Capacitance Electronic Disc (CED)
An analog video disc format developed by RCA that stored television-quality video and audio in grooves read by a conductive stylus; notable for its protective plastic caddy and 1980s consumer release.
Overview
The Capacitance Electronic Disc (CED) is an analog video storage format developed by RCA in the mid-20th century. Unlike optical or magnetic systems, the CED stores picture and sound as microscopic groove modulations on a vinyl-like disc. Playback requires a dedicated player that reads those modulations with an electrically conductive stylus, converting capacitance changes into composite video and audio signals.
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Design and operation
CEDs look superficially similar to phonograph records but are engineered to carry television-quality signals. A thin dielectric layer covers a conductive base; a modulated groove pattern encodes the analog waveform. During playback a fine metal stylus rides in the groove and senses tiny variations in capacitance between the stylus and the disc surface. Those variations are processed and amplified into the video and audio outputs used by standard television sets.
Packaging and physical characteristics
To reduce contamination and wear from handling, each disc was stored inside a protective plastic caddy. The caddy allowed users to insert the sealed shell into a player without touching the disc itself; a printed label on the outer shell identified the program title and basic information. Because the stylus contacts the disc during playback, CEDs were more susceptible to wear and dust than non-contact optical formats.
History and commercial life
Work on capacitance-based videodisc technology began decades before consumer launch, and RCA brought CED hardware and discs to market for household use in the early 1980s. The format competed with magnetic tape (VHS and Betamax) and optical disc formats such as LaserDisc and, later, digital compact discs. Production and consumer interest declined after a few years as non-contact optical systems and videocassette recorders became dominant.
Uses, legacy and distinctions
CEDs were sold primarily as prerecorded movies and special-interest titles for home viewing. Their main distinctions are the analog groove encoding, the capacitance-based stylus readout, and the protective plastic caddy. For general background on disc formats see video disc comparisons and the conceptual difference between analog and digital media. For a related consumer optical medium, see CD.
- Contact readout: stylus must touch the disc surface.
- Analog signal storage: no digital encoding on the disc.
- Protective caddy: designed to minimize user handling and dust.
Though ultimately eclipsed by newer technologies, the CED remains a notable chapter in the evolution of home video—an attempt to combine the familiarity of record-like manufacturing with the demands of moving-picture reproduction.
Questions and answers
Q: What is the Capacitance Electronic Disc?
A: The Capacitance Electronic Disc (CED) was a type of video disc made in 1964 by the company RCA.
Q: How is the CED similar to a record?
A: The CED is similar to a record in that it stores the video and sound as small grooves on a black disk.
Q: Is the CED a digital or analog format?
A: The CED is an analog disc format instead of a digital format like a CD.
Q: Why is the CED stored inside a plastic case?
A: The CED is stored inside a plastic case so you cannot touch the disk as it is very easy to damage.
Q: What information is on the label of the plastic case for the CED?
A: On the plastic case is a label that has the name of the movie on the disc as well as other information such as a summary of the movie.
Q: Who made the Capacitance Electronic Disc?
A: The Capacitance Electronic Disc was made by the company RCA.
Q: When was the Capacitance Electronic Disc made?
A: The Capacitance Electronic Disc was made in 1964 by the company RCA.
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AlegsaOnline.com Capacitance Electronic Disc (CED) Leandro Alegsa
URL: https://en.alegsaonline.com/art/16687