Capacitance Electronic Disc

The Capacitance Electronic Disc (CED) is an analog video disc playback system developed by RCA, in which video and audio could be played back on a TV set using a special needle and high-density groove system similar to phonograph records.

Development
RCA began videodisc research in 1964, in an attempt to produce a phonograph-like method of reproducing video. Research and development was slow in the early years, as the development team originally comprised only four men but by 1972, the CED team at RCA had produced a disc capable of holding ten minutes of color video (a portion of the Get Smart episode "A Tale of Two Tails", re-titled "Lum Fong").

The first CED prototype discs were multi-layered, consisting of a vinyl substrate, nickel conductive layer, glow-discharge insulating layer and silicone lubricant top layer. However, failure to fully solve the stylus and disc wear and complexity of manufacturing forced RCA to search for simpler solutions to the problem for constructing the disc. The final disc was crafted using PVC blended with carbon to allow the disc to be conductive. To preserve stylus and groove life, a thin layer of silicone was applied to the disc as a lubricant.

CED videodiscs were originally meant to be sold in jackets and handled by hand similar to audio records, but during testing, it was shown that exposure to dust caused skipped grooves. It was learned that if dust was allowed to settle on the discs, then the dust would absorb moisture from the air and cement the dust particle to the disc surface, causing the stylus to jump back in a locked groove situation. Thus, an idea was developed in which the disc would be stored and handled in a caddy from which the CED would be extracted by the player so that exposure to dust would be minimized.

After 17 years of development the first CED player was released on 1981 22 March.