Optical disc
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In computing, sound reproduction, and video, an optical disc is flat, circular, usually polycarbonate disc whereon data is stored. This data is generally accessed when a special material on the disc (often aluminum) is illuminated with a laser diode.
David Paul Gregg developed an analog optical disk for recording video and patented it in 1961 and 1969 (US patent 3430966). Of special interest is US 4,893,297, first filed in 1968 and issued in 1990, so that it will be a source of royalty income for Pioneer’s DVA till 2007. It encompasses systems such as CD, DVD, and even BluRay. Gregg's company, Gauss Electrophysics, was acquired, along with Gregg's patents, by MCA in the early 1960s.
Parallel, and probably inspired by the developments in the US, a small group of physicists started their first optical videodisc experiments at Philips Research in Eindhoven, The Netherlands in 1969. In 1975, Philips and MCA decided to join forces. In 1978, much too late, the long waited laserdisc was introduced in Atlanta. MCA delivered the discs and Philips the players. It turned out to be a total technical and commercial failure, and quite soon the Philips/MCA cooperation came to an end. In Japan and the US, Pioneer has been successful with the videodisc till the advent of DVD.
Philips and Sony formed a consortium in 1979 to develop a digital audio disc, which resulted in the very successful introduction of the compact disc in 1983.
The promotion of standardised optical storage is undertaken by the Optical Storage Technology Association (OSTA).
The information on an optical disc is stored sequentially on a continuous spiral track from the innermost track and outermost track.
Types of disc
There are many standards using optical discs:
References
- http://web.mit.edu/invent/iow/russell.html
- http://seattletimes.nwsource.com/html/businesstechnology/2002103322_cdman29.html
- http://inventors.about.com/library/inventors/blopticaldisk.htm
External link
- Optical Storage Technology Association (http://www.osta.org)hr:Optički zapis
ms:Cakera optik nl:Digitale opslagmedia ja:光ディスク pl:Dysk optyczny zh:光盘