The world’s Big Nine electronics companies have swallowed corporate pride and agreed on a single standard and name – Blu-Ray – for the next generation video and computer optical disc. Although good for the consumer, they are putting the future of their fledgling recordable DVD systems in jeopardy.
Blu-Ray is backed by Hitachi, LG, Matsushita (Panasonic), Pioneer, Philips, Samsung, Sharp, Sony and Thomson. Only Toshiba, the main inventor of DVD, and JVC, which has a vested interest in VHS, are missing.
The new format will use a blue laser for recording and playback. A single-sided 12 centimetre Blu-Ray disc stores 27GB of computer data, records 13 hours of broadcast TV or holds 2 hours of High Definition video.
Prototypes already exist, and have been demonstrated by Philips, Sony and Panasonic. Licensing for manufacture begins within a couple of months and the first Blu-Ray recorders could go on sale next year.
This could be very bad news for the three rival and incompatible recordable DVD systems, DVD-RAM (Panasonic), DVD-RW (Pioneer) and DVD+RW (Philips), which are just going on sale.
All use a red laser, with 650 nm wavelength, and can only store 4.7 GB on a single sided DVD. TV recording time is only one hour in best quality mode, and two, three or four hours with compromised pictures. Data capacity is inadequate for non-stop backup of a PC hard drive. The data transfer rate, around 10 Mbps, is not fast enough for high quality video.
A blue laser, with a 405 nm wavelength, can focus light more tightly into a smaller spot and so cram more data on a 12 centimetre disc. The data streams at 36 Mbps, which is fast enough for HDTV. As with recordable DVD, the recording is made in a phase change coating. Blu-Ray uses a very thin layer, 0.1 millimetres thick, to stop any tilt of the disc optically distorting the laser beam.
Everything is different
The 27 GB capacity will increase later to….