Dr. David Paul Gregg was the inventor of the optical disc (disk). Gregg was inspired to create the optical disc in 1958 while working at Californian electronics company, Westrex. He first patent for a "Videodisk" was filed in March 1962 (USPO 3350503) where he looks to advance electron beam recording and reproducing. Gregg went to work at 3M's Mincom division with experienced television videotape engineers Wayne Johnson and Dean De Moss. The three men subsequently filed patents to cover a disc recording system, a way to duplicate discs, and reproducing TV signals from photographic discs. When Mincom contracted Stanford's SRI to further the research, Gregg left and formed his own company Gauss Electrophysics. In 1968 the Gregg and Gauss patents were purchased by MCA which helped develop the technology further. His designs and patents paved the way for the Laserdisc, which helped with the creation of the DVD, compact discs, and MiniDisc. In 1963 he also invented a video disk camera which could store several minutes worth of images onto an optical video disk. There was no patent files for the camera and only little is known about it. Gregg died in November 2001.