07-03-2011, 04:12 PM
Presented by:
P.S.Bhima Raju
A.Ratna Sudheer
Blue-ray disc.doc (Size: 105.5 KB / Downloads: 63)
Blu-Ray Disc
ABSTRACT
Blu-ray, also known as Blu-ray Disc (BD) is the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of leading consumer electronics and PC companies (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. A single-layer Blu-ray Disc can hold 25GB, which can be used to record over 2 hours of HDTV or more than 13 hours of standard-definition TV. There are also dual-layer versions of the discs that can hold 50GB.
While current optical disc technologies such as DVD, DVD±R, DVD±RW, and DVD-RAM use a red laser to read and write data, the new format uses a blue-violet laser instead, hence the name Blu-ray. Despite the different type of lasers used, Blu-ray products can easily be made backwards compatible through the use of a BD/DVD/CD compatible optical pickup and allow playback of CDs and DVDs. The benefit of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it possible to focus the laser spot with even greater precision. This allows data to be packed more tightly and stored in less space, so it's possible to fit more data on the disc even though it's the same size as a CD/DVD. This together with the change of numerical aperture to 0.85 is what enables Blu-ray Discs to hold 25GB/50GB.
With the rapid growth of HDTV, the consumer demand for recording HD programming is quickly rising. Blu-ray was designed with this application in mind and supports direct recording of the MPEG-2 TS (Transport Stream) used by digital broadcasts, which makes it highly compatible with global standards for digital TV. This means that HDTV broadcasts can be recorded directly to the disc without any quality loss or extra processing. To handle the increased amount of data required for HD, Blu-ray employs a 36Mbps data transfer rate, which is more than enough to record and playback HDTV while maintaining the original picture quality. In addition, by fully utilizing an optical disc's random accessing features, it's possible to playback video on a disc while simultaneously recording HD video.
Introduction:
In 1997, a new technology emerged that brought digital sound and video into homes all over the world. It was called DVD, and it revolutionized the movie industry.
The industry is set for yet another revolution with the introduction of Blu-ray Discs (BD). With their high storage capacity, Blu-ray discs can hold and playback large quantities of high-definition video and audio, as well as photos, data and other digital content.
What is Blu-ray disc?
A current, single-sided, standard DVD can hold 4.7 GB (gigabytes) of information. That's about the size of an average two-hour, standard-definition movie with a few extra features. But a high-definition movie, which has a much clearer image , takes up about five times more bandwidth and therefore requires a disc with about five times more storage. As TV sets and movie studios make the move to high definition, consumers are going to need playback systems with a lot more storage capacity.
Blu-ray is the next-generation digital video disc. It can record, store and play back high-definition video and digital audio, as well as computer data. The advantage to Blu-ray is the sheer amount of information it can hold:
• A single-layer Blu-ray disc, which is roughly the same size as a DVD, can hold up to 27 GB of data -- that's more than two hours of high-definition video or about 13 hours of standard video.
• A double-layer Blu-ray disc can store up to 54 GB, enough to hold about 4.5 hours of high-definition video or more than 20 hours of standard video. And there are even plans in the works to develop a disc with twice that amount of storage.
Building a Blu-ray:
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.
The design of the Blu-ray discs saves on manufacturing costs. Traditional DVDs are built by injection molding the two 0.6-mm discs between which the recording layer is sandwiched. The process must be done very carefully to prevent birefringence.
1. The two discs are molded.
2. The recording layer is added to one of the discs.
3. The two discs are glued together.
Blu-ray discs only do the injection-molding process on a single 1.1-mm disc, which reduces cost. That savings balances out the cost of adding the protective layer, so the end price is no more than the price of a regular DVD.
Blu-ray has a higher data transfer rate -- 36 Mbps (megabits per second) -- than today's DVDs, which transfer at 10 Mbps. A Blu-ray disc can record 25 GB of material in just over an half an hour of time
How do Blu-ray formats work?
Discs store digitally encoded video and audio information in pits -- spiral grooves that run from the center of the disc to its edges. A laser reads the other side of these pits -- the bumps -- to play the movie or program that is stored on the DVD. The more data that is contained on a disc, the smaller and more closely packed the pits must be. The smaller the pits (and therefore the bumps), the more precise the reading laser must be.
Unlike current DVDs, which use a red laser to read and write data, both Blu-ray and HD-DVD use a blue laser. 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 smaller pits. Blu-ray discs and HD-DVDs can both read pits that are much smaller than the pits on a DVD. That's pretty much where the similarity ends.
The recording layer on Blu-ray and HD-DVD differs. Whereas the HD-DVD recording layer is sandwiched between two 0.6 mm layers of polycarbonate plastic -- much like the recording layer on today's DVD -- Blu-ray places the data on top of a 1.1-mm-thick polycarbonate layer. The smaller pits, smaller beam and closer recording layer 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 today's DVD and about twice that of an HD-DVD.
When will Blu-ray be available ?
Blu-ray recorders are already available in Japan, where more consumers have access to HDTV than in the United States. Outside of Japan, once more TV sets come equipped with a high-definition tuner, and more films and television shows are produced in high-definition (which is expected to happen by late 2005 or 2006), Blu-ray movies and TV shows on disc should become widely available; but the format is already available for home recording, professional recording and data storage. HD-DVD is expected to arrive in stores at the end of 2005.
Even when the new video standard begins to replace current technologies, consumers won't have to throw away their DVDs; but they may need to invest in a new player, depending upon which format they choose. HD-DVD will work on today's standard DVD players, while a straight Blu-ray will not. JVC has developed a Blu-ray hybrid disc that pairs a Blu-ray disc with a standard DVD -- this type of hybrid disc will survive the format transition. In any event, the Blu-ray coalition is planning to market backward-compatible drives with both blue and red lasers, which will be able to play traditional DVDs and CDs as well as Blu-ray discs.
What will each format mean for consumers? Blu-ray is billing itself as more high-tech, offering greater storage and capabilities, while HD-DVD is boasting lower costs and a less radical departure from the DVDs we already know and love. Comparing it to the old VHS-Betamax battle, HD-DVD looks more like VHS, and Blu-ray like Betamax. But at this point, industry insiders say the format war could go either way.
Ultimately, which format prevails will have a lot to do with its backers. HD-DVD has the DVD Forum behind it: a consortium of 230 consumer-electronics and entertainment companies, as well as movie studios New Line, Paramount, Universal and Warner Bros. Plus, Microsoft plans to support HD-DVD with its next Windows operating system, code-named Longhorn. Blu-ray has more than 10 of the top electronics companies behind it, plus the support of Columbia TriStar, Disney and MGM studios. Also, it has been rumored that the new PlayStation 3 game system will support Blu-ray.
P.S.Bhima Raju
A.Ratna Sudheer
Blue-ray disc.doc (Size: 105.5 KB / Downloads: 63)
Blu-Ray Disc
ABSTRACT
Blu-ray, also known as Blu-ray Disc (BD) is the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of leading consumer electronics and PC companies (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. A single-layer Blu-ray Disc can hold 25GB, which can be used to record over 2 hours of HDTV or more than 13 hours of standard-definition TV. There are also dual-layer versions of the discs that can hold 50GB.
While current optical disc technologies such as DVD, DVD±R, DVD±RW, and DVD-RAM use a red laser to read and write data, the new format uses a blue-violet laser instead, hence the name Blu-ray. Despite the different type of lasers used, Blu-ray products can easily be made backwards compatible through the use of a BD/DVD/CD compatible optical pickup and allow playback of CDs and DVDs. The benefit of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it possible to focus the laser spot with even greater precision. This allows data to be packed more tightly and stored in less space, so it's possible to fit more data on the disc even though it's the same size as a CD/DVD. This together with the change of numerical aperture to 0.85 is what enables Blu-ray Discs to hold 25GB/50GB.
With the rapid growth of HDTV, the consumer demand for recording HD programming is quickly rising. Blu-ray was designed with this application in mind and supports direct recording of the MPEG-2 TS (Transport Stream) used by digital broadcasts, which makes it highly compatible with global standards for digital TV. This means that HDTV broadcasts can be recorded directly to the disc without any quality loss or extra processing. To handle the increased amount of data required for HD, Blu-ray employs a 36Mbps data transfer rate, which is more than enough to record and playback HDTV while maintaining the original picture quality. In addition, by fully utilizing an optical disc's random accessing features, it's possible to playback video on a disc while simultaneously recording HD video.
Introduction:
In 1997, a new technology emerged that brought digital sound and video into homes all over the world. It was called DVD, and it revolutionized the movie industry.
The industry is set for yet another revolution with the introduction of Blu-ray Discs (BD). With their high storage capacity, Blu-ray discs can hold and playback large quantities of high-definition video and audio, as well as photos, data and other digital content.
What is Blu-ray disc?
A current, single-sided, standard DVD can hold 4.7 GB (gigabytes) of information. That's about the size of an average two-hour, standard-definition movie with a few extra features. But a high-definition movie, which has a much clearer image , takes up about five times more bandwidth and therefore requires a disc with about five times more storage. As TV sets and movie studios make the move to high definition, consumers are going to need playback systems with a lot more storage capacity.
Blu-ray is the next-generation digital video disc. It can record, store and play back high-definition video and digital audio, as well as computer data. The advantage to Blu-ray is the sheer amount of information it can hold:
• A single-layer Blu-ray disc, which is roughly the same size as a DVD, can hold up to 27 GB of data -- that's more than two hours of high-definition video or about 13 hours of standard video.
• A double-layer Blu-ray disc can store up to 54 GB, enough to hold about 4.5 hours of high-definition video or more than 20 hours of standard video. And there are even plans in the works to develop a disc with twice that amount of storage.
Building a Blu-ray:
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.
The design of the Blu-ray discs saves on manufacturing costs. Traditional DVDs are built by injection molding the two 0.6-mm discs between which the recording layer is sandwiched. The process must be done very carefully to prevent birefringence.
1. The two discs are molded.
2. The recording layer is added to one of the discs.
3. The two discs are glued together.
Blu-ray discs only do the injection-molding process on a single 1.1-mm disc, which reduces cost. That savings balances out the cost of adding the protective layer, so the end price is no more than the price of a regular DVD.
Blu-ray has a higher data transfer rate -- 36 Mbps (megabits per second) -- than today's DVDs, which transfer at 10 Mbps. A Blu-ray disc can record 25 GB of material in just over an half an hour of time
How do Blu-ray formats work?
Discs store digitally encoded video and audio information in pits -- spiral grooves that run from the center of the disc to its edges. A laser reads the other side of these pits -- the bumps -- to play the movie or program that is stored on the DVD. The more data that is contained on a disc, the smaller and more closely packed the pits must be. The smaller the pits (and therefore the bumps), the more precise the reading laser must be.
Unlike current DVDs, which use a red laser to read and write data, both Blu-ray and HD-DVD use a blue laser. 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 smaller pits. Blu-ray discs and HD-DVDs can both read pits that are much smaller than the pits on a DVD. That's pretty much where the similarity ends.
The recording layer on Blu-ray and HD-DVD differs. Whereas the HD-DVD recording layer is sandwiched between two 0.6 mm layers of polycarbonate plastic -- much like the recording layer on today's DVD -- Blu-ray places the data on top of a 1.1-mm-thick polycarbonate layer. The smaller pits, smaller beam and closer recording layer 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 today's DVD and about twice that of an HD-DVD.
When will Blu-ray be available ?
Blu-ray recorders are already available in Japan, where more consumers have access to HDTV than in the United States. Outside of Japan, once more TV sets come equipped with a high-definition tuner, and more films and television shows are produced in high-definition (which is expected to happen by late 2005 or 2006), Blu-ray movies and TV shows on disc should become widely available; but the format is already available for home recording, professional recording and data storage. HD-DVD is expected to arrive in stores at the end of 2005.
Even when the new video standard begins to replace current technologies, consumers won't have to throw away their DVDs; but they may need to invest in a new player, depending upon which format they choose. HD-DVD will work on today's standard DVD players, while a straight Blu-ray will not. JVC has developed a Blu-ray hybrid disc that pairs a Blu-ray disc with a standard DVD -- this type of hybrid disc will survive the format transition. In any event, the Blu-ray coalition is planning to market backward-compatible drives with both blue and red lasers, which will be able to play traditional DVDs and CDs as well as Blu-ray discs.
What will each format mean for consumers? Blu-ray is billing itself as more high-tech, offering greater storage and capabilities, while HD-DVD is boasting lower costs and a less radical departure from the DVDs we already know and love. Comparing it to the old VHS-Betamax battle, HD-DVD looks more like VHS, and Blu-ray like Betamax. But at this point, industry insiders say the format war could go either way.
Ultimately, which format prevails will have a lot to do with its backers. HD-DVD has the DVD Forum behind it: a consortium of 230 consumer-electronics and entertainment companies, as well as movie studios New Line, Paramount, Universal and Warner Bros. Plus, Microsoft plans to support HD-DVD with its next Windows operating system, code-named Longhorn. Blu-ray has more than 10 of the top electronics companies behind it, plus the support of Columbia TriStar, Disney and MGM studios. Also, it has been rumored that the new PlayStation 3 game system will support Blu-ray.