The invention: A device for recording and playing back movies and television programs, the videocassette recorder (VCR) revolutionized the home entertainment industry in the late 1970′s.
The company behind the invention: Philips Corporation, a Dutch Company
Videotape Recording
Although television sets first came on the market before World War II, video recording on magnetic tape was not developed until the 1950′s. Ampex marketed the first practical videotape recorder in 1956. Unlike television, which manufacturers aimed at retail consumers from its inception, videotape recording was never expected to be attractive to the individual consumer. The first videotape recorders were meant for use within the television industry.
Developed not long after the invention of magnetic tape recording of audio signals, the early videotape recorders were large machines that employed an open reel-to-reel tape drive similar to that of a conventional audiotape recorder. Recording and playback heads scanned the tape longitudinally (lengthwise). Because video signals have a much wider frequency (“frequency” is the distance between the tops and the bottoms of the signal waves) than audio signals do, this scanning technique meant that the amount of recording time available on one reel of tape was extremely limited. In addition, open reels were large and awkward, and the magnetic tape itself was quite expensive.
Still, within the limited application area of commercial television, videotape recording had its uses. It made it possible to play back recorded material immediately rather than having to wait for film to be processed in a laboratory. As television became more popular and production schedules became more hectic, with more material being produced in shorter and shorter periods of time, videotape solved some significant problems.
Helical Scanning Breakthrough
Engineers in the television industry continued to search for innovations and improvements in videotape recording following Ampex’s marketing of the first practical videotape recorder in the 1950′s. It took more than ten years, however, for the next major breakthrough to occur. The innovation that proved to be the key to reducing the size and awkwardness of video recording equipment came in 1967 with the invention by the Philips Corporation of helical scanning.
All videocassette recorders eventually employed multiple-head helical scanning systems. In a helical scanning system, the record and playback heads are attached to a spinning drum or head that rotates at exactly 1,800 revolutions per minute, or 30 revolutions per second. This is the number of video frames per second used in the NTSC-TV broadcasts in the United States and Canada. The heads are mounted in pairs 180 degrees apart on the drum. Two fields on the tape are scanned for each revolution of the drum. Perhaps the easiest way to understand the helical scanning system is to visualize the spiral path followed by the stripes on a barber’s pole.
Helical scanning deviated sharply from designs based on audio recording systems. In an audiotape recorder, the tape passes over stationary playback and record heads; in a videocassette recorder, both the heads and the tape move. Helical scanning is, however, one of the few things that competing models and formats of videocas-sette recorders have in common. Different models employ different tape delivery systems and, in the case of competing formats such as Beta and VHS, there may be differences in the composition of the video signal to be recorded. Beta uses a 688-kilohertz (kHz) frequency, while VHS employs a frequency of 629 kHz. This difference in frequency is what allows Beta videocassette recorders (VCRs) to provide more lines of resolution and thus a superior picture quality; VHS provides 240 lines of resolution, while Beta has 400. (For this reason, it is perhaps unfortunate that the VHS format eventually dominated the market.)
In addition to helical scanning, Philips introduced another innovation: the videocassette. Existing videotape recorders employed a reel-to-reel tape drive, as do videocassettes, but videocassettes enclose the tape reels in a protective case. The case prevents the tape from being damaged in handling.
The first VCRs were large and awkward compared to later models. Industry analysts still thought that the commercial television and film industries would be the primary markets for VCRs. The first videocassettes employed wide—%-inch or 1-inch—videotapes, and the machines themselves were cumbersome. Although Philips introduced a VCR in 1970, it took until 1972 before the machines actually became available for purchase, and it would be another ten years before VCRs became common appliances in homes.
CONSEQUENCES
Following the introduction of the VCR in 1970, the home entertainment industry changed radically. Although the industry did not originally anticipate that the VCR would have great commercial potential as a home entertainment device, it quickly became obvious that it did. By the late 1970′s, the size of the cassette had been reduced and the length of recording time available per cassette had been increased from one hour to six. VCRs became so widespread that advertisers on television became concerned with a phenomenon known as “timeshifting,” which refers to viewers setting the VCR to record programs for later viewing. Jokes about the complexity of programming VCRs appeared in the popular culture, and an inability to cope with the VCR came to be seen as evidence of technological illiteracy.
Consumer demand for VCRs was so great that, by the late 1980′s, compact portable video cameras became widely available. The same technology—helical scanning with multiple heads—was successfully miniaturized, and “camcorders” were developed that were not much larger than a paperback topic. By the early 1990′s, “reality televi-sion”—that is, television shows based on actual events—began relying on video recordings supplied by viewers rather than material produced by professionals. The video recorder had completed a circle: It began as a tool intended for use in the television studio, and it returned there four decades later. Along the way, it had an effect no one could have predicted; passive viewers in the audience had evolved into active participants in the production process.
See also Cassette recording; Color television; Compact disc; Dolby noise reduction; Television; Walkman cassette player.
