Tuesday, February 23, 2010

Blu-Ray Technology (Not Blue Ray)

Blu-ray Disc (also known as BD or Blu-Ray) is an optical disc storage medium designed to supersede the standard DVD format.

While current optical disc technologies such as DVD, DVD±R, DVD±RW, and DVD-RAM rely on 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 with CDs and DVDs through the use of a BD/DVD/CD compatible optical pickup unit. 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. Recent development by Pioneer has pushed the storage capacity to 500GB on a single disc by using 20 layers.

Blu-ray is currently supported by about 200 of the world's leading consumer electronics, personal computer, recording media, video game and music companies. The format also has support from all Hollywood studios and countless smaller studios as a successor to today's DVD format. Many studios have also announced that they will begin releasing new feature films on Blu-ray Disc day-and-date with DVD, as well as a continuous slate of catalog titles every month. For more information about Blu-ray movies, check out our Blu-ray movies and Blu-ray reviews section which offers information about new and upcoming Blu-ray releases, as well as what movies are currently available in the Blu-ray format.


Its main uses are for storing high-definition video, PlayStation 3 video games, and other data, with up to 25 GB per single layered, and 50 GB per dual layered disc. Although these numbers represent the standard storage for Blu-Ray drives, the specification is open-ended, with the upper theoretical storage limit left unclear. 200 GB discs are available, and 100 GB discs are readable without extra equipment or modified firmware.[3] The disc has the same physical dimensions as standard DVDs and CDs.
The name Blu-ray Disc derives from the blue-violet laser used to read the disc. While a standard DVD uses a 650 nanometer red laser, Blu-ray uses a shorter wavelength, a 405 nm blue-violet laser, and allows for almost ten times more data storage than a DVD.

During the format war over high-definition optical discs, Blu-ray competed with the HD DVD format. Toshiba, the main company supporting HD DVD, ceded in February 2008, and the format war ended;[4] in July 2009, Toshiba announced plans to put out its own Blu-ray Disc device by the end of 2009.[5]

Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. As of June 2009, more than 1,500 Blu-ray disc titles are available in Australia, with 2,500 in Japan, 1,500 in the United Kingdom, and 2,500 in the United States and Canada.[6][7]



Media type High-density optical disc
Encoding MPEG-2, H.264/MPEG-4 AVC, and VC-1
Capacity 25 to 50 GB (single-layer)
50 to 100 GB (dual-layer)
Block size 64kb ECC
Read mechanism 400 nm laser:
1× @ 36 Mbit/s (4.5 MByte/s)
2× @ 72 Mbit/s (9 MByte/s)
4× @ 144 Mbit/s (18 MByte/s)
6× @ 216 Mbit/s[1] (27 MByte/s)
8× @ 288 Mbit/s (36 MByte/s)
12× @ 432 Mbit/s (54 MByte/s)
Developed by Blu-ray Disc Association[2]
Usage Data storage
1080p High-definition video
High-definition audio Quad HD 2160p
future possibility Ultra HD

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