What is Blu-ray?
Blu-ray, also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format. It has the same physical dimensions as standard DVDs and CDs, but offers more than five times the storage capacity of traditional DVDs, holding up to 27 GB of data on a single-layer disc (that's more than 2 hours of high-definition video or about 13 hours of standard video) and up to 50 GB on a dual-layer disc. Recent development by Pioneer has pushed the storage capacity to 500GB on a single disc by using 20 layers.
This extra capacity combined with the use of advanced video and audio codecs offers consumers an unprecedented HD experience. In addition, extras such as bonus material and special features can be included in high quality on the same disc, so there is no need for separate bonus discs to accompany the film title.
Blu-ray was jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics, personal computer and media manufacturers (including Dell, Apple, HP, Hitachi, JVC, Mitsubishi, Pioneer, LG, Panasonic, Philips, Sony, Samsung, Sharp, Thomson and TDK). It was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data.
Whilst current optical disc technologies such as DVD rely on a red laser to read and write data, the Blu-ray format uses a blue-violet laser instead. The benefit of using a blue-violet laser (405 nm) is that it has a shorter wavelength than a red laser (650 nm), 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. However, 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 name Blu-ray is derived from the blue coloured optical laser ray used to read and write this type of disc. According to the manufacturers, the 'e' in 'blue' was purposefully left off, because an everyday word cannot be trademarked.
During the format war over high-definition optical discs, Blu-ray Disc competed with the HD DVD format. However, on February 19, 2008, Toshiba (the main company supporting HD DVD) announced that it would no longer develop, manufacture, or market HD DVD players and recorders, leading almost all other HD DVD companies to follow suit, and thus effectively ending the format war. Blu -ray is currently supported by about 200 of the world's leading personal computer, consumer electronics, recording media, music and video game companies. The format also has support from all Hollywood studios and other smaller studios as a successor to today's DVD format. Major blank media manufacturers such as TDK also support the Blu-ray Disc format as the successor of DVD.
Blu-ray provides some of the strongest copy protection methods ever developed for any consumer format, making it the best choice for any content publisher wanting assurance that their valuable assets are protected from piracy. The format incorporates a robust copy protection mechanism, which not only relies on implementation at the playback device, but which also includes precautions at replicator level, which are strictly controlled. Unlike the voluntary implementation of CSS protection in DVD, the copy protection mechanism for Blu-ray Disc is mandatory and will be governed by strict licensing procedures.
