Philips Compact Disc

Development.

1974 The Philips Research Lab, in co-operation with the Audio division, started the investigation for registration of audio signal on an optical disc.

1978 During the “Digital Audio Disc Convention” in Tokyo Philips suggests specifying a world standard.

1979 A prototype CD System is demonstrated in Europe and Japan.
Sony en Philips starts with a joint development.

1980 The CD standard is proposed by Philips and Sony.

1981 The “Digital Audio Disc Committee” accepts the proposed standard to be the world standard. It is fixed in the “Red Book”.

1982 Both Sony and Philips introduce the Compact Disc system.
Philips with the CD100 and Sony with the CDP-101.

	Operation The surface of the Compact Disc contains billions microscopic small holes. These holes contain the digital (zeros and ones) coded information. From this: - the sound will be reconstructed, - the speed controlled, - the laser beam controlled. - errors corrected A laser beam senses the recorded information. There is no contact between the disc and the sensing system. The reflected light, via a prism, hits a photo detector and will be converted into an electrical signal.
Compact Disc surface 12.500 x enlarged. The information density is 50-100 x larger then a  grammophone record. The track will read from inside to the outside with a speed decreasing from 500 till 200 rotations per minute. The total track length is about 30 km.
	CD100 Small freestanding Compact Disc player. Price in 1983 ƒ 1995 (€ 907)
Museum display with CD100,  CD200, CD300, CD prototype, DVD RW prototype, CD ROM prototype, CDI
	On 8 March 1979 the compact disc was demonstrated for the first time publicly. It is still a disc of 11.5 cm diameter and a play time of an hour.