Optical disc of light. An early optical disc system existed in 1935, named . An early analog optical disc used for video recording was invented by David Paul Gregg in 1958 and patented in the US in 1961 and 1969. This form of optical disc was a very early form of the DVD (). It is of special interest that , filed 1989, issued 1990, generated royalty income for Pioneer Corporation's DVA until 2007 —then encompassing the CD, DVD, and Blu-ray systems. In the early 1960s, the Music Corporation of America bought Gregg's patents and his company, Gauss Electrophysics. American inventor James
Compressed audio optical disc Compressed audio optical disc A compressed audio optical disc, MP3 CD, or MP3 CD-ROM or MP3 DVD is an optical disc (usually a CD-R, CD-RW, DVD-R or DVD-RW) that contains digital audio in the MP3 file format. Discs are written in the "Yellow Book" standard data format (used for CD-ROMs and DVD-ROMs), as opposed to the Red Book standard audio format (used for CD-DA audio CDs). Compressed audio files are supported by many modern CD players as well as DVD players. Disc players are capable of playing compressed formats, such as MP3, the most commonly used format, as well as