Kees Schouhamer Immink - Compact Disc

Compact Disc

Around 1976, Philips and Sony showed prototypes of digital audio disc players, which were based on optical videodisc technology. In 1979, Philips and Sony decided to join forces, and Immink took part in the joint Sony/Philips task force, which developed the Compact Disc standard, the Red Book. He contributed to the EFM and CIRC coding schemes.

In the article, ‘’Shannon, Beethoven, and the Compact Disc’’, Immink presents a historical review of the years leading up to the launch of the CD, and the various crucial decisions made. He refutes the urban legend that the compact disc's diameter was increased from 115 to 120mm solely to hold the 74 minutes playing time of Beethoven's Ninth Symphony conducted by Wilhelm Furtwängler. Commercial disputes also played a part. A fact that is true about the format is that the inner circle of every digital disc is exactly the same size as a Dutch florin dime.

After the CD standard was set in 1980, Immink and his co-workers conducted pioneering experiments with magneto-optical audio recording on pre-grooved discs. They also found a simple method to extend the analog videodisc standard with digital sound. The new systems were brought to market as MiniDisc and CD Video. Laserdisc’s fabricated after 1984 have digitally encoded sound signals.