CD player in 1970. Following litigation, Sony and Philips licensed Russell's patents (then held by a Canadian company, Optical Recording Corp.) in the 1980s. The Compact Disc is an evolution of LaserDisc technology, where a focused laser beam is used that enables the high information density required for high-quality digital audio signals. Prototypes were developed by Philips and Sony independently in the late 1970s. In 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. After a year of experimentation and discussion, the "Red Book" CD-DA standard was published in 1980. After their
Philips Records its classical artists, although classical recordings have also been issued on the regular Philips label. In the US, Philips eventually handled distribution and sales for Philips, Mercury, British Decca (sold under the London label in the US) and Deutsche Grammophon. In 1983, Philips became the first record label to issue compact discs, using digital recordings that had been recorded since 1978. Philips and its subsidiaries eventually re-issued many of its pre-digital stereo and mono recordings on compact disc. Philips and DuPont partnered in four CD manufacturing plants in Hanover, Germany; Blackburn in the UK (formerly the Philips Laservision Disc factory);