Television Electronic Disc (TeD) is a discontinued

video Video is an Electronics, electronic medium for the recording, copying, playback, broadcasting, and display of moving picture, moving image, visual Media (communication), media. Video was first developed for mechanical television systems, whi ...

recording format, released in 1975 by

Telefunken Telefunken was a German radio and television producer, founded in Berlin in 1903 as a joint venture between Siemens & Halske and the ''AEG (German company), Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ("General electricity company"). Prior to ...

and Teldec. The format used flexible foil discs, which spun at 1,500 rpm on a cushion of air. TeD never gained wide acceptance, and could not compete against the emerging videocassette systems of the time.

History

Initially known as "The Video Disc" or the Teldec Television Disc, TeD (Television Electronic Disc) was first announced at a press conference in

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

on June 24, 1970. It was developed by a team from two German companies: AEG-Telefunken and Teldec. Program information was stored in the form of ridges in the surface of a thin, flexible foil disc, which was claimed to be sufficiently robust to withstand being played 1,000 times. The main technological breakthrough was the vertical recording method that reduced the track pitch to 0.007 mm, and increased the rotation speed to 1,500

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 def ...

, making it possible to record 130–150 grooves per millimeter, compared with the typical 10–13 grooves on an audio disc. This increased the available bandwidth from around 15 kHz to 3

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...

. The tracks were read by a pressure pick-up, which translated the surface of the ridges, via a piezo-electric crystal, into an electrical signal. Tracking was controlled not by the pick-up resting within the walls of a groove, but by a mechanical coupling on which the pick-up mounting is supported. There was no turntable. The rotation of the disc at 1,500 rpm created a thin cushion of air between the disc and a fixed plate. Vertical movement of the disc was kept to within 0.05mm. Eight-inch discs could store five minutes of programming, twelve-inch discs about 7½ minutes.

Marketing

By autumn 1972, the name of the system had just been changed to TeD (for Television Disc) and the playing time of the eight-inch disc had been doubled to 10 minutes. TeD players were finally introduced on the West German market on 17 March 1975. Six labels offered programs: Decca, Teldec Intertel,

, Ufa/ATB, Ullstein AV and Videophon. Within the first three months 6,000 players had been shipped to 2,500 dealers, and 50,000 discs were in the shops. Sanyo Electric Co., Ltd. of

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, which had been conducting similar research itself (but was by now also developing the V-Cord videocassette recorder), was granted a licence to produce a version that would play out in the

NTSC NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170. In 1953, a second ...

television format and by the end of 1976 had devised a long-awaited auto-changer that took 12 10-minute discs. Also in Japan, General Corporation took a manufacturing licence in July 1976 with an expectation of coming to market in April 1977. A software consortium, Nippon Video Systems, was formed around the same time. By the end of 1978 Telefunken itself had adopted VHS.

References

External links

Telefunken's TED video player TP 1005
radiomuseum.org * * * {{DEFAULTSORT:Ted (Television Electronic Disc Audiovisual introductions in 1975 Video storage Film and video technology Discontinued media formats Composite video formats