INTRODUCTION TO BLU-RAY DISC
A current, single-sided, standard DVD more storage. As TV sets and movie
can hold 4.7 GB (gigabytes) of studios make the move to high definition
Information. That's about the size of an consumers are going to need playback
average two-hour, standard-definition systems with a lot more storage capacity.
movie with a few extra features. But a
high-definition movie, which has a much Blu-ray is the next-generation digital
clearer image (see how Digital video disc. It can record, store and play
Television Works), takes up about five back high definition video and digital
times more bandwidth and therefore audio, as well as computer data.
requires a disc with about five times
The advantage to BIu-ray is the sheer video or about 13 hours of standard
amount of information it can hold: video.
A single-layer BIu-ray disc, which is A double-layer Blu-ray disc can
roughly the same size as a DVD, can store up to 54 GB, enough to hold
hold up to 27 GB of data that's more about 4.5 hours of high-definition
than two hours of high-definition video or more than 20 hours of
BLU-RAY VS DVD CAPACITY
ADVANTAGES OF BLU_RAY DISC:
Record High-Definition Television Edit programs recorded on the disc.
(HDTV) without any quality loss. Automatically search for an empty
Instantly skip to any spot on the disc. space on the disc to avoid
Record one program while recording over a program.
watching another on the disc Access the web to down load
Create play lists. subtitles and other extra features
WORKING OF BLU_RAY:
Discs store digitally encoded video and laser (650 nano meters). The smaller
audio information in pits spiral beam focuses more precisely, enabling it
grooves that run from the center of the to read information recorded in pits that
disc to its edges. A laser reads the other are not only 0.15 microns long this is
side of these pits the bumps to play the more than twice as small as the pits on a
movie or program that is stored on the DVD.Plus, Blue-ray has reduced the
DVD. The more data that is contained on track pitch from 0.74 microns to 0.32
a disc, the smaller and more closely microns. The smaller pits, smaller beam
packed the pits must be. The smaller the and shorter track pitch together enable a
pita (and therefore the bumps), the more single-layer Blu-ray disc to hold more
precise the reading laser must be. than 25GB of information about five
Unlike current DVD’s, which use a red times the amount of information that can
laser to read and write data, Blu-ray uses be stores on a DVD.
a blue laser (which is where the format
gets its name). A blue laser has a shorter
wavelength (405 nanometers) than a red
Each BIu-ray disc is about the same layers, each O.6-mm thick. Having a
thickness (1.2 millimeters) as a DVD. polycarbonate layer on top of the data
But the two types of discs store data can cause a problem called
differently. In a DVD, the data is birefringence, in which the substrate
sandwiched between two polycarbonate layer refracts the laser light into two
separate beams. If the beam is split too known as disc tilt, in which the laser
widely, the disc cannot be read. Also, if beam is distorted. All of these issues
the DVD surface is not exactly flat, and lead to a very involved manufacturing
is therefore not exactly perpendicular to process.
the beam, it can lead to a problem
BLU-RAY VS OTHER NEW DISC FORMATS:
Will Blu-ray replace previous DVDs? release of video in both formats on a
Its manufactures hope so. In the single disc. But Blu-ray is not alone in
meantime JVC has developed a Blu-ray the marketplace. A few other formats are
/DVD combo disc with an approximate competeting for a share of DVD market.
33.5GB capacity, allowing for the
The other big player is HD_DVD, hold 20 GB of data; a double –layer
also called AOD(Advanced Optical disc can hold 30 GB(that’s compared
Disc), which DVD and can therefore to 27 GB and 50 GB for Blu-ray).
be manufactured with the same The read-only versions hold slightly less
equipment, saving on costs. The data. Also, HD_DVD doesn’t offer the
disadvantage is that it can’t match the interactive capabilities of Blu-ray ,
storage capacity of Blu-ray. A although it will probably be less
rewritable, single layer HD_DVD can expensive than its competitor
WHEN WILL BLUE RAY BECOME AVAILABLE
Blu-ray recorders are already available definition ( which is expected to
in Japan, where more consumers have happen by late 2005 or 2006), BIu-
access to HDTV than in the United ray movies and TV shows on disc
States. Outside of Japan, once more should become widely available. But
TV sets come equipped with a high- the format is already available for
definition tuner and more films and home recording, professional
television shows are produced in high- recording and data storage.
Another important factor is cost. Just as equipment will be pricey at first. In
with most new technologies, Blu-ray 2003, Sony released its first BIu-ray
recorder in Japan with a price tag of Even when the new video standard
around $3,000. The price is expected to begins to replace current technologies,
drop as the format gains popularity. Blu- consumers won't have to throw away
ray discs may also be initially more their DVDs, but they will need to
expensive than today's DVDs, but invest in a new player. The industry
once demand grows and they can be is planning to market backward-
mass-produced, manufacturers say the compatible drives with both blue and
price will drop to within 10 percent red lasers, which will be able to play
of the price of current DVDs. traditional DVDs and CDs as well as
The Play station 3 will be the first Blu- Sony has announced that the PlayStation
ray accessable player. 3 will be shipped with a Blu-Ray drive,
but possibly just a read-only one. Sony's
The first BIu-Ray recorder was unveiled machine will also support BD-ROM pre-
by Sony and was introduced to the recorded media, which are expected to
Japanese market. JVC and Samsung be available in early 2006.
Electronics announced Blu-ray based
products at IFA in Berlin, Germany.
PC DATA STORAGE
Blu-ray drives currently in production prototypes with a 108 Mbit/s transfer
can transfer approximately 36 Mbit/s (54 rate are in development. Rates of 8x or
Mbit/s for BD-ROM), but 2x speed more are planned for the future.
Hewlett Packard has announced plans to announced that they would also be
sell Blu-ray-equipped desktop PCs and supporting the rival HD DVD
laptops. In December 2005, HP technology. Philips was scheduled to
debut a Blu-ray computer drive in the Computer joined the Blu-ray Disc
second half of 2005, but it was also Association.
delayed. On March 10, 2005 Apple
Blu-ray disc has been a consistent works to develop a disc with twice
road map to emerging disc that amount of storage.
technologies. Blue-ray can store up to It’s very likely that the technology
54 GB, enough to hold about 4.5 will be adopted as the next
hours of high -definition video or generation optical disc format for PC
more than 20 hours of standard video. data storage and replace technologies
And there are even plans in the such as DVD+-R, DVD+-RW, and
1. Complete Guide to Digital Audio By—Chris Middleton.
2. The Digital Bits Insider Guide to DVD By—Bill Hunt
3. DVD Demystified By – Jim Taylor