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
Archival Disc intended as a consumer storage medium as of 2014, but is intended by the two companies as a solution for professional-level data archival. In order to reach a larger capacity whilst ensuring higher playback signal quality, the standard will employ crosstalk cancellation and partial response maximum likelihood (PRML) signal processing. Both companies will market the optical format under their respective brands. Sony will be using Archival Disc in within the Optical Disc Archive professional archival product range. Sony's aim is to create at least a 6TB storage medium. An emerging use case for Archival Disc has been projected for cold