A video tape recorder is an electronic apparatus intended for the recording on a Magnetic band of a Signal Vidéo and its associated.
Its principle is, in the broad outlines, the same one as that of the Magnétophone Audio. The developments of electronics and the magnetic bands made it possible to use for the video a technology which had been developed and marketed successfully for the audio.
Invention
The first video tape recorders were marketed in 1954 by the company RCA. These first video tape recorders longitudinally recorded the video signals (like the tape recorders) on a magnetic band of 2 inches and consumed one quantitée astronomical of band. These video tape recorders had a tape speed of band of 9 meters a second!!!.
In 1956, the company Ampex solved the problem of the consumption of band by recording the video signals in a transverse way compared to the tape motion by using revolving heads video, which made it possible to reduce considerably the consumption of band while bringing back the run of this one to 38 centimetres a second. These revolutionary video tape recorders were developed by a team of only six people: Charles Ginsburg, Charles Anderson, Ray Dolby, Shelby Henderson, Alex Maxey, and Fred Pfost. The recording was done of course in black and white.
In 1959, the company Toshiba innovated by recording the video signals in a way known as helicoid with only one revolving head. In 1964, this technology was improved by Philips which added a second head tourante. In 1968, the process was integrated into the video tape recorders general public by using magnetic bands of ½ inch. This technique of recording of the video signals will be preserved for all the professional video tape recorders and general public manufactured thereafter.
Professional formats
Analogical technique:
- 1954 : RCA lance the video tape recorder with recording " longitudinal" sigaux video on magnetic band of 2 inches;
- 1956 : Ampex lance the video tape recorder with recording " transversal" video signals on magnetic band of 2 inches;
- 1959 : Toshiba lance the video tape recorder with recording " hélicoïdal" video signals on magnetic band of 2 inches;
- 1970 : video tape recorder on tape of 1 inch (Sony, Ampex and Fernseh);
- 1971 : 1st video tape recorder, the U matic of Sony using of the magnetic band of ¾ of inch; it is especially used by the companies and the schools;
- 1982 : video tape recorder Betacam born from the alliance of Sony and Thomson; it became the standard of the studios of television throughout the world; at its beginnings, the Betacam did not use that cassettes identical has those of the Betamax of Sony of which it was a derivative for the professionals; later, the cassette known as " large format" appeared;
- 1993 : numerical video tape recorder Betacam;
- video tape recorder DVCAM.
Formats general public
Analogical technique
The important dates of the evolution of analogical technology are:
- 1968: Philips and Sony launches on the market various models of using video tape recorder with reels of the magnetic band of ½ inch;
- March 1972: Philips markets the first video tape recorder with use general public, VCR ( Video Cassette To retie ) with a capacity of 45 minutes recording (arrived on the French market in 1975 and disappearance in 1977);
- November 1975: Sony markets the Betamax with, at its beginnings, a capacity of 60 minutes recording; little time afterwards, it had a maximum capacity of recording of 3 hours and 35 minutes for the European models and up to 5 a.m. for the Japanese models and American in long mode play (arrived to France in September 1978 and disappearance in 1983 but it continued to be produced for the markets German, English and different until 1985 and until 2002 for the only Japanese markets and American);
- February 1976: JVC markets VHS ( Video Home System ) with as of its beginning a capacity of recording maximum 3 a.m., then pushed at 4 a.m. then 5 hours, and finally 10 hours in long mode play (arrived to France in May 1978);
- August 1977: new version long play for VCR of Philips carrying the capacity of recording at 2 a.m. and 30 minutes, and was INCOMPATIBLE with his/her big brother, VCR " standard" for reasons technique, although using the same cassettes (arrived to France in October 1977 and disappearance in 1979);
- June 1978: Grundig markets the SVR ( Video Super To retie ) which was a direct derivative of the VCR of which it used the same cassette but with which it was incompatible; it revolutionized the duration of recording while reaching as of its exit one duration of 5 hours recording, against 3 a.m. and 35 minutes for the Betamax, 3 hours for VHS, 2 hours and 30 minutes for VCR LP (arrived to France in November 1978 and disappearance in 1979).
- 1979: Philips and Grundig markets the V2000 or Vidéo 2000 having the enormous advantage compared to its competitors of using video cassettes recordable on the 2 faces (like the audio cassette) and thus carrying the autonomy of recording has 8:00 by cassette (2x4 hours) (arrived to France in 1979, disappeared in 1983) but continued to be developed primarily for the markets German, English, etc… until 1988 making improvements such as stereophony, the " length play" carrying the capacity of recording at 4 p.m. per cassette (2x8 hours).
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ultimate should have been born for the general public in 1979: LVR (Video Longitudinal To retie ) developped at the point by BASF, this standard made exception to the recording of the video signals said helicoid by recording them in a longitudinal way with a fixed video head. The band of ½ inch contained in a cassette " débitrice" (the reception of the band this made by a plate contained in the video tape recorder, from where impossibility of ejecting the cassette without to have rewound it as a preliminary) ravelled at a speed of 4M/s and contained 72 tracks, each one explored in 2,30 minutes. The change from one track to another was done by a micro engine " not-with-pas" fixed on the video head in 20 ms and a memory storing 80 ms of video to avoid a cut with the change of track. It offered an autonomy of 30 minutes recording. Of course autonomy would have been wide if its development had continued.
Digital technique
The numerical recording can be done on three supports:
- on tape: used only by the vidéastes amateurs (FD, then Mini-FD);
- on optical disk DVD, and sometimes DVD-RAM;
- on magnetic disk: to see Numériscope.
An important advantage of digital technology is to allow the compression of the video.
The cassettes VHS (analogical) and discs DVD (numerical) are equal popularities in 2006, but the near total of the new purchases prévilégient the pure DVD or compounds DVD + VHS.
History
The first video tape recorders are related to the development of the Télévision and were used a long time only for professionals.
In the years 1980, the Industriel S reflect on the market of the models at affordable prices and an easy handling for the neophytes of the video.
Several technologies were then in compétition : VCR of Philips, Betamax of Sony, V2000 of Philips and VHS of JVC.
The quality of the images of Bétamax was higher, but its duration of recording was insufficient for the needs for the general public which was especially interested to record whole films on only one support. Because of this weakness, Bétamax was popular only near the informed amateurs. V2000, in spite of its quality, did not manage to be essential and ceased being produced. That, and the fact that pornographic industry decided to market mainly cassettes VHS, made VHS of JVC the first video standard de facto concerning very a general public.
References
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