Colour television

Colour television was by no means a new idea. In the late 19th century a Russian scientist by the name of A.A. Polumordvinov devised a system of spinning Nipkow disks and concentric cylinders with slits covered by red, green, and blue filters. But he was far ahead of the technology of the day; even the most basic black-and-white television was decades away. In 1928, Baird gave demonstrations in London of a colour system using a Nipkow disk with three spirals of 30 apertures, one spiral for each primary colour in sequence. The light source at the receiver was composed of two gas-discharge tubes, one of mercury vapour and helium for the green and blue colours and a neon tube for red. The quality, however, was quite poor.

In the early 20th century, many inventors designed colour systems that looked sound on paper but that required technology of the future. Their basic concept was later called the “sequential” system. They proposed to scan the picture with three successive filters coloured red, blue, and green. At the receiving end the three components would be reproduced in succession so quickly that the human eye would “see” the original multicoloured picture. Unfortunately, this method required too fast a rate of scanning for the crude television systems of the day. Also, existing black-and-white receivers would not be able to reproduce the pictures. Sequential systems therefore came to be described as “noncompatible.”

An alternative approach—practically much more difficult, even daunting at first—would be a “simultaneous” system, which would transmit the three primary-colour signals together and which would also be “compatible” with existing black-and-white receivers. In 1924, Harold McCreary designed such a system using cathode-ray tubes. He planned to use a separate cathode-ray camera to scan each of the three primary-colour components of a picture. He would then transmit the three signals simultaneously and use a separate cathode-ray tube for each colour at the receiving end. In each tube, when the resulting electron beam struck the “screen” end, phosphors coated there would glow the appropriate colour. The result would be three coloured images, each composed of one primary colour. A series of mirrors would then combine these images into one picture. Although McCreary never made this apparatus actually work, it is important as the first simultaneous patent, as well as the first to use a separate camera tube for each primary colour and glowing colour phosphors on the receiving end. In 1929 Herbert Ives and colleagues at Bell Laboratories transmitted 50-line colour television images between New York City and Washington, D.C.; this was a mechanical method, using spinning disks, but one that sent the three primary colour signals simultaneously over three separate circuits.

After World War II, the Columbia Broadcasting System (CBS) began demonstrating its own sequential colour system, designed by Peter Goldmark. Combining cathode-ray tubes with spinning wheels of red, blue, and green filters, it was impressive enough that The Wall Street Journal had “little doubt that color television [had] reached the perfection of black and white.” Thus began a long battle between CBS and RCA to decide the future of colour television. While CBS lobbied for the Federal Communications Commission (FCC) to authorize the Goldmark system for commercial television, Sarnoff warned against using a “horse-and-buggy” system that was noncompatible with monochrome TV. At the same time, Sarnoff whipped his troops at RCA into developing the first all-electronic compatible colour system.

In 1950 the FCC approved CBS's colour television and corresponding broadcast standards for immediate commercial use. However, out of 12 million television sets in existence, only some two dozen could receive the CBS colour signal, and after only a few months the broadcasts were abandoned. Then, in June 1951, Sarnoff and RCA proudly unveiled their new system. The design used dichroic mirrors to separate the blue, red, and green components of the original image and focus each component on its own monochrome camera tube. Each tube created a signal corresponding to the red, green, or blue component of the image. The receiving tube consisted of three electron guns, one for each primary-colour signal. The screen in turn comprised a grid of hundreds of thousands of tiny triangles of discrete phosphors, one for each primary colour. Every ¹/₆₀ of a second the entire picture was scanned, separated into the three colour components, and transmitted; and every ¹/₆₀ of a second the receiver's three electron guns painted the entire picture simultaneously with red, green, and blue, left to right, line by line.

And the RCA colour system was compatible with existing black-and-white sets. It managed this by converting the three colour signals into two: the total brightness, or luminance, signal (called the “Y” signal) and a complex second signal containing the colour information. The Y signal corresponded to a regular monochrome signal, so that any black-and-white receiver could pick it up and simply ignore the colour signal.

In 1952 the National Television Systems Committee (NTSC) was reformed, this time with the purpose of creating an “industry color system.” The NTSC system that was demonstrated to the press in August 1952 and that would serve into the 21st century was virtually the RCA system. The first RCA colour TV set, the CT-100 (see the photograph), rolled off the production line in early 1954. It had a 12-inch screen and cost $1,000, as compared with current 21-inch black-and-white sets selling for $300. It was not until the 1960s that colour television became profitable.

In 1960 Japan adopted the NTSC colour standard. In Europe, two different systems came into prominence over the following decade: in Germany Walter Bruch developed the PAL (phase alternation line) system, and in France Henri de France developed SECAM (système électronique couleur avec mémoire). Both were basically the NTSC system, with some subtle modifications. By 1970, therefore, North America and Japan were using NTSC; France, its former dependencies, and the countries of the Soviet Union were using SECAM; and Germany, the United Kingdom, and the rest of Europe had adopted PAL. These are still the standards of colour television today, despite preparations for a digital future.

DIGITALTELEVISION

Digital television technology emerged to public view in the 1990s. In the United States professional action was spurred by a demonstration in 1987 of a new analog high-definition television (HDTV) system by NHK, Japan's public television network. This incited the FCC to declare an open competition to create American HDTV, and in June 1990 the General Instrument Corporation (GI) surprised the industry by announcing the world's first all-digital television system. Designed by the Korean-born engineer Woo Paik, the GI system displayed a 1,080-line colour picture on a wide-screen receiver and managed to transmit the necessary information for this picture over a conventional television channel. Heretofore, the main obstacle to producing digital TV had been the problem of bandwidth. Even a standard-definition television (SDTV) signal, after digitizing, would occupy more than 10 times the radio frequency space as conventional analog television, which is typically broadcast in a six-megahertz channel. HDTV, in order to be a practical alternative, would have to be compressed into about 1 percent of its original space. The GI team surmounted the problem by transmitting only changes in the picture, once a complete frame existed.

Within a few months of GI's announcement, both the Zenith Electronics Corporation and the David Sarnoff Research Center (formerly RCA Laboratories) announced their own digital HDTV systems. In 1993 these and four other TV laboratories formed a “Grand Alliance” to develop marketable HDTV. In the meantime, an entire range of new possibilities aside from HDTV emerged. Digital broadcasters could certainly show a high-definition picture over a regular six-megahertz channel, but they might “multicast” instead, transmitting five or six digital standard-definition programs over that same channel. Indeed, digital transmission made “smart TV” a real possibility, where the home receiver might become a computer in its own right. This meant that broadcasters might offer not only pay-per-view or interactive entertainment programming but also computer services such as e-mail, two-way paging, and Internet access.

In late 1996 the FCC approved standards proposed by the Advanced Television Systems Committee (ATSC) for all digital television, both high-definition and standard-definition, in the United States. According to the FCC's plan, all stations in the country would be broadcasting digitally by May 1, 2003, on a second channel. They would still be broadcasting in analog as well; programs would be “simulcast” in digital and analog, giving the public time to make the switch gradually. In 2006 analog transmissions would cease, old TV sets would become useless, and broadcasters would return their original analog spectrum to the government to be auctioned off for other uses.

At least such was the plan. In a very short time the FCC's schedule seemed in doubt, as the future form of digital TV remained unclear. Less than 3 percent of the 25 million TV sets sold in America in 2000 were digital, and although 150 stations in 52 cities were broadcasting digitally by that year, most of those stations were merely broadcasting standard-definition programs in digital format. Almost no HDTV was to be seen, and few viewers were even aware of the digital channels. Furthermore, although two-thirds of American viewers had cable TV, most cable companies were refusing to carry the new digital channels. In response, the FCC was considering a rule requiring them to do so; but this in turn would require consumers to purchase a digital cable box, and there was much disagreement within the industry on how to design such a box.

Europe, meanwhile, was far ahead of the United States in digital broadcasting, partly because there was no requirement to incorporate HDTV. In 1993 a consortium of European broadcasters, manufacturers, and regulatory bodies agreed on the Digital Video Broadcasting (DVB) standard, and efforts were begun to apply this standard to satellite, cable, and then terrestrial broadcasting. By the end of the decade some 30 percent of all homes in the United Kingdom had access to digital programming via digital TV sets or via conversion boxes atop their analog sets. Japan began its own digital broadcasting via satellite in December 2000 and planned to begin digital terrestrial broadcasting, using a modification of DVB, in 2003. Both Japan and Europe had target dates similar to that of the United States for ultimate conversion to digital television—i.e., between 2006 and 2010. However, they too faced similar stumbling blocks, so that timetables for the full transition to digital television were in doubt around the world.

CABLE TELEVISION

generally, any system that distributes television signals by means of coaxial or fibre-optic cables. The term also includes systems that distribute signals solely via satellite. Cable-television systems originated in the United States in the early 1950s and were designed to improve reception of commercial network broadcasts in remote and hilly areas. During the 1960s they were introduced in many large metropolitan areas where local television reception is degraded by the reflection of signals from tall buildings. Commonly known as community antenna television (CATV), these cable systems use a “community antenna” to receive broadcast signals (often from communications satellites), which they then retransmit via cables to homes and establishments in the local area subscribing to the service. Subscribers pay a specified monthly service charge in addition to an initial installation fee.

Since the mid-1970s there has been a proliferation of cable-television systems offering special services. Besides bringing high-quality signals to subscribers, the systems provide additional television channels. Some of these systems can deliver 50 or more channels because they distribute signals occurring within the normal television broadcast band as well as nonbroadcast frequencies. A frequency-conversion device is connected to the television set of the subscriber to accommodate these signals of nonbroadcast frequencies. The increased number of channels allows expanded programming, including broadcasts from distant cities, continuous weather and stock-market reports, programs produced by community groups and educational institutions, and access to pay-TV program materials such as recent motion pictures and sports events not telecast by other broadcasters.

Another feature offered by more and more cable operators is two-way channel capability, which enables subscribers to communicate with programming facilities or information centres within the system. Using the cable connection, home viewers can, for example, participate in public-opinion polls or call up various kinds of written and graphic materials (e.g., citations from reference books, concert schedules, and recipes). The latter feature is offered by systems called videotex, which were first introduced in Great Britain and West Germany. Two-way cable-television systems increasingly allow subscribers with home computers to link up with computer networks, giving the subscribers access to data banks and permitting them to interact with other online users. Cable operators have also experimented with video compression, digital transmission, and high-definition television (HDTV).

In the United States, government deregulation of the cable-television industry in the 1990s allowed cable companies to experiment with telephony and allowed telephone companies to distribute cable-television programming.

BRITISH BROADCASTING CORPORATION (BBC)

publicly financed broadcasting system in Great Britain, operating under royal charter. It held a monopoly on television in Great Britain from its introduction until 1954 and on radio until 1972. Headquarters are in the Greater London borough of Westminster.

The first initiatives in British radio after World War I were taken by commercial firms that regarded broadcasting primarily as point-to-point communications. The British Broadcasting Company, Ltd., was established in 1922 as a private corporation, in which only British manufacturers were permitted to hold shares. In 1925, upon recommendation of a parliamentary committee, the company was liquidated and replaced in 1927 by a public corporation, the British Broadcasting Corporation. Although ultimately answerable to Parliament, the BBC has virtually complete independence in the conduct of its activities. The British monarch appoints a board of governors, who in turn select a director general and other executives to oversee day-to-day operations.

The original charter gave the BBC a monopoly covering all phases of broadcasting in Britain. A key figure in the early history of the corporation was John Reith (later Lord Reith), general manager from 1922 and director general from 1927 to 1938. He developed radio broadcasting throughout the British Isles, inaugurated the empire shortwave broadcasting service, and directed the development of the world's first regular television service in 1936. His concept of public service broadcasting prevailed in Great Britain and influenced broadcasting in many other countries.

British television service was interrupted during World War II but resumed in 1946. The BBC established its second channel in 1964, and it introduced the first regular colour television service in Europe in 1967. It retained its monopoly of television service in Britain until the passage of the Television Act of 1954 and the subsequent creation of a commercial channel operated by the Independent Television Authority (later the Independent Broadcasting Authority) in 1955. A second IBA-run commercial channel commenced broadcasting in 1982. The BBC's radio monopoly ended with the government's decision to permit local commercial broadcasts starting in the early 1970s.

BBC World Service radio broadcasts began in 1932 as the Empire Service. By the early 21st century the service broadcast in more than 40 languages to roughly 120 million people worldwide. World Service Television began broadcasting in 1991 and unveiled a 24-hour news channel, BBC News 24, in 1997. The BBC also has been successful with the overseas syndication of its television programming. In the United States series such as All Creatures Great and Small, Mr. Bean, and Upstairs, Downstairs have been featured on the Public Broadcasting Service.

The BBC is financed by annual license fees paid by owners of television and radio sets. It offers five radio networks in Britain, ranging from popular music to news and information services, as well as national television channels. Under its charter the BBC may not advertise or broadcast sponsored programs. It is required to refrain from broadcasting any opinion of its own on current affairs and matters of public policy and to be impartial in its treatment of controversy.

EDUCATIONAL BROADCASTING

It is difficult to give an account of educational broadcasting in countries where broadcasting is largely or wholly a matter of private management and where the larger and more important stations and networks are private commercial enterprises. Nevertheless, considerable numbers of educational transmissions are made in the United States and Latin America by universities and colleges and sometimes by municipal or state-owned stations. The Public Broadcasting Service in the United States has increased the amount of educational and generally more thought-provoking material available on the air, and in Latin America some countries use broadcasts not only to support the work of teachers in schools but also to combat illiteracy and to impart advice to isolated rural populations in matters of public health, agricultural methods, and other social and practical subjects. The Roman Catholic Church has been in the forefront of the latter activity, operating, for example, the Rede Nacional de Emissôras Católicas in Brazil and the Acción Cultural Popular in Colombia. A similar use of broadcasting is made in most of the tropical countries of Africa and Asia.

Japan's NHK has the most ambitious educational-broadcasting output in the world. Each of its two television and AM radio services is devoted wholly to education, while general television services and FM radio also transmit material of this nature. Japan prepares programs for primary, secondary, and higher education, special offerings for the mentally and physically handicapped, and a wide range of transmissions under the general heading of “social education,” which includes foreign languages, vocational and technical instruction, advice on agriculture, forestry, fisheries, and business management, plus special programs for children, adolescents, and women. The educational broadcasts of NHK reach more than 90 percent of Japan's primary and secondary schools.

In Europe the French state broadcasting service devotes more than one-half of its radio output to educational and cultural broadcasts in the arts, letters, and sciences; and on television about 14 percent of its first and second networks are devoted to adult education. Primary and secondary instruction is offered, as are refresher courses for teachers and university-level courses.

Although Italian radio devotes less than 1 percent of its output specifically to educational programs for children, nearly 20 percent is given to cultural and allied offerings. Educational television began in Italy in 1958 with courses of a vocational nature, followed by transmissions aimed at secondary schools. In 1966 special programs were initiated for areas where there are no secondary schools. By the early 1980s, 17 percent of Italian television time was devoted to educational and school broadcasts and 4 percent to cultural programs.

Swedish radio offers a comprehensive service of educational and cultural broadcasting, with the output on television higher than that on radio. There is also a substantial output of adult education at the primary, secondary, and university levels, with about 1,400 school broadcasts a year, and Sweden has concentrated on vocational training and refreshment for teachers. German broadcasting, by contrast, has been used much less for formal education. In The Netherlands more than two and a half hours of school and continuing education broadcasting are broadcast weekly on the radio; in addition, nearly eight hours of educational television are transmitted every week.

The BBC pioneered in education; its work, in both radio and television, has steadily expanded. The BBC offers primary and secondary students more than 100 radio series and nearly 40 television series. The BBC also offers a wide range of biweekly programs especially designed for study in degree courses with the Open University, created and financed by the government, with the broadcast teaching supplemented by publications and correspondence work. By the mid-1970s, BBC broadcasts for the Open University averaged 16 hours weekly on radio and more than 18 hours on television. In addition, the Independent Broadcasting Authority in the United Kingdom has required the commercial-program companies to contribute educational material both for schools and for adults; by 1970 this amounted to 10 hours weekly during periods totalling 28 weeks of the year.

In Australia there is a small educational output on the commercial stations, both radio and television, but by far the greater part of educational broadcasting is undertaken by the Australian Broadcasting Corporation. Educational programming accounts for about 4 percent of radio time and 18 percent of television output, the majority of which is broadcast to schools and kindergartens. The Canadian Broadcasting Corporation is required to provide educational programs in both English and French and does so on its AM and FM radio networks, as well as on television.

INDEPENDENT TELEVISION

in the United Kingdom, television network consisting of a consortium of private companies in competition with the British Broadcasting Corporation. It is regulated by the Independent Broadcasting Authority, which was originally the Independent Television Authority. The ITV network was authorized by act of Parliament in 1954, when the BBC's monopoly over radio and television broadcasting was modified to permit a single channel to operate by selling airtime to advertisers.

The innovation came into existence amid fierce political controversy. ITV differed from the American commercial-television model in that there was only one channel for the independent facility, and its broadcasts were subject to much greater regulation of advertising and involved a greater range of variety and program content.

There were four original contractors who were to share ITV's single network: Rediffusion, Granada, ATV, and ABC. All were based on established cinema and show-business interests, and they quickly set about providing the popular peak-time viewing: variety shows, big-money quizzes, pop-music programs, and open-ended drama serials, or “soap operas.” ATV's Sunday Night at the London Palladium remained a staple of the weekend viewing diet for 13 years; Granada's Coronation Street, a twice-weekly saga of working-class life in Northern England, achieved great popularity. ATV in particular, under the dynamic leadership of Lew Grade (later Lord Grade), embarked on a series of fast-moving adventure programs, beginning with The Saint and Danger Man.

The immediate popularity of ITV had a devastating effect on the BBC, and ITV revenues soared from an initial £2,000,000 to more than £60,000,000. The BBC reacted by adding popular programming in prime viewing hours, and ITV programmers greatly enhanced their reputation by developing superiority in coverage of current affairs and in some documentary areas.

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