Blu-ray Disc (BD) is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs an CDs. Conventional (pre-BD-XL) Blu-ray Discs contain 25 GB per layer, with dual layer discs (50 GB) being the industry standard for feature-length video discs. Triple layer discs (100 GB) an quadruple layers (128 GB) are available for BD-XL re-writer drives.[3] The name Blu-ray Disc refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength read laser used for DVDs. The major application of Blu-ray Discs is as a medium for video material such as feature films. Besides the hardware specifications, Blu-ray Disc is associated with a set of multimedia formats. Generally, these formats all are for the video and audio to be stored with greater definition than on DVD.

Blu-ray Disc
Blu-ray Disc.svg
Blu-ray Disc.svg
Reverse side o a Blu-ray Disc
Media teepHeich-density optical disc
EncodinH.262/MPEG-2 Part 2
H.264/MPEG-4 AVC
Capacity25 GB (single-layer)
50.1 GB (dual-layer)
100.1/128 GB (BDXL)
Block size64 kb ECC
Read mechanism405 nm diode laser:
1× @ 36 Mbit/s (4.5 MB/s)
Developed biBlu-ray Disc Association[1]
Dimensions120 mm diameter (4,72 in)
1.2 mm thickness[2]
UisageData storage
Heich-defineetion video (1080p)
Heich-defineetion audio
Stereoscopic 3D
PlayStation 3 gemmes
Futur PlayStation 4 gemmes
Futur Xbox Ane gemmes

The format was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, an motion pictures. The first Blu-ray Disc prototypes were unveiled in October 2000, and the first prototype player was released in April 2003 in Japan. Afterwards, it continued to be developed till its officially release in June 2006. As o June 2008, more than 2,500 Blu-ray Disc titles were available in Australia an the United Kingdoms, with 3,500 in the United States and Canada.[4] In Japan, as o July 2010, more than 3,300 titles have been released.[5]

During the high definition optical disc format war, Blu-ray Disc competed with the HD DVD format. Toshiba, the main company that supports HD DVD, conceded in February 2008,[6] releasing its own Blu-ray Disc player in late 2009.[7]


  1. Blu-ray FAQ. Retrieved on 2010-12-22.
  4. "Now Available". Retrieved October 22, 2008.
  5. "Blu-ray/HD DVD releases in Japan". AV Watch. Retrieved August 26, 2010.
  6. "Toshiba Announces Discontinuation of HD DVD Businesses" (Press release). Toshiba. February 19, 2008. Retrieved February 26, 2008.
  7. Yomiuri Shimbun. Page 1. July 19, 2009. Ver. 13S.

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