], 2.06[2] infra.
   87.50
          Pennwalt Corp. v. Durand-Wayland Inc., 833 F.2d 931, 936-939, 4 U.S.P.Q.2d (BNA)
1737, 1741 (Fed. Cir. 1987) (en banc), cert. denied 485 U.S. 1009 (1988), discussed in §
2.05[3][b][i][A] infra (ruling that, in order to infringe, an accused device or process must have
an element that corresponds to each and every element of the claimed invention—and therefore
to each and every claim limitation—either directly or under the doctrine of equivalents).
    87.51
          See § 2.05[3][b][i][A] infra.
    87.52
           See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997) (“Each element contained in a patent claim is deemed
material to defining the scope of the patented invention, and thus the doctrine of equivalents
must be applied to individual elements of the claim, not to the invention as a whole”), discussed
in § 2.05[3][b][i][A] infra.
    87.53
          See generally, § 2.05[3][b][i][B] infra.
    87.54
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1835, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002):
   “When the patentee responds to [am examiner’s] rejection by narrowing his claims, this
   prosecution history estops him from later arguing that the subject matter covered by the orig-
   inal, broader claim was nothing more than an equivalent. Competitors may rely on the es-
   toppel to ensure that their own devices will not be found to infringe by equivalence.”
   See also, 535 U.S. at 734, quoting Exhibit Supply Co. v. Ace Patents Corp., 315 U.S. 126,
136-137 (1942):
   “The doctrine of equivalents allows the patentee to claim those insubstantial alterations that
   were not captured in drafting the original patent claim but which could be created through
   trivial changes. When, however, the patentee originally claimed the subject matter alleged to
   infringe but then narrowed the claim in response to a rejection, he may not argue that the
   surrendered territory comprised unforeseen subject matter that should be deemed equivalent
   to the literal claims of the issued patent. On the contrary, ‘by the amendment [the patentee]
   recognized and emphasized the difference between the two phrases[,]. . . and the difference
   which [the patentee] thus disclaimed must be regarded as material.’”
See generally, § 2.05[3][b][i][B] infra.
   87.55
         See N.87.54 supra.


                                                                                     (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

the Federal Circuit has also endorsed estoppel based upon applicants’ volun-
                    87.56
tary amendments             and arguments made by patent applicants during the
                               87.57
patent prosecution process.           The Supreme Court strengthened the doc-
trine of prosecution history estoppel by recognizing two rebuttable presump-
tions: (1) that every unexplained narrowing claim amendment relates to
patentability and therefore creates an estoppel; and (2) that any such estoppel
bars applying the doctrine of equivalents unless the patentee proves other-
      87.58
wise.        All of these rules focus on claim limitations and corresponding
inventive elements, rather than on claims as a whole—a refinement that ap-
pears to be an important development in the evolution of patent claiming,
comparable to the evolution from “central” to “peripheral” claiming over a
             87.59
century ago.
    The Federal Circuit in Festo—with the Supreme Court’s acquies-
      87.60
cence       —also highlighted the procedural importance of evidence from
patent prosecution in two ways. First, it ruled that evidence of the reasons for
claim amendments must be taken primarily, if not exclusively, from written
public records, i.e., intrinsic evidence such as the patent itself and its prosecu-
              87.61
tion history.        In this respect, Festo harked back to Markman, Vitronics

   87.56
           See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 568, 56
U.S.P.Q.2D (BNA) 1865 (Fed. Cir. 2000) (en banc) vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), discussed
in § 2.05[3] (introduction) supra.
    87.57
           See id., 234 F.3d at 568 (“Arguments made voluntarily during prosecution may give
rise to prosecution history estoppel if they evidence a surrender of subject matter”). (Citations
omitted.)
    87.58
           See the text accompanying Ns.71.7-71.13 supra.
    87.59
           See § 2.05[3] (introduction) supra.
    87.60
           Although the Supreme Court vacated and remanded the Federal Circuit’s en banc de-
cision in Festo, it rejected only the Federal Circuit’s proposed new rule that any narrowing claim
amendment creates a complete bar to applying the doctrine of equivalents to amended claim
elements. See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1840, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“we disagree with the deci-
sion [below] to adopt the complete bar”), discussed in: § 2.05[3] (introduction) supra; §
2.05[3][b][i][B] infra. It agreed with the Federal Circuit’s rule that a narrowing claim amend-
ment related to any statutory requirement for patentability may create an estoppel. See Festo
Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., supra, 535 U.S. at 736 (“We agree with the
Court of Appeals that a narrowing amendment made to satisfy any requirement of the Patent Act
may give rise to an estoppel”). Only those two questions were before it. See 535 U.S. at 726
(grant of certiorari addressed two questions: whether prosecution history estoppel applies to
claim amendments made for reasons other than avoiding prior art and whether complete bar rule
applies). Nothing in the Supreme Court’s opinion addressed, let alone suggested disapproval of,
applying prosecution history estoppel to matters other than narrowing claim amendments made
in response to examiners’ rejections.
    87.61
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 586, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (Footnote omitted.), vacated and remanded
on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705
(2002), referring to Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117

                                                                                      (Rel. 25)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

and Cybor in focusing on the “public notice” function of patents and the im-
portance of evidence that is readily available to the public in connection with
the particular patent, as distinguished from “extrinsic” evidence, such as oral
                       88
testimony, that is not. Second, the Festo court laid yet another foundation
stone for this phase of the procedural revolution by declaring that both the all-
elements rule and the possible application of the complete bar to equivalents
as a result of prosecution history estoppel are entirely matters of law to be
                          89
determined by the judge.
   This last ruling permits, if not encourages, litigants to try preliminary ques-
tions of all-elements analysis and prosecution history estoppel in the course of
Markman hearings, before reaching the question of infringement at all, even
though both the doctrines of equivalents and prosecution history estoppel are
traditionally matters of patent infringement that might be considered inappro-
priate to consider in a hearing ostensibly dealing with claim construction
alone. At least the Federal Circuit has not precluded the idea of handling the-
                                  90
se issues in Markman hearings. This part of the revolution in patent proce-
dure is still ongoing.

S.Ct. 1040, 137 L.Ed.2d 146 (1997) (placing burden of explaining reasons for claim amend-
ments on patentee “gives proper deference to the role of claims in defining an invention and
providing public notice”) (Footnote omitted.):
   “In order to give due deference to public notice considerations under the Warner-Jenkinson
   framework, a patent holder seeking to establish the reason for an amendment must base his
   arguments solely upon the public record of the patent’s prosecution, i.e., the patent’s prose-
   cution history. To hold otherwise—that is, to allow a patent holder to rely on evidence not in
   the public record to establish a reason for an amendment—would undermine the public no-
   tice function of the patent record. If the reasons for the amendment do not appear in the pub-
   lic record of the patent’s prosecution, the reasons in most cases will be known only to the
   patent holder. We therefore hold that a narrowing amendment will give rise to prosecution
   history estoppel unless the prosecution history of the patent reveals that the amendment was
   made for a purpose unrelated to patentability concerns.”
   88
        See: § 2.05[3] (introduction), [a][iii] supra.
   89
       See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 586, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 39 n.8, 117 S.Ct. 1040,
1049, 137 L.Ed.2d 146 (1997):
   “When infringement is alleged to occur under the doctrine of equivalents, two primary legal
   limitations on the doctrine ‘are to be determined by the court, either on a dispositive pretrial
   motion or on a motion for judgment as a matter of law at the close of evidence and after the
   jury verdict.’. . . Those legal limitations are prosecution history estoppel and the ‘all ele-
   ments’ rule.”
   90
        In Ethicon Endo-Surgery v. United States Surgical Corp., 93 F.3d 1572, 1583, 40
U.S.P.Q.2d (BNA) 1019 (Fed. Cir. 1996), the Federal Circuit vacated and remanded part of a
summary judgment resulting from a Markman hearing that found no infringement under the
doctrine of equivalents. It did not do so upon any general principle, however, but only because it
could not determine from the district court’s opinion even “whether the issue was briefed and

                                                                                       (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

    The importance of this broad revolution in patent litigation procedure is
difficult to overestimate. During the nineteenth century, a patent case could
go to a jury with incomplete instructions on the meaning of the claims, there-
by allowing the jury, in effect, to determine both what the patentee had in-
                                                               91
vented and whether the accused device was the same. Even with that
century’s simpler technology, this approach put a strain on district courts’—
let alone juries’—dim understanding of the relevant technology and the lan-
guage used to describe it. The result was patent litigation with all the flavor of
a game of chance.
    This approach was bad enough for the simple mechanical and rudimentary
electrical technology of the nineteenth century, of which ordinary people had
some inkling. In contrast, most of today’s inventions involve specialized ad-
vances in such esoteric fields as semiconductor processing, computers and
software, biotechnology, and genetic engineering—fields which even highly
trained scientists and technicians often have difficulty grasping. Under these
circumstances, a legal system that depends entirely on the understanding of
people who lack relevant technical expertise is less than fully adequate to
provide the certainty, predictability, and coherence of decisionmaking that
reasonable expectations of inventors and investors demand. To allow im-
portant economic decisions to turn on the understanding of people who not
only lack relevant technical expertise, but also have no training in close anal-
ysis of the written word, understanding abstract concepts and making fine
distinctions would be sheer insanity.
    The Federal Circuit has avoided using horse-and-buggy legal procedure in
the space age in three ways. First, by excluding juries from claim construc-
tion, it has made sure that complex technical-legal documents are to be con-
strued at least by people with training in abstract analysis, making fine
distinctions and interpreting complex written records. Federal district judges
                    92
have that training. Having them make decisions backed up by Federal Cir-
cuit’s review is probably the best that can be done in a system that relies on
lay generalists rather than trained specialists. The alternative would be to have
patent matters decided by panels of experts in each relevant technical special-
ty, whose decision might be more reliable and “correct” but would probably
be all but incomprehensible to the larger society and therefore less widely
respected. The Federal Circuit’s and Supreme Court’s approach represents a
compromise between expertise and political legitimacy.
    The Federal Circuit’s second improvement in patent procedure is even
more important. By forcing courts to rely primarily on “intrinsic evidence” in


argued to the district court.” 93 F.3d at 1583. It therefore remanded for “the district court to
articulate whether any triable issues of fact with respect to infringement by equivalents exist.”
Id.
    91
       See generally, § 2.05[3] (introduction) supra.
    92
        Judges’ training in this regard was one of the chief rationales for allowing them to con-
strue patent claims to the exclusion of juries. See § 2.05[3] (introduction), [a][ii] supra.

                                                                                     (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                            93
the written record, prepared in advance by patent attorneys, it forces inven-
tors and their patent attorneys to pay greater attention to distinguishing their
inventions from prior art in a way that ordinary people can understand. It thus
puts one of lawyers’ chief skills—making the complex simple and accessible
to ordinary people—in the service of identifying protected inventive contribu-
tions precisely before any dispute arises. While this procedural improvement
will no doubt increase patenting costs, it should serve two vital goals. First, it
should produce better, more predictable and cheaper decisions in business
planning, litigation and settlement. Second, it should promote the democratic
values of transparency and public accessibility of important economic deci-
sions by allowing them to continue to be made, perhaps more reliably, by lay
generalists and to be understood and respected by the general public.
   The Federal Circuit’s final procedural revolution is equally important. By
focusing on claim limitations and corresponding inventive elements, rather
                               94
than on inventions as a whole, the court has raised claiming in patent law to
a new level of precision. This new precision limits the doctrine of equiva-
                                      95
lents—the “wild card” in patent law —by requiring it to be applied on an
                           96
element-by-element basis.

         [b]—The Doctrine of Equivalents



   93
        See: § 2.05[3] (introduction), [a][iii] supra; the text accompanying Ns.87.59-88 supra.
   94
        See: § 2.05[3] (introduction), [a][ii] supra; the text accompanying Ns.87.46-87.52 supra.
   95
       See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997):
   “We do . . . share the concern of the dissenters below that the doctrine of equivalents . . . has
   taken on a life of its own, unbounded by the patent claims. There can be no denying that the
   doctrine of equivalents, when applied broadly, conflicts with the definitional and public-
   notice functions of the statutory claiming requirement.”
See also, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 591-592, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (concurring opinion by Plager, J.) (noting undesirable
uncertainty and unpredictability of doctrine of equivalents, particularly when applied by juries,
and possibility for second-guessing its application upon appeal).
    96
       See, e.g.:
    Supreme Court: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117
S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (“Each element contained in a patent claim is
deemed material to defining the scope of the patented invention, and thus the doctrine of equiva-
lents must be applied to individual elements of the claim, not to the invention as a whole”),
discussed in § 2.05[3][b][i][A] infra.
    Federal Circuit: Pennwalt Corp. v. Durand-Wayland Inc., 833 F.2d 931, 936-939, 4
U.S.P.Q.2d (BNA) 1737, 1741 (Fed. Cir. 1987) (en banc), cert. denied 485 U.S. 1009 (1988)
(ruling that, in order to infringe, an accused device or process must have an element that corre-
sponds to each and every element of the claimed invention—and therefore to each and every
claim limitation—either directly or under the doctrine of equivalents), discussed in §
2.05[3][b][i][A] infra.

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

   If patent infringement were measured only by “literal” application of the
patent's claims, infringers in many cases could copy patented inventions with
impunity simply by making trivial or insubstantial variations. Every field of
intellectual property law has a doctrine that captures such colorable varia-
       97-99                                 100
tions,       and patent law is no exception.

               [i]—Utility Patents
   In utility patent law, the doctrine that captures colorable infringement de-
spite minor variations is called the “doctrine of equivalents.” The Ninth Cir-
cuit has explained both the rationale for the doctrine and the primary reason
for limiting its scope:

   “[Strict construction of each utility patent claim is necessary] to give no-
   tice to possible infringers of the claim's limits . . . [and] to relieve the
   courts of the burden of deciding just what elements are material to the va-
   lidity of the claim. But where attempts are made to avoid infringement by a
   relatively slight, well known variation in the claimed process or product,
                                                               101
   the strict rule is relaxed by the doctrine of equivalents.”

                                                                                               102
The doctrine thus reflects the fundamental primacy of substance over form.
   The tension between substance and form, between literalism and justice, is
          102.1
enduring.       To the extent the doctrine of equivalents modifies the literal

   97-99
           See § 1.07[2] supra.
   100
         See § 1.07[2][a] supra.
   101
         Cutter Laboratories, Inc. v. Lyophile-Cryochem Corp., 179 F.2d 80, 89 (9th Cir. 1949).
See also, Ziegler v. Phillips Petroleum Co., 483 F.2d 858, 868 (5th Cir.), cert. denied 414 U.S.
1079 (1973) (“In recognition of the fact that a patent would be virtually worthless if it did not
protect against devices which incorporate unimportant variations of the patented device, courts
developed the doctrine of equivalents to protect the patentee from devices that differ merely in
name, form, or shape from the patented invention . . . but perform substantially the same func-
tion in substantially the same way to obtain the same result”). (Citations omitted.)
    102
         See Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 960 (Fed. Cir. 1987), cert.
denied 485 U.S. 961 (1988) (Pauline Newman, J., dissenting).
    102.1
           The Supreme Court has noted its own discussion and resolution of the tension in its
decisions on the doctrine of equivalents and has suggested that only Congress can change the
balance between these pairs of values. See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki
Co., 535 U.S. 722, 122 S.Ct. 1831, 1837-1838, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705
(2002) (“Each time the [*1838] Court has considered the doctrine, it has acknowledged . . .
uncertainty as the price of ensuring the appropriate incentives for innovation, and it has affirmed
the doctrine over dissents that urged a more certain rule”); 535 U.S. at 733 (“Most recently, in
Warner-Jenkinson, the Court reaffirmed that equivalents remain a firmly entrenched part of the
settled rights protected by the patent. A unanimous opinion concluded that if the doctrine is to
be discarded, it is Congress and not the Court that should do so”), citing Warner-Jenkinson Co.
v. Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997);
122 S.Ct. at 1841, citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117
S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (“the doctrine of equivalents and the rule of prosecu-

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

scope of claims, it creates uncertainty and undermines the “public notice”
                             102.2
function of patent claiming.       Yet to the extent only the literal claims pre-
vail, a pirate can appropriate the essence of someone else’s invention by mak-
                           102.3
ing insubstantial changes.       There is no escape from the tension between

tion history estoppel are settled law. The responsibility for changing them rests with Congress”);
122 S.Ct. at 1841 (“there is no more reason for holding the patentee to the literal terms of an
amended claim than there is for abolishing the doctrine of equivalents altogether and holding
every patentee to the literal terms of the patent”). See also, § 2.50[3] (introduction) supra.
    102.2
           See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997):
   “We do . . . share the concern of the dissenters below that the doctrine of equivalents . . . has
   taken on a life of its own, unbounded by the patent claims. There can be no denying that the
   doctrine of equivalents, when applied broadly, conflicts with the definitional and public-
   notice functions of the statutory claiming requirement.”
See also, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct. 1831,
1837, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002):
    “It is true that the doctrine of equivalents renders the scope of patents less certain. It may be
   difficult to determine what is, or is not, an equivalent to a particular element of an invention.
   If competitors cannot be certain about a patent’s extent, they may be deterred from engaging
   in legitimate manufactures outside its limits, or they may invest by mistake in competing
   products that the patent secures. In addition the uncertainty may lead to wasteful litigation
   between competitors, suits that a rule of literalism might avoid.”
But see, N.102.1 supra.
   102.3
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1837, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), citing Winans v. Denmead,
56 U.S. (15 How.) 330, 347, 14 L.Ed. 717 (1854) (seminal decision on doctrine of equivalents):
   “The language in the patent claims may not capture every nuance of the invention or de-
   scribe with complete precision the range of its novelty. If patents were always interpreted by
   their literal terms, their value would be greatly diminished. Unimportant and insubstantial
   substitutes for certain elements could defeat the patent, and its value to inventors could be
   destroyed by simple acts of copying. For this reason, the clearest rule of patent interpreta-
   tion, literalism, may conserve judicial resources but is not necessarily the most efficient rule.
   The scope of a patent is not limited to its literal terms but instead embraces all equivalents to
   the claims described.”
See also, Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 607, 700
S.Ct. 854, 94 L.Ed. 1097 (1950):
   “[C]ourts have . . . recognized that to permit imitation of a patented invention which does
   not copy every literal detail would be to convert the protection of the patent grant into a hol-
   low and useless thing. Such a limitation would leave room for—indeed encourage—the un-
   scrupulous copyist to make unimportant and insubstantial changes and substitutions in the
   patent which, though adding nothing, would be enough to take the copied matter outside the
   claim, and hence outside the reach of law. One who seeks to pirate an invention, like one
   who seeks to pirate a copyrighted book or play, may be expected to introduce minor varia-
   tions to conceal and shelter the piracy. Outright and forthright duplication is a dull and very
   rare type of infringement. To prohibit no other would place the inventor at the mercy of ver-
   balism and would be subordinating substance to form. It would deprive him of the benefit of
   his invention and would foster concealment rather than disclosure of inventions, which is
   one of the primary purposes of the patent system.”


                                                                                         (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

these two conflicting values—certainty and justice—and there probably never
         102.4
will be.
   As a result, the doctrine of equivalents has always been controversial.
Two of the most notable Supreme Court decisions applying it, Winans v.
           102.5                    102.6
Denmead          and Graver Tank,         were both split decisions with strong
          102.7
dissents.        In the last decade of the twentieth century, the force of these
                                                       102.8
dissents gathered strength, as the Federal Circuit            and the Supreme

   102.4
           See § 2.05[3] (introduction) supra. See also, Festo Corp. v. Shoketsu Kinzoku Kogyo
Kabushiki Co., 234 F.3d 558, 564, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (“the
doctrine [of equivalents] attempts to strike a balance between ensuring that the patentee enjoys
the full benefit of his patent and ensuring that the claims give ‘fair notice’ of the patent’s scope.
. . . This balance can be easily upset, however, because ‘the doctrine of equivalents, when ap-
plied broadly, conflicts with the definitional and public-notice functions of the statutory claim-
ing requirement’”), citing London v. Carson Pirie Scott & Co., 946 F.2d 1534, 1538, 20
U.S.P.Q.2d (BNA) 1456, 1458-1459 (Fed. Cir. 1991), and Warner-Jenkinson Co. v. Hilton
Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997).
     102.5
           Winans v. Denmead, 56 U.S. (15 How.) 330, 347, 14 L.Ed. 717 (1854).
     102.6
           Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 608, 700
S.Ct. 854, 94 L. Ed. 1097 (1950), quoting Sanitary Refrigerator Co. v. Winters, 280 U.S. 30, 42,
50 S.Ct. 9, 74 L.Ed. 147 (1929) (accused device is equivalent to claimed invention “if is per-
forms substantially the same function in substantially the same way to obtain the same result”),
quoted also in N.102.3 supra.
     102.7
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 26 n.3, 117
S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (noting vigorous dissents to holdings of infringement
under doctrine of equivalents in both Winans v. Denmead and Graver Tank—decisions from
1854 and 1950, respectively—both based in part on ground that application of doctrine under-
mines public notice function of claims); Winans v. Denmead, 56 U.S. (15 How.) 330, 347, 14
L.Ed. 717 (1854) (dissenting opinion of four Justices, written by Campbell, J.) (“Fulness, clear-
ness, exactness, preciseness, and particularity, in the description of the invention, its principle,
and of the matter claimed to be invented, will alone fulfil the demands of Congress or the wants
of the country. Nothing, in the administration of this law, will be more mischievous, more pro-
ductive of oppressive and costly litigation, of exorbitant and unjust pretensions and vexatious
demands, more injurious to labor, than a relaxation of these wise and salutary requisitions of the
act of Congress”); Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605,
617, 700 S.Ct. 854, 94 L. Ed. 1097 (1950) (dissenting opinion of Justices Black and Douglas)
(“The Court’s ruling today sets the stage for more patent ‘fraud’ and ‘piracy’ against business
than could be expected from faithful observance of the congressionally enacted plan to protect
business against judicial expansion of precise patent claims. Hereafter a manufacturer cannot
rely on what the language of a patent claims. He must be able, at the peril of heavy infringement
damages, to forecast how far a court relatively unversed in a particular technological field will
expand the claim’s language after considering the testimony of technical experts in that field.
To burden business enterprise on the assumption that men possess such a prescience bodes ill
for the kind of competitive economy that is our professed goal”).
     102.8
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 575, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (majority opinion) (“In [the previous twen-
ty] years, the notice function of patent claims has become paramount, and the need for certainty
as to the scope of patent protection has been emphasized. A problem with the flexible bar ap-
proach [to the effect of prosecution history estoppel on the doctrine of equivalents] is that it is
virtually impossible to predict before the decision on appeal where the line of surrender is
drawn”).

                                                                                         (Rel. 25)
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       102.9
Court        came to the conclusion that the doctrine had become overused and
unpredictable. In the interest of creating greater certainty regarding the scope
of patents and promoting the “public notice” function of patent clams, the
Federal Circuit, with the Supreme Court’s supervision, accordingly refined
                              102.10
and restricted the doctrine.
    The courts’ primary refinement of the doctrine of equivalents has become
                                      102.11
known as the “all elements” rule.            Under this rule, equivalence is not
assessed for the invention as a whole, but on an element-by-element ba-
     102.12
sis,        and there is no infringement under the doctrine of equivalents unless
every element of the claimed invention, i.e., every element corresponding to
                          102.13
every claim limitation,          appears in the accused device, either directly or

   See also, Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1537, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir.1995) (dissenting opinion) (Footnote omitted.), rev’d on
other grounds 520 U.S. 17, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997):
   “Is something broke that needs fixing? The short answer is yes. One problem is that, whatev-
   er role the doctrine of equivalents may have played in earlier times—and while that is not
   immaterial it is largely irrelevant—today the doctrine is regularly used by patentees to seek
   greater coverage for their patents than the patent statute grants. Their demands are pre-
   sented to a jury which is told to decide the issue based on a formulaic chant—function, way,
   result—which . . . provides little in the way of guidance, and in some cases may be of no
   persuasive significance at all.”
   102.9
           See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997), quoted in N.102.2 supra.
    102.10
            See generally: § 2.05[3] (introduction) supra; § 2.06[2] infra.
    102.11
            See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 564, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (noting
possible application of “all elements rule” but declining to reach issues whether applying flexi-
ble bar in case would violate it by eliminating particular claim element entirely); Pennwalt Corp.
v. Durand-Wayland, Inc., 833 F.2d 931, 949-950, 4 U.S.P.Q.2d (BNA) 1737, 1741 (Fed. Cir.
1987) (en banc) (concurring opinion, outlining and naming rule). See generally: § 2.05[3] (in-
troduction) supra; § 2.05[3][b][i][A] infra.
    102.12
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997) (“Each element contained in a patent claim is deemed
material to defining the scope of the patented invention, and thus the doctrine of equivalents
must be applied to individual elements of the claim, not to the invention as a whole”), discussed
in § 2.05[3][b][i][A] infra.
    102.13
            The words “element” and “limitation” refer to different aspects of the same thing.
The “element” is the physical embodiment in the accused device or invention corresponding to a
“limitation” in the claim, which is a narrowing word, phrase, clause, or sentence. See Festo
Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 563 n.1, 56 U.S.P.Q.2d (BNA)
1865 (Fed. Cir. 2000) (en banc), citing Lemelson v. United States, 752 F.2d 1538, 1551, 224
U.S.P.Q. (BNA) 526, 533 (Fed. Cir. 1985) (using “element”), and Sextant Avionique, S.A. v.
Analog Devices, Inc., 172 F.3d 817, 826-827, 49 U.S.P.Q.2d (BNA) 1865, 1870-1871 (Fed. Cir.
1999) (using “limitation”):
   “In our prior cases, we have used both the term ‘element’ and the term ‘limitation’ to refer to
   words in a claim.. It is preferable to use the term ‘limitation’ when referring to claim lan-

                                                                                      (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW

                           102.14
through an equivalent.         Ultimately this more focused approach, based on
parsing separate claim limitations separately, may represent a refinement in
patent infringement analysis as important as the transition from so-called
                                                                         102.15
“central” claiming to “peripheral” claiming in the nineteenth century.
   The courts’ restriction of the doctrine of equivalents also depended on an-
other doctrine of patent infringement known as prosecution history estop-
     102.16
pel.        Under this doctrine, a patentee is estopped to claim infringement by
subject matter that the patentee surrendered during the patent prosecution
                                                                             102.17
process, whether by argument, admission, or amendment of her claims.
Applying notions of prosecution history estoppel, the Supreme Court in effect
was imposed a complete bar to the doctrine of equivalents as applied to
                                                               102.18
amended claim elements whose amendment is unexplained.                It did so by

   guage and the term ‘element’ when referring to the accused device. See Dawn Equip. Co. v.
   Kentucky Farms, Inc., 140 F.3d 1009, 1014 n.1, 46 U.S.P.Q2d [(BNA)]1109, 1112 n.1 (Fed.
   Cir. 1998). However, because the en banc questions use the term ‘element,’ we use that term
   in this opinion.”
   102.14
             See Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 937, 4 U.S.P.Q.2d
(BNA) 1737, 1741 (Fed. Cir. 1987) (en banc) (“device that does not satisfy [a claim limitation]
at least equivalently does not function in substantially the same way as the claimed invention,”
and thus cannot infringe under the doctrine of equivalents).
    102.15
            See § 2.05[3] (introduction) supra. See also, Hilton Davis Chemical Co. v. Warner-
Jenkinson Co., 62 F.3d 1512, 1564-1569, 35 U.S.P.Q.2d (BNA) 1641 (Fed. Cir.1995) (dissent-
ing opinion) (Footnote omitted.), rev’d on other grounds 520 U.S. 17, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997) (discussing historical interaction between transition from central to
peripheral claiming and doctrine of equivalents).
    102.16
            See, e.g.:
    Supreme Court: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122
S.Ct. 1831, 1835, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“When the patentee
responds to [a patent examiner’s] rejection by narrowing his claims, this prosecution history
estops him from later arguing that the subject matter covered by the original, broader claim was
nothing more than an equivalent. Competitors may rely on the estoppel to ensure that their own
devices will not be found to infringe by equivalence”).
    Federal Circuit: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 564,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (majority opinion), vacated and remand-
ed on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA)
1705 (2002) (“Prosecution history estoppel is one tool that prevents the doctrine of equivalents
from vitiating the notice function of claims”), citing Charles Greiner & Co. v. Mari-Med Manu-
facturing, Inc., 962 F.2d 1031, 1036, 22 U.S.P.Q.2d (BNA) 1526, 1529-1530 (Fed. Cir. 1992).
    102.17
            See: §§ 2.05[3][b][i][B], 2.06[2] infra.
    102.18
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1842, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting and explaining
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997):
   “When the patentee is unable to explain the reason for amendment, estoppel not only applies
   but also ‘bars the application of the doctrine of equivalents as to that element.’ . . . These
   words do not mandate a complete bar; they are limited to the circumstance where ‘no expla-
   nation is established.’ They do provide, however, that when the court is unable to determine

                                                                                     (Rel. 25)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

recognizing an important presumption allocating the burden of proof regard-
ing claim amendments’ estoppel effect.102.19 Any claim amendment, ruled the
Court, is presumed to relate to patentability unless the patentee bears the bur-
den of proving other reasons for it.102.20 If the patentee fails to bear this bur-
den, and there therefore the claim amendment is presumed to relate to
patentability, a second presumption arises: the doctrine of equivalents is pre-
sumed inapplicable,102.21 and the patentee must bear the burden of proving the
extent of any equivalents remaining despite the claim amendment’s estoppel
effect.102.22 The operation of these presumptions, which are rebuttable, 102.23 is
explained in more detail elsewhere.102.24


   the purpose underlying a narrowing amendment—and hence a rationale for limiting the es-
   toppel to the surrender of particular equivalents—the court should presume that the patentee
   surrendered all subject matter between the broader and the narrower language.”
See also, Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997) (“where no explanation [for a claim amendment] is estab-
lished, . . . the court should presume that the patent applicant had a substantial reason related to
patentability for including the limiting element added by the amendment” and therefore “prose-
cution history estoppel would bar the application of the doctrine of equivalents as to that ele-
ment”).
    102.19
              See generally: § 2.05[3] (introduction) supra; § 2.05[3][b][i][B] infra.
    102.20
              See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997) (“Where no explanation [for narrowing a claim limitation
by amendment] is established. . . . the court should presume that the PTO had a substantial
reason related to patentability for including the limiting element added by amendment. In those
circumstances, prosecution history estoppel would bar the application of the doctrine of equiva-
lents as to that element”), discussed in: § 2.05[3] (introduction) supra; § 2.05[3][b][i][B] infra.
See also, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S. Ct.
1831, 1841-1842, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (reaffirming that burden
is “on the patentee to show that an amendment was not for purposes of patentability”), citing
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., supra, 520 U.S. at 33.
    102.21
              See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1842, 152 L.Ed. 2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002):
   “The patentee, as the author of the claim language, may be expected to draft claims encom-
   passing readily known equivalents. A patentee’s decision to narrow his claims through
   amendment may be presumed to be a general disclaimer of the territory between the original
   claim and the amended claim.”
See also, id., 535 U.S. at 741(“When the patentee has chosen to narrow a claim, courts may
presume the amended text was composed with awareness of this rule and that the territory sur-
rendered is not an equivalent of the territory claimed”).
    102.22
             See id., 535 U.S. at 741:“This presumption is not . . . just the complete bar by anoth-
er name. Rather, it reflects the fact that the interpretation of the patent must begin with its literal
claims, and the prosecution history is relevant to construing those claims. When the patentee has
chosen to narrow a claim, courts may presume the amended text was composed with awareness
of this rule and that the territory surrendered is not an equivalent of the territory claimed.
    102.23
             See: N.102.20 supra; Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535
U.S. 722, 122 S.Ct. 1831, 1842, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“[T]he
patentee still might rebut the presumption that estoppel bars a claim of equivalence. The patent-
ee must show that at the time of the amendment one skilled in the art could not reasonably be

                                                                                           (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

               [A]—The General Nature of the Doctrine of Equivalents
    The doctrine of equivalents in patent law has a long history, during which
                                              102.25
it has undergone considerable evolution.             Its modern contours, however,
                                                                        102.26
derive from the Supreme Court’s 1950 decision in Graver Tank.                  That
decision endorsed as the standard for equivalency the “function-way-result”
      102.27                                                    102.28
test,         which is also known as the “tripartite,”                  or “triple-
           102.29
identity”         test. Under this test, an accused device infringes a patent, even
if the patent claims do not literally “read on” it, “if it performs substantially
the same function [as the patented invention] in substantially the same way to
                           103
obtain the same result.”



expected to have drafted a claim that would have literally encompassed the alleged equivalent”);
122 S.Ct. at 1842 (“There are some cases, . . . where the amendment cannot reasonably be
viewed as surrendering a particular equivalent. . . . In those cases the patentee can overcome the
presumption that prosecution history estoppel bars a finding of equivalence”).
    102.24
            See: § 2.05[3] (introduction) supra; § 2.05[3][b][i][B] infra.
    102.25
             See Pennwalt Corp. v. Durand-Wayland Inc., 833 F.2d 931, 957-970, 4 U.S.P.Q.2d
(BNA) 1737, 1741 (Fed. Cir. 1987) (en banc), cert. denied 485 U.S. 1009 (1988) (“Commen-
tary” of Judge Newman). See also, Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62
F.3d 1512, 1563-1580, 35 U.S.P.Q.2d (BNA) 1641 (Fed. Cir.1995) (dissenting opinion) (Foot-
note omitted.), rev’d on other grounds 520 U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997)
(exhaustive review of doctrine of equivalents from its origins by late Judge Nies).
    102.26
             Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 700
S.Ct. 854, 94 L. Ed. 1097 (1950). See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520
U.S. 17, 21, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (“Nearly 50 years ago, this Court in Grav-
er Tank & Mfg. Co. v. Linde Air Products Co. . . . set out the modern contours of what is known
in patent law as the ‘doctrine of equivalents’”), citing Graver Tank & Manufacturing Co. v.
Linde Air Products Co., supra.
    102.27
             See Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605,
608, 700 S.Ct. 854, 94 L. Ed. 1097 (1950), quoting Sanitary Refrigerator Co. v. Winters, 280
U.S. 30, 42, 50 S.Ct. 9, 74 L.Ed. 147 (1929) (accused device is equivalent to claimed invention
“if is performs substantially the same function in substantially the same way to obtain the same
result”).
    102.28
             Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1577, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir.1995) (dissenting opinion of late Nies, J.) (Footnote omit-
ted.), rev’d on other grounds 520 U.S. 17, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (Su-
preme Court in Graver Tank “stated that a patentee may invoke th[e] doctrine [of equivalents]
against a producer of a device that performs substantially the same function in substantially the
same way to obtain the same result as the patented invention, quoting the tripartite test of Sani-
tary Refrigerator”), referring to Graver Tank & Manufacturing Co. v. Linde Air Products Co.,
339 U.S. 605, 608, 700 S.Ct. 854, 94 L. Ed. 1097 (1950), quoted in N.102.24 infra, and Sani-
tary Refrigerator Co. v. Winters, 280 U.S. 30, 42, 50 S.Ct. 9, 74 L.Ed. 147 (1929).
    102.29
             See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 39-40, 117
S.Ct. 1040, 137 L.Ed.2d 146 (1997) (describing and characterizing test).
    103
          Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 608, 700
S.Ct. 854, 94 L.Ed. 1097 (1950), quoting Sanitary Refrigerator Co. v. Winters, 280 U.S. 30, 42,
50 S.Ct. 9, 74 L.Ed. 147 (1929). See also, e.g.:

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    The thrust of this test is best illustrated by the Supreme Court's decision in
                      104
Graver Tank itself.        There a patent for a welding flux claimed alkaline
                                                         105
earth metal silicates, including magnesium silicate.          The allegedly infring-
ing flux consisted primarily of manganese silicates, with some calcium sili-
                                106
cates and other ingredients.         There was therefore no literal infringement
because manganese is not an alkaline earth metal, while magnesium is. Never-
                                                                  107
theless, the Supreme Court found the two fluxes equivalent,           relying on: (1)
the patent specification, which noted that manganese silicate could be used as
a substitute for magnesium silicate, (2) expert testimony that the two ingredi-
ents performed comparably, and (3) the lack of any evidence that the infringer
                                     108                            109
had done independent research.            Over a vigorous dissent,      the majority
ruled that the alleged infringer had appropriated the patentee's inventive con-
                                                110
tribution in an immaterially different form.
    The doctrine of equivalents is not limited as to subject matter. As the
Graver Tank case itself suggests, it applies to chemical as well as mechanical
         111
patents.     Lower courts have applied it in various fields to find infringement
                 112                113
of both process      and product         patents. In other instances, however, they


    Fifth Circuit: Rothstein v. Atlanta Paper Co., 321 F.2d 90, 95 (5th Cir. 1963) (“The doctrine
of equivalents is based on substantial identity between the teaching of the claims of the patent in
suit and the accused device in structure, mode of operation and result to be accomplished”).
    Tenth Circuit: McCullough Tool Co. v. Well Surveys, Inc., 343 F.2d 381, 401 (10th Cir.
1965), cert. denied 383 U.S. 933 (1966).
    104
         Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 700 S.Ct.
854, 94 L.Ed. 1097 (1950).
    105
         See id., 339 U.S. at 610.
    106
         Id.
    107
         Id., 339 U.S. at 607-608.
    108
         Id., 339 U.S. at 610-612; 339 U.S. at 613 (dissenting opinion).
    109
         Id., 339 U.S. at 618 (Douglas, J., dissenting), quoted in part in N.102.7 supra.
    110
         See also, Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1261
(Fed. Cir. 1989) (“substitution of an ingredient known to be an equivalent to that required by the
claim represents a classic example for a finding of infringement under the doctrine of equiva-
lents”).
    111
         See Ziegler v. Phillips Petroleum Co., 483 F.2d 858, 869 (5th Cir.), cert. denied 414
U.S. 1079 (1973) (noting extension to chemical patents and citing authorities).
    Cf., Atlas Powder Co. v. E.I. Du Pont de Nemours & Co., 750 F.2d 1569, 1579-1580 (Fed.
Cir. 1984) (where literal infringement of emulsion is avoided by changing one ingredient, equiv-
alence depends upon whether “changed ingredient has the same purpose, quality, and function
as the claimed ingredient”).
    112
         See, e.g.:
    Fifth Circuit: Ziegler v. Phillips Petroleum Co., 483 F.2d 858, 868 (5th Cir.), cert. denied
414 U.S. 1079 (1973) (catalytic process for polymerization and related catalyst).
    Seventh Circuit: Binks Manufacturing Co. v. Ransburg Electro-Coating Corp., 281 F.2d
252, 258 (7th Cir. 1960), cert. denied 366 U.S. 211 (1961), citing Cochrane v. Deener, 94 U.S.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

have refused to find infringement under the doctrine of equivalents, reasoning
that the accused item did not correspond closely enough to the claimed inven-
                 114                  115          116
tion in function, mode of operation, or result.

780, 787-788, 24 L.Ed. 139 (1877) (“Infringement of a method patent is not dependent on the
form of apparatus used”).
    Eighth Circuit: Sbicca-Del Mac, Inc. v. Milius Shoe Co., 145 F.2d 389, 397 (8th Cir. 1944)
(use of accurate machine infringed process for preparing shoe soles by hand, even though ma-
chine improved method by making shoe parts interchangeable).
    Ninth Circuit: Cutter Laboratories, Inc. v. Lyophile-Cryochem Corp., 179 F.2d 80, 87 (9th
Cir. 1949) (substitution of well-known slower-freezing step for part of process did not avoid
infringement where defendant used all inventive elements of quick-freezing combination pro-
cess).
    113
         See, e.g.:
    Second Circuit: Medeco Security Locks, Inc. v. Lock Technology Corp., 199 U.S.P.Q.
(BNA) 519, 522 (S.D.N.Y. 1976) (composite key, prepared by locksmith from individual bits
for each lock tumbler to replace lost key, infringed patented, integral key blade); Lathrop v. Rice
& Adams Corp., 17 F. Supp. 622, 631-632 (W.D.N.Y. 1936).
    Fourth Circuit: Baker-Cammack Hosiery Mills, Inc. v. Davis Co., 181 F.2d 550, 557 (4th
Cir.), cert. denied 340 U.S. 824 (1950). (Citations omitted.)
    Eighth Circuit: Priebe & Sons Co. v. Hunt, 188 F.2d 880, 883-884 (8th Cir.), cert. dis-
missed 342 U.S. 801 (1951) (rubber fingers in chicken-plucking machine were equivalent to
those claimed).
    Tenth Circuit: McCullough Tool Co. v. Well Surveys, Inc., 343 F.2d 381, 400 (10th Cir.
1965), cert. denied 383 U.S. 933 (1966) (for purposes of radioactivity well logging, Geiger
counters, ionization chambers and scintillation counters were equivalents).
    Federal Circuit: Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251,
1259-1261 (Fed. Cir. 1989) (doping that negatively altered refractive index of cladding of opti-
cal fiber was equivalent to doping that positively altered refractive index of core, because each
caused similar core/cladding differential); Atlas Powder Co. v. E.I. Du Pont de Nemours & Co.,
750 F.2d 1569, 1580 (Fed. Cir. 1984) (blasting emulsion with substitute ingredient performing
same function as equivalent ingredient in patented product infringed patent).
    114
         See, e.g.:
    Third Circuit: Q-Tips, Inc. v. Johnson & Johnson, 207 F.2d 509, 511 (3d Cir. 1953), cert.
denied 347 U.S. 935 (1954) (there was no infringement of combination where accused device
had in common with patented invention only subcombination subject to previously expired
patent).
    Sixth Circuit: Deyerle v. Wright Manufacturing Co., 496 F.2d 45, 52 (6th Cir. 1974) (pin
used in hip fixation device was not equivalent to nail four times its diameter where two did not
function in same way for medical purposes).
    115
         See, e.g.:
    Sixth Circuit: Dunlop Co. v. Kelsey-Hayes Co., 484 F.2d 407, 416-417 (6th Cir. 1973), cert.
denied 415 U.S. 917 (1974) (no infringement where accused device performed same function in
substantially different way).
    Federal Circuit: Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 937-939 (Fed. Cir.
1987), cert. denied 485 U.S. 961 (1988) (programmable sorter did not infringe hard-wired sorter
under doctrine of equivalents where former lacked means for “continuously indicating the posi-
tion of an item to be sorted” but instead used random access memory for storing weight and
color data) (en banc); Universal Gym Equipment, Inc. v. ERWA Exercise Equipment Ltd., 827
F.2d 1542, 1548 (Fed. Cir. 1987) (“fact that the two devices achieve substantially the same
result creates no presumption that they do so in substantially the same way”).
    116
         See Ziegler v. Phillips Petroleum Co., 483 F.2d 858, 872-875 (5th Cir.), cert. denied
414 U.S. 1079 (1973) (patent directed to catalyst and process for polymerizing ethylene did not

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                    117
    Although the doctrine has evolved over the years,      one of the most im-
portant refinements was made by the Federal Circuit. That court, with the
Supreme Court’s approval, endorsed incremental application of the doctrine,
                                            118
one claim element or limitation at a time.      Under this approach, if the ac-
cused device lacks the means specified by a claim limitation, or the equivalent
                                      119
of those means, it does not infringe,     especially where the claim limitation
                                                                120
was added to obtain a patent in a field crowded with prior art.
                                                                        121
    This element-by-element approach, called the “all-elements” rule,       may
ultimately prove to be as useful an innovation in patent law as the transition
                                                                 122
from central to peripheral claiming in the nineteenth century.       At the mo-
ment, however, its precise effect is not completely resolved. The major ques-
tion remaining unresolved is whether there must be one-to-one
correspondence (directly or by equivalents) between the elements of the ac-

cover polymerization of butadiene to produce cis polybutadiene where specification mentioned
only ethylene, specified embodiment worked poorly with butadiene, and cis butadiene produced
by allegedly infringing process had special, desirable properties).
     117
          See sources cited in N.102.22 supra.
     118
          See, e.g.:
     Supreme Court: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117
S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 at *22 (1997), quoted in N.128.13 infra.
     Federal Circuit: Sofamor Danek Group, Inc. v. Depuy-Motech, Inc., 74 F.3d 1216, 1220, 37
U.S.P.Q.2d (BNA) 1529 (Fed. Cir. 1996) (“To infringe, an accused device must embody each
claim limitation or its equivalent”), citing Charles Greiner & Co. v. Mari-Med Manufacturing,
Inc., 961 F.2d 1031, 1034, 22 U.S.P.Q.2d (BNA) 1526 (Fed. Cir. 1992); Pennwalt Corp. v.
Durand-Wayland, Inc., 833 F.2d 931, 938-939 (Fed. Cir. 1987), cert. denied 485 U.S. 961
(1988) (where accused computer-based sorter contained nothing corresponding to claim limita-
tion for indicating position of items being sorted, it was not equivalent to mechanical sorter) (en
banc); 833 F.2d at 953-954 (concurring opinion) (doctrine of equivalents applies separately to
each element of each claim, not to invention as a whole, because general doctrine of equivalents
unrestricted to claim elements would be so vague as to violate due process).
     The Supreme Court's language confirming this point echoed the Federal Circuit's language
from its seminal 1988 en banc decision in Pennwalt Corp. v. Durand Wayland, Inc., supra.
Compare, Warner-Jenkinson Co. v. Hilton Davis Chemical Co., supra, 520 U.S. at 29, quoted
in N.128.13 infra, with Pennwalt Corp. v. Durand Wayland, Inc., supra, 833 F.2d at 935 (“It is
. . . well settled that each element of a claim is material and essential, and that in order for a
court to find infringement, the plaintiff must show the presence of every element or its substan-
tial equivalent in the accused device)), quoting Lemelson v. United States, 752 F.2d 1538, 1551,
224 U.S.P.Q. (BNA) 526 (Fed. Cir. 1985). (Footnote omitted.)
     See also, the text accompanying Ns.128.12-128.14 infra.
     119
          See Smithkline Diagnostics, Inc. v. Helena Laboratories Corp., 859 F.2d 878, 889 (Fed.
Cir. 1988), citing Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 938-939 (Fed. Cir.
1987) (en banc), cert. denied 485 U.S. 961 (1988) (patentee has burden of proving “that every
limitation of the patent claims asserted to be infringed is found in the accused device, either
literally or by an equivalent”).
     120
          See Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 938-939 (Fed. Cir. 1987)
(en banc), cert. denied 485 U.S. 961 (1988).
     121
          See § 2.05[3][b][i] (introduction) supra.
     122
          See § 2.05[3] (introduction), [b][iv] supra.


                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

cused device and the limitations of the claims, or whether a different element
of the accused device may serve, or several elements of the accused device
may be combined to serve, as an equivalent to a single limitation of the
                                                                   122.1
claims. The Federal Circuit left this question open in Festo,            and it re-
mains unresolved.
    The Federal Circuit’s decision in Corning Glass Works v. Sumitomo Elec-
                  122.2                 122.3
tric U.S.A., Inc.       best illustrates      the nature of the controversy. There
the patentee had exploited a well-known principle of physics to achieve great-
er transmission efficiency in optical fibers. The principle of physics was the
internal reflection that occurs when light attempts to travel at certain oblique
angles from a medium of greater index of refraction to one of lesser index of
            122.4
refraction.       The patentee exploited this principle by doping the core of an
optical fiber to increase its index of refraction over that of the cladding, and
                                                                 122.5
the key limitation of its claim was a positively doped core.           The alleged

   122.1
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 564, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (declining
to reach question whether giving particular element range of equivalents would violate all ele-
ments rule by eliminating it entirely).
    122.2
          Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 9 U.S.P.Q.2d
(BNA) 1962 (Fed. Cir. 1989).
    122.3
          The same sort of issue arose in the Pennwalt case, but there the Federal Circuit, sitting
en banc, declined to find infringement under the doctrine of equivalents. See Pennwalt Corp. v.
Durand-Wayland, Inc., 833 F.2d 931, 937-939, 4 U.S.P.Q.2d (BNA) 1737, 1741 (Fed. Cir.
1987) (en banc), outlined in N.115 supra; 833 F.2d at 937 (“device that does not satisfy [a
claim limitation] at least equivalently does not function in substantially the same way as the
claimed invention,” and thus cannot infringe under the doctrine of equivalents). Dissenters
argued that several elements of the accused device together performed the same function, in the
same way, with the same result at the claim limitation at issue, but they did not prevail. See 833
F.2d at 945 (dissenting opinion) (“To preclude the possibility of finding equivalent functions
and therefore preclude finding infringement under the doctrine of equivalents simply because
the accused device does not perform its functions in the same order as the claimed invention
reduces the doctrine of equivalents, in practical effect, to nothing more than the test for literal
infringement”). The Pennwalt case is less instructive than Sumitomo, however, because it was
not a case of pure “element melding;” questions of the nature of the functions performed by the
elements and of prosecution history estoppel complicated the picture. See 833 F.2d at 936.
    122.4
          See Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1254, 9
U.S.P.Q.2d (BNA) 1962 (Fed. Cir. 1989). This principle is responsible for the shimmering,
mirror-like effect that appears when a swimmer, while under water, attempts to look upward
through the surface of the water into the air, which has a lower index of refraction than the dens-
er water.
    122.5
          The key limitation of Claim 1 read as follows:

   “(b) a core formed of fused silica to which a dopant material on at least an elemental basis
   has been added to a degree in excess of that of the cladding layer so that the index of refrac-
   tion thereof is of a value greater than the index of refraction of said cladding layer, said core
   being formed of at least 85 percent by weight of fused silica and an effective amount up to
   15 percent by weight of said dopant material.”


                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

infringer, however, took an opposing but equally effective approach—using
negative doping in the cladding to reduce its index of refraction relative to
                   122.6
that of the core.        Technology for doping the cladding to reduce its index
                                          122.7
of refraction had been known in the art,        but the patentee had not included
                                                          122.8
it in its claims, so there was no literal infringement.         Nor was there any
element of the accused fiber precisely equivalent to the positively doped core
in the claimed invention, because the core in the accused fiber was not doped
        122.9
at all.       Nevertheless, a panel of the Federal Circuit affirmed a finding of
                                                   122.10
infringement under the doctrine of equivalents,            reasoning that the com-
bination of undoped core and negatively doped cladding in the accused de-
vice was the equivalent of the positively doped core in the claim
            122.11
limitation         because the two performed the same function (increasing
transmission efficiency) with the same result (a better fiber) by the same
                                                                    122.12
means (exploiting the physical principle of internal reflection).
                                                        122.13
    Because it is a pure case of “element melding,”             the Sumitomo case
highlights the controversy over the all elements rule. Restricting the claim
limitation of a positively doped core to the element of the invention corre-
sponding to the fiber’s core alone would have produced a different result. It
would have precluded finding an equivalent in the negatively doped cladding,
even though that cladding operated in precisely the same way, by making the

Id., 868 F.2d at 1256.
     122.6
           See id., 868 F.2d at 1258-1259.
     122.7
           See id., 868 F.2d at 1261 (citing prior patent).
     122.8
           See id., 868 F.2d at 1258-1259 (patentee conceded absence of literal infringement).
     122.9
           See id., 868 F.2d at 1260 (defining key question for equivalence as whether limitation
to positive doping of core was met equivalently).
     122.10
            See id., 868 F.2d at 1261 (“we are unpersuaded of error . . . in the district court's un-
derstanding of the law [or] in its finding that adding negative dopant to the cladding is equiva-
lent to adding positive dopant to the core”).
     122.11
            In so affirming, the court was quite conscious of the all-elements rule. See id., 868
F.2d at 1259 (Footnotes and citation omitted.)
   “[The infringer’s] analysis illustrates the confusion sometimes encountered because of mis-
   understanding or misleading uses of the term ‘element’ in discussing claims. ‘Element’ may
   be used to mean a single limitation, but it has also been used to mean a series of limitations
   which, taken together, make up a component of the claimed invention. In the All Elements
   rule, ‘element’ is used in the sense of a limitation of a claim. . . . [The infringer’s] analysis is
   faulty in that it would require equivalency in components, that is, the substitution of some-
   thing in the core for the absent dopant. However, the determination of equivalency is not
   subject to such a rigid formula. An equivalent must be found for every limitation of the
   claim somewhere in an accused device, but not necessarily in a corresponding component,
   although that is generally the case.”
   122.12
            See id., 868 F.2d at 1259-1261.
   122.13
            See N.122.3 supra.


                                                                                           (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

index of refraction greater in the core. The Sumitomo court refused to take
such a restrictive approach, instead finding that a different element or compo-
nent of the accused device (the negatively doped cladding) could be equiva-
lent to the positively doped core.
    The Sumitomo decision thus raises several questions. First, is it generally
proper, in equivalents analysis, to find an element in the accused device that
is different in physical structure or properties from a claim limitation to be
                               122.14
equivalent to that limitation?        Second, is it possible for two or more ele-
ments in the accused device, all of which are different in physical structure or
properties from the element in the claim limitation, to be in combination
equivalent to that limitation, even if separately each is not equivalent to
    122.15
it?        Third, if the answer to the latter question is affirmative, is there any
limit to the number of elements in the accused device that can be combined to
form an “equivalent” of a claim limitation?


   122.14
             As in Sumitomo, the Federal Circuit again answered this question in the affirmative
in a 1991 panel decision. See Intel Corp. v. International Trade Commission, 946 F.2d 821, 831-
832, 20 U.S.P.Q.2d (BNA) 1161, 1171 (Fed. Cir. 1991) (holding accused EPROM that used
multiplexer to switch between page mode and normal addressing equivalent to claimed inven-
tion in which address buffer served same function, where “the multiplexer performed the selec-
tive signal acceptance function of the claimed address buffer and . . . , while the multiplexer did
not act as a buffer, that function was performed elsewhere” in accused EPROM), citing, inter
alia, Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 9 U.S.P.Q.2d
(BNA) 1962 (Fed. Cir. 1989). There is, however, no definitive en banc decision that finally
resolves this issue.
    122.15
             This was a question raised in Pennwalt. See Pennwalt Corp. v. Durand-Wayland,
Inc., 833 F.2d 931, 944, 4 U.S.P.Q.2d (BNA) 1737, 1741 (Fed. Cir. 1987) (en banc) (dissenting
opinion of four judges) (where fruit sorter contained hard-wired means for continuously indicat-
ing position of each fruit on conveyor, and accused device used programmed microprocessor
with shift-register “queues” containing fruit data and programmed “pointers” identifying fruit,
“[t]he real question to be answered . . ., one which the district court and the majority never
reached, [was] whether the queues and pointers perform in substantially the same way the func-
tions of the claimed position indicating means when the latter are interpreted in light of the
specification”). The Pennwalt court’s apparently negative answer, however, is not definitive
because the question was not raised in pure form. See N.122.3 supra.
    Two later panel decisions of the Federal Circuit answered this same question in the affirma-
tive, but there is no definitive, en banc decision on point. See: Toro Co. v. White Consolidated
Industries, Inc., 2001 U.S. App. LEXIS 20915 at *6-7 (Fed. Cir. Sept. 24, 2001) (jury with
proper understanding of technology could find that vacuum blower’s restriction ring separate
from cover performed same function with insubstantial differences from restriction ring inte-
grated with cover in patented invention); Vaupel Textilmaschinen KG v. Meccanica Euro Italia
S.P.A., 944 F.2d 870, 881-882, 20 U.S.P.Q.2d (BNA) 1045 (Fed. Cir. 1991) (district court did
not err in finding combination of smooth temple bar and threaded spreader bar in accused broad
weaving loom for labels equivalent to threaded guide bar limitation of patent).
    See generally, Toro Co. v. White Consolidated Industries, Inc., supra, 2001 U.S. App.
LEXIS 20915 at *7 (“An accused device may infringe under the doctrine of equivalents even
though a combination of its components performs a function performed by a single element in
the patented invention”), quoting Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 398, 29
U.S.P.Q.2d 1767, 1770 (Fed. Cir. 1994) (dictum: not every limitation of claim was present in
accused device, whether literally or by equivalents).

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    The answers to these questions may ultimately determine how much the
all-elements rule restricts the practical application of the doctrine of equiva-
                                                                           122.16
lents and thereby promotes the “notice function” of patent claims.                A
                                                                              122.17
restrictive approach may be appropriate for means-plus-function claims
because of the peculiarly limiting statutory framework under which they oper-
     122.18
ate.        For more general structural and process claims, however, the ques-
tion how closely to parse inventive elements in applying the doctrine of
equivalents raises in miniature all of the questions of form over substance,
literalism versus justice, and certainty versus flexibility that make the doctrine
                                  122.19
so controversial to begin with.          The Federal Circuit is wise to proceed
cautiously in this area in the hope that, with experience, practical and predict-
able rules may be worked out, on a case-by-case basis, at least for particular
classes of cases. At this stage any general solution might only tilt too far in
the direction of certainty at the expense of justice, or vice versa.
                                                                              122.20
    In any event, the doctrine of equivalents is generally a matter of fact.
Proof of equivalence may be “made in any form: through testimony of experts
or others versed in the technology; by documents, including texts and treatis-
                                                           123
es; and, of course, by the disclosures of the prior art.”      It depends in large
measure, however, on the function or functions the patented invention is to
perform. If the claims recite general “means” for performing a specific func-
tion, the doctrine requires “the patent owner to establish . . . that the structure
in the accused device which performs [the claimed] function is the same as or
                                                                   124
an equivalent of the structure disclosed in the specification.”        If there are


   122.16
            See generally, § 2.05[3] (introduction), [a][iv] supra.
   122.17
             Means-plus-function claims are those described in Section 112, ¶6 of the patent stat-
ute, 35 U.S.C. § 112, ¶ 6. See generally, § 2.05[3][c] infra. See also, § 2.05[3][c][ii] infra (dis-
cussing what constitutes means-plus-function claim and how to identify one).
    122.18
             See § 2.05[3][c][iv] infra (discussing effect of 35 U.S.C. § 112, ¶6 on application of
doctrine of equivalents to means-plus-function claims).
    122.19
             See § 2.05[3] (introduction), [a][iv] supra.
    122.20
             See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1520, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995), rev’d on other grounds 520 U.S. 17, 117 S.Ct. 1040,
1049, 137 L.Ed.2d 146 (1997) (“Infringement, whether literal or under the doctrine of equiva-
lents, is a question of fact”), citing: Winans v. Denmead, 56 U.S. (15 How.) 330, 338, 14 L.Ed.
717 (1854) (seminal decision on doctrine of equivalents) and SRI International, Inc. v. Matsu-
shita Electric Corp., 775 F.2d 1107, 1125, 227 U.S.P.Q. (BNA) 577, 589 (Fed. Cir. 1985) (en
banc).
    123
          Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 609, 700
S.Ct. 854, 94 L.Ed. 1097 (1950), quoted in part in Corning Glass Works v. Sumitomo Electric
U.S.A., Inc., 868 F.2d 1251, 1261 (Fed. Cir. 1989).
    124
          Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934 (Fed. Cir. 1987) (en banc),
cert. denied 485 U.S. 961 (1988) (showing is part of patentee's ultimate burden of proof). See
also, § 2.05[3][c][i] infra (discussing means-plus-function claims generally).

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

several functions, the accused device must perform all of them in substantially
                                                 125
the same way as does the patented invention.
    The doctrine of equivalents also has some other interesting aspects. First,
although there is no such thing as the “essence” or “heart” of an invention for
purposes of patent validity, it is legitimate to seek the gist of an invention for
                                                      126
purposes of applying the doctrine of equivalents.          Second, equivalency is
                                                         126.1
determined as of the time infringement takes place,            so that accused de-
vices may infringe under the doctrine of equivalents even though they use
                                           126.2
post-issuance advances in technology.            Third, like the determination of
                       126.3
literal infringement,        the doctrine of equivalents is subject to the general
rule that matter disclosed but not claimed in a patent is dedicated to the pub-
     126.4
lic,       subject for two years to the possibility of broadening the claims on
          126.5
reissue.        As a result, if a patent's claims are not broad enough to cover
matter disclosed in the specification literally, the doctrine of equivalents will
                                                         127
not stretch them to provide the necessary coverage.           Finally, the fact that


   125
         See Perkin-Elmer Corp. v. Westinghouse Electric Corp., 822 F.2d 1528, 1535 (Fed. Cir.
1987) (refusing to hold tap-coupling for electrodeless discharge lamp equivalent to loop-
coupling, although both performed power transfer in same way, because they performed addi-
tional functions of frequency-and impedance-matching in different ways).
    126
         See Atlas Powder Co. v. E.I. Du Pont de Nemours & Co., 750 F.2d 1569, 1582 (Fed.
Cir. 1984).
    126.1
           See, e.g.:
    Supreme Court: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117
S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 at *35 (March 3, 1997).
    Federal Circuit: Atlas Powder Co. v. E. I. DuPont de Nemours & Co., 750 F.2d 1569, 1581
(Fed. Cir. 1984) (citing authorities).
    126.2
           See Hughes Aircraft Co. v. United States, 717 F.2d 1351, 1365 (Fed. Cir. 1983).
    126.3
           See § 2.05[3][a] supra.
    126.4
           See, e.g.: Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *20 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam); Maxwell v. J. Baker, Inc.,
86 F.3d 1098, 1106-1107, 39 U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996), discussed in N.127.2
infra.
    126.5
           See: 35 U.S.C. § 251; Maxwell v. J. Baker, Inc., 39 U.S.P.Q.2d (BNA) 1001, 1006 &
n.2 (Fed. Cir. 1996) (noting that dedication rule is subject to broadening of claims in reissue for
two years, as provided by Section 251).
    127
         See Maxwell v. J. Baker, Inc., 39 U.S.P.Q.2d (BNA) 1001, 1006 (Fed. Cir. 1996) (Cita-
tions omitted):
       “A patentee may not narrowly claim his invention and then, in the course of an infringe-
   ment suit, argue that the doctrine of equivalents should permit a finding of infringement be-
   cause the specification discloses the equivalents. Such a result would merely encourage a
   patent applicant to present a broad disclosure in the specification of the application and file
   narrow claims, avoiding examination of broader claims that the applicant could have filed
   consistent with the specification.”


                                                                                       (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

the patentee itself is unable to make the thing accused of infringement does
                                                                          127.1
not preclude a finding of infringement under the doctrine of equivalents.
   The dedication rule—that matter disclosed but not claimed is dedicated to
                                                                      127.2
the public and cannot be recovered under the doctrine of equivalents        —is
worth discussion. The doctrine is well established as a limitation of both lit-
                  127.3                                                     127.4
eral infringement       and infringement under the doctrine of equivalents.
Indeed, the Federal Circuit’s 2002 en banc, per curiam decision in Johnson &




   127.1
           See Atlas Powder Co. v. E.I. Du Pont de Nemours & Co., 750 F.2d 1569, 1581 (Fed.
Cir. 1984).
    127.2
           See, e.g.: Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *20 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam), overruling YBM Magnex,
Inc. v. International Trade Commission, 145 F.3d 1317, 1320, 46 U.S.P.Q.2d (BNA)1843 (Fed.
Cir. 1998); Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1106-1107, 39 U.S.P.Q.2d (BNA) 1001
(Fed. Cir. 1996).
    Even before these decisions, the dedication rule had been established beyond question as a
limitation on literal infringement. See:
    Supreme Court: Milcor Steel Co. v. George A. Fuller Co., 316 U.S. 143, 146, 62 S.Ct. 969,
86 L.Ed. 1332 (1942) (“Out of all the possible permutations of elements which can be made
from the specifications, [the patentee] reserves for himself only those contained in the claims”)
(Citation to opinion below and internal quotation marks omitted.); Mahn v. Harwood, 112 U.S.
354, 361, 5 S.Ct. 174, 28 L.Ed.665 (1884) (“The public is notified and informed by the most
solemn act on the part of the patentee, that his claim to invention is for such and such an ele-
ment or combination, and for nothing more. Of course, what is not claimed is public property”);
Miller v. Bridgeport Brass Co., 104 U.S. (14 Otto) 350, 352, 35, 26 L.Ed. 783 (1882) (“The
claim of a specific device or combination, and an omission to claim other devices or combina-
tions apparent on the face of the patent, are, in law, a dedication to the public of that which is
not claimed”).
    Federal Circuit: Unique Concepts, Inc. v. Brown, 939 F.2d 1558, 1562-1563, 19
U.S.P.Q.2d (BNA) 1500 (Fed. Cir. 1991) (“subject matter disclosed but not claimed in a patent
application is dedicated to the public”).
    See generally, § 2.05[3[a][i] supra.
    What Maxwell and Johnson & Johnston Associates did was to establish the same rule as a
limitation on the doctrine of equivalents. Their facts indicate how that limitation operates. In
Johnson & Johnston Associates, the patent claimed a removable substrate for handling printed
circuit boards made of “a sheet of aluminum[,]” while the specification disclosed, but did not
claim, substrates made of “other metals, such as stainless steel or nickel alloys[.]” 2002 U.S.
App. LEXIS 5171 at *22. The en banc Federal Circuit held, as a matter of law, that the claims
could not encompass steel substrates under the doctrine of equivalents because they had been
disclosed but not claimed. See 2002 U.S. App. LEXIS 5171 at *22-24. In Maxwell v. J. Baker,
Inc., the patent claimed fastening tabs used to join mated pairs of shoes, which were stitched
between the shoes’ inner and outer soles; it disclosed, but did not claim, fastening tabs stitched
into the shoes’ lining seams. See 86 F.3d at 1102-1103. The Federal Circuit held that the dedica-
tion rule prohibited applying the doctrine of equivalents to the lining-seam fasteners. See 86
F.3d at 1106-1107.
    For discussion of how Johnson & Johnston Associates overruled YBM Magnex, supra, see
N.127.6 infra.
    127.3
           See § 2.05[3][a][i] supra.
    127.4
           See N.127.2 supra.


                                                                                      (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                          127.5                                               127.6
Johnston Associates          virtually set the doctrine in stone.     Yet concur-
ring opinions in the same case raised two issues that might ultimately under-
mine the rule and are therefore worth brief discussion.
   The first issue is a possible inconsistency with the Supreme Court’s deci-
                        127.7
sion in Graver Tank.          As even this book’s brief summary of the case re-
       127.8
veals,       the flux ingredient—manganese silicate—that the Court ultimately
found equivalent to the rare-earth-metal silicates claimed had been disclosed
                      127.9                    127.10             127.11
in the specification.       As Justices Black         and Douglas        argued in

   127.5
           Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App. LEXIS
5171 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam).
    127.6
           See: id., 2002 U.S. App. LEXIS 5171 at *20 (“when a patent drafter discloses but de-
clines to claim subject matter, as in this case, this action dedicates that unclaimed subject matter
to the public”); 2002 U.S. App. LEXIS 5171 at *14-15 (discussing derivation of rule from prin-
ciple that claims, not specification, define scope of patent); 2002 U.S. App. LEXIS 5171 at *20-
22 (discussing policy basis for rule).
    Out of thirteen Judges sitting for the en banc decision, twelve signed the majority’s per
curiam opinion. See 2002 U.S. App. LEXIS 5171 at *2-3. Only Judge Newman dissented. See
2002 U.S. App. LEXIS 5171 at *48-72.
    Judge Newman’s dissent was hardly surprising, as the en banc, per curiam majority over-
ruled a panel decision she had written, which had attempted to narrow the dedication rule ex-
pressed in Maxwell by limiting it to situations in which the disclosed but unclaimed alternative
embodiment is “distinct from the claimed alternative[.]” YBM Magnex, Inc. v. International
Trade Commission, 145 F.3d 1317, 1320, 46 U.S.P.Q.2d (BNA)1843 (Fed. Cir. 1998), distin-
guishing Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1106-1108, 39 U.S.P.Q.2d (BNA) 1001 (Fed.
Cir. 1996). Faced with a choice between a full-strength and a diluted Maxwell rule, the en banc,
per curiam majority chose full strength. See: Johnson & Johnston Associates, Inc. v. R.E. Ser-
vice Co., 2002 U.S. App. LEXIS 5171 at *12 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam)
(“[T]his court in YBM Magnex purported to limit Maxwell to situations where a patent discloses
an unclaimed alternative distinct from the claimed invention. Thus, this court must decide
whether a patentee can apply the doctrine of equivalents to cover unclaimed subject matter dis-
closed in the specification”); 2002 U.S. App. LEXIS 5171 at *20 (“As stated in Maxwell, when
a patent drafter discloses but declines to claim subject matter, as in this case, this action dedi-
cates that unclaimed subject matter to the public”).
    Although the en banc, per curiam opinion did not explicitly say so, it necessarily overruled
YBM Magnex, as Judge Clevenger, joined by four other judges, pointed out in his concurrence.
See: 2002 U.S. App. LEXIS 5171 at *25 (concurring opinion) (“For the reasons stated in the
court’s opinion in this case, it is not possible for the older holding in Maxwell to live comforta-
bly with the newer holding in YBM Magnex. Our choice in this case was simple: whether to
overrule Maxwell or YBM Magnex”); 2002 U.S. App. LEXIS 5171 at *25 (stating that perceived
conflict between Maxwell and YMB Magnex was only reason for hearing case en banc).
    127.7
           Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 608, 700
S.Ct. 854, 94 L.Ed. 1097 (1950), quoting Sanitary Refrigerator Co. v. Winters, 280 U.S. 30, 42,
50 S.Ct. 9, 74 L.Ed. 147 (1929) (accused device is equivalent to claimed invention “if it per-
forms substantially the same function in substantially the same way to obtain the same result”).
    127.8
           See the text accompanying Ns.107-108 supra.
    127.9
           See: Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 613,
700 S.Ct. 854, 94 L.Ed. 1097 (1950) (dissenting opinion of Justice Black) (quoting trial court as
reporting “‘the fact that manganese is a proper substitute . . . is fully disclosed in the specifica-
tion’ of respondent’s patent”); 339 U.S. at 618 (dissenting opinion of Justice Douglas).

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dissent, that fact should have invoked the dedication rule, precluding applica-
tion of the doctrine of equivalents and requiring judgment for the alleged in-
fringer. In Johnson & Johnston Associates, twelve of the thirteen judges
                                                                    127.12
sitting en banc attempted to explain these inconvenient facts away.        Only
Judge Newman, dissenting, argued that the en banc decision was in “egre-
                                    127.13
gious conflict” with Graver Tank.
    Yet however inconvenient these facts may be, and notwithstanding the two
dissents in Graver Tank, it is hardly tenable to argue that Graver Tank did
away with the dedication rule. The majority opinion in Graver Tank contains
                            123.14
no discussion of that rule,        which was well-founded prior to the Court’s
                           127.15
decision in Graver Tank.          Moreover, the rule has a solid basis in patent

   127.10
             See id., 339 U.S. at 614 (dissenting opinion of Justice Black) (“What is not specifi-
cally claimed is dedicated to the public”).
    127.11
            Id., 339 U.S. at 618 (dissenting opinion of Justice Douglas) (“Manganese silicate, the
flux which is held to infringe, is not an alkaline earth metal silicate. It was disclosed in the ap-
plication and then excluded from the claims. It therefore became public property”).
    127.12
            See Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App. LEXIS
5171 at *17-18 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (majority opinion of twelve
judges, reasoning that “[t]he Court's holding and the history of [the case] show that the patentee
had not dedicated unclaimed subject matter to the public”); 2002 U.S. App. LEXIS 5171 at *38-
41, *45 (concurring opinion of Judge Dyk, reasoning that Graver Tank may have established
dedication rule with volitional component and that patentee had not intended to dedicate man-
ganese silicates to public, as shown by their inclusion in earlier-invalidated claims, but conclud-
ing that “the better reading of Graver Tank . . . is that the issue of dedication by specification
disclosure simply was not decided” and “[t]here is thus no holding on this issue that binds this
court”); 2002 U.S. App. LEXIS 5171 at *24 (concurring opinion of Judge Clevenger, joined by
Judge Dyk and three others) (“For the reasons stated in the opinions for the court and by Judge
Dyk, our decision is not inconsistent with Graver Tank”).
    127.13
              Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App. LEXIS
5171 at *50 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (dissenting opinion of Judge New-
man) (“This en banc court has placed itself in egregious conflict with the Supreme Court’s deci-
sions” in Graver Tank and Warner-Jenkinson), referring to: Warner-Jenkinson Co. v. Hilton
Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) and Graver
Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 700 S.Ct. 854, 94 L.Ed.
1097 (1950).
    123.14
               See Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *38-39 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (concurring opinion of
Judge Dyk) (“Despite Justice Jackson’s usual elegance and precision of expression, the majority
opinion does [*39] not respond to either dissent or explain why there had been no dedication to
the public as a result of the disclosures in the specification. As a result, we must look to the facts
of the case to determine the scope of the Court’s holding” in Graver Tank).
    127.15
              Both Justices Black and Douglas, in their dissents, cited cases establishing the rule,
although none had directly addressed its application to the doctrine of equivalents. See Graver
Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 614-615, 700 S.Ct. 854,
94 L.Ed. 1097 (1950) (dissenting opinion of Justice Black), citing: Miller v. Bridgeport Brass
Co., 104 U.S. (14 Otto) 350, 352, 35, 26 L.Ed. 783 (1882) (“The claim of a specific device or
combination, and an omission to claim other devices or combinations apparent on the face of the
patent, are, in law, a dedication to the public of that which is not claimed”) and Milcor Steel Co.
v. George A. Fuller Co., 316 U.S. 143, 146, 62 S.Ct. 969, 86 L.Ed. 1332 (1942) (“Out of all the

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        127.16
policy,       which the majority opinion in Graver Tank, focusing narrowly
on the factual question of equivalence in that case, did not address at all. To
presume that Graver Tank overruled the dedication rule is therefore to assume
that the Supreme Court overruled an important basic principle of patent
claiming and several precedents by implication—a tenuous conclusion at best.
   The second question was raised by Judge Rader’s concurrence in Johnson
& Johnson Associates, in which he proposed a “foreseeability” test for apply-
                                        127.17
ing the dedication rule to equivalents.        Equivalents of what is claimed, he
proposed, should be not be covered by the claims if they would have been
                                               127.18
foreseeable, during the application process,          to a person of ordinary skill
                                          127.19
in the art in light of the specification.        Judge Rader suggested, among

possible permutations of elements which can be made from the specifications, [the patentee]
reserves for himself only those contained in the claims”) (Citation to opinion below and internal
quotation marks omitted.); Graver Tank & Manufacturing Co. v. Linde Air Products Co., supra,
339 U.S. at 518, Citing: Milcor Steel Co. v. George A. Fuller Co., 316 U.S. 143, 62 S.Ct. 969,
86 L.Ed. 1332 (1942) and Mahn v. Harwood, 112 U.S. 354, 361, 5 S.Ct. 174, 28 L.Ed.665
(1884) (“The public is notified and informed by the most solemn act on the part of the patentee,
that his claim to invention is for such and such an element or combination, and for nothing
more. Of course, what is not claimed is public property”).
    127.16
              See Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *21-22 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam), citing Maxwell v. J.
Baker, Inc., 86 F.3d 1098, 1107, 39 U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996) (Internal citations
omitted.):
       “[A] patentee cannot narrowly claim an invention to avoid prosecution scrutiny by the
   PTO, and then, after patent issuance, use the doctrine of equivalents to establish infringe-
   ment because the specification discloses equivalents. ‘Such a result would merely encourage
   a patent applicant to present a broad disclosure in the specification of the application and file
   narrow claims, avoiding examination of broader claims that the applicant could have filed
   consistent with the specification.’ . . . By enforcing the Maxwell rule, the courts avoid the
   problem of extending the coverage of an exclusive right to encompass more than that proper-
   ly examined by the PTO. Keystone Bridge Co. v. Phoenix Iron Co., 95 U.S. 274, 278, 24
   L.Ed. 344 (1877) [*22] (‘The courts have no right to enlarge a patent beyond the scope of its
   claim as allowed by the Patent Office, or the appellate tribunal to which contested applica-
   tions are referred.’).”
See also, § 2.05[3][a][i] supra.
     127.17
              See Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App.
LEXIS 5171 at *24-37 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (concurring opinion of
Judge Rader).
     127.18
             One of several weaknesses in Judge Rader’s proposal is that it does not specify pre-
cisely when “foreseeability” should be assessed. His general reference to the “application pro-
cess,” however, suggests that foreseeability may depend on the give and take of the patent
prosecution process as a whole. See 2002 U.S. App. LEXIS 5171 at *25 (concurring opinion of
Judge Rader).
     127.19
             See id., 2002 U.S. App. LEXIS 5171 at *25-26 (concurring opinion of Judge Rad-
er):
   “[T]he doctrine of equivalents does not capture subject matter that the patent drafter reason-
   ably could have foreseen during the application process and included in the claims. This
   principle enhances the notice function of claims by making them the sole definition of in-

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other things, that such a rule would preserve the doctrine of equivalents as
applied to after-discovered technology because it would not have been fore-
                                                127.20
seeable at the time the invention was made.            Judge Lourie, also concur-
                                                   127.21
ring, however, found this proposal unworkable.
    Whatever may be its merits for the doctrine of equivalents as a whole, a
“foreseeability” limitation on the dedication rule would be both undesirable
and unnecessary. Although Judge Rader apparently intended the foreseeabil-
ity test to limit the dedication rule, and thereby to breath new life into the doc-
trine of equivalents, it could have the opposite effect. A dedication rule based
on what the specification suggests (if foreseeable), rather than on what it dis-
closes, would open up infringement law to expansive interpretation of the
specification that would impose limits on equivalence far beyond those liter-
ally stated in the disclosure. More important, as Judge Lourie noted in his
               127.22
concurrence,          a foreseeability test would require the same sort of extrin-



   vention scope in all foreseeable circumstances. This principle also protects patentees against
   copyists who employ insubstantial variations to expropriate the claimed invention in some
   unforeseeable circumstances.”
Judge Rader viewed the dedication rule, as applied to the facts of Johnson & Johnston Associ-
ates, as merely a special case of his foreseeability rule. That is, he viewed explicit disclosure of
an alternative embodiment in the patent specification as an extreme case of foreseeability and
failure to claim, thus restricting application of the doctrine of equivalents. See 2002 U.S. App.
LEXIS 5171 at *35-36 (concurring opinion of Judge Rader) (“Johnson’s patent disclosure ex-
pressly admits that it foresaw other metals serving as substrates. Yet the patent did not claim
anything beyond aluminum. Foreseeability bars Johnston from recapturing as an equivalent
subject matter not [*36] claimed but disclosed”).
    127.20
             Id., 2002 U.S. App. LEXIS 5171 at *31-32, discussing Sage Products, Inc. v. Devon
Industries, Inc., 126 F.3d 1420, 44 U.S.P.Q.2d (BNA)1103 (Fed. Cir. 1997).
    127.21
            Id., 2002 U.S. App. LEXIS 5171 at *46-47 (concurring opinion of Judge Lourie):

        “I do not agree that the concept of foreseeability would simplify equivalence issues and
   make them more amenable to summary judgment. In fact, it would raise new factual issues.
   Determining what is foreseeable would often require expert testimony as to what one skilled
   in the art would have foreseen. How would a trial judge know whether to grant summary
   judgment other than to make factual findings? What is foreseeable is quite different from
   what is disclosed in the patent, as in our case here, which is readily determinable. Foreseea-
   bility is not solely a question of law.

       “Moreover, the concept of foreseeability seems akin to obviousness. Assuming that the
   concepts are similar, and that foreseeability or obviousness precludes equivalence, would not
   a plaintiff asserting equivalence [*47] have to show that the accused device would not have
   been obvious, or foreseeable, in order to avoid a finding of nonequivalence? And would not
   a defendant have to assert that his device was obvious and hence ineligible for equivalence
   protection in order to escape liability for patent infringement? It seems counterintuitive for a
   patentee to have to assert that an accused device was nonobvious or for the accused to have
   to assert that it was obvious.”
   127.22
            See N.127.21 supra.


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                127.23
sic evidence         —inventors’ and experts’ testimony—that the Federal Cir-
cuit has been trying assiduously to exclude from the claim-interpretation pro-
cess in the interests of certainty, predictability, and the “notice function” of
                127.24
patent claims.         Imposing a “foreseeability” requirement on the dedication
rule would be a step backward in the direction of an equivalents jurisprudence
with all the certainty of a game of chance.
    Moreover, a foreseeability limitation on the dedication rule is unnecessary
to preserve the rule that after-discovered technology can be equivalent to
claimed technology. If an accused technology is truly after-discovered, it is
unlikely to have been disclosed in the specification of a patent previously
issued, and therefore the dedication rule is unlikely to exclude it from the
scope of equivalence.
    When properly applied, the dedication rule is a good rule. It is virtually
                                                                             128
unique among patent-infringement rules in its clarity, ease of application,
reliance on the terms of the patent alone, economic rationality, and sound
        128.1
policy.       In order to realize all these advantages, however, the rule neces-

   127.23
             For a discussion of this term and its significance, see § 2.05[3][a][iii] supra.
   127.24
             See: § 2.05[3] (introduction) supra; § 2.05[3][a][iii] supra.
   128
        See Johnson & Johnston Associates, Inc. v. R.E. Service Co., 2002 U.S. App. LEXIS
5171 at *18 (Fed. Cir. Mar. 28, 2002) (en banc, per curiam) (“one of the advantages of the
Maxwell rule is that it is a purely objective test. The patentee’s subjective intent is irrelevant to
determining whether unclaimed subject matter has been disclosed and therefore dedicated to the
public”), referring to Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1106-1107, 39 U.S.P.Q.2d (BNA)
1001 (Fed. Cir. 1996), discussed in N.127.2 supra.

   128.1
           As the Federal Circuit has noted on several occasions, the rule preserves the integrity
of the patent examination process by forcing the patent applicant to include in the claims all
matter in the specification that the applicant wants to control, thereby insuring that claims to
such matter will be subjected to careful scrutiny by the patent examiner. See: Johnson & John-
ston Associates, Inc. v. R.E. Service Co., 2002 U.S. App. LEXIS 5171 at *21-22 (Fed. Cir. Mar.
28, 2002) (en banc, per curiam), quoting Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1107, 39
U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996) (Internal citations omitted.) (“[A] patentee cannot
narrowly claim an invention to avoid prosecution scrutiny by the PTO, and then, after patent
issuance, use the doctrine of equivalents to establish infringement because the specification
discloses equivalents. ‘Such a result would merely encourage a patent applicant to present a
broad disclosure in the specification of the application and file narrow claims, avoiding exami-
nation of broader claims that the applicant could have filed consistent with the specification’”);
Sage Products, Inc. v. Devon Industries, Inc., 126 F.3d 1420, 1421, 44 U.S.P.Q.2d (BNA) 1103
(Fed. Cir. 1997):
   “If Sage desired broad patent protection for any container that performed a function similar
   to its claimed container, it could have sought claims with fewer structural encumbrances.
   Had Sage done so, then the Patent and Trademark Office (PTO) could have fulfilled its
   statutory role in helping to ensure that exclusive rights issue only to those who have, in fact,
   contributed something new, useful, and unobvious. Instead, Sage left the PTO with manifest-
   ly limited claims that it now seeks to expand through the doctrine of equivalents. However,
   as between the patentee who had a clear opportunity to negotiate broader claims but did not
   do so, and the public at large, it is the patentee who must bear the cost of its failure to seek
   protection for this foreseeable alteration of its claimed structure.”


                                                                                         (Rel. 25)
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sarily requires a clear statement in the patent specification of the disclosure
that is deemed preclusive. After the relevant claim has been interpreted by the
                                        128.2
court, what it covers will be clear.          Yet interpreting the claim literally
                                                                128.3
requires judicial proceedings (usually Markman hearings)               which, in the
                                                                  128.4
general case, are matters of some nuance and complexity.                It would be
inappropriate and counterproductive to require the same sort of complex and
time-consuming interpretation of the specification’s language for the purpose
of assessing the dedication rule’s preclusive effect.
    The dedication rule therefore should not allow an allegedly preclusive dis-
                                                            128.5
closure to be twisted like the proverbial nose of wax.            It should be con-
fined to unclaimed disclosures that are explicit in the specification, and not
extended to alleged “disclosures” that are merely implied, suggested or fore-
seeable. A broader approach would only import into dedication jurisprudence
all the complexity and uncertainty of claim interpretation, robbing the dedica-
tion rule of its signal advantages: clarity and simplicity.
    The Supreme Court tested and reconfirmed many features of the doctrine
of equivalents in an important 1997 decision. In that decision—Warner-
                                                    128.6
Jenkinson Co. v. Hilton Davis Chemical Co.                —the Supreme Court re-
versed and remanded a splintered en banc decision of the Federal Cir-
      128.7
cuit.        Its reversal, however, was on a point of prosecution history
estoppel. The Supreme Court directed that the doctrine of prosecution history
estoppel be applied to bar equivalents analysis unless the patentee can
demonstrate that claim amendments were made for reasons other than patent-
        128.8                                   128.8a
ability       —a ruling it reaffirmed in Festo.        With respect to the viability

   128.2
           See § 2.05[3][a] supra (discussing claim interpretation).
   128.3
           See § 2.05[3][a][iv] supra.
   128.4
           See § 2.05[3][a][ii]-[iv] supra.
   128.5
            See White v. Dunbar, 119 U.S. 47, 51, 7 S.Ct. 72, 30 L.Ed.303 (1886) (“Some per-
sons seem to suppose that a claim in a patent is like a nose of wax which may be turned and
twisted in any direction, by merely referring to the specification, so as to make it include some-
thing more than, or something different from, what its words express”).
    128.6
           Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040,
137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (March 3, 1997).
    128.7
           Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 35 U.S.P.Q.2d
(BNA) 1641 (Fed. Cir. 1995) (en banc), rev'd and remanded 520 U.S. 17, 117 S.Ct. 1040, 137
L.Ed.2d 146, 1997 U.S. LEXIS 1476 (March 3, 1997). The court below had produced three
separate dissenting opinions of five judges, leaving a majority of seven concurring with the
court's view. See 1997 U.S. LEXIS at *13.
    128.8
           See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33-34, 40-41,
117 S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 at *26-30, *41 (March 3, 1997),
discussed in: § 2.05[3] (introduction) supra; § 2.05[3][b][i][B], infra.
    The patent at issue had claimed a process for chemical ultrafiltration “through a membrane
having a nominal pore diameter of 5-15 Angstroms under a hydrostatic pressure of approximate-
ly 200 to 400 p.s.i.g., at a pH from approximately 6.0 to 9.0[.]” Id., 520 U.S. at22 (quoting

                                                                                      (Rel. 25)
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                                     128.9
of the doctrine of equivalents       and its major features at issue in that case,
however, the Supreme Court either affirmed the majority view of the Federal
Circuit sitting en banc or deferred to that court's expert judgment.
    In particular, the Warner-Jenkinson Court reconfirmed three key principles
of the doctrine of equivalents. First, it affirmed the doctrine's continuing vital-
ity against arguments that, inter alia, adoption of the Patent Act of 1952 had
                                     128.10
impliedly repealed or narrowed it.           Second, it ruled that the doctrine of

claim of patent) (Emphasis omitted.) The accused process had operated at the same pore diame-
ter and an overlapping range of pressure, but at a pH of only 5.0, below the claimed range. See
520 U.S. at 23. Both the upper and lower limits of the claimed range of pH had been added by
narrowing amendments during patent prosecution. See 520 U.S. at 22 & n.2. The upper limit—
which was not an issue in the case—had been added to avoid prior art, but the reason for the
lower limit was unclear and disputed. See 520 U.S. at 22 n.2, 32-33.
    The Federal Circuit affirmed a jury's verdict of infringement under the doctrine of equiva-
lents, declining to find an estoppel, apparently because even the defendant's proffered reason for
the narrowing amendment had nothing to do with patentability, insofar as concerned the critical
lower limit of pH. See 520 U.S. at 23. The Supreme Court, however, reversed and remanded,
instructing the Federal Circuit to address the real reason for the amendment and to require the
patentee to bear the burden of proving that the reason did not relate to patentability. See 520
U.S. at 33:
   “Mindful that claims do indeed serve both a definitional and a notice function, we think the
   better rule is to place the burden on the patent-holder to establish the reason for an amend-
   ment required during patent prosecution. The court then would decide whether that reason is
   sufficient to overcome prosecution history estoppel as a bar to application of the doctrine of
   equivalents to the element added by that amendment. Where no explanation is established,
   however, the court should presume that the PTO had a substantial reason related to patenta-
   bility for including the limiting element added by amendment. In those circumstances, pros-
   ecution history estoppel would bar the application of the doctrine equivalents as to that
   element.”
     Justices Ginsburg and Kennedy concurred but cautioned lest the presumption be applied un-
fairly to patentees who had no notice of the importance of establishing a record of reasons at the
time they made their narrowing amendments. See 520 U.S. at 41-42 (“The new presumption, if
applied woodenly, might in some instances unfairly discount the expectations of a patentee who
had no notice at the time of patent prosecution that such a presumption would apply. Such a
patentee would have had little incentive to insist that the reasons for all modifications be memo-
rialized in the file wrapper as they were made”).
     128.8a
             See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1841-1842, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (reaffirming that burden
is “on the patentee to show that an amendment was not for purposes of patentability”), citing
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997). See generally: § 2.05[3] (introduction) supra; § 2.05[3][b][i][B] infra.
     128.9
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 40, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997) (“Today we adhere to the doctrine of equivalents”). See also, the
text accompanying Ns.128.09-128.10 infra.
     128.10
             See: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 25-28, 117
S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 at *26-30, *41 (March 3, 1997); N.128.9
supra.
     The Supreme Court considered and rejected arguments that the doctrine of equivalents: (1)
undermines the “public notice” function of the distinct claims required by 35 U.S.C. § 112,
discussed in § 2.05[3] (introduction), [a][iv] supra; (2) undermines the reissue process under 35

                                                                                      (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

equivalents, like patent infringement in general, does not depend upon the
                            128.11
alleged infringer's intent.        Finally, the Court ruled that prosecution histo-

U.S.C. § 251, discussed in § 2.03[1][d][iii] supra, which permits claims to be broadened upon
reissue, but only after renewed examination within two years; (3) “is inconsistent with the pri-
macy of the Patent and Trademark Office (PTO) in setting the scope of a patent through the
patent prosecution process[,]” Warner-Jenkinson Co. v. Hilton Davis Chemical Co., , supra,
520 U.S. at 25; and (4) was extinguished by implication in the enactment of 35 U.S.C. § 112, ¶
6, which mentions equivalent elements in means-plus-function claims only, see Warner-
Jenkinson, supra, 520 U.S. at 25-26. As the Supreme Court put it, see 520 U.S. at 26 n.3, the
first three of these arguments had been raised in a vigorous dissent in Graver Tank and rejected,
see Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 613-615 & n.3,
700 S.Ct. 854, 94 L. Ed. 1097 (1950) (Black, J., dissenting), and the first argument had been
rejected in substance as early as 1854, see Winans v. Denmead, 56 U.S. 330, 347, 15 How. 330,
14 L.Ed. 717 (1854) (dissenting opinion, arguing that doctrine of equivalents was inconsistent
with requirement for particular claiming in 1836 Patent Act). Reasoning that the Patent Act of
1952 was “not materially different from the 1870 Act with regard to claiming, reissue, and the
role of the PTO[,]” the Court refused to overrule Graver Tank, which had applied the 1870 Act.
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., supra, 520 U.S. at 26-27. As for Section
112, ¶ 6, the Court reasoned that it was intended only to overrule a judicial decision that had
invalidated means-plus-function claims entirely, and to limit the scope of those claims, but that
it had no broader purposes. See 520 U.S. at 27-28 (citing Halliburton Oil Well Cementing Co. v.
Walker, 329 U.S. 1, 8, 67 S.Ct. 6, 91 L.Ed. 3 (1946), as rejecting means-plus-function claims).
Accordingly, the Court refused to reject the “lengthy history” of the doctrine of equivalents and
left its repeal or substantial modification to Congress. See 520 U.S. at 28 (“Congress can legis-
late the doctrine of equivalents out of existence any time it chooses”). The Supreme Court reaf-
firmed this point in Festo. See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535
U.S. 722, 732-733, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“[I]n
Warner-Jenkinson, the Court reaffirmed that equivalents remain a firmly entrenched part of the
settled rights protected by the patent. A unanimous opinion concluded that if the doctrine is to
be discarded, it is Congress and not the Court that should do so”), citing Warner-Jenkinson Co.
V. Hilton Davis Chemical Co., supra, 520 U.S. at 28; 122 U.S. at 1841 (In [Warner-Jenkinson]
we made it clear that the doctrine of equivalents and the rule of prosecution history estoppel are
settled law. The responsibility for changing them rests with Congress”).
     128.11
             See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 35, 117 S.Ct.
1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997):
   “If the essential predicate of the doctrine of equivalents is the notion of identity between a
   patented invention and its equivalent, there is no basis for treating an infringing equivalent
   any differently than a device that infringes the express terms of the patent. Application of the
   doctrine of equivalents, therefore, is akin to determining literal infringement, and neither re-
   quires proof of intent.”
    The Federal Circuit had reasoned that a defendant's intention to copy the patentee's invention
justified at least a rebuttable presumption of insubstantial differences between the claimed in-
vention and the accused device. See 62 F.3d at 1517-1520. The Supreme Court, however,
soundly rejected this analysis, pointing out the difficulty of distinguishing “between the inten-
tional copyist making minor changes to lower the risk of legal action, and the incremental inno-
vator designing around the claims, yet seeking to capture as much as is permissible of the
patented advance.” Warner-Jenkinson Co. v. Hilton Davis Chemical Co., supra, 520 U.S. at 36.
In the end, the Supreme Court found permissible only one inference arising from intent: the
absence of independent experimentation might show that the interchangeability of one claimed
ingredient or element with another was known to persons of ordinary skill in the art. See 520
U.S. at 36 (“Independent experimentation by the alleged infringer would not always reflect upon
the objective question whether a person skilled in the art would have known of the interchange-
ability between two elements, but in many cases it would likely be probative of such

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

ry estoppel remains a viable limitation on the extent to which the doctrine of
                                                                    128.12
equivalents may expand the scope of a patent claim's literal reach.
   Besides confirming these venerable principles of equivalence in patent
law, however, the Warner-Jenkinson Court clarified the doctrine of equiva-
lents in three respects. First, it confirmed the rule that the doctrine must be
                                                                           128.13
applied on an element-by-element basis, not to the invention as a whole.
In this regard the Court followed the lead of the majority of judges on the
                  128.14
Federal Circuit.         Second, it ruled that the precise verbal formulation of
the standard of equivalents may depend upon the nature of the inven-
      128.15                                                          128.16
tion.        It noted, as separately opining judges had done below,          that
the so-called “triple identity” test (for substantially the same function, way



knowledge”). The Court concluded that “[t]he better view, and the one consistent with Graver
Tank's predecessors and the objective approach to infringement, is that intent plays no role in
the application of the doctrine of equivalents.” Id.
    128.12
            See id., 520 U.S. at 30 (“We can readily agree with petitioner that Graver Tank did
not dispose of prosecution history estoppel as a legal limitation on the doctrine of equivalents”).
For further discussion of prosecution history estoppel, see: §§ 2.05[3][b][i][B], 2.06 [2] infra.
    128.13
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct.
1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (“Each element contained in a patent
claim is deemed material to defining the scope of the patented invention, and thus the doctrine
of equivalents must be applied to individual elements of the claim, not to the invention as a
whole”). See also, N.128.19 infra.
    128.14
            The Supreme Court cited for this proposition the dissenting opinion of Judge Nies in
the same case below, see id., 520 U.S. at 29, quoting 62 F.3d at 1573-1574 (Nies, J., dissenting),
but a significant body of pre-existing Federal Circuit precedent also had supported the same
view. See the text accompanying Ns.116-122 supra.
    128.15
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 40, 117 S.Ct.
1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (“Different linguistic frameworks may
be more suitable to different cases, depending on their particular facts”).
    128.16
            See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1546, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995) (en banc), rev'd and remanded on other grounds 520
U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (dissenting opinion,
arguing that function-way-result test is inappropriate for chemical and biological inventions). As
an example, this dissenting opinion offered:
   “the well-known analgesics aspirin and ibuprofen. These compounds have the same function
   (to provide analgesia, antiinflammatory activity, and lower temperature), do so in the same
   way (by inhibiting prostaglandin synthesis), and give the same results (kill pain, relieve in-
   flammation, and lower fever). Yet, they have different structures, which makes them differ-
   ent compounds, and no knowledgeable person would consider that a claim to aspirin would
   be infringed by the sale of ibuprofen.”
    The en banc majority of the Federal Circuit also had recognized this point. See id., 62 F.3d
at 1518 (majority opinion) (function-way-result test is not “'the' test for equivalency announced
by Graver Tank” because it “arose in an era characterized by relatively simple mechanical tech-
nology[;]” “[a]s technology becomes more sophisticated, and the innovative process more com-
plex, the function-way-result test may not invariably suffice to show the substantiality of the
differences” between claimed invention and accused device).

                                                                                       (Rel. 25)
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              128.17
and result),         might be less appropriate for certain inventions than a test
                                        128.18
based upon insubstantial differences.          The Court refused, however, to
choose between the two verbal formulations, leaving the development of the
standard to the Federal Circuit's expert judgment on a case-by-case ba-
     128.19
sis.        The Supreme Court thus left substantially intact a key aspect of the
Federal Circuit's en banc decision, which recharacterized the test for equiva-
lence from the old triple-identity test to a standard of insubstantial differ-
       128.20
ences         between the literal claims of the patent and the accused device,
assessed on an objective basis from the point of view of those skilled in the
              128.21
relevant art.        Finally, the Supreme Court ruled that prosecution history
                                                                  128.22
estoppel, which limits the scope of the doctrine of equivalents,         depends

   128.17
            See the text accompanying Ns.102.22-103 supra.
   128.18
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 39-40, 117
S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (“There seems to be substantial
agreement that, while the triple identity test may be suitable for analyzing mechanical devices, it
often [*40] provides a poor framework for analyzing other products or processes”).
    128.19
           See id., 520 U.S. at 40:

       “In our view, the particular linguistic framework used is less important than whether the
   test is probative of the essential inquiry: Does the accused product or process contain ele-
   ments identical or equivalent to each claimed element of the patented invention? Different
   linguistic frameworks may be more suitable to different cases, depending on their particular
   facts. A focus on individual elements and a special vigilance against allowing the concept of
   equivalence to eliminate completely any such elements should reduce considerably the im-
   precision of whatever language is used. An analysis of the role played by each element in the
   context of the specific patent claim will thus inform the inquiry as to whether a substitute el-
   ement matches the function, way, and result of the claimed element, or whether the substi-
   tute element plays a role substantially different from the claimed element. With these
   limiting principles as a backdrop, we see no purpose in going further and micro-managing
   the Federal Circuit's particular word-choice for analyzing equivalence. We expect that the
   Federal Circuit will refine the formulation of the test for equivalence in the orderly course of
   case-by-case determinations, and we leave such refinement to that court's sound judgment in
   this area of its special expertise.”
   128.20
            See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1517, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995) (en banc), rev'd and remanded on other grounds 520
U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (majority opinion)
(“the application of the doctrine of equivalents rests on the substantiality of the differences
between the claimed and accused products or processes, assessed according to an objective
standard”).
     128.21
            See id., 62 F.3d at 1519 (“the vantage point of one of ordinary skill in the relevant art
provides the perspective for assessing the substantiality of the differences. The test is objective,
with proof of the substantiality of the differences resting on objective evidence rather than unex-
plained subjective conclusions, whether offered by an expert witness or otherwise”). The suspi-
cion of expert testimony expressed in this passage echoes the disfavor of expert testimony
expressed by the Federal Circuit for the purpose of literal claim interpretation. See §
2.05[3][a][iii] supra.
     128.22
            See: the text accompanying Ns.128.11-128.12 supra; §§ 2.05[3][b][i][B], 2.06[2] in-
fra.

                                                                                         (Rel. 25)
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                                                128.23
on the reason for claim amendments,           and that narrowing amendments
made for reasons other than patentability do not create an estoppel and there-
                                                      128.24
fore do not limit the scope of available equivalents.
    The Supreme Court refused to address one important issue that had trou-
                                   128.25
bled the en banc Federal Circuit          —the jury's role in applying the doc-
                                                                      128.26
trine of equivalents. While expressly refusing to decide this issue,         the
Supreme Court hinted that precedent already had entrenched the jury's

   128.23
            Reviewing several precedents involving estoppel, see Warner-Jenkinson Co. v. Hil-
ton Davis Chemical Co., N. 128.19 supra, 520 U.S. at *30-32, the Court concluded that the
narrowing claim amendment that had created the estoppel in each case had been made “because
the claim as otherwise written [had been] viewed as not describing a patentable invention at
all—typically because what it described was encompassed within the prior art.” 520 U.S. at 31.
    The Court noted, however, that what counts is the reason for claim amendments at the time
they are made, not their legal correctness. See 520 U.S. at 33 n.7. A patentee is still estopped by
a narrowing amendment made to avoid unpatentability, even if the amendment turns out to have
been unnecessary for that purpose, because the public should be able to rely on it.
    128.24
            See id., 520 U.S. at 32 (“Our prior cases have consistently applied prosecution histo-
ry estoppel only where claims have been amended for a limited set of reasons, and we see no
substantial cause for requiring a more rigid rule invoking an estoppel regardless of the reasons
for a change”).
    Through its brief as amicus curiae, the PTO had argued that it often had requested claim
amendments “without the intent to limit equivalents[,]” 520 U.S. at 31-32, and the Court felt it
would be unfair to change the rules of the game in the middle. See 520 U.S. at 32 n.6, (“To
change so substantially the rules of the game now could very well subvert the various balances
the PTO sought to strike when issuing the numerous patents which have not yet expired and
which would be affected by our decision”).
    In Festo, however, the Supreme Court clarified that it did not mean to limit estoppel when
claim amendments relate to questions of patentability. There it ruled unambiguously that a claim
amendment related to any statutory requirement for patentability may give rise to an estoppel.
See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 741, 122 S.Ct.
1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“We agree with the Court of Ap-
peals that a narrowing amendment made to satisfy any requirement of the Patent Act may give
rise to an estoppel); 122 S.Ct. 1839-1840 (specifically citing requirement for novelty, utility,
nonobviousness, written description, enablement, and best mode. But cf., 122 S.Ct. at 1840
(giving as examples of amendments not related to patentability those made “to clarify an ambig-
uous term, to improve the translation of a foreign word, or to rewrite a dependent claim as an
independent one”).
    128.25
            See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1537, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995) (en banc), rev'd and remanded on other grounds 520
U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (dissenting opinion,
lamenting “continued unfettered use of the doctrine of equivalents, at the discretion of a jury[,]”
which encourages lawyers to invoke the doctrine in nearly every case); id., 62 F.3d at 1537
(“The cases typically come to us on appeal with nothing more than a general verdict finding
infringement. There is no explanation by the jury of the rationale behind their verdict, if any
exists. This case is a good example”).
    128.26
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 38, 117 S.Ct.
1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (footnote omitted.):
    “Because resolution of whether, or how much of, the application of the doctrine of equiva-
lents can be resolved by the court is not necessary for us to answer the question presented, we
decline to take it up. . . . Whether, if the issue were squarely presented to us, we would reach a
different conclusion than did the Federal Circuit is not a question we need decide today.”

                                                                                       (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

     128.27
role.      It encouraged the district courts to control unbridled jury discre-
                                                                            128.28
tion—a point about which several judges below had complained                       —
through such procedural devices as partial or complete summary judgments,
judgments as a matter of law, and “special verdict[s] and/or interrogatories on
                        128.29
each claim element[.]”
   The Supreme Court thus impliedly endorsed the Federal Circuit's view that
the doctrine of equivalents is not a matter of equity in the procedural sense of
         128.30                                                      128.31
that term       and is not to be applied at the court's discretion.         The Su-
preme Court viewed the doctrine's expanding the literal scope of the patent's
                             128.32                         128.33
claims as a matter of right,        and it strongly implied        that the doctrine
                                                                              128.34
invokes the right of trial by jury guaranteed by the Seventh Amendment.


   128.27
            See id., 520 U.S. at 38 (“The Federal Circuit [below] held that it was for the jury to
decide whether the accused process was equivalent to the claimed process. There was ample
support in our prior cases for that holding”), citing: Machine Co. v. Murphy, 97 U.S. 120, 125,
24 L.Ed. 935 (1878) and Winans v. Denmead, 56 U.S. (15 How.) 330, 344, 14 L.Ed. 717
(1854). See also, 520 U.S. at 38-39 (“Markman cites with considerable favor, when discussing
the role of judge [*39] and jury, the seminal Winans decision”), referring to Markman v.
Westview Instruments, Inc., 517 U.S. 37-, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996), discussed in
§ 2.05[3][a][iv] supra.
    128.28
            See N. 128.25 supra.
    128.29
            Warner-Jenkinson Co. v. Hilton Davis Chemical Co., N.128.26 supra, 520 U.S. at
39 n.8.
    128.30
            See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1521, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995) (en banc), rev'd and remanded on other grounds 520
U.S. 17, 117 S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997) (majority opinion).
    128.31
            See id. (“The trial judge does not have discretion to choose whether to apply the doc-
trine of equivalents when the record shows no literal infringement”).
    128.32
            The Supreme Court recognized that the doctrine of equivalents does not so much ex-
tend the literal scope of a patent's claim as recognize when the claim in substance covers an
accused device, despite the limitations of its literal language, because the claimed invention and
accused device are really the same. See Warner-Jenkinson Co. v. Hilton Davis Chemical Co.,
520 U.S. 17, 35, 117 S.Ct. 1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997), quoting
Machine Co. v. Murphy, 97 U.S. 120, 125, 24 L.Ed. 935 (1878):
   “The substantial equivalent of a thing, in the sense of the patent law, is the same as the thing
   itself; so that if two devices do the same work in substantially the same way, and accomplish
   substantially the same result, they are the same, even though they differ in name, form, or
   shape.”
    See also, N.128.11 supra.
    128.33
            See the text accompanying Ns.128.25-128.29 supra.
    128.34
             The Federal Circuit was explicit on this point. See Hilton Davis Chemical Co. v.
Warner-Jenkinson Co., 62 F.3d 1512, 1521, 35 U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995) (en
banc), rev'd and remanded on other grounds 520 U.S. 17, 117 S.Ct. 1040, 137 L Ed.2d 146,
1997 U.S. LEXIS 1476 (March 3, 1997) (majority opinion), citing Graver Tank & Manufactur-
ing Co. v. Linde Air Products Co., 339 U.S. 605, 609-610, 700 S.Ct. 854, 94 L. Ed. 1097 (1950)
(other citations omitted.) (“infringement under the doctrine of equivalents is an issue of fact to

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    It is important to note, however, that the Supreme Court did not require the
ultimate issue of equivalence vel non to be decided as a matter of fact or by a
      128.35
jury.         There are suggestions in the Court's opinion that certain subsidiary
facts may be for the jury to decide, leaving the ultimate issue of equivalence
                 128.36
to the Court.           More important, the doctrine of equivalents is circum-
                                                     128.37
scribed not only by prosecution history estoppel,            but also by the prior
     128.38
art.         The question whether a hypothetical claim that would cover an
                                           128.39
equivalent would trench upon prior art            seems much akin to the sort of
                                                                         128.40
question of literal claim interpretation that the Markman decision,             for
                                                       128.41
sound policy reasons, assigned to the judge alone.            At the very least, a
trial judge must police the element-by-element approach to the doctrine of
              128.42
equivalents           and the presumption regarding reasons for claim amend-
        128.43
ments          that the Supreme Court has mandated. There are thus a number of
                        128.44                           128.45
points, in substance           as well as in procedure,         on which district




be submitted to the jury in a jury trial with proper instructions, and to be decided by the judge in
a bench trial”).
    128.35
            See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 38, 117 S.Ct.
1040, 137 L.Ed.2d 146, 1997 U.S. LEXIS 1476 (1997), quoted more fully in N. 128.27 supra
(“resolution of whether, or how much of, the application of the doctrine of equivalents can be
resolved by the court is not necessary for us to answer”). (Emphasis added.)
    128.36
            See id., 520 U.S. at 25, quoting Graver Tank & Manufacturing Co. v. Linde Air
Products Co., 339 U.S. 605, 609, 700 S.Ct. 854, 94 L. Ed. 1097 (1950):
   “Consideration must be given to the purpose for which an ingredient is used in a patent, the
   qualities it has when combined with the other ingredients, and the function which it is in-
   tended to perform. An important factor is whether persons reasonably skilled in the art would
   have known of the interchangeability of an ingredient not contained in the patent with one
   that was.”
   128.37
             See N. 128.8 supra and the text accompanying Ns.128.11-128.12, 128.21-128.24
supra. See generally: §§ 2.05[3][b][i][B], 2.06[2] infra.
    128.38
            See the text accompanying Ns. 132-134 infra.
    128.39
            See the text accompanying Ns. 133-133.1 and N. 133.1 infra.
    128.40
            Markman v. Westview Instruments, Inc., 517 U.S. 370, 372, 116 S.Ct. 1384, 1387,
134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (“We hold that the
construction of a patent, including terms of art within its claim, is exclusively within the prov-
ince of the court”), discussed in § 2.05[3] (introduction), [a][ii], [iv] supra.
    128.41
            See § 2.05[3][a][iv] supra.
    128.42
            See the text accompanying Ns.128.12-128.13 and N. 128.13 supra.
    128.43
            See N. 128.8 supra.
    128.44
            See the text accompanying Ns.128.35-128.43 supra.
    128.45
            See the text accompanying Ns.128.27-128.29 supra.


                                                                                        (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

courts can police the outer boundaries of the doctrine of equivalents and save
                                                129
the important notice function of patent claims from runaway juries.
Apart from the foregoing observations, it is difficult to generalize about the
doctrine of equivalents, for its primary purpose is to do justice in the individ-
          130
ual case.     Nevertheless, the doctrine has several additional features worth
mentioning. First, the starting point for its application is the claims of the pa-
                                     131
tent, not the inventor's embodiment.      Correct interpretation of the claims, in
                                                                      132
accordance with the rules used for assessing literal infringement,        is thus a
prerequisite to application of the doctrine.
   Second, the doctrine of equivalents does not “extend [patent coverage] to
an infringing device within the public domain, i.e., found in the prior art at the

   129
         See: N.128.8 supra; § 2.05[3] (introduction), [a][iii], [iv] supra.
   130
        See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 732, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), citing Winans v. Denmead,
56 U.S. (15 How.) 330, 347, 14 L.Ed. 717 (1854) (seminal decision on doctrine of equivalents):
   “The language in the patent claims may not capture every nuance of the invention or de-
   scribe with complete precision the range of its novelty. If patents were always interpreted by
   their literal terms, their value would be greatly diminished. Unimportant and insubstantial
   substitutes for certain elements could defeat the patent, and its value to inventors could be
   destroyed by simple acts of copying. For this reason, the clearest rule of patent interpretation,
   literalism, may conserve judicial resources but is not necessarily the most efficient rule. The
   scope of a patent is not limited to its literal terms but instead embraces all equivalents to the
   claims described.”
See also, Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 607, 700
S.Ct. 854, 94 L. Ed. 1097 (1950), quoted in part in Festo Corp. v. Shoketsu Kinzoku Kogyo
Kabushiki Co., 234 F.3d 558, 615, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (opinion by
Judges Michel and Rader, concurring on all but complete bar rule) , vacated and remanded on
other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705
(2002):
       “[C]ourts have . . . recognized that to permit imitation of a patented invention which
   does not copy every literal detail would be to convert the protection of the patent grant into a
   hollow and useless thing. Such a limitation would leave room for—indeed encourage—the
   unscrupulous copyist to make unimportant and insubstantial changes and substitutions in the
   patent which, though adding nothing, would be enough to take the copied matter outside the
   claim, and hence outside the reach of law. One who seeks to pirate an invention, like one
   who seeks to pirate a copyrighted book or play, may be expected to introduce minor varia-
   tions to conceal and shelter the piracy. Outright and forthright duplication is a dull and very
   rare type of infringement. To prohibit no other would place the inventor at the mercy of ver-
   balism and would be subordinating substance to form. It would deprive him of the benefit of
   his invention and would foster concealment rather than disclosure of inventions, which is
   one of the primary purposes of the patent system.” See also, N.143 infra.
   131
         See, e.g.: Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 870 (Fed. Cir. 1985); SRI Inter-
national v. Matsushita Electric Corp., 775 F.2d 1107, 1121 (Fed. Cir. 1985) (“Infringement,
literal or by equivalence, is determined by comparing an accused product not with a preferred
embodiment described in the specification, or with a commercialized embodiment of the patent-
ee, but with the properly and previously construed claims in suit”). (Citations omitted.)
     132
         See § 2.05[3][a] supra.


                                                                                        (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                             133
time the patent issued.”    Thus, prior art limits the scope of equivalents. The
limitations may be assessed by drafting a hypothetical patent claim to cover
the device accused of infringement; if that hypothetical claim would not have
been allowed over prior art, the doctrine of equivalents cannot reach the de-
               133.1
vice at issue.       The range of equivalents allowable under this approach is
confined not only by what the prior art anticipates, but also by what it renders
         134
obvious.
   The third general feature of the doctrine of equivalents is that the breadth
of equivalents considered depends on the character and importance of the
                     135
patented invention. As the Supreme Court observed:



   133
          Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 870 (Fed. Cir. 1985). See also: Wilson
Sporting Goods Co. v. David Geoffrey & Associates, 904 F.2d 677, 683 (Fed. Cir.), cert. denied
498 U.S. 992 (1990) (“there can be no infringement if the asserted scope of equivalency of what
is literally claimed would encompass the prior art) (Citations omitted.); Black & Decker, Inc. v.
Hoover Service Center, 886 F.2d 1285, 1295 (Fed. Cir. 1989) (“the range of equivalents to
which a claimed invention is entitled may never be so great as to encompass a structure in the
prior art”) (Citation omitted.); Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934 n.1
(Fed. Cir. 1987), cert. denied 485 U.S. 961 (1988) (en banc) (same).
     133.1
            See Wilson Sporting Goods Co. v. David Geoffrey & Associates, 904 F.2d 677, 684
(Fed. Cir.), cert. denied 498 U.S. 992 (1990) (Emphasis in original.):
   “[I]t may be helpful to conceptualize the limitation on the scope of equivalents by visualiz-
   ing a hypothetical patent claim, sufficient in scope to literally cover the accused product.
   The pertinent question then becomes whether that hypothetical claim could have been al-
   lowed by the PTO over prior art. If not, then it would be improper to permit the patentee to
   obtain that coverage in an infringement suit under the doctrine of equivalents. If the hypo-
   thetical claim could have been allowed, then prior art is not a bar to infringement under the
   doctrine of equivalents.”
    This approach may encounter conceptual difficulties when the accused devise is itself pa-
tented. See, e.g., National Presto Industries, Inc. v. West Bend Co., 76 F.3d 1185, 1192, 37
U.S.P.Q.2d (BNA) 1685 (Fed. Cir. 1996) (suggesting need to “reconcile the asserted
unpatentability of a hypothetical claim that covers [the accused device] with [defendant's] ar-
gument that its device is itself patented”).
    For this reason the Federal Circuit has not endorsed this approach as the exclusive method of
assessing the effect of prior art on the doctrine of equivalents. See 76 F.3d at 1192 (“The Trial
court need not create a hypothetical claim and determine its hypothetical patentability before the
jury can find the fact of equivalency vel non”).
    134
         See Wilson Sporting Goods Co. v. David Geoffrey & Associates, 904 F.2d 677, 685
(Fed. Cir.), cert. denied 498 U.S. 992 (1990) (refusing to find equivalents where hypothetical
claim would have been obvious in light of prior art).
    135
         See: Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 608-
609, 700 S.Ct. 854, 94 L.Ed. 1097 (1950); Eibel Process Co. v. Minnesota & Ontario Paper Co.,
261 U.S. 45, 63, 43 S.Ct. 322, 67 L.Ed. 523 (1923); Continental Paper Bag Co. v. Eastern Paper
Bag Co., 210 U.S. 405, 414-415, 28 S.Ct. 718, 52 L.Ed. 1122 (1908) (doctrine applies to more
than pioneer patents, but range of equivalents varies with degree of invention).
    See generally, Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 963-964 (Fed. Cir.
1987), cert. denied 485 U.S. 961 (1988) (dissenting opinion) (reviewing authorities).

                                                                                      (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

   “[T]he court first looks into the art to find what the real merit of the al-
   leged discovery or invention is and whether it has advanced the art sub-
   stantially. If it has done so, then the court is liberal in its construction of
   the patent to secure to the inventor the reward he deserves. If what he has
   done works only a slight step forward and that which he says is a discovery
   is on the border line between mere mechanical change and real invention,
   then his patent, if sustained, will be given a narrow scope and infringement
   will be found only in approximate copies of the new device. It is this dif-
   fering attitude of the courts toward genuine discoveries and slight im-
   provements that reconciles the sometimes apparently conflicting instances
   of construing specifications and the finding of equivalents in alleged in-
                   136
   fringements.”

Thus, fundamental or “pioneer” inventions are entitled to a broad range of
             137
equivalents,     while small advances in the art receive only narrow additional
            138
protection.     Even a minor advance in the art, however, is entitled to protec-
                                                  139
tion against more than just literal infringement,     while a pioneering inven-



   136
          Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45, 63, 43 S.Ct. 322, 67
L.Ed. 523 (1923).
    137
          See, e.g.:
    Second Circuit: International Nickel Co. v. Ford Motor Co., 166 F. Supp. 551, 554-557, 564
(S.D.N.Y. 1958) (use of magnesium in iron alloy contrary to conventional wisdom was “daring
accomplishment,” and, together with long-felt need and commercial success, marked pioneering
invention entitled to broad range of equivalents).
    Eighth Circuit: Priebe & Sons Co. v. Hunt, 188 F.2d 880, 881 (8th Cir.), cert. dismissed 342
U.S. 801 (1951) (“A primary or pioneer invention is entitled to a broad and liberal construction
and to a broad and liberal range of equivalents and is not to be limited to the precise device and
instrumentality disclosed”). (Citations omitted.)
    Tenth Circuit: McCullough Tool Co. v. Well Surveys, Inc. 343 F.2d 381, 401 (10th Cir.
1965), cert. denied 383 U.S. 933 (1966) (combination patent “which constitutes a marked im-
provement in the art” was entitled to a “substantial range” of equivalents). (Citations omitted.)
    138
          See, e.g.:
    Fifth Circuit: Rothstein v. Atlanta Paper Co., 321 F.2d 90, 94, 95 (5th Cir. 1963) (paper car-
rier for soft-drink bottles had “no basic or pioneer aspects” and was “in old and crowded art”).
    Sixth Circuit: Deyerle v. Wright Manufacturing Co., 496 F.2d 45, 51 (6th Cir. 1974) (claims
in crowded art are entitled to only narrow range of equivalents); Krantz v. Van Dette, 165 F.
Supp. 776, 782 (N.D. Ohio 1958), aff'd 272 F.2d 709 (6th Cir. 1959) (prior art included same
inventor's dominant patent).
    139
          See, e.g.:
    Supreme Court: Continental Paper Bag Co. v. Eastern Paper Bag Co., 210 U.S. 405, 414-
415, 28 S.Ct. 748, 52 L.Ed. 1122 (1908) (range of equivalents depends upon degree and nature
of invention, but invention need not be “primary” or “pioneer” in order to enjoy protection of
doctrine of equivalents).
    Third Circuit: Baldwin-Lima-Hamilton Corp. v. Tatnall Measuring Systems Co., 169 F.
Supp. 1, 8 (E.D. Pa. 1958) (doctrine applies even to “secondary invention consisting of a com-
bination of old ingredients which will produce a new and useful result”).

                                                                                      (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

tion may be entitled to a range of equivalents exceeding numerical limitations
                      140
in the specification.
    The fourth salient feature of the doctrine of equivalents is that it has a cor-
ollary: the so-called “reverse doctrine of equivalents.” Under this doctrine, an
alleged infringer can escape liability for literal infringement if the accused
device or process, although literally covered by the patent's claims, performs
the same function as the patented invention in a substantially different
     140.1
way.

               [B]—The Effect of Prosecution History Estoppel
   Under the doctrine of prosecution history estoppel, a patentee cannot re-
                                                                         141
cover in infringement litigation ground given up in patent prosecution.
Any relinquishment of claim coverage in the course of patent prosecution,
whether by argument, admission, or amendment of claims, creates an estoppel
that restricts the scope of coverage of the patent in infringement litiga-
      141.1
tion.       For practical purposes, however, claim amendments are by far the


   140
           See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 22-23, 40-41,
117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (after reaffirming vitality of doctrine of equiva-
lents, remanding for determination whether “ultrafiltration” process for dyes that operated a pH
of 5.0 infringed patent on similar process claiming pH range from 6.0 to 9.0).
     Cf., International Nickel Co. v. Ford Motor Co., 166 F. Supp. 551, 564-565 (S.D.N.Y. 1958)
(patent claiming “small but effective” amount of magnesium in iron alloy covered magnesium
concentrations as low as 0.02% under doctrine of equivalents, although patent disclosure speci-
fied 0.04% as probable minimum).
     140.1
            See § 2.06[3] infra.
     141
          See: § 2.05[3] (introduction), [b][i][B] supra; § 2.06[2] infra.
     141.1
            See, e.g.: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 568,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“Argu-
ments made voluntarily during prosecution may give rise to prosecution history estoppel if they
evidence a surrender of subject matter. . . . There is no reason why an amendment-based surren-
der of subject matter should be given less force than an argument-based surrender of subject
matter”); KCJ Corp. v. Kinetic Concepts, Inc., 223 F.3d 1351, 1359-1360, 55 U.S.P.Q.2d 1835
(BNA), 1841-1842 (Fed. Cir. 2000) (patentee’s statements made during prosecution “reflect[ed]
a clear and unmistakable surrender” of subject matter that could not be reclaimed through the
doctrine of equivalents); Bayer AG v. Elan Pharmaceutical Research Corp., 212 F.3d 1241,
1252-1253, 54 U.S.P.Q.2d (BNA) 1711, 1719 (Fed. Cir. 2000) (statements and declarations
filed with PTO constituted “clear and unmistakable surrender of subject matter” which patentee
could not recapture under doctrine of equivalents); Pharmacia & Upjohn Co. v. Mylan Pharma-
ceuticals, Inc., 170 F.3d 1373, 1377, 50 U.S.P.Q. (BNA) 2d 1033, 1036 (Fed. Cir. 1999) (“A
number of activities during prosecution may give rise to prosecution history estoppel, . . . in-
cluding arguments made to obtain allowance of the claims at issue”) (Citation omitted.);
Southwall Technologies., Inc. v. Cardinal IG Co., 54 F.3d 1570, 1583, 34 U.S.P.Q.2d (BNA)
1673, 1682 (Fed. Cir. 1995) (“Clear assertions made during prosecution in support of patentabil-
ity, whether or not actually required to secure allowance of the claim, may . . . create an estop-
pel”); Texas Instruments Inc. v. United States International Trade Commission, 988 F.2d 1165,
1174, 26 U.S.P.Q.2d (BNA) 1018, 1025 (Fed. Cir. 1993) (arguments made during prosecution

                                                                                      (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

most important sources of prosecution history estoppel because they affect
claim coverage by their very nature. Other possible sources, such as corre-
spondence, argument, and admissions, must be clear and must clearly surren-
                                                                   141.2
der claim coverage in order to serve as the basis for an estoppel.
                                                             141.3
   The doctrine of prosecution history estoppel is general;        it restricts the
applied scope of patent claims both literally and under the doctrine of equiva-
       141.4
lents.       For two reasons, however, it has special importance as applied to
the doctrine of equivalents.
   The first reason is a practical one. Most instances of estoppel arise from
narrowing amendments to claims made during the patent prosecution pro-
      141.5
cess.        Since a narrowing amendment ipso facto changes the literal scope

emphasizing feature of invention estopped patentee from asserting that device lacking it in-
fringed under doctrine of equivalents).
    See also, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., supra, 234 F.3d at 564
(“Actions by the patentee, including claim amendments and arguments made before the Patent
Office, may give rise to prosecution history estoppel”), citing Pharmacia & Upjohn Co. v. Mylan
Pharmaceuticals, Inc., 170 F.3d 1373, 1376-1377, 50 U.S.P.Q.2d 1033, 1036 (Fed. Cir. 1999).
    141.2
           See Rambus Inc. v. Infineon Technologies, AG, 318 F.3d 1081, 1089-1090 (Fed. Cir.
2003) (holding that patentee’s letter responding to rejection, which set forth three general char-
acteristics of invention by way of imprecise introduction, did not impose corresponding limita-
tions on all claims, some of which recited them and some of which did not, whether by
prosecution history estoppel or otherwise: “[t]he claim language itself controls the bounds of the
claim, not a facially inaccurate remark during prosecution”), citing Intervet America, Inc. v.
Kee-Vet Laboratories, Inc., 887 F.2d 1050, 1054, 12 U.S.P.Q.2d (BNA) 1474 (Fed. Cir. 1989).
    141.3
           See: § 2.05[3][a][i] supra; § 2.06[2] infra.
    141.4
           See id.
    141.5
           During the patent prosecution process, the patent examiner often rejects one or more
proposed claim in an application for patent. See § 1.06[1] supra (outlining patent application
procedure). A rejection may be based on any statutory requirement for patentability. See 37
C.F.R. § 1.104(a) (“The examination shall be complete with respect both to compliance of the
application . . . with the applicable statutes and rules and to the patentability of the invention as
claimed, as well as with respect to matters of form, unless otherwise indicated”). Upon receiving
notice of a rejection, the applicant has three options: (1) to withdraw the rejected claim(s), (2) to
amend them, or (3) to argue with the examiner and, if the examiner persists in the rejection, to
appeal it within the Patent and Trademark Office and then to the courts. See § 1.06[1] supra.
When the applicant narrow a claim by amendment in order to avoid a rejection and obtain a
patent, the narrowing amendment creates a prosecution history estoppel. See Festo Corp. v.
Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct. 1831, 1838-1839, 152
L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (Citations omitted.):
   “A rejection indicates that the patent examiner does not believe the original claim could be
   patented. While the patentee has the right to appeal, his decision to forgo an appeal and
   submit an amended claim is taken as a concession that the invention as patented does not
   reach as far as the original claim. . . . Were it otherwise, the inventor might avoid the PTO’s
   gatekeeping role and seek to recapture in an infringement action the very subject matter sur-
   rendered as a condition of receiving the patent.”
   See also, 535 U.S. at 734:
   “Prosecution history estoppel ensures that the doctrine of equivalents remains tied to its un-
   derlying purpose. Where the original application once embraced the purported equivalent but

                                                                                         (Rel. 25)
2-05                      PATENTS               INTELLECTUAL PROPERTY LAW

of the claim, the estoppel effect for purposes of literal infringement is self-
                                                                 141.6
evident. Indeed, subject to construction of the claim language,        it appears
on the face of the patent. The limiting effect of estoppel on the doctrine of
equivalents, however, is hardly self-evident from the face of the patent, which
does not reveal whether or how any claim was amended during the patent
                      141.7
prosecution process.        As a result, a potential infringer who wishes to de-
termine whether the application to a particular claim of the doctrine of
equivalents has been restricted by the estoppel effect of an amendment made
during prosecution must request and receive the patent prosecution history or
“file wrapper,” which contains, inter alia, the correspondence between the
patent applicant and the Patent and Trademark Office (PTO) during prosecu-
      141.8
tion.       Only by studying the prosecution history or “file wrapper” can a
potential infringer determine whether any particular claim was amended and,
            141.9
if so, how.       That determination is the first step in analyzing the effect of
                                                                         141.10
prosecution history estoppel on the scope of equivalents of any claim.
    The second reason why the most important application of the doctrine of
prosecution history estoppel is to restrain equivalents analysis is legal.
                                                                   141.11
Whenever a claim has been amended for unexplained reasons                 the pa-


   the patentee narrowed his claims to obtain the patent or to protect its validity, the patentee
   cannot assert that he lacked the words to describe the subject matter in question. The doc-
   trine of equivalents is premised on language’s inability to capture the essence of innovation,
   but a prior application describing the precise element at issue undercuts that premise. In that
   instance the prosecution history has established that the inventor turned his attention to the
   subject matter in question, knew the words for both the broader and narrower claim, and af-
   firmatively chose the latter.”
   141.6
           See § 2.05[3][a][ii] supra.
   141.7
           The issued patent contains only finally allowed claims. See § 1.06[1] supra.
   141.8
           See: § 1.06[1] supra; § 2.06[2] infra.
   141.9
          See § 1.06[1] supra.
   141.10
           See § 2.05[3] (introduction), [a][iv] supra.
   141.11
           See, e.g.:
   Supreme Court: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 740,
122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting and explaining
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997):
   “When the patentee is unable to explain the reason for amendment, estoppel not only applies
   but also ‘bars the application of the doctrine of equivalents as to that element.’ . . . These
   words do not mandate a complete bar; they are limited to the circumstance where ‘no expla-
   nation is established.’ They do provide, however, that when the court is unable to determine
   the purpose underlying a narrowing amendment—and hence a rationale for limiting the es-
   toppel to the surrender of particular equivalents—the court should presume that the patentee
   surrendered all subject matter between the broader and the narrower language.”
See also, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 564, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc) (“we hold that ‘unexplained’ amendments

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

tentee is not entitled to any range of equivalents with respect to the amended
claim. Although the Supreme Court has declined to call this a “complete bar”
                                         141.12                          141.13
to applying the doctrine of equivalents,         the effect is the same.
An amended claim is presumed not to be entitled to equivalents analysis un-
less the patentee proves that the amendment was made for reasons other than
               141.14
patentability.        This presumption restrains the doctrine of equivalents by
limiting the number and type of amended claims to which it applies.
   A second presumption, wrought by the Supreme Court, has a similar ef-
fect. If a claim amendment is not shown to have been made for reasons other
than patentability, the doctrine of equivalents is presumed inapplica-
     141.15
ble.         Like the presumption regarding the amendment’s purpose, howev-
                                             141.15a
er, this presumption is rebuttable.       The patentee may prove that the
amended claim is entitled to a range of equivalents not surrendered by the
amendment, but the patentee bears the burden of proving both the entitlement

are not entitled to any range of equivalents”), vacated and remanded on other 535 U.S. 722,
740, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002).
    141.12
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 740,122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting and explaining
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997) (“When the patentee is unable to explain the reason for amendment,
estoppel not only applies but also ‘bars the application of the doctrine of equivalents as to that
element.’ . . . These words do not mandate a complete bar; they are limited to the circumstance
where ‘no explanation is established’”).
    141.13
            See id., 535 U.S. at 740 (“[W]hen the court is unable to determine the purpose un-
derlying a narrowing amendment—and hence a rationale for limiting the estoppel to the surren-
der of particular equivalents—the court should presume that the patentee surrendered all subject
matter between the broader and the narrower language”).
    141.14
             As examples of reasons other than patentability, the Supreme Court mentioned
amendments made “to clarify an ambiguous term, to improve the translation of a foreign word,
or to rewrite a dependent claim as an independent one.” Festo Corp. v. Shoketsu Kinzoku Kogyo
Kabushiki Co., 535 U.S. 722, 736,122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA)
1705 (2002).
    141.15
            See id., 535 U.S. at 740:

   “The patentee, as the author of the claim language, may be expected to draft claims encom-
   passing readily known equivalents. A patentee’s decision to narrow his claims through
   amendment may be presumed to be a general disclaimer of the territory between the original
   claim and the amended claim.”

   ***

   “This presumption is not . . . just the complete bar by another name. Rather, it reflects the
   fact that the interpretation of the patent must begin with its literal claims, and the prosecu-
   tion history is relevant to construing those claims. When the patentee has chosen to narrow a
   claim, courts may presume the amended text was composed with awareness of this rule and
   that the territory surrendered is not an equivalent of the territory claimed.”
   141.15a
              See id., 535 U.S. at 740 (“the patentee still might rebut the presumption that estop-
pel bars a claim of equivalence”). See also, 535 U.S. at 740, quoted in N.141.15c infra.

                                                                                       (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                                       141.15b
to such a range and its extent.          According to the Supreme Court, the
patentee must show that the equivalent asserted was “unforeseeable at the
time of the application[,]” that “the rationale underlying the amendment . . .
bear[s] no more than a tangential relation to the equivalent in question, or
“some other reason suggesting that the patentee could not reasonably be ex-
                                                                    141.15c
pected to have described the insubstantial substitute in question.”         If the
patentee cannot carry the burden of proving one or more of these points, the
amended claim element cannot cover equivalents of the literal matter
         141.16
claimed.        These twin presumptions—that claim amendments are made
for purposes related to patentability and that amended claim elements have no
equivalents—make it vital to determine whether a claim element has been
narrowed by amendment.
   In determining whether a claim element has been amended, substance gov-
erns form. Replacing an independent claim with a corresponding but narrow-
                                                                  141.17
er independent claim will be deemed a narrowing amendment,                even if

   141.15b
              See id., 535 U.S. at 740 (“The patentee must show that at the time of the amend-
ment one skilled in the art could not reasonably be expected to have drafted a claim that would
have literally encompassed the alleged equivalent”).
   141.15c
              The quoted material reads in context as follows:

   “There are some cases . . . where [a claim] amendment cannot reasonably be viewed as sur-
   rendering a particular equivalent. The equivalent may have been unforeseeable at the time of
   the application; the rationale underlying the amendment may bear no more than a tangential
   relation to the equivalent in question; or there may be some other reason suggesting that the
   patentee could not reasonably be expected to have described the insubstantial substitute in
   question. In those cases the patentee can overcome the presumption that prosecution history
   estoppel bars a finding of equivalence.”
     Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 740, 122 S.Ct. 1831,
152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002).
     141.16
            See id., 535 U.S. at 740 (“While estoppel does not effect a complete bar, the question
remains whether petitioner can demonstrate that the narrowing amendments did not surrender
the particular equivalents at issue. On these questions, respondents may well prevail, for the
sealing rings and the composition of the sleeve both were noted expressly in the prosecution
history. These [*1843] matters, however, should be determined in the first instance by further
proceedings in the Court of Appeals or the District Court”).
     141.17
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 588, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (where “the
only original independent claim, which did not recite a magnetizable sleeve, was replaced with
an independent claim which does recite a magnetizable sleeve,” concluding that “the amend-
ment narrowed the literal scope of the claim”); 234 F.3d at 589 (other “amendment narrowed the
literal scope of the claim because it substituted an independent claim that recited a sealing ring
element for an independent claim that did not recite such an element”).
     See generally, 234 F.3d at 587-588:
   “To determine whether a claim amendment gives rise to prosecution history estoppel, we
   first must determine whether the amendment narrowed the literal scope of the claim. Here we
   are presented with the situation where the added claim element was introduced through a
   new claim, instead of through an amendment to an original claim. Nevertheless, the addition

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                              141.18
done in reexamination proceedings.           Narrowing an element of an inde-
pendent claim will, in effect, narrow all dependent claims that depend upon
    141.19
it.         Even adding structural limitations to a means-plus-function claim
                                          141.20
may constitute a narrowing amendment.
     The Supreme Court and the Federal Circuit together have established six
important principles for applying the doctrine of prosecution history estop-
      141.21
pel.         First, prosecution history estoppel applies to any claim element
amended for any reason related to a statutory requirement for patentability,
                                                  141.22
regardless of the statutory section involved;            it is not confined to


   of the [new] element [*588] can be said to have narrowed the scope of the original claim be-
   cause the new claim replaced the original claim.”
    In reviewing the Federal Circuit’s en banc decision in Festo, the Supreme Court did not ex-
plicitly address how to determine whether an amendment narrowed a claim limitation. See Festo
Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 726, 122 S.Ct. 1831, 152
L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (grant of certiorari addressed two questions:
whether prosecution history estoppel applies to claim amendments made for reasons other than
avoiding prior art and whether complete bar rule applies). Nevertheless, the Supreme Court’s
analysis implicitly adopted the Federal Circuit’s on this point, for the Supreme Court’s entire
discussion was premised upon the existence of a narrowing amendment. See, e.g.: 535 U.S. at
726 (“When the patentee responds to [an examiner’s] rejection by narrowing his claims, this
prosecution history estops him from later arguing that the subject matter covered by the original,
broader claim was nothing more than an equivalent”) (Emphasis added.); 535 U.S. at 740
(“When . . . the patentee originally claimed the subject matter alleged to infringe but then nar-
rowed the claim in response to a rejection, he may not argue that the surrendered territory com-
prised unforeseen subject matter that should be deemed equivalent to the literal claims of the
issued patent”) (Emphasis added.); 122 S.Ct. at 1840 (“Estoppel arises when an amendment is
made to secure the patent and the amendment narrows the patent’s scope”). (Emphasis added.)
    141.18
            See id., 234 F.3d at 590 (claim element introduced during reexamination “through a
new claim, instead of through the amendment of a pending claim[,]” consisted narrowing
amendment where original claim, which had not recited pair of sealing rings, was replaced by
independent claim that did).
    141.19
            Id., 234 F.3d at 590 n.6.
    141.20
            Id., 234 F.3d at 589, citing Laitram Corp. v. Rexnord Inc., 939 F.2d 1533, 1536, 19
U.S.P.Q.2d (BNA) 1367, 1370 (Fed. Cir. 1991):
   “Even if the amendment that added the sealing ring element merely replaced the means-plus-
   function language with a recitation of the corresponding structure, the amendment had the
   effect of narrowing the scope of the claim. A claim element recited in means-plus-function
   language literally encompasses the corresponding structure and its equivalents. . . . In con-
   trast, a claim element that recites the corresponding structure does not literally encompass
   equivalents of that structure. . . . Thus, a claim amendment that replaces means-plus-
   function language with language reciting the corresponding structure narrows the literal
   scope of the claim.”
   141.21
            These principles are also discussed in § 2.05[3] (introduction) supra.
   141.22
             See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 737, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“We agree with the Court of
Appeals that a narrowing amendment made to satisfy any requirement of the Patent Act may
give rise to an estoppel”). See also, 535 U.S. at 737 (specifically citing requirements for novel-

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW




ty, utility, nonobviousness, written description, enablement, and best mode). But cf., 535 U.S. at
737 (mentioning as examples of amendments not related to patentability those made “to clarify
an ambiguous term, to improve the translation of a foreign word, or to rewrite a dependent claim
as an independent one”).
     On this point, the Supreme Court generally affirmed the Federal Circuit, although vacating
the Federal Circuit’s decision for applying a complete bar to equivalents analysis to every
amended claim element. See 535 U.S. at 737 (“we disagree with the decision to adopt the com-
plete bar”). Thus, the en banc Federal Circuit’s pronouncements with regard to reasons related
to patentability are probably still good law. See, e.g., Festo Corp. v. Shoketsu Kinzoku Kogyo
Kabushiki Co., 234 F.3d 558, 567, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc),
vacated and remanded on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62
U.S.P.Q.2d (BNA) 1705 (2002) (“substantial reasons related to patentability include 35 U.S.C.
§§ 101 and 112 issues, as well as 35 U.S.C. §§ 102 and 103 issues”); 234 F.3d at 566 (enumer-
ating subject matter, novelty, utility, nonobviousness, and disclosure requirements for patenta-
bility); 234 F.3d at 566-567, citing Manual of Patent Examining Procedure, ¶¶ 2100-1 to 2100-
173 (7th ed. rev. 1 1998), and quoting Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520
U.S. 17, 33, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997):
   “The Patent Office will reject a patent application that fails to satisfy any one of these statu-
   tory requirements. . . . And [*567] any one of these requirements may be a ground for inval-
   idating an issued patent. . . . An amendment related to any of these statutory requirements is
   an amendment made for ‘a substantial reason related to patentability.’”
    See also, e.g., 234 F.3d at 589 (rejecting argument that amendment made in response to Sec-
tion 112 rejection was not made for reason related to patentability: “[b]ecause a claim will not
issue unless it satisfies the requirements of section 112, an amendment made to satisfy the stat-
ute is an amendment made for a reason related to patentability”).
    Nevertheless, the Supreme Court seems to have taken a more cautious approach to the ques-
tion than the Federal Circuit, particularly with regard to Section 112 disclosure issues, demand-
ing some analysis in each case, rather than application of a per se rule. See Festo Corp. v.
Shoketsu Kinzoku Kogyo Kabushiki Co., supra, 535 U.S. at 735, quoting Warner-Jenkinson
Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 30-32, 33,117 S.Ct. 1040, 137 L.Ed.2d 146
(1997), and citing 520 U.S. at 40-41:
   “Our ‘prior cases have consistently applied prosecution history estoppel only where claims
   have been amended for a limited set of reasons,’ such as ‘to avoid the prior art, or otherwise
   to address a specific concern—such as obviousness—that arguably would have rendered the
   claimed subject matter unpatentable.’ While we made clear that estoppel applies to amend-
   ments made for a ‘substantial reason related to patentability,’ we did not purport to define
   that term or to catalog every reason that might raise an estoppel. Indeed, we stated that even
   if the amendment’s purpose were unrelated to patentability, the court might consider whether
   it was the kind of reason that nonetheless might require resort to the estoppel doctrine.”
See also, 535 U.S. at 736 (Emphasis added.):
   “Estoppel arises when an amendment is made to secure the patent and the amendment nar-
   rows the patent’s scope. If a § 112 amendment is truly cosmetic, then it would not narrow
   the patent’s scope or raise an estoppel. On the other hand, if a § 112 amendment is neces-
   sary and narrows the patent’s scope—even if only for the purpose of better description—
   estoppel may apply. A patentee who narrows a claim as a condition for obtaining a patent
   disavows his claim to the broader subject matter, whether the amendment was made to avoid
   the prior art or to comply with § 112. We must regard the patentee as having conceded an
   inability to claim the broader subject matter or at least as having abandoned his right to ap-
   peal a rejection. In either case estoppel may apply.”


                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                                               141.23
amendments made to skirt prior art,         although they undoubtedly will be
                                        141.24
one of its most common applications.           Second, prosecution history es-
toppel applies to voluntary amendments made on the patent applicant’s own
initiative, as well as to amendments made in response to examiners’ require-
                        141.25
ments and rejections.          Both the motive for making the amendment, as


   141.23
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct.
1831, 1839, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“[E]stoppel has been dis-
cussed most often in the context of amendments made to avoid the prior art. . . . It does not
follow, however, that amendments for other purposes will not give rise to estoppel. Prosecution
history may rebut the inference that a thing not described was indescribable. That rationale does
not cease simply because the narrowing amendment, submitted to secure a patent, was for some
purpose other than avoiding prior art”). (Citations omitted.)
    The Supreme Court generally affirmed the en banc Federal Circuit’s views on this point,
which also should be good law. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234
F.3d 558, 563, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded
on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705
(2002), quoting Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997) (Footnote omitted.):
   “[W]e hold that ‘a substantial reason related to patentability’ is not limited to overcoming
   prior art, but includes other reasons related to the statutory requirements for a patent. There-
   fore, an amendment that narrows the scope of a claim for any reason related to the statutory
   requirements for a patent will give rise to prosecution history estoppel with respect to the
   amended claim element.”
    See also, 234 F.3d at 566 (to same effect).
    The court’s rationale for this ruling was that the benefits of the notice function of patents ap-
ply equally well to every patentability requirement. See 234 F.3d at 567 (“In view of the func-
tions of prosecution history estoppel—preserving the notice function of the claims and
preventing patent holders from recapturing under the doctrine of equivalents subject matter that
was surrendered before the Patent Office—we see no reason why prosecution history estoppel
should not also arise from amendments made for other reasons related to patentability” other
than avoiding prior art).
    141.24
            Of course amendments intended to skirt prior art create an estoppel as well. See id.,
234 F.3d at 590-591 (where “pair of sealing rings” for piston constituted added element narrow-
ing claim by amendment, facts that patentee had discussed overcoming prior art and examiner
had recited that element, in combination with others, as overcoming prior art showed amend-
ment had been made for reason related to patentability and therefore created estoppel).
    In Festo, however, the Supreme Court clarified that it did not mean to limit estoppel when
claim amendments relate to questions of patentability. There it ruled unambiguously that a claim
amendment related to any statutory requirement for patentability may give rise to an estoppel.
See: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 122 S.Ct. 1831,
1839, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“We agree with the Court of Ap-
peals that a narrowing amendment made to satisfy any requirement of the Patent Act may give
rise to an estoppel”); 535 U.S. at 736 (specifically citing requirements for novelty, utility,
nonobviousness, written description, enablement, and best mode). But cf., 535 U.S. at 736 (giv-
ing as examples of amendments not related to patentability those made “to clarify an ambiguous
term, to improve the translation of a foreign word, or to rewrite a dependent claim as an inde-
pendent one”).
    141.25
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 563-564,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002):

                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                      141.26
distinguished from the legal reasons for it         and legal correctness of the
              141.27
reason for it        are irrelevant. Third, a complete bar, in effect, applies also
                                 141.28
to unexplained amendments,              which are rebuttably presumed to have


   “[W]e hold that ‘voluntary’ claim amendments are treated the same as other claim amend-
   ments; therefore, any voluntary amendment that narrows the scope of a claim for a reason re-
   lated to the statutory requirements for a patent will give rise [*564] to prosecution history
   estoppel with respect to the amended claim element”
    See also: 234 F.3d at 568 (to same effect); 234 F.3d at 587-588 (rejecting arguments that
claim amendment was voluntary and “was not made in response to any prior art rejection and
was not needed to overcome the 35 U.S.C. § 112 rejections of the original claims”).
    Again the rationale for this conclusion was that the benefits of public notice require applying
the bar to both types of amendments. See 234 F.3d at 568:
   “Both voluntary amendments and amendments required by the Patent Office signal to the
   public that subject matter has been surrendered. There is no reason why prosecution history
   estoppel should arise if the Patent Office rejects a claim because it believes the claim to be
   unpatentable, but not arise if the applicant amends a claim because he believes the claim to
   be unpatentable.”
    The Supreme Court in Festo did not address this ruling of the Federal Circuit, sitting en
banc, let alone disturb it. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S.
722, 726, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (grant of certio-
rari addressed only two questions: whether prosecution history estoppel applies to claim
amendments made for reasons other than avoiding prior art and whether complete bar rule ap-
plies). Therefore it is still good law.
    141.26
            See N.141.24 supra.
    141.27
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 576-577,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground
535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (noting that
law does not permit inquiry into whether examiner’s rejection that led to involuntary claim
amendment was proper, or whether “any given amendment was material to the [*577] prosecu-
tion of the patent because ‘the patentee makes them all material by the restricted form of his
claim’”), quoting Hubbell v. United States, 179 U.S. 77, 84, 21 S.Ct. 24, 45 L.Ed. 95 (1900)
(using prosecution history to construe claim and finding no infringement, without discussing
prosecution history estoppel). (Citations omitted.)
    141.28
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 740, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting and explaining
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, , 137
L.Ed.2d 146 (1997) (“When the patentee is unable to explain the reason for amendment, estop-
pel not only applies but also ‘bars the application of the doctrine of equivalents as to [the
amended claim] element’”). For further discussion of this point, see: § 2.05[3] (introduction),
2.05[3][b][i][A] supra. See also: Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234
F.3d 558, 591, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded
on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705
(2002) (where patentee had “not established explanations for [claim] amendments unrelated to
patentability[,]” those “amendments therefore gave rise to prosecution history estoppel. Under
these circumstances, the amended claim elements are entitled to no range of equivalents. Thus,
they cannot be infringed by equivalents”); 234 F.3d at 564 (reversing judgments of infringement
under doctrine of equivalents based on two different patents because of unexplained amend-
ments added in prosecution of one and re-examination of other, which required giving no range
of equivalents to certain limitations of each).

                                                                                       (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                                                  141.29
been made for reasons of patentability.       A patentee who seeks to avoid
the complete bar must bear the burden of proving that an amendment was
                         141.30
made for other reasons,         such as mere clarification or nonstatutory for-
mal requirements.
    As a fourth important principle the Supreme Court established a presump-
tion regarding the existence and scope of equivalents of amended claim limi-
tations. If the patentee fails to bear the burden of proving that a claim
amendment was made for reasons other than patentability (and therefore the


   141.29
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 740, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), quoting and explaining
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 137
L.Ed.2d 146 (1997):
   “When the patentee is unable to explain the reason for amendment, estoppel not only applies
   but also ‘bars the application of the doctrine of equivalents as to that element.’ . . . These
   words do not mandate a complete bar; they are limited to the circumstance where ‘no expla-
   nation is established.’ They do provide, however, that when the court is unable to determine
   the purpose underlying a narrowing amendment—and hence a rationale for limiting the es-
   toppel to the surrender of particular equivalents—the court should presume that the patentee
   surrendered all subject matter between the broader and the narrower language.”
See also, 535 U.S. at 741 (reaffirming that burden is “on the patentee to show that an amend-
ment was not for purposes of patentability”), citing Warner-Jenkinson Co. v. Hilton Davis
Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997). See generally, §
2.05[3] (introduction) supra.
    In this respect the Supreme Court did not disagree with the en banc Federal Circuit. See
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 588, 56 U.S.P.Q.2d
(BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other ground 535 U.S. 722,
122 S.Ct. 1831, 152 L.Ed.2d944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (concluding that narrow-
ing amendment made in response to rejections was unexplained where it did not respond to any
of examiner’s grounds for rejection and there was no explanation in the prosecution history;
mere argument on appeal that amendment was for purposes of clarification only was insufficient
to rebut Hilton-Davis presumption where “nothing in the prosecution history . . . indicate[d] that
the [new] sleeve element was merely added for purposes of clarification unrelated to patentabil-
ity concerns”).
    141.30
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 739-740,
122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (reaffirming that burden is
“on the patentee to show that an amendment was not for purposes of patentability”), citing
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997). In this respect also the Supreme Court did not disagree with the en
banc Federal Circuit. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558,
565, 56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded on other
ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002)
(noting that, where amendment is required during patent prosecution and no reason for it ap-
pears in record, Hilton Davis requires patentee to bear burden of establishing reason), citing
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct. 1040, 1049,
137 L.Ed.2d 146 (1997). See also, N.141.29 supra.
    This rule rests on the same “public notice” rationale of most others announced by the Festo
court. See 234 F.3d at 586, citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520
U.S. 17, 33, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (placing burden of explaining rea-
sons for claim amendments on patentee “gives proper deference to the role of claims in defining
an invention and providing public notice”).

                                                                                      (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

claim amendment is presumed to relate to patentability), the doctrine of
                                        141.30a
equivalents is presumed inapplicable.           The patentee then must bear the
burden of proving the extent of any equivalents remaining despite the claim
                               141.30b                                      141.30c
amendment’s estoppel effect.           This presumption may be rebutted
by showing that the alleged equivalent was “unforeseeable at the time of the
application[,]” that “the rationale underlying the amendment . . . bear[s] no
more than a tangential relation to the equivalent in question[,]” or “some oth-
er reason suggesting that the patentee could not reasonably be expected to
                                                            141.30d
have described the insubstantial substitute in question.”           If the patentee
does not bear the burden of proving the reason for a narrowing claim amend-
ment or of the extent of the its estoppel effect, then the doctrine of equivalents
does not apply to amended claim elements.

   141.30a
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 740,
122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002):
   “The patentee, as the author of the claim language, may be expected to draft claims encom-
   passing readily known equivalents. A patentee’s decision to narrow his claims through
   amendment may be presumed to be a general disclaimer of the territory between the original
   claim and the amended claim.”
   See also, 535 U.S. at 740:
   “This presumption is not . . . just the complete bar by another name. Rather, it reflects the
   fact that the interpretation of the patent must begin with its literal claims, and the prosecu-
   tion history is relevant to construing those claims. When the patentee has chosen to narrow a
   claim, courts may presume the amended text was composed with awareness of this rule and
   that the territory surrendered is not an equivalent of the territory claimed.
   141.30b
              See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 740,
122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“Just as Warner-
Jenkinson held that the patentee bears the burden of proving that an amendment was not made
for a reason that would give rise to estoppel, we hold here that the patentee should bear the bur-
den of showing that the amendment does not surrender the particular equivalent in question”),
referring to Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 33, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997).
     141.30c
             See: id., 535 U.S. at 740 (“[T]he patentee still might rebut the presumption that es-
toppel bars a claim of equivalence. The patentee must show that at the time of the amendment
one skilled in the art could not reasonably be expected to have drafted a claim that would have
literally encompassed the alleged equivalent”); 535 U.S. at 740 (“There are some cases, . . .
where the amendment cannot reasonably be viewed as surrendering a particular equivalent. . . .
In those cases the patentee can overcome the presumption that prosecution history estoppel bars
a finding of equivalence”).
     141.30d
             Id., 535 U.S. at 740:

   “There are some cases . . . where the amendment cannot reasonably be viewed as surrender-
   ing a particular equivalent. The equivalent may have been unforeseeable at the time of the
   application; the rationale underlying the amendment may bear no more than a tangential re-
   lation to the equivalent in question; or there may be some other reason suggesting that the
   patentee could not reasonably be expected to have described the insubstantial substitute in
   question. In those cases the patentee can overcome the presumption that prosecution history
   estoppel bars a finding of equivalence.”


                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    The fifth principle of prosecution history estoppel by amendment is, in
practice, one of the most important. In proving the reasons for an amend-
                                                         141.31
ment, a patentee must rely on “intrinsic” evidence,             primarily the paper
trail in the PTO, which serves the same “notice function” as the patent itself
                                141.32
and is available to the public.        The patentee may cite the patent itself and
                                                                     141.33
its prosecution history but cannot rely on “extrinsic” evidence             such as
                                        141.34
the inventor’s or experts’ testimony.          This rule encourages, if not forces,
patentees who make amendments for reasons unrelated to patentability to
document those reasons explicitly in correspondence with the PTO, so that
the reasons appear in the prosecution history and can be introduced into evi-
dence in infringement litigation.
    The sixth and final principle of prosecution history estoppel by amendment
also relates to the litigation process itself. Like the question of prosecution
                             141.35               141.36
history estoppel generally,         the existence        of a claim amendment, its


   141.31
            For discussion of this term and the underlying principles, see § 2.05[3][a][iii] supra.
   141.32
           See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 586, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), aff’d on this point and vacated and re-
manded on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d
(BNA) 1705 (2002) referring to Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S.
17, 33, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (Footnote omitted.):
       “In order to give due deference to public notice considerations under the Warner-
   Jenkinson framework, a patent holder seeking to establish the reason for an amendment must
   base his arguments solely upon the public record of the patent’s prosecution, i.e., the pa-
   tent’s prosecution history. To hold otherwise—that is, to allow a patent holder to rely on evi-
   dence not in the public record to establish a reason for an amendment—would undermine
   the public notice function of the patent record. If the reasons for the amendment do not ap-
   pear in the public record of the patent’s prosecution, the reasons in most cases will be known
   only to the patent holder. We therefore hold that a narrowing amendment will give rise to
   prosecution history estoppel unless the prosecution history of the patent reveals that the
   amendment was made for a purpose unrelated to patentability concerns.”
   141.33
            For the meaning of this term, see § 2.05[3][a][iii] supra.
   141.34
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 586 n.6,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), aff’d on this point and vacated and
remanded on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d944, 62 U.S.P.Q.2d
(BNA) 1705 (2002) (“in determining the reason for an amendment, a court can properly con-
sider any attorney argument regarding the reason for the amendment that is supported by the
prosecution history record. [However, p]ermitting patent holders to rely on evidence extrinsic to
the prosecution history record would undermine the public notice function of the patent rec-
ord”).
    141.35
            See id., 234 F.3d at 585 (“Prosecution history estoppel is a legal question that is sub-
ject to de novo review by this court. . . . Thus, when reviewing the jury verdict, we will inde-
pendently decide the legal question of the application of prosecution history estoppel . . . .”),
citing LaBounty Manufacturing, Inc. v. United States International Trade Commission, 867 F.2d
1572, 1576, 9 U.S.P.Q.2d (BNA) 1995, 1998 (Fed. Cir. 1989).
    See also, 234 F.3d at 586, citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520
U.S. 17, 39 n.8, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997) (Emphasis added.):

                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                      141.37                                141.38
narrowing effect,         and the reasons for it      are matters of law for the
judge, not the jury, to decide. Where disputed, these matters can be included
                            141.39
in the Markman hearings            by which judges construe the meaning of
claims. To the extent the parties request resolution of these issues in
Markman hearings, those hearing may reduce the cost and delay involved in
                                                             141.40
patent litigation even more than they have already done.            Early resolu-
tion of these issues by judges also may give rise to greater certainty in patent
litigation and perhaps increase the likelihood of early settlement.




       “When infringement is alleged to occur under the doctrine of equivalents, two primary
   legal limitations on the doctrine ‘are to be determined by the court, either on a dispositive
   pretrial motion or on a motion for judgment as a matter of law at the close of evidence and
   after the jury verdict.’. . . Those legal limitations are prosecution history estoppel and the ‘all
   elements’ rule.”
   141.36
          See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 586, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), aff’d on this point and vacated and re-
manded on other ground 535 U.S. 722, 122 S.Ct. 1831, 152 L.Ed.2d944, 62 U.S.P.Q.2d (BNA)
1705 (2002) (Citations omitted and emphasis added.):
       “The first step in a prosecution history estoppel analysis is to determine which claim el-
   ements are alleged to be met by equivalents. Then, the court must determine whether the el-
   ements at issue were amended during prosecution of the patent. If they were not,
   amendment-based estoppel will not bar the application of the doctrine of equivalents. How-
   ever, the court still may need to consider whether statements made during prosecution give
   rise to argument-based estoppel.”
   141.37
           Id., 234 F.3d at 586, citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520
U.S. 17, 40-41, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (Emphasis added.):
       “If the claim elements at issue were amended, the court first must determine whether the
   amendment narrowed the literal scope of the claim. If so, prosecution history estoppel will
   apply unless the patent holder establishes that the amendment was made for a purpose unre-
   lated to patentability. . . . If the patent holder fails to do so, prosecution history estoppel will
   bar the application of the doctrine of equivalents to that claim element.”
    The Supreme Court in Festo did not address this ruling of the Federal Circuit, sitting en
banc, let alone disturb it. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S.
722, 736, 122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (grant of certi-
orari addressed only two questions: whether prosecution history estoppel applies to claim
amendments made for reasons other than avoiding prior art and whether complete bar rule ap-
plies). Therefore it is still good law.
    141.38
            See N.141.37 supra.
    141.39
            See § 2.05[3][a][iv] supra, discussing hearings in which judges construe claims in
accordance with the holding of Markman v. Westview Instruments, Inc., 517 U.S. 370, 372, 116
S.Ct. 1384, 1387, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion)
(“We hold that the construction of a patent, including terms of art within its claim, is exclusively
within the province of the court”).
    141.40
            See § 2.05[3] (introduction), [a][iv] supra.


                                                                                           (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

   No discussion of prosecution history estoppel would be complete without
                                                                141.41
discussion of the Federal Circuit’s “complete bar” gambit.               In its en
                          141.42
banc decision in Festo,             over the dissent of four members of the
       141.43
court,        the Federal Circuit sought to declare a uniform rule that any
claim element amended for reasons of patentability is completely barred from
                          141.44
covering any equivalents.          The court itself recognized that this new rule
                                  141.45
diverged from its prior practice,        but it found the alternative—a flexible

   141.41
            For a general discussion of this point, see § 2.05[3] (introduction) supra.
   141.42
             Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded 535 U.S. 722, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002).
    141.43
            See: id., 234 F.3d at 598 (opinion of Judge Michel, joined by Judge Rader, dissent-
ing with regard to complete-bar rule); 234 F.3d at 627 (opinion of Judge Linn, joined by Judge
Rader, dissenting with regard to complete-bar rule); 234 F.3d at 641-642 (opinion of Judge
Newman, dissenting with regard to complete bar).
    See also, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 730, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) (Supreme Court’s discussion of dissenting
opinions below).
    141.44
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 574, 56
U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded 535 U.S. 722, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“We hold that prosecution
history estoppel acts as a complete bar to the application of the doctrine of equivalents when an
amendment has narrowed the scope of a claim for a reason related to patentability”). See also, §
2.05[3] (introduction) supra (discussing complete bar rule and Supreme Court’s rejection of it).
    141.45
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 574-575,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded 535 U.S. 722,
122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) , referring to Hughes
Aircraft Co. v. United States, 717 F.2d 1351, 1363, 219 U.S.P.Q. (BNA) 473 (Fed. Cir. 1983):
   “Today, we revisit the question we first addressed in Hughes I and come to a different con-
   clusion as to the proper scope of equivalents that is available when prosecution history es-
   toppel applies than we did in that case. We hold that prosecution history estoppel acts as a
   complete bar to the application of the doctrine of equivalents when an amendment has nar-
   rowed the scope of a claim for a reason related to patentability. Our decision to reject the
   flexible bar approach adopted in Hughes I comes after nearly twenty years of experience in
   performing our role as the [*575] sole court of appeals for patent matters. In those years, the
   notice function of patent claims has become paramount, and the need for certainty as to the
   scope of patent protection has been emphasized.”
   See also, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 730, 122
S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002), referring to Warner-
Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040, 1049, 137 L.Ed.2d
146 (1997) (Citations to opinion below omitted.):
   “The [Federal Circuit] acknowledged that its own prior case law did not go so far [as to cre-
   ate a complete bar]. . . . [*1837] . . . In four separate opinions, the dissenters argued that the
   majority’s decision to overrule precedent was contrary to Warner-Jenkinson and would un-
   settle the expectations of many existing patentees. Judge Michel, in his dissent, described in
   detail how the complete bar required the Court of Appeals to disregard 8 older decisions of
   this Court, as well as more than 50 of its own cases.”


                                                                                          (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

bar rule requiring detailed analysis of equivalents and the effect of prosecu-
                                141.46                   141.47
tion history estoppel on them           —“unworkable.”            The en banc
majority’s opinion made clear that the new rule was grounded largely on the
policy of providing greater certainty in patent infringement analysis and there-
fore greater notice to the public of the actual coverage of patent
        141.48
claims.
   The Supreme Court vacated and remanded the Federal Circuit’s decision
               141.49
on this point.         It acknowledged the uncertainty that the doctrine of
                     141.50
equivalents creates.        Yet it reasoned that a per se rule for prosecution
                 141.51
history estoppel         would be inconsistent with both the purposes of es-
       141.52                                                   141.53
toppel         and the purpose of the doctrine of equivalents.          Equally

   141.46
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 574-575,
56 U.S.P.Q.2d (BNA) 1865 (Fed. Cir. 2000) (en banc), vacated and remanded 535 U.S. 722,
122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002).
    141.47
            Id., 234 F.3d at 575 (“We believe that the current state of the law regarding the scope
of equivalents that is available when prosecution history estoppel applies is ‘unworkable’”),
quoting United States v. IBM Corp., 517 U.S. 843, 856, 116 S.Ct. 1793, 135 L.Ed.2d 124
(1996) (noting that Supreme Court itself has overruled precedent that is “unworkable” or “badly
reasoned”). (Citations omitted.)
    141.48
            See id., 234 F.3d at 575 (“In [recent] years, the notice function of patent claims has
become paramount, and the need for certainty as to the scope of patent protection has been
emphasized”).
    141.49
            See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 736-737,
122 S.Ct. 1831, 152 L.Ed.2d 944, 62 U.S.P.Q.2d (BNA) 1705 (2002) (“we disagree with the
decision to adopt the complete bar”).
    141.50
            See id., 535 U.S. at 731:

   “It is true that the doctrine of equivalents renders the scope of patents less certain. It may be
   difficult to determine what is, or is not, an equivalent to a particular element of an invention.
   If competitors cannot be certain about a patent’s extent, they may be deterred from engaging
   in legitimate manufactures outside its limits, or they may invest by mistake in competing
   products that the patent secures. In addition the uncertainty may lead to wasteful litigation
   between competitors, suits that a rule of literalism might avoid. These concerns with the doc-
   trine of equivalents, however, are not new. Each time the [*1838] Court has considered the
   doctrine, it has acknowledged this uncertainty as the price of ensuring the appropriate incen-
   tives for innovation, and it has affirmed the doctrine over dissents that urged a more certain
   rule.”
   141.51
             See id., 535 U.S. at 737 (“Though prosecution history estoppel can bar challenges to
a wide range of equivalents, its reach requires an examination of the subject matter surrendered
by the narrowing amendment. The complete bar avoids this inquiry by establishing a per se rule
. . .”).
      141.52
             See id.:

   “[A per se] approach is inconsistent with the purpose of applying the estoppel in the first
   place—to hold the inventor to the representations made during the application process and to
   the inferences that may reasonably be drawn from the amendment. By amending the applica-
   tion, the inventor is deemed to concede that the patent does not extend as far as the original
   claim. It does not follow, however, that the amended claim becomes so perfect in its descrip-

                                                                                        (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

important, it feared the adverse effect that a new complete bar rule would
have on numerous patents still outstanding, which were prosecuted on the
                                         141.54
understanding that no such rule existed.        In the final analysis, it viewed
both the doctrine of equivalents and prosecution history estoppel—as well as
the policy balance between certainty and protecting patents that they re-
      141.55
flect       —as “settled law” that would require congressional action to
         142
change.     Accordingly, the Supreme Court instructed the lower courts, in-
cluding the Federal Circuit, to analyze in detail how great a range of equiva-




   tion that no one [*1841] could devise an equivalent. After amendment, as before, language
   remains an imperfect fit for invention. The narrowing amendment may demonstrate what the
   claim is not; but it may still fail to capture precisely what the claim is. There is no reason
   why a narrowing amendment should be deemed to relinquish equivalents unforeseeable at
   the time of the amendment and beyond a fair interpretation of what was surrendered. Nor is
   there any call to foreclose claims of equivalence for aspects of the invention that have only a
   peripheral relation to the reason the amendment was submitted. The amendment does not
   show that the inventor suddenly had more foresight in the drafting of claims than an inventor
   whose application was granted without amendments having been submitted. It shows only
   that he was familiar with the broader text and with the difference between the two.”
   141.53
              See id., 535 U.S. at 738 (“there is no more reason for holding the patentee to the lit-
eral terms of an amended claim than there is for abolishing the doctrine of equivalents altogether
and holding every patentee to the literal terms of the patent”); 122 S.Ct. at 1841 (“a complete
bar . . . resorts to the very literalism the equivalents rule is designed to overcome”).
    141.54
              See id., 535 U.S. at 738, referring to Warner-Jenkinson Co. v. Hilton Davis Chemi-
cal Co., 520 U.S. 17, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997), and citing 520 U.S. at 28,
32 n.6. and 520 U.S. at 41 (Ginsburg, J., concurring):
   “The Court of Appeals ignored the guidance of Warner-Jenkinson, which instructed that
   courts must be cautious before adopting changes that disrupt the settled expectations of the
   inventing community. . . . The petitioner in Warner-Jenkinson requested another bright-line
   rule that would have provided more certainty in determining when estoppel applies but at the
   cost of disrupting the expectations of countless existing patent holders. We rejected that ap-
   proach: ‘To change so substantially the rules of the game now could very well subvert the
   various balances the PTO sought to strike when issuing the numerous patents which have
   not yet expired and which would be affected by our decision.’ . . . As Warner-Jenkinson rec-
   ognized, patent prosecution occurs in the light of our case law. Inventors who amended their
   claims under the previous regime had no reason to believe they were conceding all equiva-
   lents. If they had known, they might have appealed the rejection instead. There is no justifi-
   cation for applying a new and more robust estoppel to those who relied on prior doctrine.”
   141.55
            See id., 535 U.S. at 731, quoted in N.141.50 supra.
   142
         See id., 535 U.S. at 731 (“in Warner-Jenkinson, the Court reaffirmed that equivalents
remain a firmly entrenched part of the settled rights protected by the patent. A unanimous opin-
ion concluded that if the doctrine is to be discarded, it is Congress and not the Court that should
do so”), citing Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct.
1040, 1049, 137 L.Ed.2d 146 (1997); 535 U.S. at 738, referring to Warner-Jenkinson Co. v.
Hilton Davis Chemical Co., supra (“In that case we made it clear that the doctrine of equiva-
lents and the rule of prosecution history estoppel are settled law. The responsibility for changing
them rests with Congress”).

                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                     143
lents each claim amendment surrendered.         In this regard, it decision can be
viewed as the first rebuff to the Federal Circuit’s general quest for certainty in
                            144
patent claim construction,      suggesting that there are other important values
that must be considered in shaping patent law.

           [ii]—Design Patents
   There is no precise analogue of the doctrine of equivalents in the field of
design patents. That doctrine is based upon similarity of function, and func-
                                                              145
tion is excluded from the scope of design patent protection.      Moreover, the
traditional standard for design patent infringement leaves little room for a
doctrine of equivalents, for that standard by itself has much the same effect as
the doctrine of equivalents in utility patent law. Design patent infringement
occurs “if, in the eye of an ordinary observer, giving such attention as a pur-
chaser usually gives, [the accused and patented] designs are substantially the
          146
same[.]”      If the accused and patented designs make the same impression
upon the ordinary observer, there is infringement, notwithstanding differences
          147
in detail. Thus, the standard for design patent infringement serves the same
purpose and has the same effect as the doctrine of equivalents for useful in-
ventions: it prevents a copyist from escaping liability through immaterial dif-
ferences in detail.
   There is also another reason why a doctrine of equivalents is unnecessary
in design patent law. The focus of a design patent is the drawing, not the


   143
          See id., 535 U.S. at 738 (“[The flexible bar] is consistent with our precedents and re-
spectful of the real practice before the PTO. While this Court has not weighed the merits of the
complete bar against the flexible bar in its prior cases, we have consistently applied the doctrine
in a flexible way, not a rigid one. We have considered what equivalents were surrendered during
the prosecution of the patent, rather than imposing a complete bar that resorts to the very literal-
ism the equivalents rule is designed to overcome”). (Citations omitted.)
     144
           See generally, § 2.05[3] (introduction) supra.
     145
         See § 2.02[1][b] supra. See also, Lindgren, “The Sanctity of the Design Patent: Illusion
or Reality? Twenty Years of Design Patent Litigation since Compco v. Day-Brite Lighting, Inc.,
and Sears, Roebuck & Co. v. Stiffel Co.,” 10 Okla. City L. Rev. 195, 198 & n.6 (1985) (stating
flatly that there is no doctrine of equivalents for design patents).
     But see, Lee v. Dayton-Hudson Corp., 838 F.2d 1186, 1190 (Fed. Cir. 1988) (suggesting in
dictum that doctrine applies in design patent case).
     146
         Gorham Manufacturing Co. v. White, 81 U.S. (14 Wall.) 511, 528, 20 L.Ed. 731 (1871).
See also: Burger Train Systems, Inc. v. Ballard, 552 F.2d 1377, 1381 (2d Cir.), cert. denied 434
U.S. 860 (1977) (citing Gorham for design patent infringement standard); Black & Decker, Inc.
v. North American Philips Corp., 632 F. Supp. 185, 189-190 (D. Conn. 1986) (applying
Gorham test of infringement and finding none where designs were “substantially different”).
     147
          See Gorham Manufacturing Co. v. White, 81 U.S. (14 Wall.) 511, 531, 20 L.Ed. 731
(1871) (“whatever differences there may be between the plaintiffs' design and those of the de-
fendant in details of ornament, they are still the same in general appearance and effect”).
     Numerous differences in detail, however, can negate infringement. See Black & Decker, Inc.
v. North American Philips Corp., 632 F. Supp. 185, 190 (D. Conn. 1986).

                                                                                        (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

                                                  148
claim. Only a single claim is required,     and it need contain nothing besides
                             149
a reference to the drawing.      Thus, the drawing of a patented design deter-
                                   150
mines the scope of protection,         and it makes little sense to speak of
“equivalents” based on verbal claims.
   Modern developments, however, may have created a rationale for intro-
ducing a doctrine of equivalents into design patent law. Under modern prece-
dent, there is an additional requirement for design patent infringement. The
infringing design must not only show overall similarity to the patented design;
it also “must appropriate the novelty in the patented device which distin-
                                 151
guishes it from the prior art.”      Reliance on this point-of-novelty test for
design patent infringement may require the development of a design patent
analogue to the doctrine of equivalents, in order to cover cases in which a
copyist appropriates the point of novelty but makes enough additional chang-
es to avoid overall similarity.

       [c]—Means-Plus-Function Claims
                                                                        152
   Patent claims may use a variety of forms of words,      but one particular
form has special importance. This is the so-called “means-plus-function” form
                                                        153
governed by Section 112, ¶ 6 of the Patent Act of 1952.     Only elements of
                   154
combination claims     may take this form, as described by the following stat-
utory language:



   148
         See 37 C.F.R. § 1.153.
   149
         Id. “No description, other than a reference to the drawing, is ordinarily required.”
   150
         See § 2.02[1][b] supra.
   151
        Burger Train Systems, Inc. v. Ballard, 552 F.2d 1377, 1381-1382 (2d Cir.), cert. denied
434 U.S. 860 (1977) (there was no infringement where defendant's building did not use only
features of patented building design that were patentable, and other features arguably copied
were functional). See also, e.g.:
    Second Circuit: Black & Decker, Inc. v. North American Philips Corp., 632 F. Supp. 185,
191-192 (D. Conn. 1986) (applying and explaining point-of-novelty test for design patent in-
fringement and finding no infringement).
    Federal Circuit: Avia Group International, Inc. v. L.A. Gear California, Inc., 853 F.2d 1557,
1565 (Fed. Cir. 1988) (“Even though the court compares two items through the eyes of the ordi-
nary observer, it must, nevertheless, to find infringement, attribute their similarity to the novelty
which distinguishes the patented device from the prior art”). (Citations omitted.)
    The fact that the accused device is marketed to different customers, however, does not pre-
clude infringement; the accused design “need only appropriate a patentee's protected design, not
a patentee's market as well.” Id., 853 F.2d at 1565 (shoes for children infringed design patent of
shoes for tennis players). (Citation omitted.)
    152
        See generally, § 2.05[3][a] supra.
    153
        35 U.S.C. § 112, ¶ 6.
    154
        For a discussion of combination claims, see § 2.03[3][c] supra.


                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

   “An element in a claim for a combination may be expressed as a means or
   step for performing a specified function without the recital of structure,
   material, or acts in support thereof, and such claim shall be construed to
   cover the corresponding structure, material, or acts described in the speci-
                                      155
   fication and equivalents thereof.”

   Claiming language conforming to this statutory provision is called “means-
                          156
plus-function” language       if it covers a machine, manufacture or composi-
                157                                                           158
tion of matter,     and “step-plus-function” language if it covers a process.
This book often uses the term “means-plus-function” claiming as a generic
descriptor of all claiming language that conforms to Section 112, ¶ 6, alt-
hough the term “step-plus-function” claiming might be more appropriate for
process or method claims. However designated, both forms of claiming are
                                                             159
among the few forms that the statute specifically mentions.

           [i]—Background and Purpose
   The statutory endorsement of means-plus-function claims is an exception
to the rule against claiming function. Judge-made law prohibits patentees


     As used in Section 112, ¶ 6, the word “combination” may include steps in a process, as well
as structure or material in a product invention. See O.I. Corp. v. Tekmar Co., 115 F.3d 1576,
1582-1583, 42 U.S.P.Q.2d (BNA) 1777 (Fed. Cir. 1997), quoted in N.156 infra.
     155
         35 U.S.C. § 112, ¶ 6. A “combination” is an invention consisting of more than one ele-
ment. See § 2.03[3][c] supra. The judge-made rule against claiming function, see § 2.05[3][c][i]
infra, precludes using “means-plus-function” language to claim an invention consisting of a
single element.
     156
         See, e.g., Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1582, 39 U.S.P.Q.2d
(BNA) 1787 (Fed. Cir. 1996).
     157
         The precise object of claiming depends upon the subject matter of the invention at issue,
i.e., upon whether it is a “process, machine, manufacture, or composition of matter, or . . . [an]
improvement thereof[.]” 35 U.S.C. § 101, discussed in § 2.02[1][a] supra.
     158
         As the Federal Circuit noted:

   “The statute of course uses terms that might be viewed as having a similar meaning, namely,
   steps and acts. It refers to means and steps, which must be supported by structure, material,
   or acts. It does not state which goes with which. The word 'means' clearly refers to the gener-
   ic description of an apparatus element, and the implementation of such a concept is obvious-
   ly by structure or material. We interpret the term 'steps' to refer to the generic description of
   elements of a process, and the term 'acts' to refer to the implementation of such steps. This
   interpretation is consistent with the established correlation between means and structure. In
   this paragraph, structure and material go with means, acts go with steps. . . . The statute thus
   in effect provides that an element in a combination method or process claim may be recited
   as a step for performing a specified function without the recital of acts in support of that
   function.”
   O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1582-1583, 42 U.S.P.Q.2d (BNA) 1777 (Fed. Cir.
1997).
   159
        The others are dependent and multiple dependent claims. See 35 U.S.C. § 112, ¶¶ 3-5.


                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                           160
from claiming entire inventions by function;            they may claim particular
                                         161
structures, materials, or process steps      that perform a specified function, but
                                                           162
a generic claim for function alone would be too broad.
    The rationale for this rule is straightforward. An invention is a means to an
end—performing a specified function or reaching a specified result. If the
first inventor to find a viable means to an end were able to claim the end ge-
nerically, his patent would foreclose other paths to the same end, as yet undis-
                                                   163
covered, and would impair further research.             The rule against claiming
function thus prevents patentees from “fencing off” more than they have dis-
covered and gives technology and science room to grow. Its policy basis is
similar to that for the rules against claiming, in the abstract, broad principles
                                                    164
of science, mathematics, or business operations.
    As applied to entire inventions, the rule against claiming function has a
solid foundation in precedent and policy. Yet the same rule would wreak hav-
oc if applied strictly to claim elements, i.e., to components of inventions.
Consider, for example, a mechanical invention that requires a fastener for
assembly or for maintaining physical integrity. Suppose that the fastener's
type and function has nothing to do with what made the invention novel or
                             165
nonobvious over prior art;        a myriad of different types of fasteners would
work just as well. If the inventor could not claim this component by function,
as a generic “fastener,” she would have to write a separate claim or claim


   160
         See, e.g.: United Carbon Co. v. Binney & Smith Co., 317 U.S. 228, 234, 63 S.Ct. 165,
87 L.Ed. 232 (1942) (claim at issue fell “afoul of the rule that a patentee may not broaden his
claims by describing the product in terms of function”) (Citations omitted.); General Electric
Co. v. Wabash Appliance Corp., 304 U.S. 364, 371, 58 S.Ct. 899, 82 L.Ed. 1402 (1938) (“The
claim uses indeterminate adjectives which describe the function . . . to the exclusion of any
structural definition, and thus falls within the condemnation of the doctrine that a patentee may
not broaden his product claims by describing the product in terms of function”) (Footnote omit-
ted.); 304 U.S. at 372-373 (“The difficulty of making adequate description may have some
bearing on the sufficiency of the description attempted, but it cannot justify a claim describing
nothing new except perhaps in functional terms”); Holland Furniture Co. v. Perkins Glue Co.,
277 U.S. 245, 257, 48 S.Ct. 474, 72 L.Ed. 868 (1928) (“That the patentee may not by claiming a
patent on the result or function of a machine extend his patent to devices or mechanisms not
described in the patent is well understood”) (Citations omitted.); 277 U.S. at 257-258 (rule
applies to composition of matter as well as to machine or device).
    161
         See N.156 supra.
    162
         See N.158 supra.
    163
         See: Holland Furniture Co. v. Perkins Glue Co., 277 U.S. 245, 257, 48 S.Ct. 474, 72
L.Ed. 868 (1928) (without rule against claiming function, “[t]he patent monopoly would . . . be
extended beyond the discovery and would discourage rather than promote invention”); N.158
supra. See also, General Electric Co. v. Wabash Appliance Corp., 304 U.S. 364, 374-375, 58
S.Ct. 899, 82 L.Ed. 1402 (1938) (applying similar rationale to product-by-process claims, where
product was described in terms of function).
    164
         See § 2.02[2][a], [b], [c] supra.
    165
         For discussion of these statutory criteria for patent protection, see § 2.03[1], [3] supra.


                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

element for every type of fastener then known to those skilled in the art; her
                                                                    166
claims would therefore become needlessly complex and prolix.
    Moreover, even a Herculean effort to identify and claim all then-known
“fasteners” would not secure our hypothetical inventor against the use of sub-
sequent advances in fastener technology. A competitor could appropriate
what made the patentee's invention nonobvious, and yet avoid literal in-
                            167
fringement of her patent,       simply by using fastener technology that arose
after she wrote her specification, which its various claim elements relating to
fasteners did not cover. By allowing inventors to claim such components of
                                                 168                    169
inventions generically, in terms of function,        Section 112, ¶ 6,       reduces
both the incentive to write prolix claims and the risk of competitors circum-
venting patent protection by making immaterial alterations in components of
            170
inventions.     The statute thus provides a more complete scope of infringe-
ment coverage for qualifying claim elements without prolix claiming, thereby
promoting administrative convenience and fairness to patentees and, at the
same time, providing the full encouragement for disclosure of inventions that
                          171
patent policy demands.        It limits these benefits, however, to elements of
                     172
combination claims,       so as not to undermine the general rule against claim-
                                    173
ing function for entire inventions.
                                    174
    Statutory means-plus-function language covers the structure, material or
                                     175                                     176
acts disclosed in the specification      as well as all their “equivalents.”     The



   166
         See O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 U.S.P.Q.2d (BNA) 1777 (Fed.
Cir. 1997), quoted in N.194 infra.
    167
         There might be infringement under the doctrine of equivalents, which encompasses ad-
vances in technology occurring after the patent's issuance. See: § 2.05[3][b][i] supra; the text
accompanying Ns. 187-188 infra. A finding of infringement by equivalents, however, would be
far less certain than the finding of literal infringement that a generic claim element expressed in
terms of function would permit. See § 2.05[3][b][i] supra.
    168
         See § 2.05[3][c] (introduction) supra.
    169
         35 U.S.C. § 112, ¶ 6, quoted in the text accompanying N.155 supra.
    170
          It is not surprising that the statute governing means-plus-function claims refers to
“equivalents,” see id., for the doctrine of equivalents serves much the same purposes. See §
2.05[3][b]i] supra.
    171
         See: §§ 2.01, 2.04[1] supra.
    172
         See 35 U.S.C. § 112, ¶ 6, quoted more fully in the text accompanying N.155 supra (“An
element in a claim for a combination may be expressed as a means or step for performing a
specified function”). (Emphasis added.)
    173
         See the text accompanying Ns.159-164 supra.
    174
          This term is not meant to exclude process claims in similar form, i.e., “step-plus-
function” claiming. See § 2.05[3][c] (introduction) supra. The term “means-plus-function” is
used by itself for brevity.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

statute does not define the term “equivalents.” Moreover, the term as used in
                                                177
Section 112, ¶ 6, is not necessarily synonymous with the same term as used
                                                                     178
in connection with the generally applicable doctrine of equivalents.
   Nevertheless, the two terms are equivalent, to coin a phrase, in at least
three respects. First, both serve the same purpose: preventing competitors
from circumventing patents by making immaterial variations in patented in-
          179
ventions.     Second, the general doctrine of equivalents applies on an ele-
                                                       180
ment-by-element basis, not to inventions as a whole,       and this is the exact
                                                                             181
same approach that Section 112, ¶ 6's explicit statutory language demands.
Third, one of the principal limitations of the doctrine of equivalents—
                                                 182
prosecution history or “file wrapper” estoppel —operates the same way
                                                      183
with respect to “equivalents” under Section 112, ¶ 6.
“Equivalents” under Section 112, ¶ 6, thus have much in common with
“equivalents” under the general doctrine. This is no accident. Congress chose

   175
         The words “structure, material, or acts” refer to the different kinds of inventions that
may enjoy utility patents under 35 U.S.C. § 101, namely, machines, manufactures, compositions
of matter, and processes. See § 2.05[3][c] (introduction) supra.
    176
         35 U.S.C. § 112, ¶ 6, quoted in the text accompanying N.155 supra. See also, Patent
and Trademark Office, Examination Guidelines for Computer-Related Inventions, 61 Fed. Reg.
7478, 7480 (Feb. 28, 1996) (in determining whether means-plus-function claims to computer-
related inventions recite statutory subject matter, PTO should “give the claimed means plus
function limitations their broadest reasonable interpretation consistent with all corresponding
structures or materials described in the specification and their equivalents”).
    177
         See Endress + Hauser, Inc. v. Hawk Measurement Systems Pty. Limited, No. 96-1245,
1997 U.S. App. LEXIS 22437 at *9 (Fed. Cir. Aug. 21, 1997) (“it is well understood that
'equivalents' under § 112 ¶ 6 is a different concept from 'equivalents' under the judicially created
doctrine of equivalents”) (citing no authority), quoted more fully in N.181 infra.
    178
         See § 2.05[3][b][i] supra.
    179
          See: the text accompanying Ns.165-171 supra (discussing Section 112, ¶ 6); §
2.05[3][b][i] supra (discussing doctrine of equivalents).
    180
         Warner-Jenkinson Co. v. Hilton Davis Chemical Co., ____ U.S. ____, 117 S.Ct. 1040,
1049, 137 L.Ed.2d 146 (1997) (“Each element contained in a patent claim is deemed material to
defining the scope of the patented invention, and thus the doctrine of equivalents must be ap-
plied to individual elements of the claim, not to the invention as a whole”). See also, §
2.05[3][b][i] infra.
    181
         See § 2.05[3][c] (introduction) supra.
    See also, Endress + Hauser, Inc. v. Hawk Measurement Systems Pty. Limited, No. 96-1245,
1997 U.S. App. LEXIS 22437 at *9 (Fed. Cir. Aug. 21, 1997) (“Though it is well understood
that 'equivalents' under § 112 ¶ 6 is a different concept from 'equivalents' under the judicially
created doctrine of equivalents, the district judge correctly recognized that the statutorily re-
quired construction under § 112 ¶ 6 must proceed on a limitation-by-limitation basis, not dis-
similar to the analysis under the doctrine of equivalents”), citing Warner-Jenkinson Co. v. Hilton
Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040, 1049, 137 L.Ed.2d 146 (1997).
    182
         See: § 2.05[3][b][i] supra; § 2.06[2] infra.
    183
         See Alpex Computer Corp. v. Nintendo Co., 102 F.3d 1214, 1220, 1121, 40 U.S.P.Q.2d
(BNA) 1667 (Fed. Cir. 1997), cert. denied 117 S.Ct. 2480 (1997).

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the word “equivalents” against a background of over ninety-two years of evo-
                                                                  184
lution of the doctrine of equivalents generally in patent cases.      If Congress
had another concept in mind, it is odd that it did not choose another word
with less precedential baggage. The common purposes of the two concepts,
their intertwined origin, and the principle of doctrinal simplicity thus all argue
for giving “equivalents” the same scope, whether they arise under Section
112, ¶ 6, or more generally. Indeed, it has been argued that, because Section
112, ¶ 6 contains the only explicit reference to “equivalents” in the Patent
Act, the general doctrine of equivalents is limited to means-plus-function
         185                          186                         187
claims.      Both the Supreme Court       and the Federal Circuit     have reject-
ed that argument, but its mere assertion demonstrates how closely the general
doctrine of equivalents and means-plus-function claims are intertwined.
    It is well established that the general doctrine of equivalents covers later-
                         188
developed technology.        There is no reason why the same should not hold
                                                  189
true for “equivalents” under Section 112, ¶ 6.        Not only does the congru-
                                       190
ence of the two doctrines generally        demand this result, but so does good
policy. Any construction of “equivalents” under Section 112, ¶ 6, that exclud-
ed afterdeveloped technology would undercut the apparent purpose of the


   184
         Section 112, ¶ 6, was adopted to overrule Halliburton Oil Well Cementing Co. v. Walk-
er, 329 U.S. 1, 8, 67 S.Ct. 6, 91 L.Ed. 3 (1946), which had invalidated functional claiming gen-
erally. See N.194 infra. Yet the doctrine of equivalents had its origin at least 92 years before that
decision, in the case of Winans v. Denmead, 56 U.S. (15 How.) 330, 343-344, 14 L.Ed. 717
(1854). See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1527, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995) (en banc), rev'd on other grounds 520 U.S. 17, 117
S.Ct. 1040, 137 L.Ed.2d 146 (1997) (“the Supreme Court has recognized actions at law for
recovery for infringement under the doctrine of equivalents since its Winans v. Denmead deci-
sion in 1854”).
    185
         See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040,
1047-1048, 137 L.Ed.2d 146 (1997), reversing and remanding 62 F.3d 1512, 35 U.S.P.Q.2d
(BNA) 1641 (Fed. Cir. 1995).
    186
         See id., 520 U.S. at 28 (“Because § 112, ¶ 6 was enacted as a targeted cure to a specific
problem, and because the reference in that provision to 'equivalents' appears to be no more than
a prophylactic against potential side effects of that cure, such limited congressional action
should not be overread for negative implications”).
    187
         See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1526-1527, 35
U.S.P.Q.2d (BNA) 1641 (Fed. Cir. 1995) (en banc), rev'd on other grounds 520 U.S. 17, 117
S.Ct. 1040, 137 L.Ed.2d 146 (1997).
    188
         See: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 37, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997) (“the proper time for evaluating equivalency—and thus
knowledge of interchangeability between elements—is as the time of infringement, not at the
time the patent was issued”); § 2.05[3][b][i] infra.
    189
         The very purpose of means-plus-function claiming is to permit patent drafters to cover a
range of claim elements with simple, generic claiming language. See the text accompanying
Ns.164-173 supra. See also, N.193 infra.
    190
         See the text accompanying Ns.178-188 supra.


                                                                                         (Rel. 25)
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         191
statute    by discouraging the use of means-plus-function claims. In an envi-
ronment of rapidly developing technology, few patent drafters would use Sec-
tion 112, ¶ 6, if “equivalents” under it were limited to pre-existing
technology, when a broader scope of equivalents not so limited would be
available under the general doctrine of equivalents simply by specifying alter-
                                       192                                  193
native structures, instead of function, or “specifying” a generic device.
   “Equivalents” under Section 112, ¶ 6, however, do differ from those under
the general doctrine in one respect. Section 112, ¶ 6 equivalents were intend-
                               194
ed to have a limiting effect.      The statutory reference to “equivalents” was
intended to prevent means-plus-function language from covering every means
                                                              195
of performing a specified function, and to restrict its scope     to the “equiva-

   191
         See the text accompanying Ns.164-171 supra.
   192
         See § 2.05[3][c][ii] infra.
   193
         See § 2.05[3][c][iii] infra.
    See also, Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *9 (Fed.
Cir. Sept. 10, 1998) (“The 'means' term in a means-plus-function limitation is essentially a ge-
neric reference for the corresponding structure disclosed in the specification”), citing
Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303, 1308, 46
U.S.P.Q.2d (BNA) 1752, 1755-1756 (Fed. Cir. 1998).
    194
         See, e.g.:
    Supreme Court: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 27-28,
117 S.Ct. 1040, 137 L.Ed.2d 146 (1997) (statutory predecessor to Section 112, ¶ 6, was intend-
ed to “overrule” decision that had invalidated means-plus-function claims entirely and to limit
scope of those claims), citing Halliburton Oil Well Cementing Co. v. Walker, 329 U.S. 1, 8, 67
S.Ct. 6, 91 L.Ed. 3 (1946), and quoted in N.196 infra.
    Federal Circuit: O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 U.S.P.Q.2d (BNA)
1777 (Fed. Cir. 1997) (Citation omitted.):
   “Section 112, ¶ 6, as is well-documented, was intended to permit use of means expressions
   without recitation of all the possible means that might be used in a claimed apparatus. . . .
   The price that must be paid for use of that convenience is limitation of the claim to the
   means specified in the written description and equivalents thereof.”
     See also, Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1582, 39 U.S.P.Q.2d
(BNA) 1787 (Fed. Cir. 1996) (“Congress adopted a compromise solution, one that had support
in the pre-Halliburton case law: Congress permitted the use of purely functional language in
claims, but it limited the breadth of such claim language by restricting its scope to the structure
disclosed in the specification and equivalents thereof”), citing Valmont Industries, Inc. v.
Reinke Manufacturing Co., 983 F.2d 1039, 1041-1042, 25 U.S.P.Q.2d (BNA) 1451 (Fed. Cir.
1993). (Other citation omitted.)
     195
         See N.194 supra. The scope restrictions apply equally well in patent prosecution and lit-
igation, for means-plus-function claims are interpreted the same way in patent prosecution and
litigation. See, e.g., In re Dossel, 115 F.3d 942, 42 U.S.P.Q.2d (BNA) 1881, 1884 (Fed. Cir.
1997) (“Section 112 paragraph 6 mandates the manner in which the Commissioner and the
courts shall construe the work of a drafter who avails himself of the authority granted by the
provision”) (Citation omitted); In re Donaldson Co., 16 F.3d 1189, 1193, 1194, 29 U.S.P.Q.2d
(BNA) 1845 (Fed. Cir. 1994), cited with approval in In re Morris, No. 96-1425 (Serial No.
07/673,967), 1997 U.S. App. LEXIS 21713 at *15-16 (Fed. Cir. Aug. 18, 1997) (like courts in
litigation, PTO in patent prosecution must consult the specification to construe means-plus-
function claims).

                                                                                       (Rel. 25)
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                                                                         196
lents” of the embodiments disclosed in the specification.        The statute thus
                                197
both giveth and taketh away.        It giveth by allowing an inventor to claim all
equivalent means of performing a specified function without listing or de-
                      198
scribing all of them.     It taketh away by allowing the inventor to claim only
                199
those elements      that are equivalent to ones described in the specification,
                                                     200
whether as the preferred embodiment (best mode)          or otherwise.
   Means-plus-function claiming has become more important since 1997,
when the Supreme Court rendered its decision in Hilton Davis Chemical
    201
Co.     The Court ruled that the doctrine of equivalents extends just to indi-

   196
        See: 35 U.S.C. § 112, ¶ 6, quoted in the text at N.155 supra; Warner-Jenkinson Co. v.
Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997):
   “Section 112, ¶ 6 now expressly allows so-called 'means' claims, with the proviso that appli-
   cation of the broad literal language of such claims must be limited to only those means that
   are 'equivalent' to the actual means shown in the patent specification. This is an application
   of the doctrine of equivalents in a restrictive role, narrowing the application of broad literal
   claim elements.”
    See also, Robert Tyer & Associates, Inc. v. Environmental Dynamics, Inc., Nos. 95-1270,
96-1324, 96-1541, 1997 U.S. App. LEXIS 19101 at *21-22 (Fed. Cir. 1997) (summary con-
tempt proceeding may have been improper where claim recited “means for clamping said first
and second saddle sections on the pipe” and defendant's bolt-type fastener may not have been
equivalent to wedge-type fastener disclosed in patent); Fonar Corp. v. General Electric Co., 107
F.3d 1543, 1551-1552, 41 U.S.P.Q.2d (BNA) 1801 (Fed. Cir. 1997), cert. denied 118 S.Ct. 266
(1997) (where specification supporting means-plus-function language disclosed use of generic
gradient waveform and stated that other waveforms might be used but failed to specifically
identify them, Section 112, ¶ 6, limited claim to use of generic gradient waveform and its equiv-
alents); Invacare Corp. v. Ortho-Kinetics, Inc., No. 95-1428, 1996 U.S. App. LEXIS 11288 at
*4-5 (Fed. Cir. 1996) (unpublished) (“to prevent a completely open-ended interpretation, a claim
limitation written in means-plus-function language is construed to cover only corresponding
structures disclosed in the specification and equivalents thereof”).
    197
         See Ns.194, 196 supra.
    198
         See Invacare Corp. v. Ortho-Kinetics, Inc., No. 95-1428, 1996 U.S. App. LEXIS 11288
at *6 (Fed. Cir. 1996) (unpublished), quoting D.M.I., Inc. v. Deere & Co., 755 F.2d 1570, 1574,
225 U.S.P.Q. (BNA) 236 (Fed. Cir. 1985) (“The statute, § 112-6, was written precisely to avoid
a holding that a means-plus-function limitation must be read as covering only the means dis-
closed in the specification”). This holds true for process inventions as well as other kinds of
inventions. See O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 U.S.P.Q.2d (BNA) 1777
(Fed. Cir. 1997) (“The statute thus in effect provides that an element in a combination method or
process claim may be recited as a step for performing a specified function without the recital of
acts in support of the function”). See also, § 2.05[3][c] (introduction) supra.
    199
         The statute refers to “structure, material and acts.” See 35 U.S.C. § 112, ¶ 6, quoted in
the text at N.155 supra. These words encompass elements of the processes, machines, manufac-
tures, and compositions of matters that may qualify as patentable subject matter. See §
2.05[3][c] (introduction) supra.
    200
         See § 2.04[1][d] supra.
    201
         Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040, 137
L.Ed.2d 146 (1997), rev'ing and remanding 62 F.3d 1512, 35 U.S.P.Q.2d (BNA) 1641 (Fed.
Cir. 1995) (en banc), discussed in § 2.05[3][b][i] supra.

                                                                                       (Rel. 25)
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vidual elements of a claim—one by one—rather than to a claimed invention
            202                                            203
as a whole.      While this question remained unsettled,        patent attorneys
may have been reluctant to use means-plus-function claims for fear of narrow-
                                                                204
ing the scope of equivalents that their inventions might enjoy.     Now that the
element-by-element approach is well established, they need not fear that using
means-plus-function claims will narrow the scope of equivalents that might
otherwise apply to the inventions they describe.
   There is still a question, however, whether a different form of claim lan-
guage, which claims function by reciting generic structure, material, or acts,
has greater breadth of coverage as compared to the means-plus-function
      205
form.     Until this question is fully resolved, patent drafters would be well
advised to consider alternative claiming techniques before relying on means-
plus-function language.

           [ii]—Identifying Means-Plus-Function Claims
   Means-plus-function language defines a claim element by reciting a struc-
ture, material, or acts used to perform a specified function without precisely
                                                        206
specifying the structure, material, or acts themselves.     For example, consid-
er a mechanical invention that requires Part A to be permanently affixed to
Part B. A patent applicant may claim this element of the invention by reciting
“fastening means for permanently affixing Part A to Part B.” This language
defines the function of the element without describing a particular structure
(such as a screw, clamp, weld or other means) to perform it, thereby recogniz-


   202
         See the text accompanying Ns.179-181 and N.180 supra.
   203
         The question arose at least as early as 1988, in the Federal Circuit's split en banc deci-
sion in Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931 (Fed. Cir. 1987) (en banc), cert.
denied 485 U.S. 961 (1988). Compare, 833 F.2d at 935 (majority opinion, affirming finding of
no infringement by equivalents under element-by-element approach), and 833 F.2d at 949-952
(concurring opinion: same), with 833 F.2d at 939-941 (dissenting opinion, arguing vigorously
for “invention as a whole” approach). By the time of the Federal Circuit's en banc decision in
Hilton Davis, there was near-consensus among the judges of the Federal Circuit on the element-
by-element approach. See § 2.05[3][b][i] infra. The Supreme Court resolved the matter finally
in its decision in Hilton Davis reversing and remanding the Federal Circuit's decision on other
grounds. See N.180 supra.
    204
         If the general doctrine of equivalents applied to an invention as a whole, then a collec-
tion of claims reciting specified structures might enjoy a wider range of “equivalents” under the
general doctrine of equivalents than would a corresponding means-plus-function claim reciting
no structure but relying on embodiments described in the specification and their “equivalents,”
because the latter claim would address equivalents of the specified structures only on an ele-
ment-by-element basis, not in relation to the invention as a whole. See Pennwalt Corp. v. Du-
rand-Wayland, Inc., 833 F.2d 931, 939-941 (Fed. Cir. 1987) (en banc), cert. denied 485 U.S.
961 (1988) (dissenting opinion, arguing that majority's element-by-element approach was, in
substance, little more than analysis of literal infringement).
    205
         See § 2.05[3][c][iii] infra.
    206
         See § 2.05[3][c] (introduction), [i] supra.


                                                                                       (Rel. 25)
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ing that a number of alternative means may support the invention as a whole,
as claimed. The means-plus-function language thus informs the world that the
particular means for performing the specified function is not a material part of
the invention and that any equivalent means will do.
                                                  207
   Explicit in the governing statutory language,      however, is an important
            208
limitation.     Means-plus-function language can be used only for claim ele-
                                                                              209
ments, i.e., components of an invention, and not the invention as a whole.
Thus, there is no such thing as an entire means-plus-function claim, i.e., a
claim whose sole element is in means-plus-function form; such a claim would
                                                               210
violate the rule against claiming inventions by function.          Means-plus-
function language is ordinarily used in patent claims for structures, material
or acts for which a number of alternatives are known in the art, without hav-
                                     211
ing to list or describe all of them.
                                          212
   Use of this form of claim is optional.     The patent drafter may elect to in-
voke or not to invoke the means-plus-function language of Section 112, ¶ 6;
that much is clear. Two important things, however, remain to be fully settled:
                                                                  213
(1) precisely how this election is made and (2) its consequences.
   Ordinarily an inventor invokes Section 112, ¶ 6 by using standard “means”
                                                          214
or “steps” language for an element of a patent claim.         Yet these “magic

   207
         See 35 U.S.C. § 112, ¶ 6, quoted in the text accompanying N.155 supra.
   208
          The disclosure requirements of patent law also impose two additional conditions. The
first is the requirement for definite claims. See § 2.04[1][b] supra. The claim language used,
when read together with the rest of the specification, must be reasonably understandable to a
person of ordinary skill in the relevant field. See id. Second, such a person, after reading the
claims together with the rest of the specification, must be able to produce a workable embodi-
ment of the invention without “undue experimentation.” See § 2.04[1][a] supra. If too much
experimentation is required to find an embodiment of the claim element that works, the patent is
invalid for lack of an enabling disclosure. See id.
     209
          See § 2.05[3][c][i] supra.
     210
          See id.
     211
          See: § 2.05[3][c][i] supra; § 2.05[3][c][iii] infra.
     212
          See 35 U.S.C. § 112, ¶ 6, quoted in the text accompanying N.155 supra (“An element in
a claim for a combination may be expressed . . .”). (Emphasis added.) See also, e.g.: O.I. Corp.
v. Tekmar Co., 115 F.3d 1576, 1583, 42 U.S.P.Q.2d (BNA) 1777 (Fed. Cir. 1997) (“Being
drafted with the permissive 'may,' the statute does not require that steps in a method claim be
drafted in step-plus-function form but rather allows for that form”); Greenberg v. Ethicon Endo-
Surgery, Inc., 91 F.3d 1580, 1584, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996) (to same effect),
outlined in N.223 infra.
     213
          For the consequences, see § 2.05[3][c][iii] infra.
     214
          See Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1583, 39 U.S.P.Q.2d
(BNA) 1787 (Fed. Cir. 1996) (“Claim drafters conventionally use the preface 'means for' (or
'step for') when they intend to invoke section 112(6), and there is therefore seldom any confu-
sion about whether section 112(6) applies to a particular element”). See also, 91 F.3d at 1584,
quoted in N.219 infra. For an example of means-plus-function language, see the text accompa-
nying Ns.206-207 supra. With respect to process steps, see § 2.05[3][c] (introduction) supra.

                                                                                     (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

words” are not the sole statutory requirement for mean-plus-function lan-
guage. The statute also requires the “means” or “steps” to be claimed by func-
tion alone, “without the recital of structure, material, or acts in support
            215                                                             216
thereof[.]”      Consequently, claim language invokes Section 112, ¶ 6 if
             217
and only if      it recites “means” or process “steps” without reciting specific
                                               218
structure, material or acts to perform them.       (In determining whether the


   215
       35 U.S.C. § 112, ¶ 6, quoted in the text accompanying N.155 supra. See also, Cole v.
Kimberly-Clark Corp., 102 F.3d 524, 531, 41 U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996):
   “To invoke this statute, the alleged means-plus-function claim element must not recite a def-
   inite structure which performs the described function. Patent drafters conventionally
   achieved this by using only the words 'means for' followed by a recitation of the function
   performed. Merely because a named element of a patent claim is followed by the word
   'means,' however, does not automatically make that element a 'means-plus-function' ele-
   ment[.]”
    216
         See, e.g.: Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *21-22
(Fed. Cir. Sept. 10, 1998) (although word “movable” in claim limitation reciting “movable link
member” by itself did not invoke means-plus-function format, subsequent functional language—
(1) “for holding the lever out of engagement with the cam surface before entry of a combina-
tion,” and (2) “for releasing the lever after entry of the combination”—was “precisely what was
intended by the statutory phrase in section 112, ¶ 6 requiring that means-plus-function limita-
tions provide 'a specified function'“) (Citation to statute omitted.); 1998 U.S. App. LEXIS
22116 at *22-23 (where claim limitation reciting “movable link member” was followed by two
qualifying phrases reciting functions, and nothing reciting particular structure, limitation at issue
was properly construed in means-plus-function format); O.I. Corp. v. Tekmar Co., 115 F.3d
1576, 1580, 42 U.S.P.Q.2d (BNA) 1777 (Fed. Cir. 1997) (there was “no question” that Section
112, ¶ 6 applied to “apparatus claim with means-plus-function clauses and no structure . . .
recited in support of any means”); Serrano v. Telular Corp., 111 F.3d 1578, 1582, 42
U.S.P.Q.2d (BNA) 1538 (Fed. Cir. 1997) (“The 'determination means' limitation of [the] claim
recites a means for determining the last digit without reciting definite structure in support of that
function, and that limitation therefore is a 'means plus function' limitation subject to the re-
quirements of 35 U.S.C. § 112, ¶ 6”) (Citations omitted.); Fonar Corp. v. General Electric Co.,
107 F.3d 1543, 1551, 41 U.S.P.Q.2d (BNA) 1801 (Fed. Cir. 1997), cert. denied 118 S.Ct. 266
(1997) (“An apparatus claim requires definite structure in the specification to support the func-
tion in a means clause. Because claim 12 does not recite such structure in support of the defined
function, it is therefore subject to section 112, ¶ 6”).
    217
         See, e.g.: O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 U.S.P.Q.2d (BNA) 1777
(Fed. Cir. 1997) (Section 112, ¶ 6 “is implicated only when means plus function without definite
structure are present, and that is similarly true with respect to steps, that the paragraph is impli-
cated only when steps plus function without acts are present”) (Emphasis in original.); York
Products, Inc. v. Central Tractor Farm & Family Center, 99 F.3d 1568, 1574, 40 U.S.P.Q.2d
(BNA) 1619 (Fed. Cir. 1996), quoted in N.219 infra; Greenberg v. Ethicon Endo-Surgery, 91
F.3d 1580, 1583-1584, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996), outlined in N.225 infra.
See also, Ns.225, 226 infra.
    218
         The question is whether the supporting structure, material, or acts are described in the
claims or elsewhere in the specification. Even a means-plus-function claim requires supporting
structure, materials or acts to be described somewhere in the specification, see Section 112, ¶ 6,
quoted in the text accompanying N.155 supra, lest the specification as a whole fail to meet
statutory disclosure requirements. See N.208 supra. See also, § 2.04[1] supra (discussing dis-
closure requirements generally).

                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

specification recites such specific structure, material, or acts, a court must
                                                 218.1
apply the perspective of one skilled in the art.       ) Therefore the apparent
debate between different panels of the Federal Circuit over whether the magic
                         219            220
words by themselves do       or do not      raise a presumption is beside the


    If the specification does not adequately describe embodiments that perform the stated func-
tion, then the patent may fail for lack of distinct claiming under Section 112, ¶ 2, i.e., indefi-
niteness. See: In re Dossel, 115 F.3d 942, 42 U.S.P.Q.2d (BNA) 1881, 1884 (Fed. Cir. 1997)
(“Failure to describe adequately the necessary structure, material, or acts in the written descrip-
tion means that the drafter has failed to comply with the mandate of § 112 ¶ 2 . . .—the mandate
that all claims must particularly point out and distinctly claim the subject matter which the ap-
plicant regards as his invention”); In re Donaldson Co., 16 F.3d 1189, 1195, 29 U.S.P.Q.2d
(BNA) 1845 (Fed. Cir. 1994) (“if one employs means-plus-function language in a claim, one
must set forth in the specification an adequate disclosure showing what is meant by that lan-
guage. If an applicant fails to set forth an adequate disclosure, the applicant has in effect failed
to particularly point out and distinctly claim the invention”). In addition, the specification as a
whole (including the claims) must provide an enabling disclosure in accordance with Section
112, ¶ 1 “whether claims are written in means-plus-function form or not.” In re Dossel, supra,
42 U.S.P.Q.2d (BNA) at 1884. See also, § 2.04[1][a] supra (discussing enablement require-
ment).
    The rules for disclosure, however, are not stricter for means-plus-function claims than for
other claims. See Patent and Trademark Office, Examination Guidelines for Computer-Related
Inventions, 61 Fed. Reg. 7478, 7486 (Feb. 28, 1996) (disclosure of hardware or software means
in means plus function claims may be express, implied, or inherent and may rely on knowledge
of one skilled in art).
    218.1
            See Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1365-1366 (Fed. Cir.
2003) (in construing means-plus-function claim, “[w]hether the specification adequately sets
forth structure corresponding to the claimed functions must be considered [*1366] from the
perspective of one skilled in the art”), citing Budde v. Harley-Davidson, Inc., 250 F.3d 1369,
1376 (Fed. Cir. 2001).
    219
         See York Products, Inc. v. Central Tractor Farm & Family Center, 99 F.3d 1568, 1574,
40 U.S.P.Q.2d (BNA) 1619 (Fed. Cir. 1996) (dictum: “the use of the word 'means' triggers a
presumption that the inventor used this term advisedly to invoke the statutory mandates for
means-plus-function clauses”). See also, Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d
1580, 1584, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996) (“the use of the term 'means' has come
to be so closely associated with 'means-plus-function' claiming that it is fair to say that the use
of the term 'means' (particularly as used in the phrase 'means for') generally invokes section
112(6) and that the use of a different formulation generally does not”).
    The York Products panel's assertion was dictum, for the same panel decided not to treat the
language there at issue as a means-plus-function claim. See York Products, Inc. v. Central Trac-
tor Farm & Family Center, supra, 99 F.3d at 1574:
   “Without an identified function, the term 'means' in this claim cannot invoke 35 U.S.C. §
   112, ¶ 6. Without a 'means' sufficiently connected to a recited function, the presumption in
   use of the word 'means' does not operate. In any case, the express structural limits of the
   claim language limit its scope.”
   220
         See, e.g.: O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 U.S.P.Q.2d (BNA) 1777
(Fed. Cir. 1997) (“a statement in a preamble of a result that necessarily follows from performing
a series of steps does not convert each of those steps into step-plus-function clauses”); Cole v.
Kimberly-Clark Corp., 102 F.3d 524, 531, 41 U.S.P.Q.2d (BNA) 1001 (Fed. Cir. 1996), quoted
also in N.215 supra (presence or absence of word “means” creates no presumption for or against
characterization as means-plus-function claim: “[w]e decide on an element-by-element basis,

                                                                                        (Rel. 25)
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point, because the magic words “means for” or “step for” by themselves fulfill
                                          221
only parts of the statutory requirements.
   Thus, whether particular claim language invokes Section 112, ¶ 6, is a mat-
                              222
ter of substance, not form.       An important question is whether the claim
                                        223
drafter intended to invoke the statute.     If an intention to invoke the statute
                                                                          224
appears, failure to use magic words like “means” will not be decisive.        On
the other hand, if a contrary intention appears, mere use of the magic words



based upon the patent and its prosecution history, whether §112, ¶ 6 applies”) (Citations omit-
ted.).
    See also, Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *16 (Fed.
Cir. Sept. 10, 1998) (upholding finding that following language in claim for electronic combina-
tion lock mechanism was in means-plus-function form) (Emphasis omitted.):
   “a substantially non-resilient lever moving element for moving the lever from its disengaged
   position for engaging the protrusion of the lever with the cam surface on the cam wheel so
   that the rotation of the cam wheel thereafter in the given direction changes the locking
   mechanism from the locked condition to the unlocked condition. . . .”
   221
         See, e.g., Cole v. Kimberly-Clark Corp., 102 F.3d 524, 531, 41 U.S.P.Q.2d (BNA) 1001
(Fed. Cir. 1996) (claim element was not in means-plus-function form although drafter “was
clearly enamored of the word 'means':” six of seven claim elements included it, and it occurred
in claim fourteen times); Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1583-1584, 39
U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996) (claim element was not in means-plus-function form
although patent “drafter . . . appear[ed] to have been enamored of the word 'means,' as the word
[was] used repeatedly in the summary of the invention”).
    See also, Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *17 (Fed.
Cir. Sept. 10, 1998) (“Although [presumption that claim without 'means for' language is not in
means-plus-function form] is helpful in beginning the claim construction analysis, it is not the
end of the inquiry”).
    222
         See: Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *18 (Fed.
Cir. Sept. 10, 1998) (“while traditional 'means' language does not automatically make an ele-
ment a means-plus-function element, conversely, lack of such language does not prevent a limi-
tation from being construed as a means-plus-function limitation”), citing Cole v. Kimberly-
Clark Corp., 102 F.3d 524, 531, 41 U.S.P.Q.2d (BNA) 1001, 1006 (Fed. Cir. 1996); Greenberg
v. Ethicon Endo-Surgery, 91 F.3d 1580, 1583-1584, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir.
1996).
    223
         See id., 91 F.3d at 1584 (issue is one of drafter's intent, since “may be expressed” lan-
guage of Section 112, ¶ 6, gives patent applicant option of using means-plus-function formula-
tion or not); 91 F.3d at 1584 (distinguishing Interspiro U.S.A., Inc. v. Figgie International, Inc.,
815 F. Supp. 1488, 1504, 27 U.S.P.Q.2d (BNA) 1321 (D. Del. 1993), aff'd 18 F.3d 927, 930-
931, 30 U.S.P.Q.2d (BNA) 1070 (Fed. Cir. 1994), outlined in N.226 infra, on grounds that
patentee there had chosen “classic 'means-plus-function' format, thereby ma[king] it clear that
the patentee had elected to invoke section 112(6)”).
    224
         See, e.g.: Cole v. Kimberly-Clark Corp., 102 F.3d 524, 531, 41 U.S.P.Q.2d (BNA) 1001
(Fed. Cir. 1996) (dictum: “merely because an element does not include the word 'means' does
not automatically prevent that element from being construed as a means-plus-function element”)
(Citations omitted.); Raytheon Co. v. Roper Corp., 724 F.2d 951, 957, 220 U.S.P.Q. (BNA) 592
(Fed. Cir. 1983), cert. denied 469 U.S. 835 (1984) (construing functional language beginning
with words “so that” as equivalent to “means for” claim language).

                                                                                        (Rel. 25)
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                                                                            225
will not foreclose a finding that the statute was not invoked.    For example,
a claim element reciting specific structure will not be interpreted as a means-
                                                            226
plus-function element despite its use of the word “means.”

           [iii]—Consequences of Means-Plus-Function Claiming
   There has been considerable litigation over whether particular claim lan-
guage invokes or does not invoke Section 112, ¶ 6, i.e., over whether a claim
                                            227
element is in means-plus-function form.         Clear language should resolve the
issue, for it is settled that the inventor has a choice whether or not to invoke
                                                                        228
the statute and that he can do so by an appropriate choice of words.        Thus,
for example, claim language reciting “fastening means for permanently affix-
ing Part A to Part B” ought to invoke the statute, as long as it does not recite
any particular structure, while claim language reciting “a fastener” and its
                                 229
structure probably should not.
   What is not so clear, however is the consequence of this election. Consider
an alternative form of claiming, which might be called “generic structure-by-




   225
         See: Cole v. Kimberly-Clark Corp., 102 F.3d 524, 530-531, 41 U.S.P.Q.2d (BNA) 1001
(Fed. Cir. 1996) (claim in product patent that referred to definite structure—including location
and extent—of “perforation means” for removing outer layer of disposable brief for toilet train-
ing was not means-plus-function claim under Section 116, ¶ 6); Greenberg v. Ethicon Endo-
Surgery, 91 F.3d 1580, 1583-1584, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996) (refusing to
treat words “detent mechanism” in claim as synonymous with “detent means,” although “sum-
mary of invention” portion of specification used “detent means” twice: use of means language in
summary was simply shorthand for key structural elements of invention, each of which was
described later in specification and claimed without using term “means”).
    226
         See, e.g.: Cole v. Kimberly-Clark Corp., 102 F.3d 524, 531, 41 U.S.P.Q.2d (BNA) 1001
(Fed. Cir. 1996) (“To invoke this statute, the alleged means-plus-function claim element must
not recite a definite structure which performs the described function”); York Products, Inc. v.
Central Tractor Farm & Family Center, 99 F.3d 1568, 1574, 40 U.S.P.Q.2d (BNA) 1619 (Fed.
Cir. 1996), quoted in N.219 supra; Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580,
1584, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996) (“detent” element was not claimed in means-
plus-function form, despite repeated use of word “means” in patent specification, where it and
other key structural elements were “subsequently described in detail, without the use of the term
'means,' in the 'description of the invention' portion of the specification, and each [was] subse-
quently claimed, again without the use of the term 'means,' in claim 1 of the patent”).
    Cf., Interspiro U.S.A., Inc. v. Figgie International, Inc., 815 F. Supp. 1488, 1504, 27
U.S.P.Q.2d (BNA) 1321 (D. Del. 1993), aff'd 18 F.3d 927, 930-931, 30 U.S.P.Q.2d (BNA)
1070 (Fed. Cir. 1994) (claim element reciting “detent means . . . for moving and maintaining
[the] movable member” was in classic means-plus-function format and was governed by Section
112, ¶ 6).
    227
         For discussion of some of it, see § 2.05[3][c][ii] supra.
    228
         See id.
    229
         Id.


                                                                                      (Rel. 25)
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                         230
function claiming.”  As the Federal Circuit has noted, a number of common
devices have names derived from their functions:

   “Many devices take their names from the functions they perform. The ex-
   amples are innumerable, such as 'filter,' 'brake,' 'clamp,' 'screwdriver,' or
   'lock.' Indeed, several of the devices at issue in this case have names that
   describe their functions, such as 'graspers,' 'cutters,' and 'suture applica-
          231
   tors.'“

Suppose a claim element recites such a device generically, using the generic
structural-functional word alone, and leaving the description of representative
                       232                                   233
embodiments (if any)       to the rest of the specification.     In other words,
suppose the claim language recites simply “a fastener,” and not the corre-
sponding means-plus-function language, “fastening means for permanently
                            234
affixing Part A to Part B.”     What are the legal consequences of this choice?
Under the command of Section 112, ¶ 6, statutory means-plus-function claims
cover equivalents of all those means—but only those means—disclosed in the

   230
         Although the examples here focus on structure, the same principles apply to material
and (process) acts—the two other types of subject matter that inventors may cover indirectly
through means-plus-function claims. See § 2.05[3][c] (introduction) supra.
    231
         Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1583, 39 U.S.P.Q.2d (BNA)
1787 (Fed. Cir. 1996).
    The same point holds true for material and (process) steps; consider, for example, the words
“damper,” “nutrient,” “matrix,” or “solvent” (for material) or the words “tempering,” “refining,”
“annealing,” or “purifying” (for process steps).
    232
         No description of such devices in the specification is necessary to support the claims if
the claims themselves meet the statutory disclosure requirements. See § 2.04[1] supra. For ex-
ample, a claim element reciting simply a “bolt” would pass muster (unless the bolt had special
properties required for the invention) because the term is understandable and enabling to those
skilled in the art. As long as there is nothing special about the bolt, anyone skilled in the art who
reads the specification and wishes to duplicate the invention could simply go to the nearest
hardware store and select a bolt of appropriate size and strength.
    233
         Lawyers and judges are not entirely consistent in their use of the term “specification.”
Some use this term to mean the narrative including the claims, while others use it to refer to the
patent narrative excluding the claims, i.e., the “description of the invention” portion of the pa-
tent. The statute, however, appears to endorse the more inclusive meaning, and that is the one
used in this book. See 35 U.S.C. § 112, ¶ 2 (“The specification shall conclude with one or more
claims. . . .”). The title of Section 112, “Specification,” corroborates this view, for Section 112
governs both the written description and the claims.
    234
         Both common sense and precedent suggest that claiming in such a manner is permissi-
ble. Without such a mode of claiming, an inventor would have to describe every nut and bolt of
her invention in great detail. See also, Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580,
1583, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996):
   “[T]he fact that a particular mechanism—here 'detent mechanism'—is defined in functional
   terms is not sufficient to convert a claim element containing that term into a 'means for per-
   forming a specified function' within the meaning of section 112(6).”


                                                                                         (Rel. 25)
2-05                      PATENTS               INTELLECTUAL PROPERTY LAW

                 235
specification.     Then what does the corresponding generic structure-by-
function language cover?
   Only three answers are logically possible. First, a claim element expressed
in generic structure-by-function language might be limited to the precise em-
bodiments disclosed in the specification, not including their equivalents. The
general doctrine of equivalents, however, forecloses this result, for it applies
                                              236
to every claim element, however expressed.        A second possible answer is
that generic structure-by-function language—like the corresponding means-
plus-function language expressed in statutory form—covers equivalents of
what is disclosed in the specification, and nothing else. This option, if correct
as a matter of law, would make the choice between the two corresponding
claim forms—means-plus-function and generic structure-by-function—a mat-
ter of indifference to the rational patent drafter, at least insofar as infringe-
ment coverage is concerned.
   A third possible answer, however, is that claim elements expressed in ge-
neric structure-by-function language cover all means of performing the speci-
fied function known to those skilled in the art (or later developed), without
regard to their equivalency to disclosed means. If that is the law, generic
structure-by-function language would have broader coverage than the corre-
sponding means-plus-function form. The Federal Circuit's rulings suggest just
               237
such a result.     They support the view that a claim reciting generic “struc-
tures” by function, without invoking Section 112, ¶ 6, is a generic claim to all
structures known in the art that perform the specified function and fairly meet
                 238
the description.


   235
         See § 2.05[3][c][i], [ii] supra.
   236
         See § 2.05[3][b][i] supra.
   237
         See, e.g.: In re Morris, No. 96-1425 (Serial No. 07/673,967), 1997 U.S. App. LEXIS
21713 at *16 (Fed. Cir. Aug. 18, 1997), quoted in N.239 infra; Greenberg v. Ethicon Endo-
Surgery, Inc., 91 F.3d 1580, 1582, 1584, 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996) (holding
that claim element reciting “cooperating detent mechanism defining the conjoint rotation of said
shafts in predetermined intervals” was not in means-plus-function form—and therefore was not
limited to equivalents of disclosed means, and vacating summary judgment of noninfringement).
    Cf., Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *19 (Fed. Cir.
Sept. 10, 1998) (where “lever moving element” was described in terms of its function, not its
mechanical structure, accepting argument that Section 112, ¶ 6 did not apply would allow claim
element to cover “any device that can cause the lever to move”; claim could not “be construed so
broadly to cover every conceivable way or means to perform the function of moving a lever”).
    238
         See Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1583, 39 U.S.P.Q.2d
(BNA) 1787 (Fed. Cir. 1996):
   “It is true that the term 'detent' does not call to mind a single well-defined structure, but the
   same could be said of other commonplace structural terms such as 'clamp' or 'container.'
   What is important is not simply that a 'detent' or 'detent mechanism' is defined in terms of
   what it does, but that the term, as the name for structure, has a reasonably well understood
   meaning in the art.”


                                                                                        (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

    If this is indeed the law, the generic form of claiming should have broader
            239
coverage,        and the rational patent drafter should prefer it under most cir-
cumstances. Both forms cover things not specifically known at the time the
                                                                    240
patent application was filed—i.e., later-developed technology.          However,
                                              241
as applied to means-plus-function claims,          the doctrine of equivalents re-
stricts the alternative structures, materials or acts in infringing devices to
                                                              242
equivalents of those disclosed in the patent specification.       This means that
the differences between the embodiments disclosed in the specification and
                                                                            243
the alternatives in an allegedly infringing device must be insubstantial.       Or,
                                            244
under the tripartite test of Graver Tank,       it means that the alternatives and
the disclosed embodiments must not differ substantially in function, means



     Cf., In re Dossel, 115 F.3d 942, 42 U.S.P.Q.2d (BNA) 1881, 1885 (Fed. Cir. 1997) (means-
plus-function claim element that recited “reconstruction means for determining the current dis-
tributions at said predetermined volume locations from said stored values” did not fail for indef-
initeness, although specification did not mention magic word “computer,” where what was
claimed was “a device that receive[d] digital data words from a memory and data input from a
user” and calculated variables from received data by means of mathematical operations that,
although not specified, were described as “known algorithms” to solve “standard equations
which [were] known in the art”), discussed in the text accompanying Ns.251-285 infra.
     239
          See In re Morris, No. 96-1425 (Serial No. 07/673,967), 1997 U.S. App. LEXIS 21713 at
*16 (Fed. Cir. Aug. 18, 1997) (“There is no comparable mandate in the patent statute that re-
quires the claim scope of non-§ 112 ¶ 6 claims to be restricted to the embodiments shown in the
specification. Nor would it make sense to have one since in non-§ 112 ¶ 6 claims it is the lan-
guage of the claims, not the written description, that defines the scope of the patent right”).
(Citations omitted.) See also, Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1582,
1584 39 U.S.P.Q.2d (BNA) 1787 (Fed. Cir. 1996) (patentee successfully overturned summary
judgment of noninfringement by arguing that claim language did not invoke Section 112, ¶ 6,
and therefore should not have been limited to detent mechanisms disclosed in specification and
its structural equivalents).
     240
          The doctrine of equivalents generally covers later-developed technology, and so should
“equivalents” under Section 112, ¶ 6. See § 2.05[3][c][i] supra. As for the corresponding gener-
ic claiming language, it, like generic claims in general, see § 2.04[1][b][i], must cover species
not known at the time of filing, for otherwise generic language—and indeed patent claims in
general—would be of little use. See id. As long as the claim language is reasonably understand-
able to a person of ordinary skill in the art, and as long as such a person could develop a work-
ing embodiment of the claim element without undue experimentation, generic claim language
should cover all embodiments that meet its terms (literally or under the doctrine of equivalents),
whether or not known that the time. See Ns.238, 239 supra.
     241
          See § 2.05[3][c][i] supra.
     242
          See generally, § 2.05[3][c] (introduction), [i] supra.
     243
          See § 2.05[3][b][i] supra.
     244
          See Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 608,
700 S.Ct. 854, 94 L. Ed. 1097 (1950). See also, Warner-Jenkinson Co. v. Hilton Davis Chemical
Co., ___ U.S. ___, 117 S.Ct. 1040, 1054, 137 L.Ed.2d 146 (1997) (approving tripartite test as
one method of verbalizing standard of equivalence, but leaving precise specification to expertise
of Federal Circuit), discussed in § 2.05[3][b][i] supra.

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

              245
and result.      On the other hand, the corresponding generic structure-by-
function language covers all species of structures, materials, or acts within the
genus, as long as a person of ordinary skill in the art could understand the
language used and could determine which species within the genus do and do
                                           246
not work without undue experimentation.
                                        247
    Consider the example of fasteners.      A claim element reciting “fastening
means for permanently affixing Part A to Part B” would cover fasteners dis-
closed in the patent specification and their equivalents, while one reciting “a
fastener” (with supporting disclosure elsewhere in the specification as neces-
       248
sary)      would cover all fastening technology known to those skilled in the
     249
art.     The only limitations on the scope of the generic claim element would
                                           250
be the requirements of proper disclosure.
    Given a free choice between these two alternatives, few would choose the
means-plus-function form. The generic style of claiming, if ultimately upheld
                                  251
by the courts as described here,      would supplant claiming using statutory
means-plus-function language, thereby rendering Section 112, ¶ 6 a dead let-
ter.
A 1997 decision of the Federal Circuit, however, breathed life into Section
112, ¶ 6, by giving it the potential to achieve comparably broad scope. In In
            252                                                 253
re Dossel       the Federal Circuit upheld as not indefinite        means-plus-
function language reciting means for “reconstructing” certain medical imag-
ing data from measured data, although the patent specified neither the data



   245
         See § 2.05[3][b][i] supra.
   246
         See: Ns.208, 218, 240 supra. See generally, § 2.04[1][a], [b] supra. The specification
also would have to disclose the embodiment providing the “best mode,” where relevant. See §
2.04[1][d] supra.
    247
         See the text accompanying Ns.233-234 supra.
    248
         See N.208, 218 supra.
    249
         See Ns.208, 218, 240 supra.
    250
         See id.
    251
         See the text accompanying Ns.229-238 supra.
    252
         In re Dossel, 115 F.3d 942, 42 U.S.P.Q.2d (BNA) 1881 (Fed. Cir. 1997).
    253
          The court focused on the definiteness requirement of Section 112, ¶ 2. See id., 42
U.S.P.Q.2d (BNA) at 1883, 1885. It did not decide whether the specification met all the re-
quirements of Section 112, ¶ 6. See 42 U.S.P.Q.2d (BNA) at 1885. It seemed to imply, however,
that a specification adequate to satisfy the requirements of Section 112, ¶ 2, would also be suffi-
cient to meet the implicit requirement of Section 112, ¶ 6 that “corresponding structure, materi-
al, or acts [be] described in the specification[.]” 35 U.S.C. § 112, ¶ 6, quoted in full in N.155
supra. See In re Dossel, supra, 42 U.S.P.Q.2d (BNA) at 1884-1885.
    For the text of Section 112, ¶ 2, which implements the definiteness requirement, see §
2.04[1][a] supra. For discussion of the definiteness requirement, see § 2.04[1][b] supra.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                  254
processor nor the method of calculation precisely.          The specification did
not even use the word “computer” and had not described any algorithm for
                                  255
performing the reconstruction.        Nevertheless, relying on the nature of the
problem to be solved and common practice in the field of medical imaging,
                                                                        256
the court reasoned that a digital computer was impliedly specified.         As for
the method of calculation, the court said that known algorithms and known
                                      257
standard equations could be used.         The Dossel decision thus appears to
have approved, as valid under Section 112, ¶ 2, a specification supporting
means-plus-function claims that “described” embodiments performing the
stated functions only by implication, with reference to what was known by
those skilled in the art. A 2003 decision reinforced the validity of this ap-
proach by upholding, against an indefiniteness challenge, a means-plus-
function claim in which the corresponding structure was expressed generical-
    257.1
ly.
                                                              258
    If this result survives scrutiny under Section 112, ¶ 6,      it will have the
advantage of preserving “neutrality” in the choice between means-plus-
function language and corresponding generic structure-by-function lan-
        259
guage.       A 2003 decision of the Federal Circuit, which upheld a similar
claim against a challenge on ground of indefiniteness, suggests that generic
descriptions of structure, material or acts, which rely on the knowledge of the
                                                      259.1
person of ordinary skill, will survive such scrutiny.       Yet such a result may
seem to have drifted a long way from the sort of detailed specification of em-
bodiments that Congress probably contemplated under Section 112, ¶ 6, when
it enacted that provision as a limited exception to the general rule against

   254
         See In re Dossel, N.252 supra, 42 U.S.P.Q.2d (BNA) at 1885 (upholding claim lan-
guage, in light of specification, as not indefinite under Section 112, ¶ 2).
    255
         See id., 42 U.S.P.Q.2d (BNA) at 1885.
    256
         Id.
    257
         See id., 42 U.S.P.Q.2d (BNA) at 1885 (“While the written description does not disclose
exactly what mathematical algorithm will be used to compute the end result, it does state that
'known algorithms' can be used to solve standard equations which are known in the art”).
    257.1
            See Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1366-1367 (Fed. Cir.
2003) (where core logic of computer was structure corresponding to specified function in
means-plus-function claim, and where it had to be modified to perform stated function, “[a]
generic description of the core logic, as adapted to practice [that function] pursuant to the speci-
fication, [was] not inadequate solely because no circuitry [was] disclosed on how to modify the
core logic;” disclosing “how to modify the core logic to perform [the function] on the circuitry
level may also be properly left to the knowledge of those skilled in the art, and need not be spec-
ified in the patent”), citing In re Dossel, 115 F.3d 942, 946, 42 U.S.P.Q.2d (BNA) 1881 (Fed.
Cir. 2003). (Citation to opinion below omitted.)
    258
         See N.253 supra.
    259
         Cf., the text accompanying Ns.250-252 supra.
    259.1
           See N.257.1 supra.


                                                                                        (Rel. 25)
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                       260
claiming function.        Congress intended that provision to limit the scope of
means-plus-function claims to disclosed embodiments and their equiva-
       261
lents.     It mocks that limitation to read into a patent specification, by impli-
cation, embodiments never mentioned in it merely because they ought to be
understood by those skilled in the art.
                                                   262
    To the extent that Dossel reached this result,     it also has another infirmi-
ty. Under Section 112, ¶ 6, means-plus-function claim limitations cover “the
corresponding structure, material, or acts described in the specification and
                          263
equivalents thereof[.]”        This language presupposes that the specification
                                                                                264
contains some description of a particular embodiment or embodiments
against which the scope of “equivalents” can be measured. Without such a
              265
description,      the determination of equivalents would be completely at large.
Dossel, for example, appeared to approve a specification that “disclosed”
nothing, other than the hypothetical knowledge of persons of ordinary skill in
         266
the art.     A 2003 decision, relying on Dossel to uphold a generic structural
                                                                266.1
description in the specification, had much the same effect.           Determining
the scope of “equivalents” of such phantoms will be problematic at best.
    This is not to criticize the Dossel court, which truly had a Hobson's choice.
If it had taken a narrow view of means-plus-function claiming, it could have
                                              267
honored the apparent congressional intent         and have avoided infringement
                        268
practice difficulties,       but at the cost of rendering means-plus-function

   260
         See § 2.05[3][c][i] supra.
   261
         See id.
   262
         See N.253 supra.
   263
         35 U.S.C. § 112, ¶ 6, quoted in the text accompanying N.155 supra.
   264
          “Embodiments” here means specific structure, material or acts that constitute the
“means” or “step” to achieve the specified function. See § 2.05[3][c][i] supra.
    265
         The description need be only as complete as the state of the art requires. A reference to a
publication, a standard part number, or a commercially available embodiment should be suffi-
cient, as long as those skilled in the art would know where to find it and how to use it. Cf., §
2.04[1][a] supra (discussing enabling disclosure under Section 112, ¶ 1).
    266
         See the text accompanying Ns.251-258 supra.
    266.1
           See Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1366-1367 (Fed. Cir.
2003) (where core logic of computer was structure corresponding to specified function in
means-plus-function claim, and where it had to be modified to perform stated function, “[a]
generic description of the core logic, as adapted to practice [that function] pursuant to the speci-
fication, [was] not inadequate solely because no circuitry [was] disclosed on how to modify the
core logic;” disclosing “how to modify the core logic to perform [the function] on the circuitry
level may also be properly left to the knowledge of those skilled in the art, and need not be spec-
ified in the patent”), citing In re Dossel, 115 F.3d 942, 946, 42 U.S.P.Q.2d (BNA) 1881 (Fed.
Cir. 2003). (Citation to opinion below omitted.)
    267
         See the text accompanying Ns.259-262 supra.
    268
         See the text accompanying Ns.261-267 supra.


                                                                                        (Rel. 25)
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                        269                                                    270
claims a dead letter.     If it took the broader view, as it in fact did,    it could
maintain the practical value of means-plus-function claiming, but at the cost
                                                                      271
of ignoring the spirit, if not the letter, of congressional intent,       as well as
considerably complicating infringement practice involving means-plus-
                     272
function language.       Understandably, the court chose the more practical re-
sult: it allowed means-plus-function claiming to survive. Yet in so doing, it
                                                                        273
encouraged further litigation and an appeal to the Supreme Court.
    The heart of the matter in Dossel, as indeed in most cases under Section
     274
112,      is the perennial tension between two competing goals of the patent
drafting process. On the one hand, patent specifications are supposed to pro-
vide a means by which the public can practice inventions freely and with rela-
                                     275
tive ease after the patents expire.      This goal has constitutional overtones; a
patent specification that fails to serve it would not “promote the Progress of . .
               276
. useful Arts”     as the Constitution commands. All else being equal, this goal
is best served if the specification is complete and comprehensive.
    On the other hand, patent specifications also must be succinct and focused
enough to be practically useful, both in facilitating the public's practice of the
                          277
inventions they disclose        and in keeping patent litigation within reasonable
bounds of time and expense. A specification that creates “information over-
load” or hides the essence of the inventor's contribution in a mass of trivia is
                                                                        278
not the best way to “promote the Progress of . . . useful Arts[.]”          Nor is it
the best way to promote efficiency in litigation and lower transaction costs for
                                               279
inventors and those who invest their efforts.
    Anyone who reads patent decisions regularly knows how often lawyers' ar-
guments stray from the center of an inventor's contribution to matters that—
while perhaps important for maintaining the integrity and consistency of the
legal system—have little real relevance to scientific or technological progress.
At the same time, advances in word-processing technology facilitate the pro-

   269
         See the text accompanying Ns.250-252.
   270
         See the text accompanying Ns.251-258 supra.
   271
         See the text accompanying Ns.259-262 supra.
   272
         See the text accompanying Ns.261-267 supra.
   273
        See Fonar Corp. v. General Electric Co., 107 F.3d 1543, 41 U.S.P.Q.2d (BNA) 1801
(Fed. Cir. 1997), cert. denied 118 S.Ct. 266 (1997).
    274
        See also, § 2.04[1][a], [b] supra.
    275
        See: §§ 2.01, 2.04[1] supra.
    276
        U.S. Const., Art. I, § 8, cl. 8, quoted in full in § 2.01 supra.
    277
        See the text accompanying Ns.274-277.
    278
        U.S. Const., Art. I, § 8, cl. 8.
    279
        See § 2.01 supra (discussing importance of patent system in encouraging financial in-
vestment in innovative enterprise).

                                                                                  (Rel. 25)
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duction, filing and retrieval of longer and longer patents and longer and long-
er patent law decisions, while the capacity of the human mind to analyze them
has not noticeably evolved in step with these advances. The result is infor-
mation overload and friction in the machine of innovation. No doubt the deci-
                                                                          280
sion in Dossel—implying so much that the patent drafter left unsaid —was
motivated at least in part by the Federal Circuit's desire to encourage more
succinct patent disclosures.
                                           281
   One way out of the Dossel dilemma           may be to recognize that, at least
insofar as disclosure is concerned, not all claim elements are created equal.
Courts properly eschew seeking the “gist” of an invention for purposes of
                 282
nonobviousness        or prioritizing claim elements in determining infringe-
       283
ment.      There is no need to change these well-established doctrines, but
common sense suggests that not all parts of an invention are equally important
in practice. If one of the goals of disclosure is to strike an appropriate balance
                                                             284
between comprehensiveness and information overload,              it follows that the
amount of disclosure—if nothing else in patent law—ought to depend on the
importance of the matter disclosed. Proper balance between the goals of ef-
fective substance and effective brevity may require more detailed disclosure
                                       285
of material portions of the invention.
   An approach to disclosure that focuses on the materiality of the inventive
                                                                                 286
element disclosed may provide a way out of the Dossel court's dilemma.
                                                         287
The practical use of means-plus-function language,            along with its limita-
       288
tions,     might survive if that language is required for claiming material ele-
ments of an invention other than by recitation of specific structure, material or



   280
         See the text accompanying Ns.251-258 supra.
   281
         See the text accompanying Ns.266-273 supra.
   282
        See § 2.03[3][a] supra.
    Courts' refusal to look for a “gist” in this context is justified by specific statutory language,
which requires that each invention be considered “as a whole.” 35 U.S.C. § 103(a), discussed in
§ 2.03[3][a] supra.
    283
        See § 2.05[3][a] supra. This refusal is justified by the hoary notion that every claim el-
ement, let alone every claim, is material. See N.180 supra.
    284
        See the text accompanying Ns.276-279 supra.
    285
        Cf.: Invacare Corp. v. Ortho-Kinetics, Inc., No. 95-1428, 1996 U.S. App. LEXIS 15188
at *5 (Fed. Cir. 1996) (unpublished) (“To properly interpret the means-plus-function claim, the
court must also take into account the claimed invention as a whole and the importance of the
recited means to the invention as a whole”); 1996 U.S. App. LEXIS 11288 at *6 (refusing to
construe claim elements to be limited as argued after considering invention as a whole).
    286
        See the text accompanying Ns.266-273 supra.
    287
        See the text accompanying Ns.250-252 supra.
    288
        See: the text accompanying Ns.259-262 supra; § 2.05[3][c][i] supra.


                                                                                         (Rel. 25)
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     289
acts.     The largely silent “disclosure” that generic structure-by-function lan-
               290
guage permits      can also survive—and its conflict with means-plus-function
                            291
language can be reduced —if it is confined to immaterial elements of an
invention. The standard for determining materiality could be the view of a
                                                                           292
familiar hypothetical person—the person of ordinary skill in the art.          If
such a person would consider the disclosure of specific means or steps for
performing the specified function important for effective disclosure of the
invention as a whole, then means-plus-function language, along with disclo-
sure of specific embodiments, would be required for claiming an element in
                    293
terms of function.      If, however, such a person would not consider disclos-
ing such means important for effective disclosure of the invention as a whole,
the inventor would have a choice between means-plus-function language and
generic structure-by-function language, as well as other language reciting
                                      294
specific structure, material or acts.
   Such an approach would offer four advantages. First, it would avoid the
                                295
Hobson's choice of Dossel.          By confining generic structure-by-function
language to immaterial elements of an invention, it would encourage the use
of means-plus-function language wherever doubt existed about an element's
                                                                     296
materiality. Far from rendering Section 112, ¶ 6 a dead letter,          this ap-
proach would encourage its use. Second, this approach would preserve the
optional character of means-plus-function language that the statute re-
        297
quires.     For the material elements of an invention, patent drafters could use
not only means-plus-function language; they could also use language reciting
specific structure, material or acts, or generic language based upon the recita-

   289
         These words relate to differing classes of invention. See § 2.05[3][c] (introduction) su-
pra.
   290
         See the text accompanying Ns.236-246 supra.
   291
         See the text accompanying Ns.250-252 supra.
   292
         This same hypothetical person provides the baseline for judging nonobviousness and
many aspects of proper disclosure. See: 35 U.S.C. § 103 (nonobviousness); § 2.03[3][a] supra
(same); 35 U.S.C. § 112, ¶ 1 (enabling disclosure); § 2.04[1][a] supra (same); § 2.04[1][b], [d]
supra (definiteness and “best mode” disclosure).
    293
        This rule would affect only means-plus-function and generic structure-by-function lan-
guage, see the text accompanying Ns.229-235 supra. It would not affect other claiming language
that does not rely on recitation of function, for example, (1) a recitation of specific structure,
material, or acts, or (2) a generic claim for a genus of structures, materials, or acts coupled with
a description of specific embodiments elsewhere in the specification. See § 2.04[1][b][i] supra
(discussing generic claiming generally).
    294
        This rule also would not affect claiming conventions that do not rely upon recitation of
function. See N.293 supra.
    295
        See the text accompanying Ns.266-273 supra.
    296
        See the text accompanying Ns.250-252 supra.
    297
        See § 2.05[3][c][ii] supra.


                                                                                        (Rel. 25)
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                                                                             298
tion of structure, material or acts, without reference to function.     For imma-
                                                                       299
terial elements, patent drafters could use any form of claiming,           but the
                                                       300
scope limitations of the means-plus-function form          would encourage them
                                                301
to use one of the more generic alternatives.        For elements of uncertain ma-
teriality, patent drafters could “play it safe” and use any of the forms of claim-
                                       302
ing available for material elements,        or they could use other forms at the
risk of patent invalidation.
    The third advantage of an approach based on materiality is that is could be
adopted by judicial interpretation, without congressional action. Not only
                                                                                303
would it preserve the optional character of means-plus-function language;
it would also preserve the scope limitations of the language that Congress
                      304
evidently intended.       Doing all this would require confining the use of ge-
neric structure-by-function language to immaterial elements of an inven-
      305
tion,     but this the courts could do themselves, as nothing in the statute sets
the parameters for such claiming. Finally, this approach would have an im-
portant practical, common-sense advantage: it would encourage more com-
plete and specific disclosure for material elements than for immaterial ones.
    Adopting this approach, however, might require modifying the Dossel de-
        306
cision.     Apparently to avoid undermining the use of means-plus-function
           307
language,      the Dossel court approved virtual nondisclosure of relevant ele-
                     308
ments of a claim.         To the extent the inventor could prove disclosure of
those elements immaterial to effective disclosure of the invention as a whole,
the approach suggested here would support the same result. Yet if the ele-
ments of the Dossel invention covered by the means-plus-function language—
the computer and the algorithms for “reconstruction” of the data there at is-

   298
         See N.293 supra.
   299
         See id.
   300
         See: the text accompanying Ns.238-246, 259-262 supra; § 2.05[3][c][i] supra.
   301
         They could use generic structure-by-function language or generic language reciting
structure with representative embodiments disclosed. See N.293 supra. See also, § 2.04[1][b][i]
supra (discussing generic claiming generally).
    302
        See the text accompanying Ns.286-289 & N.293 supra.
    303
        See § 2.05[3][c][ii] supra.
    304
        See: the text accompanying Ns.238-246, 259-262 supra; § 2.05[3][c][i] supra.
    305
        See the text accompanying Ns.295-301 supra.
    306
         In re Dossel, 115 F.3d 942, 42 U.S.P.Q.2d (BNA) 1881 (Fed. Cir. 1997), discussed in
text accompanying Ns.251-258 supra. The Federal Circuit may have made such a modification
in 2003, in the case of Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1366-1367 (Fed.
Cir. 2003). See the text accompanying Ns.312.1-313 infra.
    307
        See the text accompanying Ns.266-273 supra.
    308
        See the text accompanying Ns.251-258 supra.


                                                                                    (Rel. 25)
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    309                                                                      310
sue —were shown to be material for disclosure purposes,             then the “im-
                                                                               311
plied” or “virtual” disclosure of embodiments accepted by the Dossel court
should have been deemed inadequate, at least for purposes of Section 112, ¶
   312
6.      If these elements were material, the approach suggested here would
                                                        312.1
have required the Dossel inventor to disclose or refer        to at least one em-
bodiment capable of performing each of the stated functions—an embodiment
that would aid effective disclosure and provide a baseline for measuring
“equivalents” in the infringement phase of any litigation.
    In 2003, the Federal Circuit suggested a similar approach, but one based
on the novelty of the structure, material or act disclosed, rather than its mate-
riality to the invention. In the case of Intel Corp. v. VIA Technologies.,
      312.2
Inc.,       a Federal Circuit panel upheld a generic structural specification to
support a means-plus-function claim on the ground that the structure involved
                                           312.3
was not what made the invention novel.           In so doing, it implied that ge-
neric specification of structure, material, or acts may be invalid for indefinite-
ness if they touch a point of novelty.
    The difficulty with this approach, however, is that novelty in mean-plus-
function claims often lies in the concatenation of steps or acts, and not in the
                                                            312.4
structure, material or acts disclosed in the specification.       In other words,

   309
          See the text accompanying Ns.254-258 and N.257 supra.
   310
        The elements were the means, including hardware and software, required to perform cer-
tain data reconstruction functions in a medical imaging system. See the text accompanying
Ns.254-258 & N.257 supra. They may well have been material to the invention as a whole.
    311
        See the text accompanying Ns.254-258 supra.
    312
        For means or steps that are material to the invention as a whole, Section 112, ¶ 6 should
require at least one explicit description or reference to an embodiment of the structure, material,
or act performing the specified function. Such a requirement is consistent with the limiting role
of Section 112, ¶ 6, see: the text accompanying Ns.259-262 supra; § 2.05[3][c][i] supra, and
would avoid the difficulty of assessing “equivalents” without specific embodiments against
which to measure them, see the text accompanying Ns.261-267 supra.
    312.1
           See Ns.265, 312 supra.
    312.2
           Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1366-1367 (Fed. Cir. 2003).
    312.3
           See id., 319 F.3d at 1367:

   “The novelty of the invention as claimed in the . . . patent lies in the signal protocol for im-
   plementing [the claimed function], i.e., use of the signal WBF # , not in unclaimed circuitry
   for carrying out the specified protocol. Thus, one may design around the invention by using
   another signal protocol, but not by simply changing a circuit that uses the same signal proto-
   col. By analogy, if a chair is disclosed in the specification that corresponds to the ‘means for
   seating’ limitation in a claim, asserting that there are infinite numbers of structures that
   could make a chair or there are unlimited types of chairs in the world would not necessarily
   make the claim indefinite.”
   312.4
          This is often, if not invariably, so for software-related means-plus-function claims, in
which the point of novelty inheres in the concatenation of abstract, logical program steps, re-
gardless of the means for carrying them out (which, in many cases, is simply a properly pro-

                                                                                       (Rel. 25)
2-05                    PATENTS                INTELLECTUAL PROPERTY LAW

there may be few or no means-plus-function claims in which the specification
of structure, material or acts involves a point of novelty, and therefore the
novelty test implied in Intel may fail to discriminate among means-plus-
                                                        312.5
function claims in practice. To the extent this is so,        the Intel decision
                                           312.6
appears to continue the Dossel approach,         with “claiming neutrality” be-
tween means-plus-function and generic structural claims, at the risk of vitiat-
ing the apparent congressional intent, expressed in Section 112, ¶ 6, to require
precise specification of structure, material or acts to which means used must
                312.7
be equivalent.        For computer program related inventions, this approach
may exacerbate the Federal Circuit’s “open door” approach to patentable sub-
            312.8
ject matter       by allowing alleged “inventors” to claim broadly an abstract
series of process steps, without having invented (and without specifying, other
than generically) any particular structure, material or acts to carry them
     313
out.

           [iv]—Infringement of Means-Plus-Function Claims
   In the 1990s means-plus-function claims became increasingly common.
                                                    313.1
Their greater use reflected their potential breadth       and the Federal Cir-
cuit's encouragement, if not endorsement, of their use for inventions involving
                                                             313.2
computer software, mathematics and algorithmic elements.           As a result of
this increasing use of means-plus-function claims, the Federal Circuit focused
greater attention on their infringement. The court's decisions, however, still
leave some troubling questions unanswered. In general, assessing infringe-



grammed general-purpose digital computer not invented by the patent applicant). See §
2.02[2][b][iv][C] supra.
    312.5
            It may not be so as often for inventions not related to computers. See §
2.02[2][b][iv][D] supra (discussing how Morse’s telegraph and Fermi’s atomic pile might have
been claimed in means-plus-function form).
    312.6
           See Intel Corp. v. VIA Technologies., Inc., 319 F.3d 1357, 1366-1367 (Fed. Cir.
2003) (relying on Dossel to reject indefiniteness challenge to means-plus-function claim in
which specified structure was described generically, leaving details to knowledge of those
skilled in art), referring to In re Dossel, 115 F.3d 942, 946, 42 U.S.P.Q.2d (BNA) 1881 (Fed.
Cir. 2003), and outlined more particularly in Ns.266.1, 313.3 supra.
    312.7
           See the text accompanying Ns.257-267 supra.
    312.8
           See § 2.02[2][b][iv] supra.
    313
         This result, described in § 2.02[2][b][iv][E] supra, is difficult to square with the ra-
tionale for the judge-made exceptions to patentable subject matter for abstract ideas and laws of
nature. See § 2.02[2][b][iv][E]-[G] supra. See also, Dratler, “Does Lord Darcy Yet Live?: The
Case Against Software and Business-Method Patents,” 43 Santa Clara L. Rev. 823, 853-871,
876-899 (2003) (discussing pernicious economic effects of such broad claims).
    313.1
           See § 2.05[c][iii] supra.
    313.2
           See § 2.02[2][b] supra.


                                                                                     (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                                                       313.3
ment of a patent claim involves two steps:           (1) construing the claim—a
                                      313.4
task exclusively for the trial judge;       and (2) reading the claim on the ac-
                           313.5                                      313.6
cused device or process          —a task for the jury, if empaneled.        The se-
cond step includes both literally applying the claims to the accused device or
        313.7                                              313.8
process        and applying the doctrine of equivalents          —a task in which
                                    313.9
the jury must at least participate.       In order for infringement to be found,
every element of the claim at issue must appear in the accused device or pro-
                      313.10                              313.11
cess, either literally       or by way of an equivalent.         No limitation of a

   313.3
           See generally, § 2.05[3][a] supra.
     See also, e.g.: Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1454, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (“An infringement analysis involves two steps. First, the
court determines the scope and meaning of the patent claims asserted, . . . and then the properly
construed claims are compared to the allegedly infringing device”) (Citations omitted.); Engel
Industries, Inc. v. Lockformer Co., 96 F.3d 1398, 1403-1404, 40 U.S.P.Q.2d (BNA) 1161 (Fed.
Cir. 1996) (“Analysis of patent infringement involves two steps: (1) claim construction to
[*1404] determine what the claims cover, i.e., their scope, followed by (2) determination of
whether the properly construed claims encompass the accused structure. On appeal after a bench
trial, we review step (1) de novo and step (2) for clear error”), citing Markman v. Westview
Instruments, Inc., 52 F.3d 967, 976, 34 U.S.P.Q.2d (BNA) 1321, 1326 (Fed. Cir.) (en banc)
(Markman I), aff'd, ____ U.S. ____, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA)
1461 (1996) (Markman II); Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 397, 29
U.S.P.Q.2d (BNA) 1767 (Fed. Cir. 1994), citing Becton Dickinson & Co. v. C.R. Bard, Inc.,
922 F.2d 792, 796, 17 U.S.P.Q.2d (BNA) 1097, 1099 (Fed. Cir. 1990); Carroll Touch, Inc. v.
Electro Mechanical Systems, Inc., 15 F.3d 1573, 1576, 27 U.S.P.Q.2d (BNA) 1836 (Fed. Cir.
1993) (“The law is well established that the determination whether a claim has been infringed
requires a two-step analysis”), citing Read Corp. v. Portec, Inc., 970 F.2d 816, 821, 23
U.S.P.Q.2d (BNA) 1426, 1431 (Fed. Cir. 1992), and ZMI Corp. v. Cardiac Resuscitator Corp.,
844 F.2d 1576, 1578, 6 U.S.P.Q.2d (BNA) 1557, 1559 (Fed. Cir. 1988).
     313.4
           See: Markman v. Westview Instruments, Inc. ____ U.S. ____, 116 S.Ct. 1384, 1387,
134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion) (“We hold that the
construction of a patent, including terms of art within its claim, is exclusively within the prov-
ince of the court”), discussed in § 2.05[3][a] supra; N.313.3 supra.
     313.5
           See: § 2.05[3][a] supra; N.313.3 supra.
     313.6
           See: § 2.05[3][a] supra; the text accompanying Ns.313.69-313.73 infra.
     313.7
           See generally, § 2.05[3][a] supra.
     313.8
           For general discussion of the doctrine of equivalents, see § 2.05[3][b][i] supra.
     313.9
           See the text accompanying Ns.313.69-313.73 and Ns.313.71, 313.72 infra.
     313.10
             See Engel Industries, Inc. v. Lockformer Co., 96 F.3d 1398, 1405, 40 U.S.P.Q.2d
(BNA) 1161 (Fed. Cir. 1996) (“Literal infringement of a claim exists when every limitation
recited in the claim is found in the accused device, i.e., when the properly construed claim reads
on the accused device exactly”), citing Johnston v. IVAC Corp., 885 F.2d 1574, 1580, 12
U.S.P.Q.2d (BNA) 1382, 1384 (Fed. Cir. 1989). (Internal citations omitted.) See generally, §
2.05[3][a] supra.
     313.11
             See, e.g., Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 397, 29 U.S.P.Q.2d
(BNA) 1767 (Fed. Cir. 1994), citing Becton Dickinson & Co. v. C.R. Bard, Inc., 922 F.2d 792,
796, 17 U.S.P.Q.2d (BNA) 1097, 1099 (Fed. Cir. 1990) (“To show infringement, the plaintiff
must establish that the accused device includes every limitation of the claim or an equivalent of

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                                 313.12
claim may be ignored, even under the doctrine of equivalents,           for Hil-
ton-Davis requires every claim to be assessed element by element, and not as
          313.13
a whole.         These rules apply to all claims, whether expressed in means-
                           313.14
plus-function form or not.
   With respect to means-plus-function claims, however, there is a conceptual
difficulty in applying the doctrine of equivalents. By statutory command, each
                                                                      313.15
of the means-and-function elements of a means-plus-function claim            al-
                                                      313.16
ready contains an intrinsic reference to equivalents.        Under Section 112,
    313.17
¶6         each claim element must be read to cover the corresponding means

each limitation”); Carroll Touch, Inc. v. Electro Mechanical Systems, Inc., 15 F.3d 1573, 1576,
27 U.S.P.Q.2d (BNA) 1836 (Fed. Cir. 1993) (“A claim covers an accused device if the device
embodies every limitation of the claim, either literally or by an equivalent”), citing Read Corp.
v. Portec, Inc., 970 F.2d 816, 822, 23 U.S.P.Q.2d (BNA) 1426, 1431 (Fed. Cir. 1992). See gen-
erally, § 2.05[3][b][i] supra.
    313.12
             See, e.g., Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 398, 29 U.S.P.Q.2d
(BNA) 1767 (Fed. Cir. 1994) (“The doctrine of equivalents is not a license to ignore claim limi-
tations”), citing Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 935, 4 U.S.P.Q.2d
(BNA) 1737 (Fed. Cir. 1987) (en banc), cert. denied 485 U.S. 961, 485 U.S. 1009 (1988); Car-
roll Touch, Inc. v. Electro Mechanical Systems, Inc., 15 F.3d 1573, 1579, 27 U.S.P.Q.2d (BNA)
1836 (Fed. Cir. 1993) (“determining whether there is infringement under the doctrine of equiva-
lents 'does not mean one can ignore claim limitations'“), quoting Pennwalt Corp. v. Durand-
Wayland, Inc., 833 F.2d 931, 935, 4 U.S.P.Q.2d (BNA) 1737, 1739 (Fed. Cir. 1987) (en banc),
cert. denied 485 U.S. 961 (1988).
    313.13
             See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 29, 117 S.Ct.
1040, 137 L.Ed.2d 146 (1997) (“Each element contained in a patent claim is deemed material to
defining the scope of the patented invention, and thus the doctrine of equivalents must be ap-
plied to individual elements of the claim, not to the invention as a whole”), discussed in §
2.05[3][b][i] supra. See also, 117 S.Ct. at 1054 (declining to choose between tripartite test of
Graver Tank and “insubstantial differences” standards, see the text accompanying Ns.242-243
supra, and noting that “[a] focus on individual elements and a special vigilance against allowing
the concept of equivalence to eliminate completely any such elements should reduce considera-
bly the imprecision of whatever [general] language [for the standard of equivalence] is used”).
    313.14
             See generally, § 2.05[3][a], [b][i] supra.
    313.15
             Section 112, ¶ 6, applies not only to product inventions, but to processes as well. See
§ 2.05[3][c] (introduction) supra. With respect to processes, the statutory term “step” is more
appropriate than the term “means,” and the patent specification is more likely to disclose corre-
sponding “material” or “acts” than “structure.” Id., quoting 35 U.S.C. § 112, ¶ 6. See also,
N.313.16 infra, quoting 35 U.S.C. § 112, ¶ 6, in part.
    For the sake of brevity and simplicity, however, this subsection refers throughout to “means”
and “structure” only. Wherever those terms are used, they are intended to include reference to
“steps,” “material,” “and/or” acts, as appropriate to the nature of the invention. For example, the
terms “means-and-function” or “means-plus-function” should be read to include “step-and-
function” or “step-plus-function,” respectively. See id. The statute makes no distinction whatso-
ever, but repeating the parallel terms throughout would only impede communication.
    313.16
             See 35 U.S.C. § 112, ¶ 6 (in part: “such claim shall be construed to cover the corre-
sponding structure, material, or acts described in the specification and equivalents thereof”),
quoted in full in § 2.05[3][c] (introduction) supra.
    313.17
             35 U.S.C. § 112, ¶ 6, quoted in part in N.313.16 supra and in full in § 2.05[3][c] (in-
troduction) supra.

                                                                                        (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                        313.18
described in the specification and equivalents thereof.              This statutory
requirement raises an important question: whether the doctrine of equivalents
is already “built into” means-plus-function claims—and therefore the
“equivalents” permitted and required by the statute are all that the law al-
lows—or whether the patentee gets two bites at the apple of equivalence—the
                              313.19
one specified by the statute         and a later application of the judge-made
                                          313.20
doctrine of equivalents more generally.
    There are three logical possibilities. First, the statutory bite at the apple of
                                                  313.21
equivalence could be all that the law allows.             That is, the scope of the
claim could be limited to the stated functions, as performed respectively by
the disclosed means and their equivalents, and no more. This is the narrowest
reasonable interpretation. Second, that narrow scope might be construed as a
mere literal interpretation of the claim, to which the doctrine of equivalents
then could be applied respectively to each function-by-means element, on an
                            313.22
element-by-element basis.           Finally, the broadest interpretation would
take a similar approach, considering the statutory command as a recipe for
                                      313.23
assessing literal infringement only,         and yet later apply the general doc-
                                                                313.24
trine of equivalents to the invention so defined as a whole.           This last and
broadest approach, however, is foreclosed by the Supreme Court's unanimous
and unambiguous endorsement of the element-by-element approach to the
                                            313.25
doctrine of equivalents in Hilton Davis.            As a result, indisputable legal
authority leaves only the first two approaches viable.
    As between those two, certain language in the Federal Circuit's opinions
opens to door to the second, broader interpretation, which allows the doctrine
of equivalents to be applied generally to each element of the claim, after a


   313.18
            See also, Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *14
(Fed. Cir. Sept. 10, 1998), quoting and following Carroll Touch, Inc. v. Electro Mechanical
Systems, Inc., 3 F.3d 404, 409, 27 U.S.P.Q.2d (BNA) 1836, 1840 (Fed. Cir. 1993) (“In order to
meet a means-plus-function limitation, an accused device must (1) perform the identical func-
tion recited in the means limitation and (2) perform that function using the structure disclosed in
the specification or an equivalent structure”). See also, Ns.313.29, 313.35 infra.
    313.19
            See the text accompanying Ns.313.14-313.18 supra.
    313.20
            See the text accompanying Ns.313.73-313.84, 313.107-313.120 infra. See generally,
§ 2.05[3][b][i] supra.
    313.21
            This is the conclusion of this book. See the text accompanying Ns.313.120-313.157
infra.
    313.22
            Some language in the Federal Circuit's opinions suggests this approach. See the text
accompanying Ns.313.73-313.84 and Ns.313.75, 313.77, 313.80, 313.100, 313.157 infra.
    313.23
            See the text accompanying Ns.31.20-313.22 supra.
    313.24
             For further discussion and rejection of this approach, see the text accompanying
Ns.313.107-313.143 infra.
    313.25
            See N.313.13 supra.


                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                313.26                313.27
search for equivalents to the disclosed structures            has failed.      For
the Federal Circuit has ruled that applying a means-plus-function claim, in
accordance with Section 112, ¶ 6, to each specified function as performed by
                                          313.28
disclosed means and their equivalents            constitutes an assessment of lit-
                         313.29
eral infringement only.         This, of course, invites a later application of the
                                 313.30
general doctrine of equivalents.
    To assess the significance of this point, it is helpful to recount in more de-
tail the special process for assessing infringement of means-plus-function
claims that the Federal Circuit has prescribed. That process includes three
steps. First, the court must determine the function performed by each set of
general means, i.e., the function corresponding to each function-and-
       313.31                        313.32
means         element of the claim.         Where that function is disputed, the




   313.26
            This word includes material and acts. See N.313.15 supra.
   313.27
            See the text accompanying Ns.313-73-313.84, 313.107-313.120 infra.
   313.28
            See the text accompanying Ns.313.14-131.18 supra.
   313.29
         See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1467, 46 U.S.P.Q.2d
(BNA) 1169, 1184 (Fed. Cir. 1998) (en banc):
   “For literal infringement of a section 112, ¶ 6 limitation, the fact-finder must determine
   whether the accused device performs an identical function to the one recited in the means-
   plus-function clause. . . . If the identical function is performed, the fact-finder must then de-
   termine whether the accused device utilizes the same structure or materials as described in
   the specification, or their equivalents.”
     See also: Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303, 1308,
46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (“To determine whether a claim limitation is met
literally, where expressed as a means for performing a stated function, the court must compare
the accused structure with the disclosed structure, and must find equivalent structure as well as
identity of claimed function for that structure”), quoting Pennwalt Corp. v. Durand-Wayland,
Inc., 833 F.2d 931, 934, 4 U.S.P.Q.2d (BNA) 1737, 1739 (Fed. Cir. 1987) (en banc) (Emphasis
omitted.); Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *15 (Fed. Cir.
Sept. 10, 1998) (where stepper motor in accused device was not equivalent to solenoid in “lever
actuating means” element of means-plus-function claim, there was no literal infringement);
Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1467, 46 U.S.P.Q.2d (BNA) 1169 (Fed.
Cir. 1998) (en banc) (concurring opinion of Judges Mayer and Newman: “For literal infringe-
ment, the fact finder must determine whether the accused device performs an identical function
to the one recited in the means-plus-function clause. . . . If the identical function is performed,
the fact finder must then determine whether the accused device utilizes the same structure or
materials as described in the specification, or their equivalents”), citing Pennwalt Corp. v. Du-
rand-Wayland, Inc., 833 F.2d 931, 934, 4 U.S.P.Q.2d (BNA) 1737, 1739 (Fed. Cir. 1987) (if the
identical function is not performed, literal infringement is not possible).
     313.30
            See the text accompanying Ns.313.73-313.84 supra.
     313.31
            This language includes reference to process steps. See N.313.15 supra.
     313.32
            See the text accompanying Ns.313.14-313.18 supra.


                                                                                        (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

court determines it as a matter of law, subject to plenary review upon ap-
      313.33                                             313.34
peal,        as a part of claim construction generally.
   Insofar as literal infringement is concerned, the function recited in each el-
ement of the means-plus-function claim must appear identically in the accused
        313.35
device.         In this analysis, it is the claimed function that counts; subsidiary

   313.33
             See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1308, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (“A determination of the claimed function,
being a matter of construction of specific terms in the claim, is a question of law, reviewed de
novo”), citing Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 46 U.S.P.Q.2d (BNA)
1169 (Fed. Cir. 1998) (en banc). (Other citation omitted.)
     But see, Carroll Touch, Inc. v. Electro Mechanical Systems, Inc., 15 F.3d 1573, 1578, 27
U.S.P.Q.2d (BNA) 1836 (Fed. Cir. 1993) (assessment of sameness of function and use of identi-
cal or equivalent structure are factual determinations reviewed for clear error), citing Durango
Associates, Inc. v. Reflange, Inc., 843 F.2d 1349, 1357, 6 U.S.P.Q.2d (BNA) 1290, 1295 (Fed.
Cir. 1988).
     313.34
            See the text accompanying Ns.313.3-313.4 and Ns.313.3, 313.4 supra.
     313.35
             See, e.g.: Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1457, 46
U.S.P.Q.2d (BNA) 1169 (Fed. Cir. 1998) (en banc) (“Under § 112, ¶ 6, an accused device with
structure not identical to the structure described in the patent will literally infringe the patent if
the device performs the identical function required by the claim with a structure equivalent to
that described in the patent”) (Emphasis added.), citing Micro Chemicals, Inc. v. Great Plains
Chemical. Co., 103 F.3d 1538, 1547, 41 U.S.P.Q.2d (BNA) 1238, 1245-1246 (Fed. Cir. 1997);
Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *10-11, *23-25 (Fed.
Cir. Sept. 10, 1998), citing Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934, 4
U.S.P.Q.2d (BNA) 1737, 1739 (Fed. Cir. 1987) (en banc) (there can be no literal infringement
where corresponding structure of accused device does not perform function specified in claim
element), outlined more fully in N.313.114 infra; Micro Chemical, Inc. v. Great Plains Chemical
Co., 103 F.3d 1538, 1547, 41 U.S.P.Q.2d (BNA) 1238, 1245-1246 (Fed. Cir. 1997) (“Literal
infringement of a claim containing a means clause requires that the accused device perform the
identical function as that identified in the means clause”), quoted in Invacare Corp. v. Ortho-
Kinetics, Inc., 1998 U.S. App. LEXIS 15202 at *5 (Fed. Cir. July 6, 1998); Carroll Touch, Inc.
v. Electro Mechanical Systems, Inc., 15 F.3d 1573, 1578, 27 U.S.P.Q.2d (BNA) 1836 (Fed. Cir.
1993) (“In order to meet a means-plus-function limitation, an accused device must (1) perform
the identical function recited in the means limitation and (2) perform that function using the
structure disclosed in the specification or an equivalent structure”), citing Valmont Industries,
Inc. v. Reinke Manufacturing Co., Inc., 983 F.2d 1039, 1042, 25 U.S.P.Q.2d (BNA) 1451, 1454
(Fed. Cir. 1993).
     See also: N.313.29 supra; Cybor Corp. v. FAS Technologies, Inc., supra, 138 F.3d at 1458
& n.9 (where question was whether dual-pump liquid-dispensing system with external fluid
reservoir infringed claims directed at similar system with reservoir included in second pump,
despite alleged prosecution history estoppel involving prior art with external reservoir, jury
instruction that accused device had to be structurally equivalent and to perform same function
was sufficient; no specific instruction on estoppel was necessary where performance of stated
function was impossible without some reservoir, and where reservoir in prior art performed
different function from merely collecting and holding fluid, at least in part); 138 F.3d at 1470
(concurring opinion of Judges Mayer and Newman: nature of cited prior art did not require
detailed instructions to jury on prosecution history estoppel because separate reservoir there
could not have performed claimed function); Carroll Touch, Inc. v. Electro Mechanical Systems,
Inc., 15 F.3d 1573, 1578, 27 U.S.P.Q.2d (BNA) 1836 (Fed. Cir. 1993) (where producing
“spaced apart” x- and y-infrared beams for computer screen finger-pointing device was “essen-
tial function” of “means for mounting” display, and where “structures disclosed in the specifica-
tion by which that function [was] achieved all ha[d] beam surfaces that d[id] not intersect[,]”

                                                                                          (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                                 313.36
or incidental functions performed by the disclosed structures             are not
                                               313.37
considered in assessing literal infringement.
   Once a court has determined the function for each means-plus-function el-
       313.38
ement,         it must take the second step, determining the corresponding
                            313.39
structure, material or acts        disclosed in the specification and the equiva-
lents thereof. Determining the corresponding structure, material or acts dis-
                                                                       313.40
closed in the specification is also a matter of claim construction,           and
                                                               313.41
therefore, under Markman v. Westview Instruments, Inc.,               a matter of
     313.42                                    313.43
law,        reviewable de novo upon appeal.           This determination of struc-

means producing beam surfaces that intersected did “not perform the identical function stated in
the means limitation” and therefore did not literally infringe).
    313.36
            This word includes material and acts involved in process steps. See N.313.15 supra.
    313.37
            See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1308, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (where specified function of skid plate in
saw for nonhardened concrete was to support surface of concrete against upward motion of
emerging saw blade, additional features of skid plate recited in specification, designed to per-
form additional functions of keeping saw blade from wobbling and supporting weight of saw,
were not to be read as limiting scope of means clause).
    Cf., B. Braun Medical, Inc. v. Abbott Laboratories, 124 F.3d 1419, 1421, 1424-1425, 43
U.S.P.Q.2d (BNA) 1896 (Fed. Cir. 1997) (where drawing, written description, and summary of
invention all pointed to traverse bar as “means” recited in specification for holding disk in place
in valve for medical applications, and where neither specification nor prosecution history indi-
cated that valve seat structure shown in diagram performed same function, patentee had “failed
to particularly point out and distinctly claim that particular means” under § 112, ¶ 2). (Citation
omitted.)
    313.38
            See the text accompanying Ns.313.30-313.37 supra.
    313.39
            See N.313.15 supra.
    313.40
            See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1308, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (“Likewise, the 'means' term in a means-
plus-function limitation is essentially a generic reference for the corresponding structure dis-
closed in the specification. Accordingly, a determination of corresponding structure is a deter-
mination of the meaning of the 'means' term in the claim and is thus also a matter of claim
construction”), citing B. Braun Med., Inc. v. Abbott Laboratories, Inc., 124 F.3d 1419, 1424-
1425, 43 U.S.P.Q.2d (BNA) 1896, 1899-1900 (Fed. Cir. 1997) (determining de novo which
structures disclosed in the specification corresponded to the means limitation). (Other citation
omitted.)
    313.41
            See: N.313.4 supra; § 2.05[3][a] supra.
    313.42
            See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1451, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (“we conclude that the Supreme Court's unanimous
affirmance in Markman . . . of our in banc judgment in that case fully supports our conclusion
that claim construction, as a purely legal issue, is subject to de novo review on appeal”), refer-
ring, respectively, to Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S.Ct. 1384,
134 L.Ed.2d 577 (1996) (Markman II), and Markman v. Westview Instruments, Inc., 52 F.3d
967, 979, 34 U.S.P.Q.2d (BNA) 1321, 1329 (Fed. Cir. 1995) (en banc) (Markman I).
    See also, 138 F.3d at 1451 (rejecting view—and precedents espousing view—that clearly er-
roneous standard applies “to findings considered to be factual in nature that are incident to the
judge's construction of patent claims”); 138 F.3d at 1456 (Citations to other disapproved deci-
sions omitted.):

                                                                                       (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

     313.44                                          313.45
ture         is an especially important step       in construction of means-plus-
function claims, for the scope of equivalents of that structure depends upon
    313.46
it.        It is also a step that relies primarily upon preferred “intrinsic” evi-


   “[W]e conclude that the standard of review in Markman I . . . was not changed by the Su-
   preme Court's decision in Markman II, and we therefore reaffirm that, as a purely legal ques-
   tion, we review claim construction de novo on appeal including any allegedly fact-based
   questions relating to claim construction. Accordingly, we today disavow any language in
   previous opinions of this court that holds, purports to hold, states, or suggests anything to the
   contrary, see, e.g., Fromson [v. Anitec Printing Plates, Inc., 132 F.3d 1437,] 1444, 45
   U.S.P.Q.2d (BNA) [1269], 1274 [(Fed. Cir. 1997)] (“The district court's findings of scien-
   tific/technological fact were material to the issue of construction of the term 'anodizing'“) . . .
   .”
     See generally, § 2.05[3][a] supra.
     313.43
             See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1456, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (“Because the [Supreme] Court [in Markman II] did not
discuss the appellate standard of review, Markman II can be read as addressing solely the re-
spective roles of the judge and jury at the trial level and not the relationship between the district
courts and this court. Although our conclusion in Markman I that claim construction is a matter
of law was affirmed in all respects, even this narrower view of Markman II leaves Markman I as
the controlling authority regarding our standard of review”).
     See also, e.g., Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *9
(Fed. Cir. Sept. 10, 1998) (“A determination of corresponding structure . . . is a determination of
the meaning of the 'means' term in the claim and is thus also a matter of claim construction”),
citing: Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303, 1308, 46
U.S.P.Q.2d (BNA) 1752, 1755-1756 (Fed. Cir. 1998) and B. Braun Medical, Inc. v. Abbott
Laboratories, Inc., 124 F.3d 1419, 1424-1425, 43 U.S.P.Q.2d (BNA) 1896, 1899-1900 (Fed.
Cir. 1997) (determining de novo which structures disclosed in the specification corresponded to
the means limitation).
     For further discussion of this point, see § 2.05[3][a] supra.
     313.44
             This word includes material and acts. See N.313.15 supra.
     313.45
             This step in the process is also especially important for another reason. Most, if not
all, of the substance of a means-plus-function claim inheres in the inventor's means or steps (as
disclosed in the specification) for performing the stated functions. Patent law does not allow
claiming function, see § 2.05[3][c][i] supra, because function is too close to result, and inven-
tion is finding a means to achieve the desired result. Simply parsing the desired function or
result into smaller or subsidiary functions or results—which often may be possible purely as an
abstract conceptual matter, without considering any means at all—may get an inventor closer to
the goal, but it is not really invention. Invention occurs when the blanks are filled in and the
inventor has found means to perform all the necessary functions, and thereby to achieve the
overall result. This is one reason why algorithmic means-plus-function claims, in which all
functions are or can be performed by the same means (a general-purpose digital computer in-
vented by someone else), are so suspect. See generally, § 2.02[2][b][iv][E] supra.
     313.46
             See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1308, 1309, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (where function recited was “support-
ing the surface of the concrete adjacent to the leading edge of the cutting blade to inhibit chip-
ping, spalling, or cracking of the concrete surface during cutting[,]” and specification “clearly
identifie[d] the structure performing that function as the skid plate, which [was]s the only em-
bodiment of the 'support surface' disclosed in the specification[,]” corresponding structure was
skid plate, not more generalized “support surface,” and two wheels used in accused device for
same purpose would infringe only if they were equivalent to skid plate).

                                                                                          (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                      313.47                                           313.48
dence in the public records,        including the patent specification       and
                         313.49
the prosecution history.        In determining what structures disclosed in the
specification correspond to the stated function, courts consider the logical and
technological relationships between the function and the disclosed struc-




   313.47
            See § 2.05[3][a] supra.
   313.48
             See B. Braun Medical, Inc. v. Abbott Laboratories, 124 F.3d 1419, 1421, 1424, 43
U.S.P.Q.2d (BNA) 1896 (Fed. Cir. 1997) (where claim is in means-plus-function form, “we
must turn to the written description of the patent to find the structure that corresponds to the
means recited in the . . . limitation”).
    That fact that Section 112, ¶ 6, refers to parts of the specification other than the patent
claims for the substance of the means or steps used to achieve the stated functions puts consid-
erable pressure on the patent drafter to disclose an appropriate range of means and, where neces-
sary, to distinguish them from prior art. This pressure is appropriate, for it helps to motivate the
drafting of clean and transparent patents that should better serve the public notice function that
patent policy assumes. See § 2.05[3][a] supra.
    313.49
            See Ns.313.50, 313.51 infra.


                                                                                        (Rel. 25)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

       313.50                                              313.51
tures       allegedly intended to perform it.         Ordinarily, the designated
                                                              313.52
structures must be able to perform the stated function fully.
   Once it has determined the disclosed structure that performs the specified
          313.53
function,        the court can take the third and final step in the analysis: de-
termining equivalents of that structure. This determination relies upon the
                                                313.54
standard of equivalence from Hilton Davis:             insubstantial differences
between the disclosed structure and the structure that performs the same func-



   313.50
              See B. Braun Medical, Inc. v. Abbott Laboratories, 124 F.3d 1419, 1421, 1425, 43
U.S.P.Q.2d (BNA) 1896 (Fed. Cir. 1997) (finding substantial evidence to support jury's verdict
of no infringement, both literally and under doctrine of equivalents, where accused device
lacked means disclosed in specification and means used in accused device, although appearing
in patent drawing, had not been associated with claimed function, either in specification or in
prosecution history); Carroll Touch, Inc. v. Electro Mechanical Systems, Inc., 15 F.3d 1573,
1577-1578, 27 U.S.P.Q.2d (BNA) 1836 (Fed. Cir. 1993) (where specification for patent on
touch-screen pointing device revealed two purposes of keeping x- and y- beams “spaced apart”
as stated in claims—allowing logic to discriminate movements by small insects and to calculate
time between penetration of x- and y-layers—and where intersecting beams would not allow
these functions to be performed, “specification [did] not disclose that the beam surfaces of the
claimed invention [could] intersect”).
    313.51
              See B. Braun Medical, Inc. v. Abbott Laboratories, 124 F.3d 1419, 1421, 1424, 43
U.S.P.Q.2d (BNA) 1896 (Fed. Cir. 1997) (“We hold that, pursuant to [Section 112, ¶ 6], struc-
ture disclosed in the specification is 'corresponding' structure only if the specification or prose-
cution history clearly links or associates that structure to the function recited in the claim. This
duty to link or associate structure to function is the quid pro quo for the convenience of employ-
ing § 112, ¶ 6”), citing O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583, 42 U.S.P.Q.2d (BNA)
1777, 1782 (Fed. Cir. 1997).
    A logical and technological relationship between structure and function is required not only
by Section 112, ¶ 6, but by the requirement for definite claims in Section 112, ¶ 2, discussed in
§ 2.04[1][b] supra. See B. Braun Medical, Inc. v. Abbott Laboratories, 124 F.3d 1419, 1421,
1424-1425, 43 U.S.P.Q.2d (BNA) 1896 (Fed. Cir. 1997) (patent drafter's obligation to link
disclosed means with stated function is also supported by requirement for definite claims), quot-
ing In re Donaldson Co., 16 F.3d 1189, 1195, 29 U.S.P.Q.2d (BNA) 1845, 1850 (Fed. Cir.
1994) (en banc) (“If one employs means-plus-function language in a claim, one must set forth in
the specification an adequate disclosure showing what is meant by that language. If an applicant
fails to set forth an adequate disclosure, the applicant has in effect failed to particularly point out
and distinctly claim the invention as required by the second paragraph of section 112”), citing In
re Dossel, 115 F.3d 942, 946-947, 42 U.S.P.Q.2d (BNA) 1881 (Fed. Cir. 1997). (Citation to
statute omitted.)
    313.52
             See Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *13 (Fed.
Cir. Sept. 10, 1998) (solenoid was “required structure” for “lever operating means” element in
means-plus-function claim because “it provide[d] the power that operate[d] the lever”).
    313.53
             See the text accompanying Ns.313.37-313.52 supra.
    313.54
              See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., 63 F.3d 1512, 1517-1518,
1524 (Fed. Cir.) (majority opinion) (restating standard for equivalence as “insubstantial differ-
ences” and applying that standard to facts of case), rev'd on other grounds 520 U.S. 17, 40, 117
S.Ct. 1040, 1054, 137 L.Ed.2d 146 (1997) (reviewing both old tripartite function-way-result test
and “insubstantial differences” test and declining to “micro-manage[] the Federal Circuit's par-
ticular word-choice for analyzing equivalence”), discussed in § 2.05[3][b][i] infra.

                                                                                           (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                                    313.55
tion in the accused device.         Courts must exercise care in applying the
                               313.56
tripartite test of Graver Tank        —substantially the same function, means,
            313.57
and result         —because the function performed by any equivalent means in
the accused device must be identical with, not just substantially the same as,



   313.55
            See, e.g., Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1309, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (“In the context of section 112 . . . an equiva-
lent results from an insubstantial change which adds nothing of significance to the structure,
material, or acts disclosed in the patent specification”), quoting Pennwalt Corp. v. Durand-
Wayland, Inc., 833 F.2d 931, 934, 4 U.S.P.Q.2d (BNA) 1737, 1739 (Fed. Cir. 1987) (en banc)
and citing Valmont Industries, Inc. v. Reinke Manufacturing Co., 983 F.2d 1039, 1043, 25
U.S.P.Q.2d (BNA) 1451, 1455 (Fed. Cir. 1993); Alpex Computer Corp. v. Nintendo Co., 102
F.3d 1214, 1222, 40 U.S.P.Q.2d (BNA) 1667, 1673 (Fed. Cir. 1996), cert. denied 117 S.Ct.
2480 (1997) (noting that equivalents under Section 112, ¶ 6, and under the doctrine of equiva-
lents both relate to insubstantial changes) (Internal citations omitted.):
   “'Section 112, paragraph 6, rules out the possibility that any and every means which per-
   forms the function specified in the claim literally satisfies that limitation. . . . The proper test
   is whether the differences between the structure in the accused device and any disclosed in
   the specification are insubstantial.”
    Cf., Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 397, 29 U.S.P.Q.2d (BNA) 1767
(Fed. Cir. 1994) (“To be an . . . 'equivalent,' the element substituted in the accused device for the
element set forth in the claim must not be such as would substantially change the way in which
the function of the claimed invention is performed”), quoting Perkin-Elmer Corp. v. Westing-
house Electric Corp., 822 F.2d 1528, 1533, 3 U.S.P.Q.2d (BNA) 1321, 1325 (Fed. Cir. 1987);
16 F.3d at 400 (lack of “stable rigid frame or equivalent structure to support additional pan-
els[,]” allowing accused device to “disassemble[] completely into its flat panel components[,]”
was “not 'insubstantial' at all”), citing Charles Greiner & Co. v. Mari-Med Manufacturing Co.,
962 F.2d 1031, 1036, 22 U.S.P.Q.2d (BNA) 1526, 1529 (Fed. Cir. 1992); Carroll Touch, Inc. v.
Electro Mechanical Systems, Inc., 15 F.3d 1573, 1579, 27 U.S.P.Q.2d (BNA) 1836 (Fed. Cir.
1993) (where claim required that computer-display pointing-device “beam surfaces be spaced
apart over the entirety of their respective surfaces areas” and it was “undisputed that all of the
accused . . . devices ha[d] beam surfaces that intersect[ed] to some degree[,]” difference “be-
tween the claimed invention and the accused devices [wa]s neither unimportant nor insubstan-
tial”).
    313.56
             Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605, 608,
700 S.Ct. 854, 94 L.Ed. 1097 (1950), quoting Sanitary Refrigerator Co. v. Winters, 280 U.S. 30,
42, 50 S.Ct. 9, 74 L.Ed. 147 (1929) (accused device is equivalent to claimed invention “if is
performs substantially the same function in substantially the same way to obtain the same re-
sult”).
    This test for substantial identity of function, means, and result has become known as the
“tripartite” or “function-way-result” test of Graver Tank. See § 2.05[3][b][i] supra.
    313.57
             See N.313.56 supra.
    See also, Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 397, 29 U.S.P.Q.2d (BNA)
1767 (Fed. Cir. 1994) (“An accused device may infringe a claim under the doctrine of equiva-
lents if it performs substantially the same overall function or work, in substantially the same
way, to produce substantially the same overall result as the claimed invention”), citing:
    Supreme Court: Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S.
605, 608, 70 S.Ct. 854, 94 L.Ed. 1097 (1950).
    Federal Circuit: Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934, 4 U.S.P.Q.2d
(BNA) 1737, 1739 (Fed. Cir. 1987) (en banc), cert. denied 485 U.S. 961, 485 U.S. 1009 (1988).

                                                                                           (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

                                                                 313.58
the corresponding specified function in the claim.           This does not mean,
however, that the entire tripartite test may not be applied in determining
whether the two structures—that disclosed in the patent and the correspond-
ing structure in the accused device—that are alleged to perform the identical
                           313.59
function are equivalent.          It is in this sense—but only in this limited
      313.60
sense         —that assessment of “equivalents” to disclosed means under Sec-
tion 112, ¶ 6 differs from assessment of “equivalents” under the general doc-
                      313.61
trine of equivalents.        The general and statutory doctrines are thus much
the same, except that the part of the general doctrine that permits nonidentical
                                                                      313.62
functions is restricted by the explicit language of Section 112, ¶ 6.        As in
                                                  313.63
applying the doctrine of equivalents generally,          evidence of interchange-
ability, known to persons of ordinary skill in the art, is probative of equiva-
       313.64
lence.        If the means used in the accused device to perform a specified



   313.58
            See the text accompanying Ns.313.34, N.313.35 supra.
   313.59
             See Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *15 (Fed.
Cir. Sept. 10, 1998) (“Similarly, under the doctrine of equivalents, if the accused . . . lock per-
forms a substantially different function or performs in a substantially different way or obtains a
substantially different result, it does not infringe claim 1”), citing Engel Industries, Inc. v. Lock
Former Co., 96 F.3d 1398, 1407, 40 U.S.P.Q.2d (BNA) 1161, 1167 (Fed. Cir. 1996).
    313.60
             See also, the text accompanying Ns.313.143-313.157 infra.
    313.61
             See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1310, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (“Although an equivalence analysis under §
112, ¶ 6, and the doctrine of equivalents are not coextensive (for example, Section 112, ¶ 6,
requires identical, not equivalent function) and have different origins and purposes, their tests
for equivalence are closely related”), citing Warner-Jenkinson Co. v. Hilton Davis Chemical
Co., 520 U.S. 17, 117 S.Ct. 1040, 1048, 137 L.Ed.2d 146, 41 U.S.P.Q.2d (BNA) 1865, 1870-71
(1997) (“[Equivalents under § 112] is an application of the doctrine of equivalents in a restric-
tive role, narrowing the application of broad literal claim elements. We recognized this type of
role for the doctrine of equivalents in Graver Tank itself”).
    313.62
              See the text accompanying Ns.313.55-313.61 supra; the text accompanying
Ns.313.113-313.118 infra.
    313.63
             See: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., ____ U.S. ____, 117 S.Ct.
1040, 1052, 137 L.Ed.2d 146 (1997) (discussing interchangeability criterion); § 2.05[3][b][i]
supra.
    313.64
             But cf.: Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1310, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (“The question of known interchangeability
is not whether both structures serve the same function, but whether it was known that one struc-
ture was an equivalent of another. Moreover, a finding of known interchangeability, while an
important factor in determining equivalence, is certainly not dispositive. . . . Such evidence does
not obviate the statutory mandate to compare the accused structure to the corresponding struc-
ture.”) (Citations omitted.); 145 F.3d at 1310 (failure of patent specification for saw for
nonhardened concrete to discuss possibility of replacing skid plate used for holding down con-
crete against upward motion of emerging saw blade with wheels, despite discussion of skid
plate's drawbacks, including drag and gouging, supported view that wheels and skidplate were
not known in art to be interchangeable).

                                                                                         (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

function are not the same as or equivalent to the means disclosed in the speci-
                                                                       313.65
fication of the patent at issue, there can be no literal infringement.
   In assessing equivalence, however, one-to-one correspondence between
the “equivalent” in the accused device and the structure disclosed in the speci-
fication is not required. This principle is well established for claims other than
                               313.66
means-plus-function claims,           and there is no reason why it should not
apply to means-plus-function claims as well. For example, more than one
element in the accused device may perform the function of a single element in
           313.67
the claim,        as long as the accused device contains every limitation of the
                          313.68
claim or its equivalent;         or separate claim limitations may be combined
                                            313.69
in a single element of the accused device.

   313.65
              See the text accompanying Ns.313.14-313.18, 313.27-313.29 supra. See also,
Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303, 1310, 46
U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (because means used in accused device was not equiv-
alent to means recited in claim, there was no literal infringement).
    313.66
             See, e.g.: Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 398, 29 U.S.P.Q.2d
(BNA) 1767 (Fed. Cir. 1994) (“The doctrine of equivalents does not require a one-to-one corre-
spondence between components of the accused device and the claimed invention. . . . An ac-
cused device may infringe under the doctrine of equivalents even though a combination of its
components performs a function performed by a single element in the patented invention”),
citing: Intel Corp. v. International Trade Commission, 946 F.2d 821, 832, 20 U.S.P.Q.2d (BNA)
1161, 1171 (Fed. Cir. 1991) and Vaupel Textilmaschinen KG v. Meccanica Euro Italia S.P.A.,
944 F.2d 870, 882, 20 U.S.P.Q.2d (BNA) 1045, 1054 (Fed. Cir. 1991); Sun Studs, Inc. v. ATA
Equipment Leasing Inc., 872 F.2d 978, 988, 10 U.S.P.Q.2d (BNA) 1338 (Fed. Cir. 1989), over-
ruled on other grounds, A.C. Aukerman Co. v. R.L. Chaides Construction Co., 960 F.2d 1020,
1038-1039, 22 U.S.P.Q.2d (BNA) 1321, 1333 (Fed. Cir. 1992) (“One-to-one correspondence of
components is not required, and elements or steps may be combined without ipso facto loss of
equivalency”), quoted with approval in Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394,
399, 29 U.S.P.Q.2d (BNA) 1767 (Fed. Cir. 1994).
    See also, Corning Glass Works v. Sumitomo Electric U.S.A., Inc., 868 F.2d 1251, 1259, 9
U.S.P.Q.2d (BNA) 1962 (Fed. Cir. 1989), quoted with approval in Dolly, Inc. v. Spalding &
Evenflo Cos., 16 F.3d 394, 399, 29 U.S.P.Q.2d (BNA) 1767 (Fed. Cir. 1994):
   “'Element' may be used to mean a single limitation, but it has also been used to mean a series
   of limitations which, taken together, make up a component of the claimed invention. In the
   [Pennwalt] All Elements rule, 'element' is used in the sense of a limitation of a claim. . . . An
   equivalent must be found for every limitation of the claim somewhere in an accused device,
   but not necessarily in a corresponding component, although that is generally the case.”
   313.67
            See Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 398, 29 U.S.P.Q.2d (BNA)
1767 (Fed. Cir. 1994) (in Intel and Vaupel, “more than a single element in the accused device
performed the function of a single limitation in the claimed invention. Every limitation or its
equivalent, however, was present in the accused device. Equivalency thus can exist when two
components of the accused device perform a single function of the patented invention. In this
case, however, a vital limitation of the claim is absent from the accused device”).
    313.68
            Id., 16 F.3d at 398 (“The accused device must nevertheless contain every limitation
or its equivalent”), citing Intel Corp. v. International Trade Commission, 946 F.2d 821, 832, 20
U.S.P.Q.2d (BNA) 1161, 1171 (Fed. Cir. 1991).
    313.69
            See: Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 398-399, 29 U.S.P.Q.2d
(BNA) 1767 (Fed. Cir. 1994) (dictum: one element of accused chair fulfilled two functions of

                                                                                        (Rel. 25)
2-05                      PATENTS                 INTELLECTUAL PROPERTY LAW

    Although the Federal Circuit has declined to decide specifically whether
determining “equivalents” under Section 112, ¶ 6, is a question of law or
      313.70                313.71
fact,         it has ruled,        and the Supreme Court has strongly suggest-
    313.72
ed,        that equivalence generally is a matter of fact within the purview of a
jury, if empaneled. This does not mean, however, that the issue may not be
resolved as a matter of law in a particular case, when the facts admit of only
             313.73
one result.

claimed chair: accused chair's panels served as both stable rigid frame and the body supporting
feature); Sun Studs, Inc. v. ATA Equipment Leasing Inc., 872 F.2d 978, 988, 10 U.S.P.Q.2d
(BNA) 1338 (Fed. Cir. 1989), overruled on other grounds A.C. Aukerman Co. v. R.L. Chaides
Construction Co., 960 F.2d 1020, 1038-1039, 22 U.S.P.Q.2d (BNA) 1321, 1333 (Fed. Cir.
1992) (functions of both claimed aligning means and “charger means” for releasably gripping
and transporting logs could be performed by single feature of accused device).
    313.70
              See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1309, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (declining to decide), citing Markman v.
Westview Instruments, Inc., 52 F.3d 967, 977 n.8, 34 U.S.P.Q.2d (BNA) 1321, 1329 (Fed. Cir.
1995) (en banc), aff'd on other grounds 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38
U.S.P.Q.2d (BNA) 1461 (1996) (also declining to decide).
    But see, Carroll Touch, Inc. v. Electro Mechanical Systems, Inc., 15 F.3d 1573, 1578, 27
U.S.P.Q.2d (BNA) 1836 (Fed. Cir. 1993) (assessment of sameness of function and use of identi-
cal or equivalent structure are factual determinations reviewed for clear error), citing Durango
Associates, Inc. v. Reflange, Inc., 843 F.2d 1349, 1357, 6 U.S.P.Q.2d (BNA) 1290, 1295 (Fed.
Cir. 1988).
    313.71
              See, e.g.: B. Braun Medical, Inc. v. Abbott Laboratories, 124 F.3d 1419, 1421, 1423,
43 U.S.P.Q.2d (BNA) 1896 (Fed. Cir. 1997) (“Infringement (whether literal or under the doc-
trine of equivalents) is a question of fact, which we review for substantial evidence in the con-
text of a jury trial”), citing Young Dental Manufacturing. Co. v. Q3 Special Products, Inc., 112
F.3d 1137, 1141, 42 U.S.P.Q.2d (BNA) 1589, 1592 (Fed. Cir. 1997); Engel Industries, Inc. v.
Lockformer Co., 96 F.3d 1398, 1406, 40 U.S.P.Q.2d (BNA) 1161 (Fed. Cir. 1996) (“Infringe-
ment under the doctrine of equivalents is an issue of fact. When infringement is tried to the
court, . . . an appellate court reviews the trial court's infringement finding for clear error”), citing
Hilton Davis Chemical Co. v. Warner-Jenkinson Co., Inc., 62 F.3d 1512, 1521, 35 U.S.P.Q.2d
(BNA) 1641, 1647 (Fed. Cir. 1995), rev'd on other grounds 520 U.S. 17, 117 S.Ct. 1040, 1048,
137 L.Ed.2d 146, 41 U.S.P.Q.2d (BNA) 1865, 1870-1871 (1997).
    Cf., § 2.05[3][a] supra (infringement generally is question of fact).
    But cf., Markman v. Westview Instruments, Inc., 52 F.3d 967, 977 n.8, 34 U.S.P.Q.2d
(BNA) 1321, 1327 n.8 (en banc), aff'd on other grounds ____ U.S. ____, 116 S.Ct. 1384, 134
L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (reserving question whether “equivalents”
under section 112, ¶ 6, is question of law or fact).
    313.72
              See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., ____ U.S. ____, 117 S.Ct.
1040, 1053, 137 L.Ed.2d 146 (1997) (noting that Markman “cite[d] with considerable favor”
seminal 1854 Winans decision, which stated that equivalence was jury question, but declining to
decide issue), referring to Markman v. Westview Instruments, Inc. ____ U.S. ____, 116 S.Ct.
1384, 134 L.Ed.2d 577, 38 U.S.P.Q.2d (BNA) 1461 (1996) (unanimous opinion), discussed in §
2.05[3][a] supra, and Winans v. Denmead, 56 U.S. (15 How.) 330, 334, 14 L.Ed. 717 (1854)
(seminal decision on doctrine of equivalents), discussed in § 2.05[3][b][i] supra.
    313.73
              See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1309, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (soft, compressible, round and rotatable
wheels were not equivalent structures to hard, flat skid plate fixedly attached to saw, although
they performed same function of holding nonhardened concrete down against upward motion of
saw blade, and no reasonable jury could find them equivalent).

                                                                                            (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

    What remains unclear under Section 112, ¶ 6, is whether, if the accused
device does not contain the same or equivalent means for performing a func-
                                                                             313.74
tion specified in the claim, and therefore there is no literal infringement,
the court must undertake an additional, fourth step: applying the general doc-
                                                          313.75
trine of equivalents to the claim element as a whole.            The Federal Cir-
                                                 313.76
cuit, although flirting with a negative answer,         has declined to make that
                    313.77
answer definitive.         Moreover, one panel's decision has suggested that the
                                            313.78
word “equivalents” in Section 112, ¶ 6,            unlike the general doctrine of
             313.79                                                          313.80
equivalents,        is not intended to include after-developed technology.

   313.74
            See the text accompanying Ns.313.52-313.69 supra.
   313.75
            See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1459, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (dictum: “An accused device that does not literally
infringe a claim may still infringe under the doctrine of equivalents if each limitation of the
claim is met in the accused device either literally or equivalently”) (Emphasis added.), citing:
    Supreme Court: Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117
S.Ct. 1040, 1054, 137 L.Ed.2d 146 (1997).
    Federal Circuit: Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 935, 4 U.S.P.Q.2d
(BNA) 1737, 1740 (Fed. Cir. 1987) (en banc).
    313.76
            See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1310, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (holding general doctrine of equivalents
inapplicable where accused means was not equivalent to claimed means). See also, Ns. infra.
    313.77
            See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1310, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (Emphasis added.):
   “Both § 112, P 6, and the doctrine of equivalents protect the substance of a patentee's right
   to exclude by preventing mere colorable differences or slight improvements from escaping
   infringement, the former, by incorporating equivalents of disclosed structures into the literal
   scope of a functional claim limitation, and the latter, by holding as infringements equivalents
   that are beyond the literal scope of the claim. They do so by applying similar analyses of in-
   substantiality of the differences. Thus, a finding of a lack of literal infringement for lack of
   equivalent structure under a means-plus-function limitation may preclude a finding of equiv-
   alence under the doctrine of equivalents.”
    See also, N.313.80 infra.
    313.78
            35 U.S.C. § 112, ¶ 6, quoted in part in N.313.16 supra and in full in § 2.05[3][c] (in-
troduction) supra.
    313.79
            See § 2.05[3][b][i] supra.
    313.80
            See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1310, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (dictum):
       “There is an important difference, however, between the doctrine of equivalents and §
   112, ¶ 6. The doctrine of equivalents is necessary because one cannot predict the future. Due
   to technological advances, a variant of an invention may be developed after the patent is
   granted, and that variant may constitute so insubstantial a change from what is claimed in
   the patent that it should be held to be an infringement. Such a variant, based on after-
   developed technology, could not have been disclosed in the patent. Even if such an element
   is found not to be a § 112, ¶ 6, equivalent because it is not equivalent to the structure dis-
   closed in the patent, this analysis should not foreclose it from being an equivalent under the
   doctrine of equivalents.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

Thus, at least part of the Federal Circuit appears to have contemplated a four-
step procedure for assessing infringement of means-plus-function claims: (1)
                                                        313.81
determining the specified function (an issue of law);          (2) determining the
                                                                    313.82
disclosed means to perform that function (also an issue of law);           (3) then
determining the statutory “equivalents” of those means, using a test of insub-
                                                                              313.83
stantial differences that might not include after-developed technology;
and (4) finally, if the foregoing does not yield infringement, applying the gen-
eral doctrine of equivalents to the claim element as a whole, including after-
                         313.84
developed technology.
    This cumbersome interpretation of the statute seems inconsistent with its
history and purpose; at best, it dulls the blade of Occam's Razor. When Con-
                                                                         313.85
gress wrote the word “equivalents” in Section 112, ¶ 6, in 1952,                 the
judge made doctrine of equivalents had been in existence for nearly 100
       313.86
years.        Moreover, the principle that equivalents include after-developed
                                     313.87
technology was well established.            If Congress had intended to create an
entirely new concept, restricted to existing technology, why did it use a word
                              313.88
with such a long pedigree?
    As for after-developed technology, its coverage is central to the very pur-
pose allowing claims to reach the equivalents of what they literally speci-
    313.89
fy.        The doctrine of equivalents exists to prevent infringers from
appropriating the technological and commercial value of someone else's in-
vention by making insubstantial changes that evade the literal language of the


      “[*1311] That is not the case here, where the equivalence issue does not involve later-
   developed technologies, but rather involves technology that predates the invention itself.”
   313.81
            See the text accompanying Ns.313.30-313.37 supra.
   313.82
            See the text accompanying Ns.313.37-313.52 supra.
   313.83
            See the text accompanying Ns.313.52-313.69 and N.313.80 supra.
   313.84
            See the text accompanying Ns.313.73-313.77 and N. 313.80 supra; N.313.100 infra.
   313.85
            For a brief discussion of the history and purpose of § 112, ¶ 6, see: § 2.05[3][c][i]
supra; Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 28, 117 S.Ct. 1040,
137 L.Ed.2d 146 (1997).
    313.86
            See Winans v. Denmead, 56 U.S. (15 How.) 330, 340-341, 343-344, 14 L.Ed. 717
(1854) (seminal decision on doctrine of equivalents).
    313.87
           See: § 2.05[3][b][i], [c][i] supra.
    313.88
           In Hilton Davis, the Supreme Court seems to have made the natural assumption that
Congress, in inserting the word “equivalents” in Section 112, ¶ 6, was referring to the well-
known doctrine. See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117
S.Ct. 1040, 1048, 137 L.Ed.2d 146, 41 U.S.P.Q.2d (BNA) 1865, 1870-1871 (1997) (“[Equiva-
lents under § 112] is an application of the doctrine of equivalents in a restrictive role, narrowing
the application of broad literal claim elements. We recognized this type of role for the doctrine
of equivalents in Graver Tank itself.”) See also, N.313.156 infra.
    313.89
           See § 2.05[3][b][i], [c][i] supra.


                                                                                        (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

        313.90
claims.         That purpose requires a doctrine including insubstantial changes
                                               313.91
made using after-developed technology.                Without such a doctrine, any
prospective infringer could appropriate the value of another's invention mere-
ly by applying insubstantially different new technology to evade the literal
language of a claim element. Evading patent claims in this manner would be
especially easy in today's world of ever-accelerating innovation, where inven-
tions are ever more complex and involve an ever-increasing number of ele-
ments. The doctrine that equivalents include after-developed technology is
therefore crucial to maintaining the economic value of patents and hence the
                      313.92
incentive to invent.         It is certainly no less crucial in the context of means-
plus-function claims, in which the invention to be protected inheres in the
combination of subsidiary functions and means to perform a specified overall
          313.93                                         313.94
function         (which cannot be claimed directly),             rather than in a par-
ticular means to perform one of the subsidiary functions addressed in the
                  313.95
claim elements.          Just as relaxing coverage of after-acquired technology
would gut the general doctrine of equivalents, so it would gut any attempt to
                                                                         313.96
give claims under Section 112, ¶ 6, commercially valuable scope.
                                                                                 313.97
   It is true that the statute's explicit reference to “a specified function”
precludes unthinking and foolish application of the tripartite test of Graver
      313.98                                                313.99
Tank          to “equivalents” under Section 112, ¶ 6.              But that does not
mean that the statutory notion of “equivalents” under Section 12, ¶ 6, differs
in some mysterious and fundamental way from the general doctrine, as some
                                                              313.100
language in the Federal Circuit's opinions has implied.               Rather, it simp-

   313.90
            See: N.313.77 supra; § 2.05[3][b][i] supra.
   313.91
            See § 2.05[3][c][i] supra.
   313.92
            The incentive to invent, and to invest in the commercialization of inventions, is the
central purpose of patent law. See § 2.01 supra.
   313.93
           See: N.313.45 supra; § 2.05[3][c] (introduction) supra.
   313.94
           See § 2.05[3][c][i] supra.
   313.95
           Id.
   313.96
           Id.
   313.97
           35 U.S.C. § 112, ¶ 6, quoted in full in § 2.05[3][c] (introduction) supra.
   313.98
           See N.313.56 supra.
   313.99
           See the text accompanying Ns.313.55-313.61 supra.
   313.100
             See Ns.313.77, 313.80 supra. See also, Cybor Corp. v. FAS Technologies, Inc., 138
F.3d 1448, 1467-1468, 46 U.S.P.Q.2d (BNA) 1169 (Fed. Cir. 1998) (en banc) (concurring
opinion of Judges Mayer and Newman):
   “Just as the fact finder's infringement analysis differs between equivalence under paragraph
   112(6) and the doctrine of equivalents, so too differs the analytical effect of statements made
   during the prosecution of the patent on construction of the claims. Under paragraph 112(6),
   a statement made during prosecution may confine the range of equivalent structures, materi-

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

ly means that the statute's specific terms limit one of the three prongs of the
                313.101                                                      313.102
tripartite test         —the one requiring substantially the same function
—as applied to claim elements under Section 112, ¶ 6. However, the essence
of the tripartite test, which is use of substantially the same means to serve a
                                                  313.103           313.104
specific function and achieve a specific result,           remains.         Indeed,
now that Hilton Davis has focused attention away from the tripartite test to a
                                            313.105
general test of insubstantial differences,           there is no reason why the
standards for “equivalents” under Section 112, ¶ 6, and the “doctrine of
equivalents” should not be conflated, subject to the statutory caveat that, for
infringement of means-plus-function claims, the specified function must be
                                                    313.106
performed identically by the accused device.                 Such a development
would provide a desirable simplification of the law and better realize the ap-
parent congressional intent of avoiding piracy through insubstantial chang-
    313.107
es.


   als, or acts that are directly claimed by the patent. However, in the context of a doctrine of
   equivalents analysis, the patentee seeks protection beyond [*1468] that claimed by the patent
   directly. As such, the judge's construction of the claims—which includes the interpretation
   of claim terms—may not be sufficient to remove from the jury's consideration all subject
   matter that was disclaimed during prosecution.”
   313.101
             See the text accompanying Ns.313.55-313.61 and N.313.56 supra.
   313.102
             See N.313.56 supra.
   313.103
             Even under the tripartite function-way-result test of Graver Tank, in most cases it is
the means of performing the function to achieve the result that makes the difference. See §
2.05[3][b][i] supra. The reason for this is obvious: an accused device that is similar enough to a
claimed invention to merit comparison in determining infringement is likely to seek the same
function and result.
    313.104
             See Engel Industries, Inc. v. Lockformer Co., 96 F.3d 1398, 1407, 40 U.S.P.Q.2d
(BNA) 1161 (Fed. Cir. 1996) (holding that, where accused device performed in substantially
different way from patented invention, finding of infringement under doctrine of equivalents
below was clearly erroneous); 96 F.3d at 1406-1407, citing Atlanta Motoring Accessories, Inc.
v. Saratoga Technologies, Inc., 33 F.3d 1362, 1366, 31 U.S.P.Q.2d (BNA) 1929, 1932 (Fed. Cir.
1994):
   “[A]lthough both duct connecting systems may perform substantially the same function (i.e.,
   permit a worker to connect duct sections without having to use rivets or spot welds to secure
   flanges or corner connectors in position) and may achieve substantially the same result (i.e.,
   adjacent duct sections may be attached in an efficient manner), they do not perform in sub-
   stantially the same way. It is not enough if both devices perform the same function when it is
   apparent from the patent [*1407] drawings that the devices are differently constructed and
   perform that function in different ways.”
   313.105
             See: the text accompanying Ns.313.53-313.55 and N.313.61 supra; § 2.05[3][b][i]
supra.
   313.106
             See the text accompanying Ns.313.55-313.61 and N.313.61 supra.
   313.107
             See: the text accompanying Ns.313.88-313.90 and N.313.77 supra; § 2.05[b][i] su-
pra.

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

   The same conclusion derives from analyzing the ways in which the general
doctrine of equivalents might be applied in a putative fourth step of the type
                   313.108
discussed above,             after assessment of “equivalents” of the disclosed
                                    313.109
means under Section 112, ¶ 6.               Hilton Davis teaches that the general
                                                               313.110
doctrine must be applied on an element-by-element basis.               By statutory
command, however, each element of a means-plus-function claim has only
two limitations: the specified function and the disclosed means (including
                     313.111
their equivalents).           Thus, if the general doctrine of equivalents is to
apply to such a claim element, there are only three analytical possibilities: it
must impact the scope of the function, the disclosed means, or both together.
   Since the statute already requires concepts of equivalence to be applied to
disclosed means in assessing what the Federal Circuit calls “literal infringe-
        313.112
ment,”          the first possibility would be redundant and would add no addi-
                               313.113
tional scope to the claim.              The second option—applying notions of
equivalence to the function—is foreclosed by strong implication from the
statutory language, as the Federal Circuit appears to have ruled in at least two
       313.114
cases.          The very statutory provision was enacted as a limited exception
                                          313.115
to the rule against claiming function.            It allows function to be claimed
indirectly, but only in a limited way: as a combination of subsidiary func-
     313.116                                                  313.117
tions          and means to reach an overarching result.              Allowing the
patentee to expand the scope of these subsidiary functions as claimed would
destroy the crispness of the limitation and definition that serve as bulwarks


   313.108
             See the text accompanying Ns.313.73-313.77 supra.
   313.109
             See the text accompanying Ns.313.52-313.69 supra.
   313.110
             See N.313.13 supra.
   313.111
              See 35 U.S.C. § 112, ¶ 6, quoted in part in N.313.16 supra and in full in §
2.05[3][c] (introduction) supra.
    313.112
             See the text accompanying Ns.313.27-313.29 supra.
    313.113
              This assumes that there is no substantive difference between “equivalents” under
the statute and the “doctrine of equivalence,” such as a difference in coverage of after-developed
technology, as argued above. See the text accompanying Ns.313.88-313.96 supra. But see,
N.313.80 supra.
    313.114
              See, e.g.: Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at
*23-25 (Fed. Cir. Sept. 10, 1998) (where claim in means-plus-function form recited two func-
tions for “movable link member” in electronic combination lock—holding and releasing—and
where accused device's corresponding structure performed no releasing function, accused device
did not infringe either literally or under doctrine of equivalents) (alternative holding: two struc-
tures were not mechanically equivalent); Phonometrics, Inc. v. Northern Telecom, Inc., 133 F.3d
1459, 1467, 45 U.S.P.Q.2d (BNA) 1421 (Fed. Cir. 1998), outlined in N.313.139 infra.
    313.115
             See § 2.05[3][c][i] supra.
    313.116
             See N.313.45 supra.
    313.117
             See: id.; § 2.05[3][c][i] supra.


                                                                                        (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW

against claiming function for the invention as a whole. The final logical pos-
        313.118
sibility        would be even worse; it would reach not only means equivalent
                                                         313.119
to the disclosed means performing identical functions,           but means—not
necessarily equivalent to the disclosed means—appropriate to performing
functions substantially the same as, but not identical to, the stated func-
      313.120
tion.
    The standard tools of statutory interpretation suggest that the more restric-
                313.121
tive approach           —requiring identical, not just substantially the same,
          313.122
function          —is the correct one, for three reasons. First, the statute is
mandatory in its terms; it describes how the claim “shall be con-
           313.123
strued[,]”          and its description includes equivalent means only, not
                        313.124
equivalent functions.           Second, the reasoning by which the Supreme
                                                                          313.125
Court in Hilton Davis preserved the doctrine of equivalents generally
does not appear to apply to means-plus-function claims. The defendant in
Hilton Davis had argued that Congress, by referring to “equivalents” only
once in its recodification of the Patent Act in 1952, namely, in Section 112, ¶
   313.126
6,         had eliminated the general doctrine of equivalents by negative impli-
        313.127                          313.128
cation.         Rejecting this argument,         the Court reasoned that Section
112, ¶ 6 had been designed to address a narrow problem, namely, allowing
claims directed not to the function of the invention as a whole, but to func-




   313.118
             See the text accompanying Ns.313.109-313.112 supra.
   313.119
             This is the undisputed minimum scope of means-plus-function claims, as specified
by the statute. See the text accompanying Ns.313.20-313.22, 313.30-313.69 supra.
    313.120
              Cf., Carroll Touch, Inc. v. Electro Mechanical Systems, Inc., 15 F.3d 1573, 1579,
27 U.S.P.Q.2d (BNA) 1836 (Fed. Cir. 1993) (patentee could not use general doctrine of equiva-
lents to cover different structure of accused device where different structure would perform two
functions of patented means disclosed in specification but not recited in claims).
    313.121
             See the text accompanying Ns.313.111-313.120 supra.
    313.122
             See the text accompanying Ns.313.111-313.113 and N.313.113 supra.
    313.123
              35 U.S.C. § 112, ¶ 6, quoted in part in N.313.16 supra and in full in § 2.05[3][c]
(introduction) supra.
    313.124
             See the text accompanying Ns.313.131-313.134 infra.
    313.125
             See § 2.05[3][b][i] supra.
    313.126
              35 U.S.C. § 112, ¶ 6, quoted in part in N.313.16 supra and in full in § 2.05[3][c]
(introduction) supra.
    313.127
             See Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 27-28, 117
S.Ct. 1040, 1047-1048, 137 L.Ed.2d 146 (1997) (discussing and rejecting this argument), dis-
cussed in § 2.05[3][b][i] infra.
    313.128
             Id.


                                                                                     (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                                                                                         313.129
tions of two or more disclosed subsidiary structures or process steps.
Since Section 112, ¶ 6, was designed to address that special problem, the
canon of statutory construction that the specific governs the general appears
to preclude applying the general doctrine of equivalents to expand the scope
                                                                     313.130
of means-plus-function claims that the statute explicitly governs,           not-
withstanding the remaining vitality of the general doctrine as applied to other
                  313.131
types of claims.          If Congress had intended means-plus-function claims
to be construed as covering equivalent functions, as well as equivalent
       313.132
means,         it could have included the words “and equivalents thereof” after
the words “specified function[,]” just as it did after the words “corresponding
                                                              313.133
structure, material, or acts described in the specification.”         But it did
not. Since the scope of means-plus-function claims was precisely the question
Congress addressed in Section 112, ¶ 6, the fact that it did not do so ought to
be decisive.
   Third, the narrow approach seems more consistent with the origin and pur-
pose of Section 112, ¶ 6, as a limited exception to the general rule against
                    313.134
claiming function.           Claiming function is an anathema in patent law be-
cause stating the function of an invention is simply describing the problem to
           313.135                                                        313.136
be solved;          how to accomplish the stated function is everything.
Section 112, ¶ 6, creates a limited exception to this rule to avoid giving an
inventor the Hobson's choice of writing a narrow and easily-circumvented
claim or describing ad nauseam every means known to the art of performing


   313.129
              Id., 520 U.S. at 28 (Section 112, ¶ 6, “was enacted as a targeted cure to a specific
problem[,]” namely, case law broadly rejecting any claiming in functional terms; it applied “the
doctrine of equivalents in a restrictive role, narrowing the application of broad literal claim
elements”), discussed in § 2.05[3][b][i] infra.
    313.130
              See: id.; § 2.05[3][c][i] (explaining how reference to “equivalents” in Section 112,
¶ 6, both expands and restricts scope of means-plus-function claims).
    Cf.: Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 398, 29 U.S.P.Q.2d (BNA) 1767
(Fed. Cir. 1994) (“The doctrine of equivalents cannot extend or enlarge the scope of the
claims”), citing Wilson Sporting Goods Co. v. David Geoffrey & Associates, 904 F.2d 677, 684,
14 U.S.P.Q.2d (BNA) 1942, 1948 (Fed. Cir.), cert. denied 498 U.S. 992 (1990); 16 F.3d at 398
(“The claims—i.e. the scope of patent protection as defined by the claims—remain the same and
application of the doctrine expands the right to exclude to 'equivalents' of what is claimed”),
quoting Wilson Sporting Goods Co. v. David Geoffrey & Associates, 904 F.2d 677, 684, 14
U.S.P.Q.2d (BNA) 1942, 1948 (Fed. Cir.), cert. denied 498 U.S. 992 (1990).
    313.131
             See the text accompanying Ns.313.124-313.129 supra.
    313.132
             The same argument applies to process steps. See N.313.15 supra.
    313.133
              35 U.S.C. § 112, ¶ 6, quoted in part in N.313.16 supra and in full in § 2.05[3][c]
(introduction) supra.
    313.134
             See: the text accompanying Ns.313.123-313.129 supra; § 2.05[3][c][i] supra.
    313.135
             See § 2.05[3][c] (introduction) supra.
    313.136
             See: Ns.313.45, 313.103 supra.


                                                                                      (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

                                                                 313.137
a function that constitutes but part of the invention.         The reason the ex-
ception works, however, is its focus on the means, i.e., the manner in which
                                                313.138
the inventor performed the stated functions.            Allowing the inventor to
claim equivalent functions, as well as equivalent means, would rip the limited
exception loose from its moorings in technique and technology and cast it into
                           313.139
an abyss of uncertainty.           For all these reasons, the Federal Circuit
                                                           313.140
should reject the hints in concurring and panel opinions           that the general
doctrine of equivalents can extend the scope of means-plus-function claims
beyond that contemplated by the statute, whether by considering equivalent
                                          313.141
functions, as well as equivalent means,           applying some more nebulous
                                   313.142               313.143
“general” doctrine of equivalents,         or otherwise.
   The general doctrine of equivalents—if it applies to means-plus-function
                                                       313.144
claims at all—thus must apply to the means alone.              The very notion of

   313.137
             See § 2.05[3][c][i] supra.
   313.138
              See, e.g.: Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at
*14-15 (Fed. Cir. Sept. 10, 1998) (stepper motor was not equivalent “lever operating means” to
disclosed solenoid in actuating mechanism for electronic combination lock, because solenoid
required continuous and considerable electrical power, was self-restoring, and operating in linear
manner, while stepper motor was actuated by short electrical pulse, remained in its new state
without continued application of power, was returned to its previous state manually, and operat-
ed in rotational fashion); Engel Industries, Inc. v. Lockformer Co., 96 F.3d 1398, 1405, 40
U.S.P.Q.2d (BNA) 1161 (Fed. Cir. 1996) (there was no infringement under doctrine of equiva-
lents where accused duct-flange connected to corner pieces in substantially different way from
claimed device because former had inward-rolled portion that held corner pieces in place by
spring force and latter did not); Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 400, 29
U.S.P.Q.2d (BNA) 1767 (Fed. Cir. 1994) (“the concept of equivalency cannot embrace a struc-
ture that is specifically excluded from the scope of the claims. A stable rigid frame assembled
from the seat and back panels is not the equivalent of a separate stable rigid frame which the
claim language specifically limits to structures exclusive of seat and back panels”).
    313.139
               See: Phonometrics, Inc. v. Northern Telecom, Inc., 133 F.3d 1459, 1467, 45
U.S.P.Q.2d (BNA) 1421 (Fed. Cir. 1998) (where accused devices provided telephone-call cost
information only at end of call, while claimed invention provided it while call was in progress,
there could “be no equivalent infringement, for one of the functions claimed in the . . . patent
[was] completely absent from the accused devices”), citing Warner-Jenkinson Co., Inc. v. Hilton
Davis Chemical Co., 520 U.S. 17, 28-30, 117 S.Ct. 1040, 137 L.Ed.2d 146 (1997); Pennwalt
Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 935, 4 U.S.P.Q.2d (BNA) 1737 (Fed. Cir. 1987)
(en banc).
    313.140
              See: Ns.313.77, 313.80, 313.100 supra; N.313.157 infra.
    313.141
              See the text accompanying Ns.313.111-313.120 supra.
    313.142
              See the text accompanying Ns.313.83-313.84 supra.
    313.143
              Cf., Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 398, 29 U.S.P.Q.2d
(BNA) 1767 (Fed. Cir. 1994) (“Claim 16's language requiring a stable rigid frame independent
of seat and back panels is not a requirement solely for literal infringement. This limitation ap-
plies under the doctrine of equivalents as well”).
    313.144
              Cf., id., 16 F.3d at 398 (“Under the doctrine of equivalents, the accused device and
the claimed invention cannot work in 'substantially the same way' if a limitation (including its

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

                                                                                313.145
equivalence requires that it include after-developed technology,         and the
statutory language requires that the scope of means-plus-function claim ele-
ments be limited to accused devices performing identical, not merely substan-
                            313.146
tially the same, functions.         Subject to these limitations, application of
the general doctrine of equivalents as a putative fourth step in the analy-
   313.147                                 313.148
sis        would duplicate the third step,         while unnecessarily confusing
the analysis. Thus, both Occam's razor and the most reasonable inferences of
                     313.149
congressional intent         cut toward a single conclusion: there should be no
difference between the concept of equivalence invoked by Section 112, ¶ 6
                                                        313.150
and that under the general doctrine of equivalence              save for the re-
striction on the former required by the statutory language—identical, rather
                                           313.151
than mere substantially similar, function.         Even the doctrine of prosecu-
                      313.152
tion history estoppel         ought to work much the same way for “equiva-
                                313.153
lents” under Section 112, ¶ 6,          as it does under the general doctrine of



equivalent) is missing”), quoting Valmont Industries, Inc. v. Reinke Manufacturing Co., 983
F.2d 1039, 1043 n.2, 25 U.S.P.Q.2d (BNA) 1451, 1455 n.2 (Fed. Cir. 1993).
    313.145
              See the text accompanying Ns.313.88-313.96 supra.
    313.146
              See the text accompanying Ns.313.113-313.143 supra.
    313.147
              See the text accompanying Ns.313.73-313.84 supra.
    313.148
              See the text accompanying Ns.313.111-313.113 supra.
    Cf., Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303, 1311, 46
U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (where accused means does not involve later-
developed technology, “a finding of non-equivalence for § 112, ¶ 6, purposes should preclude a
contrary finding under the [general] doctrine of equivalents. This is because, as we have already
determined, the structure of the accused device differs substantially from the disclosed structure,
and given the prior knowledge of the technology asserted to be equivalent, it could readily have
been disclosed in the patent. There is no policy-based reason why a patentee should get two bites
at the apple. If he or she could have included in the patent what is now alleged to be equivalent,
and did not, leading to a conclusion that an accused device lacks an equivalent to the disclosed
structure, why should the issue of equivalence have to be litigated a second time?”).
    313.149
              See the text accompanying Ns.313.120-313.143 supra.
    313.150
              See B. Braun Medical, Inc. v. Abbott Laboratories, 124 F.3d 1419, 1421, 1423, 43
U.S.P.Q.2d (BNA) 1896 (Fed. Cir. 1997) (agreeing with jury, which found no infringement,
either literally or under the doctrine of equivalents, where accused device lacked means dis-
closed in specification or its equivalent).
    313.151
              See the text accompanying Ns.313.120-313.143 supra.
    313.152
               For general discussion of prosecution history estoppel, see § 2.05[3][a], [b][i] su-
pra.
    313.153
              See: Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1457, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (prosecution history estoppel applies to construction of
means-plus-function claims); 138 F.3d at 1457 (“The relevant inquiry is whether a competitor
would reasonably believe that the applicant had surrendered the relevant subject matter”), citing
Insituform Technologies, Inc., v. CAT Contracting, Inc., 99 F.3d 1098, 1107-108, 40
U.S.P.Q.2d (BNA) 1602, 1608 (Fed. Cir. 1996).

                                                                                       (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

               313.154
equivalents.        As long as courts keep this in mind—an easier task now
that the “insubstantial differences” standard of Hilton Davis has supplement-
                                                          313.155
ed, if not supplanted, the tripartite test of Graver Tank         —courts can
      313.156
avoid         the confusion and uncertainty that comes from suggesting, but
never defining or justifying, differences between two concepts identified by a
                       313.157
single, common word.


   313.154
              See Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1460, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (en banc) (rejecting alleged limitations on equivalents under gen-
eral doctrine for same reasons as rejecting limitations on “equivalents” under Section 112, ¶ 6:
“given the marked differences between the reference and the patented and accused devices,
[prosecution history did] not show the deliberate, unequivocal surrender of all external reser-
voirs” like those used in accused device but not in disclosed embodiment), citing Read Corp. v.
Portec, Inc., 970 F.2d 816, 824, 23 U.S.P.Q.2d (BNA) 1426, 1433 (Fed. Cir. 1992) (“Every
statement made by a patentee during a prosecution to distinguish a prior art reference does not
create a separate estoppel. Arguments must be viewed in context”).
    In both cases, “[p]rosecution history estoppel is a legal question subject to de novo review on
appeal.” Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1460, 46 U.S.P.Q.2d (BNA)
1169 (Fed. Cir. 1998) (en banc), citing Insituform Technologies, Inc., v. CAT Contracting, Inc.,
99 F.3d 1098, 1107, 40 U.S.P.Q.2d (BNA) 1602 (Fed. Cir. 1996).
    313.155
             See: § 2.05[3][b][i] supra; the text accompanying Ns.313.96-313.107 supra.
    But cf.: Mas-Hamilton Group v. LaGard, Inc., 1998 U.S. App. LEXIS 22116 at *11-12 (Fed.
Cir. Sept. 10, 1998) (“One way to determine if substantial differences exist is to apply the func-
tion-way-result analysis of Graver Tank, [*12] as sanctioned by Warner-Jenkinson”), citing:
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 117 S.Ct. 1040, 1054, 137
L.Ed.2d 146 (1997) and Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S.
605, 70 S.Ct. 854, 94 L.Ed. 1097 (1950); Mas-Hamilton Group v. LaGard, Inc., supra, 1998
U.S. App. LEXIS 22116 at *20-21 (Fed. Cir. Sept. 10, 1998) (concluding for similar reasons
that “lever moving element,” determined to have been expressed in means-plus-function form,
was not infringed, either literally or under doctrine of equivalents, where specification disclosed
solenoid actuating mechanism, and accused device used stepper motor; two means were neither
equivalent structures nor functioned in substantially same way).
    313.156
              See Chiuminatta Concrete Concepts v. Cardinal Industries, Inc., 145 F.3d 1303,
1311, 46 U.S.P.Q.2d (BNA) 1752 (Fed. Cir. 1998) (“Our case law clearly provides that equiva-
lence under the doctrine of equivalents requires that each claim limitation be met by an equiva-
lent element in the accused device. Because this requirement is not met for § 112, ¶ 6, purposes
with respect to one limitation, it is therefore not met in this case for doctrine of equivalents
purposes. An element of a device cannot be 'not equivalent' and equivalent to the same struc-
ture”), citing Dawn Equipment Co. v. Kentucky Farms Inc., 140 F.3d 1009, 1018-1022, 46
U.S.P.Q.2d (BNA) 1109, 1115-1118 (Fed. Cir. 1998) (Plager, J., additional views).
    313.157
              See: Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1467, 46 U.S.P.Q.2d
(BNA) 1169 (Fed. Cir. 1998) (concurring opinion of Judges Mayer and Newman: “A claim of
infringement under the doctrine of equivalents modifies this second step by requiring that the
fact finder determine whether differences between particular elements of the accused device and
the asserted claims are insubstantial. . . . However, because they have separate origins, purposes,
and applications, determining equivalence under paragraph 112(6) requires an analysis different
from that used to determine equivalence under the doctrine of equivalents”) (Citations omitted.);
Alpex Computer Corp. v. Nintendo Co., 102 F.3d 1214, 1222, 40 U.S.P.Q.2d (BNA) 1667 (Fed.
Cir. 1996) (“Under § 112, the concern is whether the accused device, which performs the
claimed function, has the same or an equivalent structure as the structure described in the speci-
fication corresponding to the claim's means. Under the doctrine of equivalents, on the other

                                                                                       (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW

   [4]—Statutory Extensions of Exclusive Rights
    Section 271(a) of the Patent Act of 1952, as amended, defines patent in-
fringement in the United States: “Except as otherwise provided in this title,
whoever without authority makes, uses, offers to sell, or sells any patented
invention, within the United States or imports into the United States any pa-
tented invention during the term of the patent therefor, infringes the pa-
       314
tent.”     While straightforward, this definition leaves certain questions
                                                         315
unanswered. Three other subsections of Section 271           answer these ques-
tions and, in the process, extend the patent holder's exclusive rights.

       [a]—Sale of Components, Material, or Apparatus
                     316
    Section 271(c)    addresses the sale of unpatented components used in a
patented machine, manufacture, combination, or composition, as well as the
sale of unpatented material or apparatus used in a patented process. Under
certain circumstances, a patent holder may control the use and sale of these
                                                                     317
items even though they are not themselves covered by the patent.         For ex-
ample, where a patent covered the process of using a chemical as an herbi-
cide, and the chemical had no other commercial use, Section 271(c) allowed
the process patentee to control the chemical's unlicensed sale to farmers, even
                                           318
though the chemical itself was unpatented.
    Under Section 271(c), the patentee's right to control unpatented compo-
nents, material, and apparatus is subject to three conditions. First, the item at
                                                                    319
issue must constitute a “material part” of the patented invention.       Second,
the seller must know that the components, material, or apparatus is “especial-
ly made or especially adapted for use in an infringement . . . and not a staple
article or commodity of commerce suitable for substantial noninfringing



hand, the question is whether the accused device is only insubstantially different than the
claimed device”). (Internal citations omitted.) See also, Ns.313.77, 313.80, 313.100 supra.
    314
         35 U.S.C. § 271(a).
    315
         35 U.S.C. § 271.
    316
         35 U.S.C. § 271(c).
    317
         A patent for a combination normally does not cover its elements separately. See, e.g.:
    Supreme Court: Deepsouth Packing Co. v. Laitram Corp., 406 U.S. 518, 528, 92 S.Ct. 1700,
32 L.Ed.2d 273 (1972), discussed in § 2.05[4][b] infra.
    Sixth Circuit: Deyerle v. Wright Manufacturing Co., 496 F.2d 45, 50 (6th Cir. 1974) (“It is
well settled that a combination patent protects only the operable assembly of the whole and not
the manufacture of its parts”).
    318
         See Dawson Chemical Co. v. Rohm & Haas Co., 448 U.S. 176, 223, 100 S.Ct. 2061, 65
L.Ed.2d 696 (1980) (upholding finding of contributory infringement over defense of patent
misuse).
    319
         35 U.S.C. § 271(c).


                                                                                    (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW

         320
use[.]”     Finally, there must be a direct infringement of the patent to which
                      321
the sale contributes.     If these conditions are satisfied, unauthorized sale of
the unpatented components, material, or apparatus for use in practicing the
patented invention constitutes contributory infringement of the patent.
    Of the three conditions for applying Section 271(c), the second is the most
important. A sale of components, material, or apparatus cannot constitute
contributory infringement of a patent on something else if the components,
material, or apparatus is “a staple article or commodity of commerce suitable
for substantial noninfringing use.” This statutory standard codifies the end
result of prolonged judicial indecision over the line between contributory in-
fringement on the one hand and misuse of the patent through attempts to con-
                                         322
trol unpatented products on the other.       The standard reflects, among other
things, a congressional desire to provide incentives for the “extraordinarily
                                                               323
expensive” search for new uses of old chemical products.           Under Section
        324
271(d),     a patentee who refuses to license activities that constitute contribu-
                                                   325
tory infringement is not guilty of patent misuse;      thus the law gives the pa-
tentee commercial control over nonstaple goods that satisfy the standard. That
control, however, is restrained by the repair doctrine, under which repair of a
                                                         326
patented item does not constitute direct infringement,       and hence furnishing




   320
          Id. See also, Aro Manufacturing Co. v. Convertible Top Replacement Co., 377 U.S.
476, 488, 84 S.Ct. 1526, 12 L.Ed.2d 457 (1964) (Aro II) (“a majority of the Court is of the view
that § 271(c) does require a showing that the alleged contributory infringer know that the com-
bination for which his component was especially designed was both patented and infringing”).
    321
         See Aro Manufacturing Co. v. Convertible Top Replacement Co. (Aro II), 377 U.S. 476,
483-484, 84 S.Ct. 1526, 12 L.Ed.2d 457 (1964).
    322
         See Dawson Chemical Co. v. Rohm & Haas Co., N. 318 supra, 448 U.S. at 187-194
(discussing development of “staple product” standard and reviewing Supreme Court precedent
that led to it).
    The substance of the standard was judicially developed before codification. See Leitch Man-
ufacturing Co. v. Barber Co., 302 U.S. 458, 460-461, 463, 58 S.Ct. 288, 82 L.Ed. 371 (1938)
(owner of patent on method for road building involving bituminous emulsion, an unpatented
staple article of commerce useful “for many purposes,” could not sue competing supplier of
same material for contributory infringement of process patent); 302 U.S. at 463 (principle that
patent monopoly does not extend to controlling commerce in staple, unpatented materials ap-
plies “whether the patent be for a machine, a product, or a process”).
    323
         Dawson Chemical Co. v. Rohm & Haas Co., N. 318 supra, 448 U.S. at 221-222.
    324
         35 U.S.C. § 271(d).
    325
         See Dawson Chemical Co. v. Rohm & Haas Co., 448 U.S. 176, 215, 100 S.Ct. 2601, 65
L.Ed.2d 696 (1980) (Section 271(d) permits, but does not require, patentee to license acts that
would constitute contributory infringement).
    326
         See § 2.06[5] infra.


                                                                                     (Rel. 25)
2-05                    PATENTS              INTELLECTUAL PROPERTY LAW

unpatented parts or supplies for repair cannot constitute contributory in-
            327
fringement.
    There is no liability for contributory infringement or for inducing in-
fringement unless there is a direct infringer. A secondary defendant may thus
avoid liability by establishing any defense in favor of the alleged direct in-
fringers. For example, suppose a patent covers a combination of elements A
and B. A defendant sells element A to the public. Defendant’s packaging en-
courages buyers to combine elements A and B, which would potentially in-
fringe the patent. Defendant is therefore potentially liable for both
contributory infringement and for inducing infringement. The patent holder
sells element B to the public. Some members of the public thus buy element
A from defendant and element B from the patent holder. In selling element B,
the patent holder implicitly gives the buyer license to use it by combining it
with element A. The buyer is thus not liable for infringement. Because there
is no direct infringement, defendant cannot be liable as a secondary infring-
    327.1
er.

       [b]—Foreign Assembly
   Another specific statutory provision extends the doctrine of contributory
infringement, and thus the effective scope of patent protection, to the domes-
tic manufacture of unpatented components for assembly into U.S.-patented
                   328                                           329
inventions abroad.     Congress enacted this provision in 1984       to reverse
                                                       330
the result in Deepsouth Packing Co. v. Laitram Corp.       There the Supreme
Court had found no infringement in a United States firm's domestic manufac-
ture and foreign sale of all the unpatented components of a patented combina-
tion product (a shrimp deveiner), even though assembly of the patented
                                              331
product abroad took only about an hour.           In reaching that result, the
                                                                        332
Deepsouth Court noted the apparent “loophole” in patent protection,          and
                                                                           333
Congress closed it in 1984 by adding Section 271(f) to the patent statute.

   327
        See Met-Coil Systems Corp. v. Korners Unlimited, Inc., 803 F.2d 684, 687 (Fed. Cir.
1986) (without direct infringement, “there can be neither contributory infringements . . . nor
inducement of infringement”). (Citations omitted.)
   327.1
          See Anton/Bauer Inc. v. PAG, 329 F.3d 1343, 1352-1354 (Fed. Cir. 2003).
   328
        See 35 U.S.C. § 271(f).
   329
        See Patent Law Amendments Act of 1984, Pub. L. No. 98-622, Tit. I, § 101(a), 98 Stat.
3383 (Nov. 8, 1984).
   330
        Deepsouth Packing Co. v. Laitram Corp., 406 U.S. 518, 92 S.Ct. 1700, 32 L.Ed.2d 273
(1972).
   331
        Id., 406 U.S. at 531.
   332
        Id., 406 U.S. at 530.
   333
        See: 130 Cong. Rec. H10525, H10525-10526 (Oct. 1, 1984), reprinted in 1984 U.S.
Code Cong. & Admin. News 5827, 5828.

                                                                                   (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

    Section 271(f) has two subsections, each requiring a different level of cul-
pability, depending on whether the United States manufacturer supplies “all
                                                                      334
or a substantial portion” of the components of a patented invention,      or just
                                 335
a single component that is not.      The first subsection makes it an act of in-
fringement for a United States manufacturer, without authorization, to supply
“all or a substantial portion of the components of a patented invention . . . in
such manner as to actively induce” their combination abroad in a manner that
                                                                              336
would infringe the patent if the assembly occurred inside the United States.
Aside from the lack of authorization, the only culpability that this subsection
requires is that the infringer “actively induce” the foreign assembly. These
                                       337
words are taken from Section 271(b)        and were apparently intended to in-
voke the same standard of vicarious liability.
    The “active inducement” requirement of subsection (f)(1), however,
should not demand proof that the United States manufacturer initiated the
foreign assembly as a business matter, i.e., solicited a contract to supply the
parts for foreign assembly. Such proof should be sufficient under the statute,
but it should not be necessary. Otherwise, the “active inducement” require-
ment would create a loophole in a statute that was intended to close one. Even
if the United States manufacturer did not solicit the contract, practical prob-
lems of fit and finish in supplying a “substantial portion” of a patented inven-
tion should be probative evidence of the manufacturer's knowledge of the
                                                                         338
invention and of the purpose of the supply obligations. Unrebutted,           the
inference of that knowledge should be sufficient to satisfy the culpability re-
quirement of Section 271(f)(1). After all, it is not unreasonable to require a
manufacturer who is aware of supplying most of the parts for a particular de-
vice to make a patent search to determine whether that device is patented, or
to ask for indemnification from the buyer. Thus the “active inducement” re-
quirement of Section 271(f) should be met if the domestic manufacturer
knows into what product the components are to be assembled and continues




   334
         35 U.S.C. § 271(f)(1).
   335
         35 U.S.C. § 271(f)(2).
   336
         35 U.S.C. § 271(f)(1).
   337
         35 U.S.C. § 271(b) (“Whoever actively induces infringement of a patent shall be liable
as an infringer”). See 130 Cong. Rec. H10525, H10526 (Oct. 1, 1984), reprinted in 1984 U.S.
Code Cong. & Admin. News 5827, 5828 (“term 'actively induce' is drawn from existing subsec-
tion 271(b)”). See also, Dratler, Licensing of Intellectual Property § 10.02[5][b][i] (Law Journal
Press 1994) (discussing inducement to infringe in context of infringement indemnities).
    338
         The manufacturer should be allowed to rebut the inference of knowledge. For example, a
large manufacturer might present evidence that it was asked only to supply a number of its
standard products, and that it would be unreasonable to charge it with knowledge of the nature
of the final product.

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

to furnish them in a way that facilitates unlicensed assembly of a patented
                 339
product abroad.
    Section 271(f)(2), however, requires a higher level of culpability. It im-
poses liability for supplying “any component” of the patented invention, that
                                                             340
is, a component that is not a “substantial portion” of it.       Presumably, the
requirement for greater culpability in this case reflects the fact that it is easier
to make a single component that does not constitute a substantial portion of
the invention without knowing much about the device in which it is used.
    Accordingly, supplying such a single component for assembly abroad con-
                                                       341
stitutes infringement only if two conditions are met.       First, the component
must be specially made or especially adapted for use in the invention and not
a “staple article or commodity of commerce suitable for substantial
                     342
noninfringing use.”      Second, the domestic manufacturer must know that the
component is so made or adapted and must furnish it for use intending that it
be combined abroad in a manner that would infringe the United States patent
if so used domestically.
    Receipt of a cease-and-desist letter, describing the patented invention and
the component's use in it, undoubtedly should trigger the necessary culpabil-
ity. If the manufacturer continues to supply the offending component after
receipt of such a letter, liability would turn on whether the component actual-
ly had “substantial noninfringing use,” that is, commercially significant use
                                                 343
apart from assembly in the patented invention.

       [c]—Process Patents
   The last and most important extension of the United States patent holder's
exclusive rights is not part of the doctrine of contributory infringement, but
was designed to plug a longstanding loophole in United States patent law as



   339
         Certainly the “active inducement” requirement should be met if the domestic manufac-
turer continues to supply the components after receiving a cease-and-desist letter from the patent
owner, enclosing or identifying the patent.
    340
         The distinction between Section 271(f)(1) and Section 271(f)(2) is not whether the
number of components supplied is singular or plural, but whether what is supplied constitutes
“all or a substantial portion” of the invention's components. Section 271(f)(1) should govern
even a single component that meets this test.
    341
         See 35 U.S.C. § 271(f)(2).
    342
         The quoted language is identical to that defining a nonstaple article for purposes of con-
tributory infringement, see 35 U.S.C. § 271(c), and is indeed drawn from that source, see 130
Cong. Rec. H10525, H10526 (Oct. 1, 1984), reprinted in 1984 U.S. Code Cong. & Admin.
News 5827, 5828.
    343
         Since the relevant statutory language is identical to that for contributory infringement,
see § 2.05[4][a] supra, decisions on that subject should be valid precedent for what constitutes
“substantial noninfringing use” under Section 271(f).

                                                                                       (Rel. 25)
2-05                         PATENTS             INTELLECTUAL PROPERTY LAW

                                344
compared to foreign law.      This extension governs products made by patent-
ed processes.
                                                  345
   Due to territorial limits on its jurisdiction,     the United States is power-
less to prohibit the unauthorized practice abroad of a process patented in the
United States. Thus, a foreign manufacturer, without authorization, may use a
                                                                  346
process patented in the United States to make products abroad.        Until 1988,
there was little to prevent the foreign manufacturer from importing products
so produced into the United States in competition with products of domestic
manufacturers properly authorized to use the patented process, as long as the
                                                 347
products themselves were not also patented.           Many of the United States'
important trading partners had no similar loophole in their own laws, for they
defined unauthorized importation of such products as infringement of the pro-
             348
cess patent.     In 1988 Congress followed their lead by passing the Process
Patent Amendments Act of 1988 as Title IX of the Omnibus Trade and Com-
                          349
petitiveness Act of 1988.
   The Process Patent Amendments Act of 1988 made a major change in the
substance of United States patent law. For the first time, the exclusionary
power of United States process patents was extended to cover products made


   344
         See § 3.01 infra.
   345
         See § 1.09[1] supra, § 2.07[1] infra.
   346
         This assumes that the United States patent holder has no corresponding patent in the
foreign country of manufacture.
    347
         Section 337 of the Tariff Act of 1930, 19 U.S.C. § 1337, gives and even then gave the
U.S. International Trade Commission the power to issue exclusion orders and cease-and-desist
orders with respect to products made abroad by processes patented in the United States. See 19
U.S.C. § 1337(a)(1)(B), (e), (g). The ITC, however, had and has no power to award damages, so
the American patent holder could not receive compensation for its loss of market share. Moreo-
ver, in the absence of damages, any ITC action was unlikely to deter future attempts to import
such products. See S. Rep. No. 100-83, 100th Cong., 1st Sess. 36-38 (June 23, 1987). Neverthe-
less, an ITC action may be a useful supplement to a suit for damages because it provides for
speedy blockage of imports at many points of entry. See S. Rep. No. 100-83, supra, at 38; 133
Cong. Rec. S10275, S10351 (July 21, 1987) (remarks of Sen. Hatch).
    348
         See, e.g.:
    Germany: German Patent Law (Dec. 16, 1980), § 9(3), reprinted in English in 2D Sinnott,
World Patent Law and Practice West Germany 78.22 (1991).
    United Kingdom: Patents Act 1977 (U.K.), as amended through 1988, § 60(1)(c), reprinted
in 2D Sinnott, World Patent Law and Practice Great Britain 268 (1991).
    See also, S. Rep. No. 100-83, 100th Cong., 1st Sess. 29-30, 31-32 (June 23, 1987) (by virtue
of the loophole, United States law in this respect was “in contrast to [the laws] of Japan and
nearly all of the Western European nations”; of twenty-nine “Group B” countries with developed
market economies, twenty-four included direct products within coverage of process patents, and
thirteen defined unauthorized importation of products as infringement).
    349
         Omnibus Trade and Competitiveness Act of 1988, Title IX, §§ 9001-9007, Pub. L. No.
100-418, 102 Stat. 1107, 1563-1567 (Aug. 23, 1988), amending 35 U.S.C. §§ 154, 271, 287
and adding 35 U.S.C. § 295.

                                                                                     (Rel. 25)
2-05                         PATENTS              INTELLECTUAL PROPERTY LAW

                                  350
by the patented processes.      Although inspired by the threat of foreign man-
ufacture, the extension applies to products manufactured in the United States
         351
as well.     In addition, the amendments have broad application to modern
industry, including the fields of semiconductors and biotechnology.
In making this significant change in patent law, Congress carefully balanced
the interests of process patent holders against the interests of perhaps un-
knowing users and resellers of products made using patented processes. The
resulting statutory rules and procedures are among the most complex in Unit-
                      352
ed States patent law.

       [d]—Provisional Rights
                                            353
   Effective November 29, 2000,         Congress provided new interim rights,
                              354
called “provisional rights,”      intended to compensate patent applicants for
the risk of piracy of their inventions during the interim period between publi-
                                                                   355
cation of their patent applications and issuance of their patents.     The provi-
sional rights apply only if a patent application is published before patent

   350
         See § 3.01 infra.
   351
         See id.
   352
         See Chapter 3 infra for a detailed discussion of these rules.
   353
         The 1999 amendments take effect “on the date that is 1 year after the date” of their en-
actment, which was November 29, 1999. Domestic Publication of Foreign Filed Patent Applica-
tions Act of 1999, Subtitle E (Domestic Publication of Patent Applications Published Abroad) of
Tit. IV (American Inventors Protection Act of 1999), § 4508, of Intellectual Property and Com-
munications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B, Appendix I
(S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-566 through 1501A-567 (Nov.
29, 1999), discussed also in § 1.06[1] supra. They apply to all nonexcluded (see N.357 infra)
applications filed on or after that date that are: (1) filed under 35 U.S.C. § 111, (2) national-
stage applications resulting from international applications, (3) applications “voluntarily pub-
lished by the applicant under procedures established” under the amendments, or (4) applications
filed under the Patent Cooperation Treaty designating the United States. Id.
    354
         See 35 U.S.C. § 154(d) (title), as added by Domestic Publication of Foreign Filed Patent
Applications Act of 1999, Subtitle E (Domestic Publication of Patent Applications Published
Abroad) of Tit. IV (American Inventors Protection Act of 1999), § 4504, of Intellectual Property
and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B, Appen-
dix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-564 (Nov. 29, 1999).
    The term “provisional rights” may be misleading because provisional patent applications,
which are excluded from mandatory pre-issuance publication, see: N.357 infra; § 1.06[1] supra,
have no such rights. The word “provisional” refers not to the type of patent application involved,
but to the rights themselves, which are contingent upon the issuance of a valid patent with
claims “substantially identical” to the asserted claims in the application. See: N.367 infra; §
1.06[1] supra.
    355
         See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 128 (Nov. 9, 1999) (Conference Re-
port) (“For those applicants who do file abroad or who voluntarily publish their applications,
provisional rights will be available for assertion against any third party who uses the claimed
invention between publication and grant provided that substantially similar claims are contained
in both the published application and granted patent”).

                                                                                      (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

issuance as the amended statute provides, i.e., if a foreign or international
counterpart is filed or to be filed or the applicant voluntarily elects pre-
                      356                                       357
issuance publication.     For nonexcluded patent applications,      this publica-
tion is supposed to occur eighteen months after the earliest priority date of the
             358
application.
   The provisional rights appear in Section 154(d), as added by the Domestic
                                                                 359
Publication of Foreign Filed Patent Applications Act of 1999.        They allow
the patent holder to recover “a reasonable royalty,” as determined by a court,
                                                                      360
from anyone performing, during the period between publication              of the

   356
         See: 35 U.S.C. § 122(b) (governing pre-issuance publication), discussed in detail in §
1.06[1] supra; N.355 supra.
    357
         The statute excludes five types of patent applications categorically from pre-issuance
publication: (1) nonpending applications (including abandoned applications); (2) applications
under secrecy orders, see § 1.09[2]; (3) provisional applications under 35 U.S.C. § 111(b); (4)
design patent applications; and (5) applications that the applicant certifies on filing do not and
will not have foreign or international counterparts. See 35 U.S.C. § 122(b)(2), as added by Do-
mestic Publication of Foreign Filed Patent Applications Act of 1999, Subtitle E (Domestic Pub-
lication of Patent Applications Published Abroad) of Tit. IV (American Inventors Protection Act
of 1999), § 4502(a), of Intellectual Property and Communications Omnibus Reform Act of
1999, Pub. L. No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat.
1501A-521, 1501A-561 through 1501A-562 (Nov. 29, 1999), discussed in detail in § 1.06[1]
supra.
    358
         See: 35 U.S.C. § 122(b)(1)(A), as added by Domestic Publication of Foreign Filed Pa-
tent Applications Act of 1999, Subtitle E (Domestic Publication of Patent Applications Pub-
lished Abroad) of Tit. IV (American Inventors Protection Act of 1999), § 4502(a), of Intellectual
Property and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B,
Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-561 (Nov. 29, 1999),
discussed in § 1.06[1] supra.
    The PTO’s administrative rules for publication, which are complex, appear at 37 C.F.R. §§
1.211-1.291, as amended by 65 Fed. Reg. 57024, 57058-57060 (Sept. 20, 2000, effective Nov.
29, 2000). The massive corresponding Federal Register promulgation contains a wealth of sup-
plemental information as well as amendments of related rules. See generally, 65 Fed. Reg.
57024-57062 (Sept. 20, 2000, effective Nov. 29, 2000). The precise date of publication depends
in large measure upon internal procedures of the Patent and Trademark Office. See 65 Fed. Reg.
at 57028-57029.
    359
         35 U.S.C. § 154(d), as added by Domestic Publication of Foreign Filed Patent Applica-
tions Act of 1999, Subtitle E (Domestic Publication of Patent Applications Published Abroad) of
Tit. IV (American Inventors Protection Act of 1999), § 4504(2), of Intellectual Property and
Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B, Appendix I
(S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-564 through 1501A-565 (Nov.
29, 1999).
    360
         The type of publication that triggers provisional rights also includes publication of the
application abroad under the rules of the Patent Cooperation Treaty. See: N.361 infra; H.R. Rep.
No. 106-464, 106th Cong., 1st Sess. 131 (Nov. 9, 1999) (Conference Report) (referring to “ap-
plications designating the United States filed under the PCT”); H.R. Rep. No. 106-464, supra, at
132 (describing new 35 U.S.C. § 154(b)(4) as “set[ting] forth some additional rules qualifying
when an international application under the PCT will give rise to provisional rights”); the text
accompanying Ns.364-365 infra.
    For these applications, the date when provisional rights begin is the date on which the Unit-
ed States Patent and Trademark Office receives a copy of the application published under the

                                                                                      (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

application and issuance of the patent, acts that would have infringed the pub-
                                                                              361
lished claims of the patent application if it had already issued as a patent.
This right mirrors similar rights that patent applicants have with respect to the
                                                              362
publication of patent applications under many foreign laws.

PCT in English, or, if the application is not published in English, a translation of the published
application into English. See: 35 U.S.C. § 154(d)(4)(A), as added by Domestic Publication of
Foreign Filed Patent Applications Act of 1999, Subtitle E (Domestic Publication of Patent Ap-
plications Published Abroad) of Tit. IV (American Inventors Protection Act of 1999), § 4504(2),
of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-
113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-565
(Nov. 29, 1999); H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 132 (Nov. 9, 1999) (Confer-
ence Report).
    361
         35 U.S.C. § 154(d)(1) (preamble):

       “In addition to other rights provided by this section, a patent shall include the right to ob-
   tain a reasonable royalty from any person who, during the period beginning on the date of
   publication of the application for such patent under section 122(b), or in the case of an inter-
   national application filed under the treaty defined in section 351(a) designating the United
   States under Article 21(2)(a) of such treaty, the date of publication of the application, and
   ending on the date the patent is issued—[performs the specified acts.]”
    The specified acts are the same ones listed in Section 154(a)(1), 35 U.S.C. § 154(a)(1), from
which any patent holder may exclude others, with the exception that they relate to “the invention
as claimed in the published patent application[,]” 35 U.S.C. § 154(d)(1)(A)(i), (ii), (identical
language insofar as quoted), rather than simply “the invention[,]” 35 U.S.C. § 154(a)(1).
    The words “a patent shall include” make clear that provisional rights are continent upon is-
suance of a patent, as does the fact that the claims in the patent application asserted must be
substantially identical to the claims in the issued patent. See the text accompanying Ns.366-367
infra.
    362
         See § 4.06[1] Ns.13, 15 infra.
    An important difference is that, unlike the United States, many foreign countries provide for
special inter partes administrative opposition proceedings, in which interested third parties may
challenge the patent application after it is published and before issuance. See, e.g.:
    Europe: Convention on the Grant of European Patents Arts. 99-105 (allowing opposition
within nine months after publication and giving accused infringers right to intervene).
    Japan: Japanese Patent Law (Law No. 121, April 13, 1959, as amended through June 1,
1987), Arts. * * * reprinted in English in 2F Sinnott, World Patent Law and Practice, Japan 27,
31-32 (1990).
    In contrast, the 1999 amendments explicitly prohibited such proceedings in the United
States, except with the applicant’s consent. See 35 U.S.C. § 122(c), as added by Domestic Pub-
lication of Foreign Filed Patent Applications Act of 1999, Subtitle E (Domestic Publication of
Patent Applications Published Abroad) of Tit. IV (American Inventors Protection Act of 1999),
§ 4502(a), of Intellectual Property and Communications Omnibus Reform Act of 1999, Pub. L.
No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521,
1501A-562 (Nov. 29, 1999):
       “(c) Protest and Pre-Issuance Opposition.—The [PTO] shall establish appropriate proce-
   dures to ensure that no protest or other form of pre-issuance opposition to the grant of a pa-
   tent on an application may be initiated after publication of the application without the
   express written consent of the applicant.”
The PTO’s rules comply with this prohibition; they do not permit pre-issuance opposition, alt-
hough they do permit interested parties to submit “patents or publications relevant to a pending
published application” for consideration as prior art. 37 C.F.R. § 1.99, amended by 65 Fed. Reg.

                                                                                         (Rel. 25)
2-05                      PATENTS                INTELLECTUAL PROPERTY LAW

   A United States patentee’s provisional rights are subject to four conditions.
First, the defendant must have had actual notice of the published applica-
     363
tion;     constructive notice arising from the mere fact of publication is not
                                                                      364
enough—even though publication is through an on-line database.            If the
provisional rights are based on publication of the application in a foreign lan-
guage, the actual notice should include a translation of that application into
         365
English.     Consequently, the patent applicant should, in most cases, send
cease-and-desist letters, including a copy of the published patent applica-
    366
tion     and (if necessary) an English translation of it, to all persons against
whom it hopes to assert this remedy.

57024, 57056 (Sept. 20, 2000). See 65 Fed. Reg. 57024, 57056 (Sept. 20, 2000) (Responses to
Comments 29-31, explaining that opposition or protest prohibited by Section 122(c) involves
filing of complaint or objection and adversarial argument, but that Rule 1.99 does not permit
even explanation of submitted references, only their submission).
     363
         See 35 U.S.C. § 154(d)(1)(B), as added by Domestic Publication of Foreign Filed Patent
Applications Act of 1999, Subtitle E (Domestic Publication of Patent Applications Published
Abroad) of Tit. IV (American Inventors Protection Act of 1999), § 4504(2), of Intellectual Prop-
erty and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B,
Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-564 (Nov. 29, 1999):
        “[The defendant must have] had actual notice of the published patent application and, in
    a case in which the right arising under this paragraph is based upon an international applica-
    tion designating the United States that is published in a language other than English, had a
    translation of the international application into the English language.”
    364
          See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 131 (Nov. 9, 1999) (Conference Re-
port):
        “The requirement of actual notice is critical. The mere fact that the published application
    is included in a commercial database where it might be found is insufficient. The published
    applicant must give actual notice of the published application to the accused infringer and
    explain what acts are regarded as giving rise to provisional rights.”
This point of the Conference Report is important because the United States Patent and Trade-
mark Office intends to publish patent applications electronically only, and not in paper form.
See § 1.06[1] supra. That publication will not, ipso facto, give provisional rights defendants the
actual notice that they must have to trigger provisional rights.
    365
         See: Ns.363, 364 supra. The statute does not explicitly state that the actual notice and
translation (where required) must come from the same source. See N.363 supra. The Conference
Report, however, suggests that mere presence of a translation in a database—even if searchable
from the Web—is not enough. See N.364 supra. Therefore, a patent applicant seeking to assert
provisional remedies against any person with respect to an application published in a foreign
language is best advised to give that person actual notice of infringement and an English transla-
tion of the published patent application.
    366
         If the publication of the patent application is in English, the statute permits a notifica-
tion that merely refers to the published application and calls attention to it. After all, the statute
requires only “actual notice of the published patent application[,]” N.363 supra, not a copy of it.
Nevertheless, as a practical matter including a copy of the application would be preferable in
most cases. Among other things, it reduces the chance for making an error, such as transposing
numbers or letters in a serial number, URL, or similar reference, that might cast doubt on the
legal effect of a mere reference to the publication.

                                                                                          (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

   The second precondition of provisional rights is equally important. The in-
vention as claimed in the patent as issued must be “substantially identical” to
                                                  367                        368
the invention of the published patent application     allegedly “infringed.”
This condition protects the public against having to guess at which of the ap-
                                             369
plication’s published claims may be allowed.

    Sending a complete copy, however, might be inappropriate if the application is voluminous
(for example, a biotechnology application involving long nucleotide sequences that are best
handled in machine-readable form), if there are many potential defendants so that sending all
copies would be difficult or costly, or if for other reasons sending a copy or copies would be
administratively difficult or costly or less effective than a reference to a machine-readable
source. The careful wording of the statute appears to allow patent applicants to provide forms of
actual notice that best fit the circumstances and their administrative needs.
The PTO provides no assistance in making this notification. “The Office will not provide gen-
eral notification to the public of the filing of translations under 35 U.S.C. 154. Under 35 U.S.C.
154 it is the responsibility of the applicant to notify any possible infringers for the purpose of
obtaining provisional rights.” 65 Fed. Reg. 57024, 57039 (Sept. 20, 2000, effective Nov. 29,
2000) (response to Comment 6). Nor do the PTO’s regulations provide guidance regarding noti-
fication, for the PTO is not empowered to prescribe rules for provisional rights. See 65 Fed. Reg.
57024, 57048 (Sept. 20, 2000, effective Nov. 29, 2000) (response to Comment 71):
       “The Office is not charged with administering provisional rights . . . and the enforcement
   of provisional rights will not be via a proceeding in the Office. Therefore the Office is not
   promulgating regulations concerning what situation must exist for any type of application to
   have provisional rights protection. See 35 U.S.C. § 2(b)(2)(A).”
Section 2(b)(2)(A) gives the PTO plenary authority to “establish regulations . . . [that] govern
the conduct of proceedings in the Office[.]”
    367
        See 35 U.S.C. § 154(d)(2), as added by Domestic Publication of Foreign Filed Patent
Applications Act of 1999, Subtitle E (Domestic Publication of Patent Applications Published
Abroad) of Tit. IV (American Inventors Protection Act of 1999), § 4504(2), of Intellectual Prop-
erty and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B,
Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-564 (Nov. 29, 1999):
       “(2) Right based on substantially identical inventions.—The right under paragraph (1) to
   obtain a reasonable royalty shall not be available under this subsection unless the invention
   as claimed in the patent is substantially identical to the invention as claimed in the published
   patent application.”
   368
         Throughout this discussion of provisional remedies, all grammatical forms of the word
“infringe,” when shown in quotation marks, serve as a useful shorthand for acts that would
infringe the claims of the published patent application if they had been allowed and issued as
claims in a patent.
    369
        See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 131-132 (Nov. 9, 1999) (Conference
Report):
        “To allow anything less than substantial identity would impose an unacceptable burden
   on the public. If provisional rights were available in the situation where the only valid claim
   infringed first appeared in substantially that form in the granted patent, the public would
   have no guidance as to the specific behavior to avoid between publication and grant. [*132]
   Every person or company that might be operating within the scope of the disclosure of the
   published application would have to conduct her own private examination to determine
   whether a published application contained patentable subject matter that she should avoid.
   The burden should be on the applicant to initially draft a schedule of claims that gives ade-
   quate notice to the public of what she is seeking to patent.”


                                                                                       (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

   Third, a suit for the reasonable royalty must be filed within six years after
                    370
the patent issues.       Although meant as a limitation, this requirement may
allow provisional rights to cover an extended period when prosecution of the
                               371
patent application is delayed.
   The fourth and final precondition for provisional remedies applies only
when the patent applicant has redacted the published patent application, as
compared to the cumulative disclosure of all its foreign and international
counterparts, in order to preserve trade secrets while the application is pend-
     372
ing.     In that case, the redacted disclosure must enable a person of ordinary
skill in the art to practice the invention as claimed in the published patent
                                                    373
application; otherwise no provisional rights arise.




   370
        See 35 U.S.C. § 154(d)(3), as added by Domestic Publication of Foreign Filed Patent
Applications Act of 1999, Subtitle E (Domestic Publication of Patent Applications Published
Abroad) of Tit. IV (American Inventors Protection Act of 1999), § 4504(2), of Intellectual Prop-
erty and Communications Omnibus Reform Act of 1999, Pub. L. No. 106-113, Division B,
Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-521, 1501A-564 (Nov. 29, 1999):
       “(3) Time limitation on obtaining a reasonable royalty.—The right under paragraph (1)
   to obtain a reasonable royalty shall be available only in an action brought not later than 6
   years after the patent is issued. The right under paragraph (1) to obtain a reasonable royalty
   shall not be affected by the duration of the period described in paragraph (1).”
Such an action also cannot be brought before the patent issues. Otherwise, there would be no
allowed and issued patent claim against which to compare the claims in the published patent
application to see whether the two sets of claims are “substantially identical.” See the text ac-
companying Ns.366-369 and Ns.367, 369 supra.
    371
        See 35 U.S.C. § 154(d)(3), N.370 supra (last sentence).
    Although the statutory provisions for patent term adjustments encourage both the applicant
and the Patent and Trademark Office to avoid extensive delays in patent prosecution, see §
2.05[2][b][i] infra, there is no absolute time limit on those delays. In rare cases, such as those
involving secrecy orders, see § 2.09[2] infra, patent prosecution may take decades. This provi-
sion insures that provisional remedies continue no matter how long prosecution takes.
    372
        The statute permits a United States applicant to redact the application before publication
in this manner and for this purpose. See: 35 U.S.C. § 122(b)(2)(B)(v), as added by Domestic
Publication of Foreign Filed Patent Applications Act of 1999, Subtitle E (Domestic Publication
of Patent Applications Published Abroad) of Tit. IV (American Inventors Protection Act of
1999), § 4502(a), of Intellectual Property and Communications Omnibus Reform Act of 1999,
Pub. L. No. 106-113, Division B, Appendix I (S.1948), 106th Cong., 1st Sess., 113 Stat. 1501A-
521, 1501A-562 (Nov. 29, 1999), discussed in § 1.06[1] supra.
373
     See id. (last sentence):

      “The provisions of section 154(d) shall not apply to a claim if the description of the in-
   vention published in the redacted application filed under this clause with respect to the claim
   does not enable a person skilled in the art to make and use the subject matter of the claim.”
This requirement reflects the general requirement of 35 U.S.C. § 112 (first ¶) that all valid is-
sued patents must be “enabling,” i.e., must provide enough information for a person of ordinary
skill in the art to practice the inventions disclosed in them. See § 2.04[1][a] supra.

                                                                                      (Rel. 25)
2-05                     PATENTS               INTELLECTUAL PROPERTY LAW

    Although the statute does not say so explicitly, provisional remedies apply
                                                                         374
to a defendant’s unauthorized practice of a single provisional claim         in the
published patent application (if it is substantially identical to a corresponding
                                  375
allowed, issued and valid claim ), whether or not other claims in the pub-
                                            376
lished patent application are “infringed,”      and whether or not other claims
in the patent application are “substantially identical” to their counterparts in
the issued patent. That is, it should be enough to invoke provisional remedies
that the defendant “infringes” a single provisional claim in the published pa-
                                                                          377
tent application, either directly or under the doctrine of equivalents.       This
follows from the fact that the statutory language governing the defendant’s
acts giving rise to provisional remedies is identical in substance, if not in pre-
cise form, to the language of Section 154(a)(1) setting forth a patentee’s
                              378
rights to exclude generally,      which is the basis for all direct infringement
          379
analysis.     Thus, the usual rules and procedures for assessing patent in-
                                                        380
fringement should apply in assessing “infringement”         in provisional remedy
cases.
                                                                                381
    More difficult questions relate to the validity of provisional claims.
                                                                382
There can be no infringement of an invalid patent claim,            and this same
                                                       383
basic principle must apply to provisional remedies.        But on what should its
application to provisional remedies depend, (1) the “validity” of the provi-
              384
sional claims      in the published patent application, (2) the validity of the
corresponding allowed claims in the issued patent, or (3) both? Unfortunately,
neither the Conference Report nor the statute directly answers this question.
    The best answer appears to be that provisional remedies should depend on-
ly upon the validity of allowed claims in the issued patent, provided those

   374
         For the sake of brevity, this discussion of provisional rights uses the term “provisional
claim” to refer to a claim in the published patent application, whether or not it is identical or
substantially identical to an allowed claim in the issued patent. This term is not to be confused
with claims in a provisional patent application under 35 U.S.C. § 111(b). See N.354 supra.
    375
         See N.367 supra.
    376
         See N.368 supra.
    377
         See § 2.05[3] infra (discussing infringement generally).
    378
         See N.361 supra.
    379
         See 35 U.S.C. § 271(a) (defining infringement in substantially identical language). See
generally, § 2.05[3] infra (discussing infringement).
    380
         See N.368 supra.
    381
         See N.374 supra.
    382
         See § 2.03 (introduction) infra.
    383
         See H.R. Rep. No. 106-464, 106th Cong., 1st Sess. 131 (Nov. 9, 1999) (Conference Re-
port), quoted in N.369 supra (referring to “the only valid claim infringed”). (Emphasis added.)
    384
         See N.374 supra.


                                                                                      (Rel. 25)
2-05                      PATENTS                    INTELLECTUAL PROPERTY LAW

                                               385
claims are “substantially identical”       to the corresponding provisional claims
                       386
allegedly “infringed,”     as the statute requires. There are both doctrinal and
policy reasons for this conclusion.
    As a matter of doctrine, the statute itself suggests that not all the usual cri-
teria for patent validity always apply to provisional claims. By singling out
the enablement requirement for special mention with respect to redacted pub-
                            387                                               388
lished patent applications,      the statute suggests that provisional claims —
as distinguished from allowed and issued claims—should not be measured
against the other three usual disclosure requirements—best mode, definite-
                                  389
ness, and written description.         This makes sense because the provisional
remedy is designed, inter alia, to compensate a patent applicant for deliberate
piracy of an invention disclosed in a published patent application, which pub-
                                              390
lication makes possible and more likely.          It would make little sense to de-
prive a patentee of such a remedy merely because the published patent
application failed adequately to disclose the best mode known to the inventor
                              391                                      392
of practicing the invention,       failed to adequately define terms,      or failed
                                                                 393
to demonstrate the applicant’s possession of the invention,          when the dis-
closure in the published patent application proved sufficient to allow the pi-
rate to exploit the invention commercially and successfully, and the pirate did
so.
    Similar doctrinal considerations may apply even to the scope of the claims.
                                394
Suppose a provisional claim,         containing limitations A through C, reads on
                                        395
prior art and is therefore “invalid.”       Suppose further that the patent appli-
cant, in the course of patent prosecution but after publication of the provi-
sional claim, amends that claim to add limitation D, which prevents the

   385
         See the text accompanying Ns.366-369 and Ns.367, 369 supra.
   386
         See N.368 supra.
   387
         See the text accompanying Ns.371-373 and N.373 supra.
   388
         See N.374 supra.
   389
         See § 2.04[1] (introduction) infra.
   390
         See the text accompanying Ns.353-355 and N.355 supra. In the United States, pre-
issuance publication facilitates piracy because pending patent applications are kept secret unless
and until they are published in accordance with statutory requirements. This fact allows patent
applicants to protect their inventions as trade secrets until the earlier of publication of the patent
application or issuance of a patent. See: §§ 1.06[1] supra; 4.06[1] infra..
    391
        See § 2.04[1][d] infra (discussing best-mode disclosure requirement).
    392
        See § 2.04[1][b] infra (discussing definiteness requirement for patent disclosures).
    393
        See § 2.04[1][f] infra (discussing written-description disclosure requirement).
    394
        See N.374 supra.
    395
         The word “invalid” here is in quotation marks because it refers to a provisional claim,
see N.374 supra, not a claim already allowed and issued.

                                                                                          (Rel. 25)
2-05                     PATENTS                INTELLECTUAL PROPERTY LAW

amended claim from reading on prior art, so that the amended claim is there-
fore allowed and included in the issued patent. Now suppose that the provi-
sional remedy defendant’s accused device contains all of the limitations A
                                       396
through D and therefore “infringes”         both the “invalid” provisional claim
and the valid, issued claim. Should the defendant escape provisional remedies
because the provisional claim reads on prior art and therefore would have
been invalid if allowed, even though the defendant’s activities would have
infringed the corresponding narrower claim of the issued patent, which does
not read on prior art and is valid?
   In many cases the answer will be “yes” because the provisional claim,
which lacked the limitation D and therefore read on prior art, may not be
deemed “substantially identical” to the issued claim which contains limitation
D and therefore is valid. Indeed, the Conference Report suggests that provi-
sional claims which overreach generally should not be deemed substantially
                                               397
identical to their valid, issued counterparts.     But should there be an invaria-
ble rule to this effect? Can an “invalid” provisional claim can never be sub-
stantially identical to a corresponding issued claim that is valid? An
affirmative answer might unfairly deprive a patentee of the statute’s protec-
tion, for example, if the added limitation D were implicit in the patentee’s
original disclosure but omitted from the provisional claims through oversight
                                                                        398
or a misunderstanding between the inventor and her patent attorney.
   Considerations of general policy argue for the same conclusion. An im-
portant purpose of provisional remedies is to compensate patent applicants for
others’ abuse of the pre-issuance publication system in pirating inventions
                                                                               399
disclosed in published patent applications before patents can be issued.
Since the purpose of patent prosecution is to narrow patent claims so that they
become supportable and valid under all relevant criteria, a patent applicant
should not be penalized by depriving her of provisional remedies against such
a pirate merely for narrowing her claims, unless the narrowing substantially
affects the coverage of the claims and therefore deprives the public (including
the pirate) of the fair notice of prohibited conduct that the statute requires the
published patent application to give. If fair notice is absent, the provisional
remedy may be denied, but not because the provisional claim is “inva-


   396
         See N.368 supra.
   397
         See N.369 supra.
   398
         The point of having provisional remedies depend on the “infringement” (see N.368 su-
pra) of claims not yet allowed and issued is to insure that the public has notice of conduct that
may be subject to provisional remedies. See the text accompanying Ns.366-369 and Ns.367-369
supra. In some cases it might better advance this policy not to deny provisional remedies unless
the allowed and issued claim were also invalid, and to construe the statute’s “substantial identi-
ty” criterion so as to apply the provisional remedy in this case but perhaps not in others in which
denial of that remedy would be more appropriate.
    399
         See the text accompanying Ns.389-390 and N.390 supra.


                                                                                       (Rel. 25)
2-05                     PATENTS                 INTELLECTUAL PROPERTY LAW

         400
lid[;]”    rather, it may be denied because the corresponding allowed and
issued claim is invalid, or because the provisional claim is not substantially
                                                                   401
identical to the issued claim, as the provisional remedy requires.
                                                                              402
   Whatever answers to these questions eventually arise out of litigation,
two things are already clear. First, until the Federal Circuit settles these mat-
ters by developing a special jurisprudence for provisional remedies, some
                                                     403
uncertainty as to both substance and procedure           will attend assertion of
those remedies. Second, even after the Federal Circuit has developed a stable
jurisprudence of provisional remedies, litigation of claims for them will entail
much of the complexity and expense of patent litigation generally. Just like
patent infringement litigation in general, litigating provisional remedies will
require construction of claims, the assessment of validity of something
(whether of provisional claims, issued claims, or both) and the determination
                    404
of “infringement”       in a manner similar to the determination of infringement
of allowed and issued claims. In addition, of course, courts addressing provi-
sional remedies will have to determine what constitutes a “reasonable royalty”
under the circumstances, as they are authorized to do in ordinary infringement
       405
cases.
   Section 154(d)(1)’s failure to refer to Section 284 or 285 when speaking of
                                                 406
“the right to obtain a reasonable royalty[,]”        leaves two other important
questions regarding provisional remedies unanswered: whether augmented
damages and discretionary attorneys’ fee awards apply with respect to provi-
               407
sional rights.     The statute’s failure to refer to Section 284 suggests that
courts cannot augment awards of reasonable royalties for violations of provi-



   400
         See N.395 supra.
   401
         See the text accompanying Ns.366-369 and Ns.367, 369 supra.
   402
         The courts must decide these issues because the PTO has not addressed, and has no
power to address, these questions by rulemaking. See N.366 supra.
    403
         For example, should provisional remedies and claims for infringement be tried in the
same proceeding? Should a single Markman hearing, see § 2.05[3][a] supra, address proper
construction of both provisional and issued claims, or should two separate Markman hearings be
held?
    404
         See N.368 supra.
    405
         See 35 U.S.C. § 284, ¶ 1 (in full: “Upon finding for the claimant the court shall award
the claimant damages adequate to compensate for the infringement, but in no event less than a
reasonable royalty for the use made of the invention by the infringer, together with interest and
costs as fixed by the court”). See generally, § 12.03[1][a] infra.
    406
         See N.361 supra.
    407
         See generally: § 12.05[1][a] infra (discussing augmented damages under Section 284, ¶
2), § 12.06[1]-[3] infra (discussing, inter alia, discretionary awards of attorney’s fees to prevail-
ing party in “exceptional cases” under Section 285).

                                                                                         (Rel. 25)
2-05                    PATENTS               INTELLECTUAL PROPERTY LAW

sional rights, for the language of Section 284 authorizing augmentation is
                                                      408
specific to “the damages” authorized by that section.
   The failure to refer specifically to Section 285, however, seems less deci-
sive with respect to fee awards, because that section refers generally to “ex-
                                                                              409
ceptional cases” without referring to any particular kind of case.
Accordingly, particularly when provisional rights and infringement are con-
tested in a single proceeding, Section 285 appears to authorize a fee award
relating to work on provisional rights, as long as the award is made to a party
                                                      410
that is deemed “prevailing” in the “case” as a whole.     Moreover, permitting
fee awards in provisional rights cases is consistent with an important purpose
of provisional rights generally—compensating for deliberate piracy of inven-
                                                                              411
tions disclosed by published patent applications before the patent’s issue.
In the absence of a fee award, a patentee’s obligation to cover its own attor-
neys’ fees would promote undercompensation. In addition, fee awards have
the advantage of deterring deliberate piracy, thereby encouraging disclosure
through pre-issuance publication.
                                                                  412
   By limiting provisional remedies to holders of issued patents,     the statute
encourages both provisional rights and infringement to be tried in a single
action. Patentees therefore may wish to wait to file suit for provisional reme-
                                           413
dies until the six-year limitations period     has almost expired, in order to
maximize their probable monetary benefit as against the cost of litigating
claims for provisional remedies, which is likely to be considerable.




   408
        35 U.S.C. § 284, ¶ 2 (in part: “the court may increase the damages up to three times the
amount found or assessed”). (Emphasis added.) See also, 35 U.S.C. § 284, ¶ 1, quoted in N.405
supra (providing predicate for “the damages” in ¶ 2).
    409
        35 U.S.C. § 285 (“The court in exceptional cases may award reasonable attorney fees to
the prevailing party”).
    410
        See § 12.06[6] infra (discussing “prevailing party” requirement of fee-award statutes).
    411
        See the text accompanying Ns.353-355, 389-390 and Ns.355, 390 supra.
    412
        See N.361 supra.
    413
        See the text accompanying Ns.369-370 and N.370 supra.


                                                                                     (Rel. 25)
2-05   PATENTS   INTELLECTUAL PROPERTY LAW




                                     (Rel. 25)

				
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