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1969 September 30

The quest for home video
RCA HoloTape


A contemporary (and typically uninformative) promotional picture of the prototype
Source: RCA

RCA was working on a film-based video playback system when EVR, backed by its rival CBS, was unveiled. A demonstration of the prototype was arranged, still lacking any audio facility.
        Like EVR, the system used electron beam recording (EBR) to make a master recording on a plastic tape. A second tape was coated with a photoresist that hardened in proportion to its exposure to light. A laser beam passed through a beam-splitter to direct one stream through the master recording and the other directly to the photoresist tape. The interference patterns created at the intersection of the two beams was recorded on the second tape, from which the unhardened photoresist was then removed. The resultant holographic tape was nickel-plated to produce a duplication master. This was passed through rollers in contact with blank vinyl tape to replicate the holographic pattern.
        A low-power laser read the tape in the consumer player.
        The system was later the first to bear the name SelectaVision but was abandoned by RCA around three years later in favour of magnetic tape technology.

Chronomedia 1969
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Page updated 26 August 2004