Video camera tube

The video camera tube was a type of cathode ray tube used to capture the television image prior to the introduction of charge-coupled devices (CCDs) in the 1980s. Several different types of tubes were in use from the early 1930s to the 1980s.

In these tubes, the cathode ray was scanned across a target which was illuminated by the scene to be broadcast. The resultant current was dependent on the brightness of the image on the target. The size of the striking ray was tiny compared to the size of the target, allowing 483 horizontal scan lines per image in the NTSC format, or 576 lines in PAL.

Cathode ray tube

Any vacuum tube which operates using a focused beam of electrons, "cathode rays", is known as a cathode ray tube (CRT). However, in the popular lexicon "CRT" usually refers to the "picture tube" in a CRT television. With the introduction of the personal computer in the early 1980s, "cathode ray tube" (quickly replaced by the acronym "CRT") became the word used for the display, which looked like a small television. It is only one of many types of cathode ray tubes. Other CRTs include the tubes used in television, oscilloscopes, or radar displays. The camera pickup tubes described in this article are also CRTs, but they display no image, and are not kinescopes.

Video camera

A video camera is a camera used for electronic motion picture acquisition (as opposed to a movie camera, which records images on film), initially developed for the television industry but now common in other applications as well.

The earliest video cameras were those of John Logie Baird, based on the mechanical Nipkow disk and used in experimental broadcasts through the 1920s-30s. All-electronic designs based on the video camera tube, such as Vladimir Zworykin's Iconoscope and Philo Farnsworth's image dissector, supplanted the Baird system by the 1930. These remained in wide use until the 1980s, when cameras based on solid-state image sensors such as CCDs (and later CMOS active pixel sensors) eliminated common problems with tube technologies such as image burn-in and made digital video workflow practical. The transition to digital TV gave a boost to digital video cameras and by the 2010s, most video cameras were digital.

With the advent of digital video capture, the distinction between professional video cameras and movie cameras has disappeared as the intermittent mechanism has become the same. Nowadays, mid-range cameras exclusively used for television and other work (except movies) are termed professional video cameras.

Video

Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media.

Video systems vary greatly in the resolution of the display, how they are refreshed, and the rate of refreshed, and 3D video systems exist. They can also be carried on a variety of media, including radio broadcast, tapes, DVDs, computer files etc.

History

Video technology was first developed for Mechanical television systems, which were quickly replaced by cathode ray tube (CRT) television systems, but several new technologies for video display devices have since been invented. Charles Ginsburg led an Ampex research team developing one of the first practical video tape recorder (VTR). In 1951 the first video tape recorder captured live images from television cameras by converting the camera's electrical impulses and saving the information onto magnetic video tape.

Video recorders were sold for $50,000 in 1956, and videotapes cost $300 per one-hour reel. However, prices gradually dropped over the years; in 1971, Sony began selling videocassette recorder (VCR) decks and tapes to the public.