Videotape

Background

Videotape is an integral component of the video technology that has profoundly impacted the media and home entertainment industries. First controlled by the television industry, videotape and video technology are now widely available to the private sector and have led to significant changes in the way that information is distributed and entertainment is created. Videotape is all about magnetic recording. First introduced commercially in 1956, magnetic recording was a relatively new technology. Videotape and all other forms of recording tape are the same in that they are magnetic. Videotape, in fact, is very similar in composition to audiotape. Most videotapes consist of a layer of tiny magnetic particles applied to Mylar, a strong, flexible plastic material. About a billion magnetic particles cover a square inch of tape and function like microscopic bar magnets. When the tape passes over an electromagnet, information is recorded and played back. The magnetic particles are the most important part of the tape, as they are responsible for picking up and carrying the video signal. Particle size, composition, density, and distribution determine the quality of a tape. During the manufacturing process, the particles are arranged in the tape's coating. During the recording process, video heads arrange the particles into patterns dictated by the changing voltage of the video signal. When the tape is played back, the patterns are picked up by a playback head and become the video image.

History

The first video recording tapes were rust covered with paper backing. The first video recording machines recorded signals on a thin metal wire. When it was discovered that magnetic videotape produced better results, magnetic recorders were built. Some of the early machines used small electromagnets that magnetized iron alloy wire as it passed between spools while crossing over the electromagnet. Magnetic tape proved easier to work with because it does not curl or bend like wire, At first, metal oxides like iron were powdered and applied to the tape. Magnetic particles in early videotapes were relatively large. While this made the manufacturing process easier, the size of the particles limited the effectiveness of the tapes. Later, cobalt was added to particles to improve their magnetic properties. When researchers explored ways to reduce the size of the particles, they discovered that smaller particles resulted in a better tape. However, smaller particles proved more difficult to disperse in the binding material during the manufacturing process. Binding material is a liquid mix of ingredients that later harden and give structure to the magnetic layer of the tape. Researchers later focused on better binder formulations and application techniques and significantly improved videotape quality. In 1951, Bing Crosby Enterprises conducted one of the first demonstrations of magnetic videotape recording. However, the poor speed of the first videotape made it commercially impractical. Still, the benefits of videotapes were immediately recognized. Potential advantages included improved broadcast quality, reusable tapes and less expensive production costs. In 1956, the Ampex company introduced the first practical videotape machine. This first model was a large reel-to-reel machine that used four record heads and two-inch wide tape. Obviously, this invention attracted the interest of the television broadcasting industry and, on November 30, 1956, CBS became the first network to broadcast a program using videotape. A major innovation was introduced in 1969, when Sony presented its EIAJ-standard, three-quarter-inch U-Matic series, the first videocassette system to become widely accepted. The videocassette was a vast improvement on the reel-to-reel format and had a profound effect on the video field. In the early 1980s, Sony became the first company to establish a consumer market for the videocassette system with its Betamax format. Other manufactures soon followed, and the VHS system introduced by JVC, with its 0.5-in (1.3 cm) tape, soon dominated and continues to dominate the market. In 1984, Kodak and General Electric introduced the eight-millimeter video recorder, or camcorder. In 1995 digital videotape was introduced. Digital recording resulted in less background noise and less degradation of picture and sound quality. The introduction of digital tape coupled with the emergence of the Digital Video Disc (DVD), led many to believe the days of the standard videocassettes were numbered. However, in 2001, it was estimated that 90% of households had VCRs while only 10% had DVD players. With new advances in tape manufacturing, as well as a consumer preference for videotapes, it seems it will take a long time for videotape to go the way of the dinosaur.