The emergence of the compact disc

This article describes how the compact disc digital audio system, also known as the CD system, was the result of the successful merger of two major existing technologies. They are first, optical readout of information stored on an optical disc of 11.5 cm diameter, and second, the digital coding/decoding and digital processing of audio signals. I will describe how a complete digital version of this new audio system gradually emerged, within Philips, during the period 1973-1979. Finally, this paper recounts the partnership and collaboration between Philips and Sony that resulted in a common CD standard in June 1980 which soon after became the world standard. More details on the history of the CD not discussed here can be found in a lively, and accurate, doctoral thesis (in German) by J. Lang and in a recent book.