Television Electronic Disc (TeD) is a discontinued

video Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) syst ...

recording format, released in 1975 by

Telefunken Telefunken was a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the ''Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ('General electricity company'). The name "Telefunken" ap ...

and

Teldec Teldec (Telefunken-Decca Schallplatten GmbH) is a German record label in Hamburg, Germany. Today the label is a property of Warner Music Group. History Teldec was a producer of (first) shellac and (later) vinyl records. The Teldec manufacturing ...

. 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 Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocasset ...

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 and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

on June 24, 1970. It was developed by a team from two German companies: AEG-Telefunken and

. 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 with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

, 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 The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...

to 3

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

. The tracks were read by a pressure pick-up, which translated the surface of the ridges, via a

piezo-electric Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied mechanical stress. The word ''p ...

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 Decca may refer to: Music * Decca Records or Decca Music Group, a record label * Decca Gold, a classical music record label owned by Universal Music Group * Decca Broadway, a musical theater record label * Decca Studios, a recording facility in W ...

, Teldec Intertel,

, Ufa/ATB,

Ullstein AV Leopold Ullstein (6 September 1826 – 4 December 1899) was the founder and publisher of several successful German newspapers, including '' B.Z. am Mittag'' and ''Berliner Morgenpost.'' Many of these are still published today. Ullstein was als ...

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 ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, which had been conducting similar research itself (but was by now also developing the

V-Cord V-Cord is an analog recording videocassette format developed and released by Sanyo. V-Cord (later referred to as V-Cord I) was released in 1974, and could record 60 minutes on a cassette. V-Cord II, released in 1976, could record 120 minutes on a ...

videocassette recorder), was granted a licence to produce a version that would play out in the

NTSC The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...

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