Blu-ray Disc
1. Introduction
Blu-ray is a new optical disc standard based on the use
of a blue laser rather than the red laser of today’s DVD players. The standard,
developed collaboratively by
The new standard, developed jointly in order to avoid competing
standards, is also being touted as the replacement for writable DVDs The blue
laser has a 405 nanometer (nm) wavelength that can focus more tightly than the
red lasers used for writable DVD and as a consequence, write much more data in
the same 12 centimeter space Like the rewritable DVD formats, Blu-ray uses
phase change technology to enable repeated writing to the disc.
Blu-ray’s storage capacity is enough to store a
continuous backup copy of most people’s hard drives on a single disc. The first
products will have a 27 gigabyte (GB) single-sided capacity, 50 GB on
dual-layer discs. Data streams at 36 megabytes per second (Mbps), fast enough
for high quality video recording Single-sided Blu-ray discs can store up to 13
hours of standard video data, compared to single-sided DVD’s 133 minutes.
People are referring to Blu-ray as the next generation DVD, although according
to Chris Buma, a spokesman from Philips (quoted in New Scientist) “Except for
the size of the disc, everything is different.”
Blu-ray discs will not play on current CD and DVD
players, because they lack the blue-violet laser required to read them. If the
appropriate lasers are included, Blu-ray players will be able to play the other
two formats. However, because it would be considerably more expensive, most
manufacturers may not make their players backward compatible. Panasonic,
Philips, and Sony have demonstrated prototypes of the new systems.
2. Evolution of
Optical Removable Media Storage Devices
2.1 Optical Storage
Optical RMSD formats use a laser light source to read
and/or write digital data to a disc. Compact disc (CD) and digital versatile
disc (DVD, originally referred to as digital video disc) are the two major
optical formats. CDs and DVDs have similar compositions consisting of a label,
a protective layer, a reflective layer (aluminum, silver, or gold), a
digital-data layer molded in polycarbonate, and a thick polycarbonate bottom
layer.
Fig.2.l.1 Composition of optical disk
CD Formats include
·
Compact disc-read
only memory (CD-ROM)
·
Compact
disc-recordable (CD-R)
·
Compact disc-rewritable (CD-RW)
DVD formats include
·
Digital versatile
disc-read only memory (DVD-ROM)
·
Digital versatile disc-recordable (DVD-R)
·
DVD-RAM
(rewritable)
·
Digital versatile
disc-rewritable (DVD-RW)
2.1.1 CD-ROM
Data bits are permanently stored on
a CD as a spiral track of physically molded pits in the surface of a plastic
data layer that is coated with reflective aluminum. Smooth areas surrounding
pits are called lands. CDs are extremely durable because the optical pickup
(laser light source, lenses and optical elements, photoelectric sensors, and
amplifiers) never touches the disc. Because data is read through the thick
bottom layer, most scratches and dust on the d surface are out of focus, so they
do not interfere with the reading process.
With a 650-MB storage capacity
(sometimes expressed as ‘74 minutes,’ referring to audio playing time encoded
in the original CD format), one CD-ROM disc can store the data from more than
450 floppy disks. Data access speeds are reasonable, with random access rates
ranging from 80 to 120 ms for any data byte on the disc. Maximum data transfer
rates are approximately 6 MB/sec. These attributes make CD-ROMs especially well
suited for storing large multimedia presentations and software programs.
CD-ROM drives are distinguished by
different disc rotation speeds measured relative to the speed of an audio CD
player. A 1X CD-ROM accesses data at approximately 150 KB/sec, the same as an
audio player. A 32 X CD-ROM reads data thirty-two times faster at approximately
4,800 KB/sec. In general, faster speeds reduce data access time, but vibration
and noise problems limit maximum speeds to approximately 48X.
2.1.2 CD-R.
CD-R drives advanced a write
once/read many (WORM) storage technologies that appeared in the mid 1980s. CD-R
drive production ended when the cost to manufacture CD-RW drives became
comparable. CD-R discs accept multiple writing sessions to different sections
of a disc. However, CD-ROM drives must be multi-session compatible to read any
data recorded after the first writing session; all of today’s CD-ROM drives
meet this requirement.
CD-R discs use a photosensitive dye
layer that can be changed (or ‘bounded’) with a laser to simulate the molded
pits of a conventional CD. The dye layer is relatively transparent until it is
burned with a laser to make it darker and less reflective. CD-R discs use a
gold or silver reflective layer behind the dye to produce reflectives similar
to the aluminum layer used in CDs.
When a CD-R disc is read, the lands
reflect laser light off of the gold or silver layer through the more
transparent areas of the dye. The less reflective areas, produced from
recording data on the dye, read as pits.
Like CD-Rom discs, recordable discs have
650 MB (or 74 minutes) of storage capacity. The actual capacity of a 650-MB
CD-R disc is about 550 MB when they are formatted for packet writing.
Higher-capacity CD-Rs that have become available recently include:
• 700 MB (80 minutes)
• 800 MB (90 minutes)
• 880 MB (99 minutes)
The 700MB disc is the only
higher-capacity option that is fully compatible with the CD-R standard CD-R
drives provide reasonable average data access times typically less than 100 ms.
CD-R discs are the least expensive RMSD media available, but the CD-R systems
are limited as RMSD’s because they can only be written once.
2:1.3 CD-RW
CD-RW drives introduced in 1997,
record data on both CD-R and CD-RW discs. CD-R.W discs use a phase-change
technology to record. In place of the dye layer use din CD-R media, CD-RW discs
have an alloy layer composed of antimony, tellurium, and other metals that
exists in either of two stable states. This material forms a polycrystalline
structure when heated above 200 degree Celsius and cooled, but also forms an
amorphous or non-crystalline structure when heated above the melting point at
500 to 700 degrees Celsius and rapidly cooled. The alloy is changed between the
two states using two different laser power settings.
The crystalline state for this
material reflects more light than the non-crystalline form, so it simulates the
lands of a regular CD. Data bits are encoded by changing small target areas to
the non-crystalline form. This writing process can be repeated approximately
1,000 times per disc.
CD-RW drives write to both CD-R and
CD-RW media, and permit multiple writing sessions to different sections of a
disc. CD-RW drives are specified by CD-R write speed, CD-RW write speed, and
CD-ROM maximum read speed (for example, 8/4/32Xis 8X CD-R write/4X CD-RW
write/32X CD-ROM maximum read). The fastest CD-RW drives now provide
Like the CD-R discs, the actual
capacity of a 650-MB CD-RW disc is about 550 MB when formatted for packet
writing. CD-RW drives have replaced the comparably priced CD-R drives, and are
positioned to be a good RMSD solution.
2.1.4 DVD
Like CD drives, DVD drives read data
through the disc substrate, reducing interferences from surface dust and
scratches. However, DVD-ROM technology provides seven times the storage
capacity of CD discs, and accomplishes most of this increase by advancing the
technology used for CD systems. The distance between recording tracks is less
than half that used for CDs. The pit size also is less than half that on CDs,
which requires a reduced laser wavelength to read the smaller-sized pits. These
features alone give DVD-ROM discs 4.5 times the storage capacity of CDs;
2.1.4.1 Single Layers and Dual Layers
DVD discs have a much greater data
density than CD discs, and DVD-ROM drives rotate the disc faster than CD
drives. This combination results in considerably higher throughput for DVD
technology. A 1X DVD-ROM drive has a data transfer rate of 1,250 KB/sec
compared with a 150-KB/sec data transfer rate for a 1X CD-ROM drive. Current
DVD-Rom drives can read DVD discs at 16X (22 MB/sec) maximum speeds and can
read CDs at 48X (7.5 MB/sec) maximum speeds.
DVD-ROM discs provide a 4.7-GB
storage capacity for single-sided, single data-layer discs. Single-sided,
double data-layer discs increase the capacity to 8.5 GB. Double-sided, single
data layer discs offer 9.4 GB, and double-sided, double data-link layer discs
provide 17 GB of storage capacity. DVD-ROM drives also read CD-ROM, CD-R,
CD-RW, and DVD-R discs. As new software programs push the storage limits for
CD-ROM discs.
21.4.2 DVD Storage Versions
2.1.4.2.1 DVD-R
DVD-R drives were introduced in 1997
to provide write-once capability on DVD-R discs used or producing disc masters
in software development and for multimedia post-production. This technology
sometimes referred to as DVD-R for authoring, is limited to niche applications
because drives and media are expensive.
DVD-R employs a photosensitive dye
technology similar to CD-R media. At 3.94 GB per side, the first DVD-R discs
provided a little less storage capacity than DVD-ROM discs. That capacity as
now been extended to the 4.7 GB capacity of DVD-ROM discs.
The IX DVD-R data transfer rate is
1.3MB/sec. Most DVD-ROM drives and DVD video players read DVD-R discs. Slightly
modified DVD-R drives and discs have recently become available for general use.
2.1.4.2.2 DVD-RAM
DVD-Ram (rewritable) drives were
introduced in 1998. DVD-Ram devices use a phase-change technology combined with
some embossed land/pit features. Employing a format termed ‘land groove,’ data
is recorded in the grooves formed on the disc and on the lands between the
grooves. The initial disc capacity was 2.6 GB per side, but a 4.7-GB-per-side
version is now available.
Each DVD-RAM disc is reported to
handle more than 100,000 rewrites. DVD is specifically designed for PC data
storage; DVD-RAM discs use, a storage structure based on sectors, instead of
the spiral groove structure used for CD data storage. This sector storage is
similar to the storage structure used by hard drives. Sector storage results in
faster random data access speed.
Because of their high cost relative
to CD-RW technology, current consumer-oriented DVD RAM drives and media is not
a popular choice for PC applications. Slow adoption of DVD-Ram reading
capability in DVD-ROM drives has also limited DVD-RAM market acceptance.
2.1.4.2.3 DVD-RW
The DVD-RW drive format is similar
to the DVD-R format, but offers rewritability using a phase-change recording
layer that is comparable to the, phase-change layer used for CD-RW. DVD-RW is
intended for consumer video (non-PC) use, but PC applications are also expected
for this technology. The first DVD-RW drives bases on this format, which also
record DVD-R discs, were introduced in early 2001.
2.2 DVD vs. CD
DVD has a more efficient error
correction code (ECC). Fewer data bits are required for error detection, thus
freeing space for recorded data. DVD discs can also store two layers of data on
a side by using a second data layer behind a semitransparent first data layer
laser to switch between the two data layers.
DVD drives can also store data on
both sides of the disc. Manufacturers deliver the two-sided structure by
bonding two thinner substrates together, providing the potential to double a
DVD’s storage capacity. Single-sided DVD disc have the two fused substrates,
but only one side contains data.
CD-RW and DVD-ROM combination
A combination CD-RW/DVD-R0M device,
commonly called a ‘Combo’ drive, has been available since 1999. Combo drives
need a high-power laser for CD-R/CD-RW writing, and a different laser and
decoding electronics for reading DVDs. A Combo drive provides additional
functionality for PCs, and is especially valuable for space-constrained
portable systems.
Comparison table
|
|
Floppy
disk |
Compact
disc (CD) |
Digital
Video Disc (DVD) |
Blu-ray disc |
|
Capacity |
1.44MB |
650-880MB |
4.7-20GB |
23.3-50GB |
|
Transfer
Rate |
0.06
MB/s |
3.5
MB/s |
22.6MB/s |
36MB/s |
|
Interface |
IDE |
IDE/SCSI-2 |
IDE/SCSI-2 |
IDE/SCSI-2 |
3. Blu-ray Disc
Key Characteristics
3.1 Large recording capacity
up to 27GB
By adopting a 405nm blue-violet
semiconductor laser, with a 0.85NA field lens and a 0.1 mm. optical
transmittance protection disc layer structure, it can record up to 27GB video
data on a single sided 12cm phase change disc. It can record over 2 hours of
digital high definition video and more than 13 hours of standard TV
broadcasting (VHS/standard definition picture quality, 3.8Mbps)
3.2 High-speed data transfer
rate 36Mbps
It is possible for the Blu-ray Disc
to record digital high definition broadcasts or high definition images from a
digital video camera while maintaining the original picture quality. In
addition, by fully utilizing an optical disc’s random accessing functions, it
is possible to easily edit video data captured on a video camera or play back
pre-recorded video on the disc while simultaneously recording images being
broadcast on TV.
3.3 Easy to use disc
cartridge
An easy to use optical disc
cartridge protects the optical disc’s recording and playback phase from dust
and fingerprints.
3.4 Main Specifications
Recording capacity 23.3GB/25GB/27GB
Laser wavelength 405
nm, (blue-violet laser)
Lens numerical aperture (NA) 0.85
Data transfer rate 36Mbps
Disc diameter 120mm
Disc thickness 1.2mm
Recording format Phase
change recording
Tracking format Groove
recording
Tracking pitch 0.32um
Shortest pit length 0.160/0.149/0.l38um
Recording phase density 16.8/18.0/1 9.5Gbit/inch2
Video recording format MPEG2 video
Audio recording format AC3, MPEG1, Layer2, etc.
Video and audio multiplexing format MPEG2 transport stream
Cartridge dimension approximately
129 x 131 x 7mm
4. Blue Laser
A blue laser is a laser (pronounced
LAY-zer) with a shorter wavelength than the red laser used in today’s compact
disc and laser printer technologies and the ability to store and read two to
four times the amount of data. When available in the marketplace, personal
computer users may be able to buy a laser printer with a resolution up to 2400
pixels or dots per inch at an affordable price. The same technology in CD and
DVD players will provide a dramatic breakthrough in storage capability without
an increase in device size.
A laser (an acronym for “light
amplification by stimulated emission of radiation”) is a coherent (meaning all
one wavelength, unlike ordinary light which shower on us in many wavelengths)
and focused beam of photons or particles of light. The photo are produced as
the result of a chemical reaction between special materials and then focused
into a concentrated beam in a tube containing reflective mirrors. In the blue
laser technology, the special material is gallium nitride. Even a small
shortening of wavelength of light can have a dramatic effect in the ability to
store and access data. A shorter wavelength allows a single item of data (0 or
1) to be stored in a smaller space.
Red lasers used in today’s technologies
have wavelengths of over 630 nanometers (or 630 billionths of a meter). The
blue laser has a wavelength of 505 nanometers.
Shuji Nakamura, a Japanese
researcher working in a small chemical company, Nichia chemical Industries,
built the first blue laser diode. However, a number of companies have announced
progress in the ability to manufacture blue laser diodes and there are now
prototypes of working DVD writers and players. Recently, a standard called
Blu-ray has been developed for the manufacture of blue laser optical disc
technology.
4.1 Blue —Violet Laser
SANYO has developed the world’s
first blue-violet laser diode with a new low-noise (stable) beam structure
produced using ion implantation. The stable beam structure boasts lower noise,
and current consumption achieving higher performance compared with conventional
blue- violet laser diodes. This structure makes SANYO’s blue-violet laser diode
an optimum light source for large-capacity optical disc systems like Blu ray
disks.
Main Features
·
SANYO’s original
ion implantation technology has yielded the world’s first blue- violet laser
diode with a new stable beam structure that generates a low-noise beam
·
The stable beam
structure produces a vastly improved stable laser beam, which yields the low-noise,
low-operating current characteristics that are required in a light source for
next-generation large-capacity optical disc systems like advanced DVDs require
·
The laser diode
is easily mass produced because the stable beam structure reduces the number of
fabrication steps while the top and bottom electrodes structure reduces chip
size
Development Background
Laser diodes are key components in
the field of optical data processing devices. SANYO’s aggressive efforts in
this area led to the mass production and sales of AlGaAs
(aluminum-gallium-arsenide) infrared and AlGaInP
(aluminum-gallium-indium-phosphide) red laser diodes widely used in measuring
instruments and a variety of optical data processing devices like CD and DVD
optical disc systems.
In recent years, the field of
optical disc systems has seen the development of next- generation
large-capacity optical disc systems like advanced DVDs that can record more
than two hours of digital high-definition images. The blue-violet laser diode
made of InGaN (indium gallium-nitride) that is used as a light source for
reading signals recorded on the optical discs was the key to developing these
systems. Naturally demand for the laser diode is expected to rise sharply as
more large-capacity optical disc systems become available and become more
widely used.
In order to realize a blue-violet
laser diode SANYO has developed original crystal and device fabrication
technologies over the years. Now these fundamental technologies have yielded
the world’s first low-noise beam, blue-violet laser diode with a new stable
beam structure that lowered noise and current consumption for higher
performance. This development can make large-capacity optical disc systems like
advanced DVDs practical.
Features of the new technology
·
The new stable
beam structure made by ion implantation significantly improves laser beam
stability and yields the low-noise, low-operating current characteristics that
the optical disc system requires.
·
The laser diode
is easily mass-produced because the newly developed stable beam structure
reduces the number of fabrication steps while the top and bottom electrodes
structure reduces chip size.
Other Features
·
Fundamental
traverse mode
The fundamental traverse mode generates a single
stable beam which means the beam can be focused into a tiny spot using a simple
optical system.
·
Package
The package is compact at just 5.6 mm in
diameter.
·
Advanced DVDs as
well as for Polarity
A positive (+) or negative (-) power supply can be
selected
·
Built-in photodiode
for monitoring optical output
A photodiode is installed to monitor optical output
·
Applications
The new laser diode is suitable for the
next-generation large-capacity optical disc systems like and many types of
measuring instruments.
Terminology
·
Blue-violet laser
diode
This is the light source used to read signals (pits)
on discs in next-generation large-capacity optical disc systems. There is no
way the size of beams from the infrared and red laser diodes now used in CDs
and DVDs can be reduced to the size of a pit recorded on these, discs in c
optical systems. The shorter wavelength of the blue-violet laser diode however
allows the beam to be focused into a reduced spot, and therefore is the key to
next-generation large-capacity optical disc systems.
·
Stable beam
structure
The newly developed stable beam structure was produced
using ion implantation. With mode c9ntrol ‘of the laser beam and current
confinement, the implanted layer significantly improves laser beam stability
and yields the low-noise, low-operating current characteristics that an optical
disc system requires
·
Ion implantation
This technology uses a strong electric field to force
ionized atoms into a semiconductor. It is mainly used in Si LSI production for
doping impurities in semiconductors. The amount and depth of the atoms
implanted into the semiconductor can be precisely ‘controlled with consistent
reproducibility
·
Fundamental
traverse mode
This refers to a mode where distribution of light
intensity in a laser beam forms a single peak.
5. construction
5.1 structure a Blu-ray disc
Fig.5. 1.1 structure of Blu-ray disc
The
Blu-Ray format uses a blue laser to read data off the surface of the disc and
it has a capacity of 25 Gigabytes on a single layer. The structure
comprises of a single 1.1mm thick substrate layer and a 0.1mm thick cover
layer, with the pits (or also know as the data layer) residing in between the
two layers.
5.2 Bulding blu-ray disc
Unlike the DVDs ,which use a red
laser to read and write the data, Blu-ray uses a blue laser(which is where the format gets it name).A blue laser
has a shorter wavelength (405nm)than a red laser(650nm).The smaller beam focus
more precisely, enabling it to read information recorded in pits that are only
0.15µm(1 micron =10.6meters) long this is more than twice as small as the pits
on DVD’s plus Blu-ray has reduced the
track pitch from 0.74 microns to 0.32microns.The smaller pits ,smaller beam and
shorter track pitch together enable a single layer Blu-ray disc to hold more the 25GB of information –
about five times the amount of
information that can be stored on DVD.
Each Blu-ray disc is about the same
thickness (1.2µm) as DVD. But the two types of discs store the data
differently. In DVD, the data is sandwiched between two type’s polycarbonate
layers, each 0.6-mm thick. Having a polycarbonate layer on the top of the data
can cause a problem called Birefringence, in which the substrate layer refracts
the laser light in two separate beams. If the beam is split too widely, the
disc cannot be read. Also if the DVD surface is not exactly the flat, and is
therefore not exactly perpendicular to the beam, it can lead to problem known
as disc tilt, in which the laser beam is distorted .All of these issues lead to
a very involved manufacturing process.
The design of the blu-ray disc saves
on manufacturing costs. Traditional DVDs are built by injection modeling the
two 0.6mm discs between which the recording layer is sandwiched .The process
must be done very carefully to prevent birefringence.
The two discs are molded. The
recording layer is added to one of the discs .The two discs are glued together.
Blu ray discs only do the injecting-molding process on a single 1.1mm disc,
which reduces the cost .That saves the cost of adding the protective layer, so
the end price is no more than regular DVD.
Blu-ray is also has a higher data transfer rate – 36Mbps(mega
bits per seconds)—than today DVDs ,which transfer at 10Mbps.A blu-ray disc can
record 25Gb of material in just over an hour and a half.
5.3 How Blu-ray stores more
Data
A blue laser has a shorter wavelength (405
nanometers) than a red laser (650 nanometers). The smaller beam focuses
more precisely, enabling it to read information recorded in pits that are only 0.15 microns (µm) (1 micron = 10-6
meters) long -- this is more than twice as small as the pits on a DVD. Plus,
Blu-ray has and shorter pit and reduced the track pitch from 0.74 microns to 0.32 microns. The smaller pits, smaller beam track pitch together
enable a single-layer Blu-ray disc to hold more than 25 GB of information --
about five times the amount of information that can be stored on a DVD.
5.4 How Blu-ray reads data
The Blu-ray disc overcomes DVD-reading issues by placing
the data on top of a 1.1-mm-thick polycarbonate layer. Having the data
on top prevents birefringence and therefore prevents readability problems. And,
with the recording layer sitting closer to the objective lens of the
reading mechanism, the problem of disc tilt is virtually eliminated. Because
the data is closer to the surface, a hard coating is placed on the outside of
the disc to protect it from scratches and fingerprints.
5.5 Hard coating technology
Fig:-hard coating
Because the Blu-ray standard places data so close to the
surface of the disc, early discs were susceptible to dust and scratches and had
to be enclosed in plastic caddies for protection. Such an inconvenience, the
consortium worried, would retard Blu-ray's adoption in the face of the rival HD
DVD standard; HD DVDs place data further away like DVDs. CDs use a single layer
of lacquer over the reflective data backing (on the label side) and are more susceptible
to damage on the label side than DVDs, HD DVDs, or Blu-ray Discs.
A solution was announced in January 2004 with the
introduction of a clear polymer coating that gives Blu-ray Discs unprecedented
scratch resistance. The coating was developed by TDK Corporation and is called
"Durabis". It allows BDs to be cleaned safely with only a tissue. The
coating is said to successfully resist "wire-wool scrubbing"
according to Samsung Optical technical manager Chas Kalsi. HD DVDs are more
similar to current CDs and DVDs in this respect, as they can be manufactured
using essentially the same processes and do not require such a surface layer.
6. Applications
6.1 Ultra Density Optical
(UDO)
UDO is the next generation of 5.25”
professional optical storage technology. It is a convergent technology that
delivers the performance of 5.25” MO, the longevity 12-inch WORM, and the cost
effectiveness of DVD. It utilizes violet laser and phase change media recording
technology to provide a quantum leap in data storage densities. First
generation UDO products will be 30GB capacity and are scheduled to ship in
August 2003. Future generations will increase capacity to 60GB and 120GB and
will provide full backward read compatibility. Both WORM and rewritable media will
be available and the cartridge’ will be physically identical to 5.25” MO to
maintain library compatibility. Target markets include archiving, document
imaging, call centers, and e-mail archiving, GIS, medical, telecom, banking,
insurance, legal and government.
UDO is the application of Blu-ray
consumer recording technology to the professional optical storage market.
Blu-ray is the proposed successor to DVD and uses phase change recording
technology to provide the storage capacity to record a’ full-length HDTV video.
The use of violet lasers and high NA optics dramatically increases data storage
densities and necessitates a new type of disk construction with a 0.1mm cover
layer to protect the data surface. As with existing MO technology, UDO uses non
contact recording to provide robust and reliable performance.
6.2 Digital Video Recording
The Blu-ray Disc using ‘blue-violet
laser achieves over 2-hour digital high definition video recording on a 12cm
diameter CD/DVD size phase change optical disc.
The Blu-ray Disc enables the
recording, rewriting and play back of up to 27 gigabytes (GB) of data on a
single sided single layer 12cm CD/DVI) size disc using a 405nm blue-violet
laser. By employing a short wavelength blue violet laser, the Blu Disc
successfully minimizes its beam spot size by making’ the numerical aperture
(NA) on a field lens that converges the laser 0.85. In addition, by using a
disc structure with a 0.1mm optical transmittance protection layer, the Blu-ray
Disc diminishes aberration caused by disc tilt. This also allows for disc
better readout and an increased recording density. The Blu-ray Disc’s tracking
pitch is reduced to 0.32um, almost half of that of a regular DVD, achieving up
to 27 GB high-density recording on a single sided disc.
Because the Blu-ray Disc utilizes
global standard “MPEG-2 Transport. Stream” compression technology highly
compatible with digital broadcasting for video recording, a wide range of
content can be rec9rded. It is possible for the Blu-ray Disc to record digital
high definition broadcasting while maintaining high quality and other data
simultaneously with video data if they are received together. In addition, the
adoption of a unique ID written on a Blu-ray Disc realizes high quality
copyright protection functions.
The Blu-ray Disc is a technology
platform that can store sound and video while maintaining high quality and also
access the stored content in an easy-to-use way. This will be important in the
coming broadband. Era as content distribution becomes increasingly diversified.
The nine companies involved in, the announcement will respectively develop
products that take full advantage of Blu-ray Disc’s large capacity and
high-speed data transfer rate. They are also aiming to further enhance the
appeal of the new format through developing a larger capacity, such as over
30GB on a single sided single layer disc and over 50GB on a single sided double
layer disc. Adoption of the Blu-ray Disc in a variety of applications including
PC data storage and high definition video software is being considered
7. Future Development
·
Large capacity: -
sided double layer for 50 (113 by using t multilayer technology.
·
High Speed
Transfer Rate:-To realize higher recording performance
·
Media family:-
ROM,R( Write Once)
·
Application: -
Adoption in a variety of applications including PC data storage and high
definition video software.
8. Conclusion
8.1 The Blu-ray Impact
Blu-ray is expected to challenge
DVD’s run as the fastest selling consumer-electronics item in history. If that
happens, the impact would be too big for the major players to discount. For
example, the number of films sold on DVD more than doubled last year to over 37
million. In addition, almost 2.4. Million DVD players were bought in the past
year. As Blu-ray is not compatible with DVD, its success could upset the
applecart of many players. If the new format turns out to be much popular, the
demand for DVD players could come down drastically. Not withstanding the
challenge to DVD makers, the new format is seen as a big step in the quest for
systems offering higher data storage. It is expected to open up new
opportunities for broadcasting industry. Recording of high-definition
television video-an application in which more than 10GB of storage space is
filled up with just one hour of video-will get a major boost. Conversely, the
format could take advantage of the spread of high-definition television. As
Blu-ray Disc uses MPEG-2 Transport Stream compression technology, recording for
digital broadcasting would become easier its adoption will grow in the
broadband era as it offers a technology platform to manage stored content. But
the real action will begin when the companies involved develop products that
take full advantage of Blu-ray Disc’s large capacity and high-speed data
transfer rate. As that happens, Blu-ray will move beyond being a recording tool
to a variety of applications. Adoption of Blu-ray Disc in PC data storage is
already being considered.
8.2 Not Beaming As Yet
However, it will be many years
before the Blue-ray finds such high-demand applications. Blu-ray compatible
systems arc likely to hi the market only in 2003. The nine companies involved
have just begun work on the hardware. Licensing for technology to play the
discs will start within the next few months. Cost will also play a crucial role
in the development of commercial systems. A sample blue-laser diode currently
costs .around $1,000, making consumer products based on it unrealistic. I
however, the price of a blue-laser diode is expected to tumble once Nichia
Corp—the major source for blue lasers—begins commercial production. The biggest
question that is plaguing the industry is whether current DVD discs will be
compatible with the new machines. Wary of alienating DVD fins, the companies
are looking for ways to make the new products compatible with DVDs.
8.3 A Uniform Picture
Buoyed by the expected price fall,
many electronics companies’ began to work on blue-laser based development
systems in the last few months and Blu-ray is a direct outcome of these
efforts. The similarity of the work being done prompted the companies to look
for a standard format that would wipe out the differences between those made by
individual companies. The companies had learnt the need for a standard format
the hard way a la DVDs.
8.4 The Jarring Image
However, it appears that not
everyone has learnt from the DVD episode. As Blu-ray moves towards
commercialization, it could ignite a new format battle Among the Blu-ray group
are six of the 10 companies that worked, on developing the DVD format. Four of
DVD’s main backers-Mitsubishi, AOL Time Warner, Victor of Japan and Toshiba
Corp-- are staying away from the Blu-ray consortium. Toshiba’s absence is the
most conspicuous. The company has publicly stated that it intends to propose
its prototype blue-laser optical-disc format. Consequently, its absence raises
the possibility that a format battle may be about to begin again. Lending
credence to this theory is the fact that the nine companies, which are also on
the steering committee of the DVD Forum, are conducting the Blu-ray work
outside of the Forum Much like the DVD story; the battle isn’t going to end
soon. But a compromise formula can be worked out Already, there is evidence of
concessions to get major players around a single format The Blu-ray group’s
announcement’ that discs are expected to be available in three different sizes,
is one such example. Some companies want to keep the price of discs low by
using cheaper materials that will be able to hold slightly less data
8.5 Future Perfect
Despite the impending tug-of war,
the industry is excited, about the future prospects, of this technological
innovation the industry is of the view that Blu-may has the potential to
replicate, if not better, the DVD success story. The expected upswing in
high-definition television adoption and broadband implementation could act as
the catalyst. Aware that the recession in economies across the globe could come
in the way of high-definition television broadband penetration, major players
are exploring the ways in making Blu-ray compatible with DVDs. Cost can dampen
the sales in the first year. Owing to the patent and the technology involved,
Blu-ray is likely to cost more than DVDs. But sooner than later, it will move
towards commodity pricing. Once that happens, Blu-ray holds the promise to
steal a march over its immediate predecessor.
9. Bibliography
World Wide Web
·
www.whatis.com
·
www.bluraytalk.com
·
www.computerworld.com
·
www.dvdeurope2002.com
·
www.bluray.org
·
www.seminarsonly.com
Documents
·
A History Of the
Phase Change Technology Stanford Ovshinsky, president of Energy Conversion
Devices
·
Removable Media
Storage Devices Tom Pratt and Chris Steenbergen, Storage Technology
ABSTRACT
Blu-ray,
also known as Blu-ray Disc (BD) is the name of a next-generation optical disc
video recording format jointly developed by nine leading consumer electronics
companies. The format was developed to enable recording, rewriting and playback
of high-definition video (HDTV). Blu-ray makes it possible to record over 2
hours of digital high-definition video (HDTV) or more than 13 hours of
standard-definition video (SDTV/VHS picture quality) on a 27GB disc. There are
also plans for higher capacity discs that are expected to hold up to 50GB of
data.
The Blu-ray Disc technology can
store sound and video while maintaining high quality and also access the stored
content in an easy-to-use way. Adoption of the Blu-ray Disc in a variety of
applications including PC data storage and high definition video software is
being considered.
Key Characteristics of Blu-ray discs are:
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