television(redirected from Televisión)
Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Idioms.
television,transmission and reception of still or moving images by means of electrical signals, originally primarily by means of electromagnetic radiationelectromagnetic radiation,
energy radiated in the form of a wave as a result of the motion of electric charges. A moving charge gives rise to a magnetic field, and if the motion is changing (accelerated), then the magnetic field varies and in turn produces an electric field.
..... Click the link for more information. using the techniques of radioradio,
transmission or reception of electromagnetic radiation in the radio frequency range. The term is commonly applied also to the equipment used, especially to the radio receiver.
..... Click the link for more information. , now also by fiber-optic and coaxial cables and other means. Television has become a major industry, especially in the industrialized nations, and a major medium of communication and source of home entertainment. Television is put to varied use in industry, e.g., for surveillance in places inaccessible to or dangerous for human beings; in science, e.g., in tissue microscopy (see microscopemicroscope,
optical instrument used to increase the apparent size of an object. Simple Microscopes
A magnifying glass, an ordinary double convex lens having a short focal length, is a simple microscope. The reading lens and hand lens are instruments of this type.
..... Click the link for more information. ); in medicine, e.g., in endoscopic surgery (see endoscopeendoscope,
any instrument used to look inside the body. Usually consisting of a fiber-optic tube attached to a viewing device, endoscopes are used to explore and biopsy such areas as the colon and the bronchi of the lungs.
..... Click the link for more information. ); and in education.
Evolution of the Scanning Process
The idea of "seeing by telegraph" engrossed many inventors after the discovery in 1873 of variation in the electrical conductivity of selenium when exposed to light. Selenium cells were used in early television devices; the results were unsatisfactory, however, chiefly because the response of selenium to light-intensity variations was not rapid enough. Moreover, until the development of the electron tubeelectron tube,
device consisting of a sealed enclosure in which electrons flow between electrodes separated either by a vacuum (in a vacuum tube) or by an ionized gas at low pressure (in a gas tube).
..... Click the link for more information. there was no way of sufficiently amplifying the weak output signals. These limitations precluded the success of a television method for which Paul Nipkow in Germany received (1884) a patent.
His system employed a selenium photocell and a scanning disk; it embodied the essential features of later successful devices. A scanning disk has a single row of holes arranged so that they spiral inward toward the center from a point near the edge. The disk revolves in front of a light-sensitive plate on which a lens forms an image; each hole passes across, or "scans," a narrow, ring-shaped sector of the image. Thus the holes trace contiguous concentric sectors, so that in one revolution of the disk the entire image is scanned. When the light-sensitive cell is connected in an electric circuit, the variations in light cause corresponding fluctuations in the electric current. The image can be reproduced by a receiver whose luminous area is scanned by a similar disk synchronized with the disk of the transmitter.
Although selenium cells proved inadequate, the development of the phototube (see photoelectric cellphotoelectric cell
device whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is incident upon it. The most common type consists of two electrodes separated by a light-sensitive semiconductor material.
..... Click the link for more information. ) made the mechanical disk-scanning method practicable. In 1926, J. L. BairdBaird, John Logie,
1888–1946, Scottish inventor. In 1926 he gave the first demonstration of true television with a televisor of his own invention that differed from later instruments in being partially mechanical rather than wholly electronic.
..... Click the link for more information. in Great Britain and C. F. Jenkins in the United States successfully demonstrated television systems using mechanical scanning disks. While research remained at producing pictures made up of 60 to 100 scanned lines, mechanical systems were competitive. These were soon superseded, however, by electronic scanning methods; a television system employing electronic scanning was patented by V. K. ZworykinZworykin, Vladimir Kosma
, 1889–1982, American physicist, b. Russia, educated in Russia, at the Collège de France, and at the Univ. of Pittsburgh (Ph.D., 1926). He became an American citizen in 1924. On the staff of the Radio Corp.
..... Click the link for more information. in 1928. The 1930s saw the laboratory perfection of television equipment, and some programming became available in the United States beginning in 1939, but World War II almost entirely halted television programming and broadcasting. The television industry began to grow again only after 1945.
The television scanning process, used both to record and reproduce an image, operates as do the eyes in reading a page of printed matter, i.e., line by line. Prior to the introduction of television cameras using charge-coupled devices (see below), a complex circuit of horizontal and vertical deflection coils caused an electronic beam to scan the back of a mosaic of photoelectric cells in a 483-line zigzag 30 times each second, though the actual viewing area when the image was reproduced was typically 440 lines and 480 lines were used later by DVDs (digital versatile discs). (The standard was in fact a 525-line one, but not all the lines were used for the picture. The 525-line, 30-frame-per-second system was used in the United States, Japan, and elsewhere; many other countries used similar but incompatible systems.) Because of persistence of vision only about 16 pictures need be viewed each second to give the effect of motion. The development of interlaced scanning resulted in alternate lines being scanned each 1/60 sec. Half the lines were scanned in the first 1/60 sec, and the remaining lines, each one between two lines scanned during the first pass, covered in the next 1/60 sec.
Development of the Television Camera and Receiver
V. K. Zworykin's Iconoscope (1923) was the first successful camera tube in wide use. Its functioning involved many fundamental principles common to all television image pickup devices. The face of the iconoscope consisted of a thin sheet of mica upon which thousands of microscopic globules of a photosensitive silver-cesium compound had been deposited. Backed with a metallic conductor, this expanse of mica became a mosaic of tiny photoelectric cells and capacitors. The differing light intensities of various points of a scene caused the cells of the mosaic to emit varying quantities of electrons, leaving the cells with positive charges proportionate to the number of electrons lost. An electron gun, or scanner, passed its beam across the cells. As it did so, the charge was released, causing an electrical signal to appear on the back of the mosaic, which was connected externally to an amplifier. The strength of the signal was proportional to the amount of charge released. The iconoscope provided good resolution, but required very high light levels and needed constant manual correction.
The Orthicon and Image-Orthicon camera tubes improved on the Iconoscope. They used light-sensitive granules deposited on an insulator and low-velocity scanning. These could be used with lower light levels than required by the Iconoscope, and did not require the constant manual manipulation. The Vidicon was the first successful television camera tube to use a photoconductive surface to derive a video signal.
Solid-state imaging devices were first demonstrated in the 1960s. Video cameras using semiconductor charge-coupled devices (CCDs) began development in the 1970s, and began replacing tube-based cameras in the mid-1980s. Each picture element (pixel) in a CCD stores a charge that is determined by the illumination incident on it. At the end of the exposure interval, the charge is transferred to a storage register and the CCD is freed up for the next exposure. The charges in the storage register are transferred to the output stage serially during that time. By the mid-1990s, CCD-based television cameras had replaced tube-based cameras, but at the same time development was proceeding on a different solid-state technology, the complementary metal-oxide semiconductor (CMOS) image sensor. CMOS technology also is used for computer integrated circuits and random-access memory (RAM), and CMOS image sensors are less expensive to manufacture than CCDs. In general a CMOS image sensor operates similarly to a CCD, but additional processing occurs at each pixel and the pixels transfer their output more quickly and in a digital format. Although CMOS-based cameras initially were inferior for high-quality uses compared to CCD-based ones, steady improvements in CMOS techonology led by the 2010s to its replacing CCDs in many television and video cameras. High-end 3CCD and 3CMOS video cameras use three sensors, one each for red, green, and blue, for improved color image quality.
In the television receiver, the original image is reconstructed. In television receivers using cathode-ray tubescathode-ray tube
(CRT), special-purpose electron tube in which electrons are accelerated by high-voltage anodes, formed into a beam by focusing electrodes, and projected toward a phosphorescent screen that forms one face of the tube.
..... Click the link for more information. , this was done essentially by reversing the operation of the video camera. The final 483- or 480-line interlaced image was displayed on the face of the tube, where an electron beam scanned the fluorescent face, or screen, line for line with the pickup scanning. The fluorescent deposit on the tube's inside face glowed when hit by the electrons, and the visual image was reproduced. In a television set with a liquid crystalliquid crystal,
liquid whose component particles, atoms or molecules, tend to arrange themselves with a degree of order far exceeding that found in ordinary liquids and approaching that of solid crystals.
..... Click the link for more information. display (LCD, also called LED LCD or LED if light-emitting diodediode
, two-terminal electronic device that permits current flow predominantly in only one direction. Most diodes are semiconductor devices; diode electron tubes are now used only for a few specialized applications.
..... Click the link for more information. backlighting is used), which also recreates the image line by line, control signals are sent to the lines and columns formed by the hundreds of thousands of pixels in the display, and each pixel, or picture element, is connected to a switching device. In high-definition televisions, 720 or 1080 display lines are used, with 1080 typically now standard, and the scanning may be progressive (noninterlaced, 720 and 1080) or interlaced (1080 only), typically at 30 frames per second. Progressive scanning in general produces a picture with less flicker and better reproduction of motion, particularly on larger screens. An ultra high-definition, or 4K, display uses 2160 lines for the image. Other devices in the receiver extract the crucial synchronization information from the signal, demodulate (separate the information signal from the carrier wave) it, and, in the case of a digital signal, demultiplex, decrypt, and decode it.
Development of Color Television
Several systems of color television have been developed. In the first color system approved by the Federal Communications Commission (FCC), a motor-driven disk with segments in three primary colors—red, blue, and green—rotated behind the camera lens, filtering the light from the subject so that the colors could pass through in succession. The receiving unit of this system formed monochrome (black-and-white) images through the usual cathode-ray tube, but a color wheel, identical with that affixed to the camera and synchronized with it, transformed the images back to their original appearance. This method is said to be "field-sequential" because the monochrome image is "painted" first in one color, then another, and finally in the third, in rapid enough succession so that the individual colors are blended by the retentive capacities of the eye, giving the viewer the impression of a full colored image. This system, developed by the Columbia Broadcasting System (CBS), was established in 1950 as standard for the United States by the FCC. However, it was not "compatible," i.e., a good picture could not be obtained on standard black-and-white sets from the same signal, so it found scant public acceptance.
It was the development of a simultaneous compatible system by the Radio Corporation of America (RCA), first demonstrated in 1951, that led to the widespread acceptance of color television. In this electronic, "element-sequential" system, light from the subject is broken up into its three color components, which are simultaneously scanned by three pickups. The signals corresponding to the red, green, and blue portions of the scanned elements are combined electronically so that the required 4.1-MHz bandwidth can be used. In the receiver the three color signals are separated for display. The elements, or dots, on the picture tube screen are each subdivided into areas of red, green, and blue phosphor. Beams from three electron guns, modulated by the three color signals, scan the elements together in such a way that the beam from the gun using a given color signal strikes the phosphor of the same color. Provision is made electronically for forming proper gray tones in black-and-white receivers. In 1953 the FCC reversed its 1950 ruling and revised the standards for acceptable color television systems. The RCA system met the new standards (the CBS system did not) and was well received by the public.
Broadcast, Cable, and Satellite Television Transmission
Television programs may be transmitted either "live" or from a recording. The principle means of recording television programs for future use for many years was videotape recording, although programs were first recorded (when recorded) by kinescope, a method that uses motion-picture film. Appropriate changes in the signal-carrying circuitry allow kinescopes to be played back from a developed negative as well as from a positive. Videotape recording is similar to conventional tape recording (see tape recordertape recorder,
device for recording and replaying of sound, video, and digital information on plastic (usually polyester) or paper tape. The tape is coated with fine particles of a magnetic substance, usually an oxide of iron, cobalt, or chromium.
..... Click the link for more information. ; videocassette recordervideocassette recorder
(VCR), device that can record television programs or the images from a video camera on magnetic tape (see tape recorder); it can also play prerecorded tapes.
..... Click the link for more information. ) except that, because of the wide frequency range—4.2 megahertz (MHz)—occupied by a video signal, the effective speed at which the tape passes the head is kept very high. The sound is recorded along with the video signal on the same tape. Television programs may also be recorded on a computer drive that uses hard disks or solid-state flash memory and on optical disks such as DVDs in a variety of formats.
When a television program is broadcast, the varying electrical signals are then amplified and used to modulate a carrier wave (see modulationmodulation,
in communications, process in which some characteristic of a wave (the carrier wave) is made to vary in accordance with an information-bearing signal wave (the modulating wave); demodulation is the process by which the original signal is recovered from the wave
..... Click the link for more information. ); the modulated carrier is fed to an antenna, where it is converted to electromagnetic waves and broadcast over a large region. The waves are sensed by antennas connected to television receivers. The range of waves suitable for radio and television transmission is divided into channels, which are assigned to broadcast companies or services. In the United States the Federal Communications Commission (FCC) currently has assigned 12 television channels between 54 and 216 MHz in the very-high-frequency (VHF) range and 47 channels between 470 and 698 MHz in the ultra-high-frequency (UHF) range; 32 additional channels at the upper end of the UHF range (698–890 MHz) originally assigned to television broadcasting were reassigned to other uses between 1983 and 2009 (see radio frequencyradio frequency,
range of electromagnetic waves with a frequency or wavelength suitable for communication uses. Some of these waves serve as carriers of the lower-frequency audio waves; others are modulated by video or digital information.
..... Click the link for more information. ). Since the transition to digital broadcasting was completed in 2009, the UHF range has increased in importance for television broadcasting even as the number of viewers receiving broadcast television programs has declined. Originally a television station's channel number was identical to the channel number of the radio frequency channel it used for its broadcasts, but as a result of the digital transition that often is no longer true.
Most television viewers in the United States no longer receive signals by using antennas; instead, they receive programming via cable televisioncable television,
the transmission of televised images to viewers by means of coaxial cables. Cable systems receive the television signal, which is sent out over cables to individual subscribers, by a common antenna (CATV) or satellite dish.
..... Click the link for more information. . Cable delivery of television started as a way to improve reception. A single, well-placed community antenna received the broadcast signals and distributed them over coaxial cables to areas that otherwise would not be able to receive them. Today, cable television is popular because of the wide variety of programming it can deliver. Many systems now provide hundreds of channels of programming. A cable television company now typically receives signals relayed from a communications satellitecommunications satellite
artificial satellite that functions as part of a global radio-communications network. Echo 1, the first communications satellite, launched in 1960, was an instrumented inflatable sphere that passively reflected radio signals back to earth.
..... Click the link for more information. and sends those signals to its subscribers over coaxial or fiber-optic cable. Some television viewers use small satellite dishes to receive signals directly from satellites. Most satellite-delivered signals are scrambled and require a special decoder to receive them clearly.
See also broadcastingbroadcasting,
transmission, usually using radio frequencies, of sound or images to a large number of radio or television receivers. In the United States the first regularly scheduled radio broadcasts began in 1920 at 8XK (later KDKA) in Pittsburgh.
..... Click the link for more information. .
Television Technology Innovations
The FCC established a stereo audio standard for television in 1984, and by the mid-1990s all major network programming was broadcast in stereo. In 1996 the FCC adopted a U.S. standard for an all-digital HDTV system, to be used by all commercial broadcast stations by mid-2002. Although it was hoped that the transition to digital broadcasting would be largely completed by 2006, less than a third of all stations had begun transmitting digital signals by the mid-2002 deadline. In 2005 the U.S. government mandated an end to digital broadcasting in Feb., 2009 (changed to June, 2009, shortly before the deadline in 2009). After the transition to digital broadcasting was completed, older analog sets required an external digital converter in order to be able to use broadcast programs.
The next great advance was the adoption of a high-definition television (HDTV) system. Non-experimental analog HDTV broadcasting began in Japan in 1991. The most noticeable difference between the previously existing system and the HDTV system is the aspect ratio of the picture. While the ratio of the width of the old standard TV picture to its height is 4:3, the HDTV system has a ratio of 16:9, about the same as the screen used in a typical motion-picture theater. HDTV also provides higher picture resolution and high quality audio. A total of 750 or 1,125 scanlines are embedded in the HDTV signal. Each frame of video consists of 720 or 1080 visible horizontally scanned lines, and the rest of the scanlines may carry the time code, vertical synchronization information, closed-captioning, and other information.
Television networks experimented with so-called three-dimensional (3D) or stereoscopic television during the late 20th and early 21st cent., using a variety of technologies to create an illusion of depth in the picture. In the early 2010s, however, networks, filmmakers, and television manufacturers developed more regular 3D programing, an increased number of 3D motion pictures, and a variety of 3D-capable television sets (most relying on special glasses that needed to be worn while viewing 3D programs and movies). Consumers, however, did not widely embrace 3D television, leading major television manufacturers to end the production of 3D sets by mid-decade.
Because the wide availability of television has raised concerns about the amount of time children spend watching television, as well as the increasingly violent and graphic sexual content of television programming, the FCC required television set manufacturers to install, starting in 1999, "V-Chip" technology that allows parents to block the viewing of specific programs. That same year the television industry adopted a voluntary ratings system to indicate the content of each program.
Various interactive television systems now exist. Cable television systems use an interactive system for instant ordering of "pay-per-view" programming or other on-demand viewing of programs. Cable systems also may poll their subscribers' equipment to compile information on program preferences, and interactive systems can be used for instant public-opinion polls or for home shopping. So-called smart televisions include an operating system and storage, and allow users to run computer applications (apps) that resemble those designed for smartphones. Standards have also been developed for the distribution of television programming via the InternetInternet, the,
international computer network linking together thousands of individual networks at military and government agencies, educational institutions, nonprofit organizations, industrial and financial corporations of all sizes, and commercial enterprises (called gateways
..... Click the link for more information. .
See D. G. Fink and D. M. Lutyens, The Physics of Television (1960); M. S. Kiver and M. Kaufman, Television Simplified (7th ed. 1973); R. Armes, On Video (1988); K. B. Benson and J. C. Whitaker, Television and Audio Handbook (1990); K. B. Benson, Television Engineering Handbook (1992); D. E. Fisher and M. J. Fisher, Tube (1996).
television (TV)(from a compression of the Greek tele, meaning far and distant, and vision (from Latin) the faculty of seeing) the apparatus for transmitting images and sounds, arguably the most culturally significant phenomenon of the late 20th century. The importance of television is so not simply because of its impact on LEISURE patterns, nor because of its purported effect on, among other things, violent behaviour, reading abilities and family relationships, nor even because of its ability to change conceptions of space and time and stimulate global awareness, but also because of its central role in the perpetuation of CONSUMERISM (see also ADVERTISING).
In 1949 less than 2% of homes in Britain and the USA had TV sets; now over 99% do. The time spent watching TV varies across age, class, gender and other factors. A popular soap opera in Britain will typically draw 13 million viewers, or about one quarter of the population. A global event, like the Super Bowl in the USA may attract 100 million viewers in the USA alone, and billions around the world. During such an event an advertiser will pay $900,000 for a 30-second commercial. This is crucial, for advertisers rather than viewers are the main customers television companies seek to accommodate. Commentators have suggested that TV networks rent out viewers to advertisers.
Apart from scaremongering critics who accuse TV of fostering all manner of unwanted behaviour, more thoughtful writers such as Neil Postman (Amusing Ourselves to Death, 1985) have bemoaned the passing of typography as the dominant cultural medium and likened TV to Huxley's 'soma’which induces an agreeable state of euphoria, but which drains critical powers. This view has much in common with earlier theorists from such diverse sources as the FRANKFURT SCHOOL OF CRITICAL THEORY and the Columbia School at New York: they agreed that TV, along with other MASS MEDIA OF COMMUNICATION, was politically soporific and geared to the maintenance of the status quo.
More recently, the rise of DISCOURSE ANALYSIS has led to a reorientation, with more emphasis laid on the role of the viewer in reading, rather than just absorbing TV's material. In the view of researchers like John Fiske (Television Culture, 1987), reading television involves viewers in creating meaning: they engage with the programme's text in an interpretative activity that shapes the discourse. While this has permitted a more active conception of the viewer, it has also diverted attention away from ‘big’ issues like the way in which TV influences our public behaviour, in particular our spending habits.
the scientific, technical, and cultural field concerned with the transmission of visual information—moving images—over distances by electronic means; the term “television” also refers to the method used in such transmission. In addition to radio broadcasting, television is one of the most wide-reaching methods of disseminating political, cultural, scientific, and educational information. It is also one of the principal means of communication, used in science, management, technology, and other applied fields: for example, it is used in dispatching and monitoring systems for industry and transportation, in space and nuclear research, and in the military.
Fundamental principles and technology. The final receiving component in television transmission is the human eye, and television systems are therefore designed to take into account the characteristics of human vision. Man perceives the real world visually in colors. He perceives objects positioned in space of a certain size, and he senses the dynamics, or motion, in events. Consequently, the ideal television system must be able to reproduce these characteristics of the material world. The problems of transmitting motion and color have been solved successfully, both technically and practically, in modern television. Television systems capable of depicting objects and space in three dimensions are in the development stage.
Three processes are required for the transmission of images by television: conversion of the light emitted by or reflected from an object into electrical signals; transmission of the electrical signals over communications channels and reception of the signals; and reconversion of the electrical signals into light impulses that reconstruct the image. The fundamental bases for the realization of these processes were defined by W. Smith (Great Britain), who discovered the photoconductive effect (1873); A. G. Stoletov, who established the basic laws governing the photoemissive effect (1888); A. S. Popov, who invented radio communication (1895); and B. L. Rozing, who developed a system of transmitting images in which a cathode-ray tube was used to reproduce the images. Rozing used his system to achieve the world’s first television transmission under laboratory conditions in 1911. However, it was necessary to solve many other complex problems before television could become practical.
When objects are examined directly, it is possible to distinguish very fine details, depending on the resolving power of the eye. Consequently, an optical image projected on the retina can be formally regarded as comprising m resolvable components, or elements. Each such element can be characterized by its brightness (or luminance) B, chrominance (hue λ and color purity p), and geometrical location (the coordinates x and y); that is, each element can be described by the function fi(B, λ, p, x, y). The entire image is described by the function
This is also valid for television where the optical image being transmitted is projected by an optical system on the photosensitive cathode of a television camera tube; the number m in this case is determined by the resolving power of the tube and the dimensions of the television frame. The number m is limited in practice by the technical capabilities and purpose of the system. In USSR television broadcasting, one frame contains approximately 500,000 elements.
If the x and y coordinates of every element are known, the reproduction of the essential characteristics of an element requires the transmission of three of the element’s parameters—B, λ, and p—which itself requires three communications channels. In order to reproduce the entire image, 3m channels are needed. The number of channels required for stereoscopic television is doubled, because the images for the left and right eyes must be transmitted separately.
It is evident from the above that it is practically impossible to transmit all the elements of an image at the same time. Consequently, television uses the sequential transmission of images, element by element. This principle was proposed by the Portuguese scientist A. de Paiva (1878) and independently by P. I. Bakhmet’ev (1880). The feasibility of such transmission depends on a property of human vision, by which pulsating light is perceived as continuous if the frequency of the pulsations exceeds a critical value, dependent on the brightness of the source and equal to several tens of pulsations per second. The process of converting the elements of an image sequentially into electrical signals for transmission and the reverse process during reception are known as image scanning. These processes of analyzing and synthesizing an image must be carried out synchronously and cophasally.
Scanning procedure is determined by the purpose of a television system. Thus, for example, a modern television broadcasting system uses line scanning, which produces an image frame with a horizontal line structure. The scans are kept in phase by the transmission of synchronizing impulses at the end of every line and frame. A television station thereby controls the scanning of all television receivers within its operating range.
One of the first devices designed to transmit the elements of an image used a rotating disk with holes and was proposed by P. Nipkow (1884). The Nipkow disk was used in early, unperfected mechanical television systems. The image conversion and reconstruction processes in modern television are performed for the most part by means of cathode-ray tubes. The practical development of electronic television systems based on such devices took place in the late 1920’s and early 1930’s; important contributions were made by V. K. Zworykin and P. Farnsworth (USA), A. Campbell Swinton (Great Britain), and V. P. Grabovskii, S. I. Kataev, A. P. Konstantinov, B. L. Rozing, P. V. Timofeev, and P. V. Shmakov (USSR). The most commonly used television camera tubes include the vidicon, which uses the photoconductive effect, and the image orthicon, which uses the photoemissive effect. Various kinescopes are used as television picture tubes.
In the early days of television, only the brightness characteristic of each image element was transmitted. In black-and-white television, the brightness signal (video signal) at the output of the camera tube is amplified and converted. The communications channel used may be a radio channel or a cable channel. The signals picked up at the television receiver are converted in a single-beam kinescope with a screen coated with a phosphor that produces white light.
In color television, information is transmitted concerning the chrominance of every element together with the brightness component. Since the complete range of natural colors can be reproduced optically from the three primary colors—red, green, and blue—when the colors are mixed in specific proportions, a color television camera contains three tubes to create the brightness signal and the primary color signals. All the signals are coded for transmission at the broadcasting center and decoded during reception in the television receiver. A color kinescope has three beams and a mosaic screen formed by red, green, and blue phosphors.
Television systems are classified according to several major criteria. Such criteria include type of video signal—black-and-white (monochromatic), color, stereoscopic-monochromatic, or stereoscopic-color; signal form—analog or discrete (digital); and frequency spectrum of the communications channel—broadband, in which the passband is equal to or wider than the band of the broadcasting channel, or narrow band, in which the passband is narrower than the band of the broadcasting channel. Some systems can, in turn, be subdivided according to special criteria, such as the method used to scan images or the transmission sequence of certain information.
After years of use, television has become firmly established in people’s lives. Its widest use is in television broadcasting. Television equipment is also used to solve a variety of problems in science, medicine, and various branches of the national economy (seeNONBROADCAST TELEVISION, UNDERWATER TELEVISION, PROJECTION TELEVISION, and CLOSED-CIRCUIT TELEVISION SYSTEM).
Space television has been used in the USSR since 1962 as a means to conduct experiments in the study and conquest of space. Television is a necessity for artificial earth satellites and space stations launched into near-earth space. It has also made it possible to study the far side of the moon, which cannot be seen from the earth. Television equipment was used in a unique experiment to control the unmanned lunar self-propelled vehicles Lunokhod 1 and Lunokhod 2 from a distance of approximately 400,000 km. Television transmissions have been used to photograph the moon and several planets, including Mercury, Venus, Mars, and Jupiter. A striking example of the use of television in space occurred during the Soyuz-Apollo joint space flight in July 1975, which required the organization of complex television communication between two continents and with the spacecraft.
The demand for television has made it necessary to improve television systems and make use of the new capabilities of such systems. Future television developments include the application of cassette motion pictures to television, stereoscopic television, and the use of holography in the development of stereoscopic color television and multiple-angle television. Multiple-angle television produces a side view of a three-dimensional image being reproduced.
REFERENCESLazarev, P. P. Ocherki istorii russkoi nauki. Moscow-Leningrad, 1950.
Spravochnik po televizionnoi tekhnike, vols. 1–2. Moscow-Leningrad, 1962. (Translated from English.)
Televidente, 3rd ed. Edited by P. V. Shmakov. Moscow, 1970.
Shumikhin, Iu. A. Televidenie v nauke i tekhnike. Moscow, 1970.
Televizionnaia tekhnika. Moscow, 1971.
Kazinik, M. L., G. M. Makeev, and N. A. Safroshin. Osnovy televideniia, 3rd ed. Moscow, 1973.
Bratslavets, P. F., I. A. Rosselevich, and L. I. Khromov. Kosmicheskoe televidenie, 2nd ed. Moscow, 1973.
Samoilov, V. F., and B. P. Khromoi. Televidenie. Moscow, 1975.
Novakovskii, S. V. Tsvetnoe televidenie. Moscow, 1975.
In the USSR and other socialist countries, television is used to report the activities of communist and workers’ parties, the actions of government bodies, and workers’ participation in communist and socialist construction. It demonstrates individual features of the socialist way of life, molds public opinion, and helps provide for the ideological, moral, and aesthetic education of the masses. It also publicizes the peaceful foreign policies of these countries. As an active medium of communist education of the workers, Soviet television occupies an important place in the ideological work of the CPSU. It is a national tribune for public appearances by leading workers, kolkhoz workers, specialists on the national economy, state and party workers, scientists and scholars, literary figures, and artists.
In the USSR, television broadcasting covers the territory where the majority of the country’s population resides. International television systems make it possible for Soviet television programs to be received in the socialist countries and in many other countries.
Experiments with the transmission of images over a distance were begun in the USSR during the early years of Soviet power. V. I. Lenin attached great importance to television’s development prospects and applications. After receiving a report on Apr. 18, 1921, from the Nizhny Novgorod Radio Laboratory concerning the invention of a device that made it possible “to see a moving image on a screen,” Lenin requested support in perfecting this device and asked that he be informed of the results of further experiments. A mechanical television system that produced an image with 30-line scanning was developed in 1930 at the television laboratory of the All-Union Electrotechnical Institute under the direction of P. V. Shmakov. Low-definition television transmissions of nonmoving images began on a regular basis on Oct. 1, 1931. Transmissions for mechanical television systems were begun in Leningrad, Odessa, Kiev, Kharkov, Nizhny Novgorod, Smolensk, and Tomsk. The first transmission of a moving image was achieved in 1932, and sound accompaniment was added in 1934.
Special creative work in television was organized in the early 1930’s at the Moscow wire-broadcasting center. The first experimental, low-definition television transmissions included important examples of special social and political motion pictures made for television; the subjects of these films included the May Day celebration of the 15th anniversary of the October 1917 Revolution and the inauguration of the hydroelectric power plant Dneproges. Participants in the transmissions included M. I. Kalinin, G. K. Ordzhonikidze, N. V. Krylenko, N. A. Semashko, A. G. Stakhanov, V. P. Chkalov, S. S. Prokof’ev, I. M. Moskvin, and V. I. Kachalov. Special animated cartoons and excerpts from plays and concerts were also shown. There were 300 television transmissions in 1936, totaling approximately 200 hours.
A major improvement in the quality of television was achieved in the late 1930’s with the transition from low-definition mechanical television to electronic television. Experimental electronic television transmissions took place in 1938 from television centers in Moscow and Leningrad. The shift to electronic television vastly improved image quality, extended the creative potential of television, and created the conditions necessary for the development of wide-scale television broadcasting. Artistic programming accounted for the majority of transmissions, such as motion pictures, concerts, and theatrical performances. The first program expressly produced for television and the first program devoted to a specific theme—the 20th anniversary of the Komsomol —were shown on Leningrad television in 1938.
Regular electronic television programming was begun in 1939 in Moscow and Leningrad. On Mar. 10,1939, a film of the opening of the Eighteenth Congress of the ACP(B), made for television by Soiuzkinokhronika, was shown on Moscow television. The first program of major social and political importance portrayed the 20th anniversary of the First Horse Cavalry Army and was shown in November 1939. Television also began broadcasts of motion pictures, concerts, theatrical performances, and programs expressly made for the new medium. In 1940 the type 17-T-l electronic television receiver, which had a small screen but produced a clear image, was offered for sale.
During the years of the Great Patriotic War of 1941–45, television broadcasting in the USSR, as in other countries, was suspended. The first postwar program was broadcast on May 7, 1945. On Dec. 15, 1945, the Moscow television center became the first in Europe to resume regular broadcasting (twice a week), and the Leningrad television center resumed operation in 1947. Reconstruction of the Moscow television center was completed in 1949; broadcast transmissions had a standard definition of 625 lines. At the end of the 1940’s, the Moskvich T-l, Leningrad T-2, and KVN-49 television receivers went into mass production. Regular broadcasting of artistic and topical films began at the end of 1946.
Remote broadcasting, from outside the television studio, began in 1948. The first remote broadcast was of a soccer match in 1949. The technique of remote broadcasting substantially expanded the potential of television. In 1951 the Central Television Studio began operation, making it possible to carry on daily broadcasting in Moscow and to expand the number of documentary, social, political, and journalistic programs. In 1954 the studio was divided into separate departments for propaganda, industry, agriculture, science, and sports. Reports from factories, construction sites, sovkhozes, and kolkhozes became the principal form for documentary broadcasting.
In 1954 the first experimental color television transmissions were made in Moscow. In February 1956, Soviet television began broadcasting a second program from the Central Television Studio, which heralded the era of multiple programming for Soviet television. On May 1, 1956, the May Day parade and holiday demonstrations in Moscow’s Red Square were broadcast live for the first time. The 1957 World Festival of Youth and Students in Moscow was also given extensive coverage. Other innovations included regular programming devoted to the life of the country, events abroad, and films of theatrical performances, the first of which was the Malyi Theater production Truth Is Good, but Happiness Is Better (1951). The Committee for Radio Broadcasting and Television of the Council of Ministers of the USSR was established in 1957, and television reception was available throughout the country by the end of the 1950’s. In 1960 there were 103 television studios and relay transmitters in operation, and daily programming totaled 276.5 hours. In 1961 the USSR became a member of the international organization Intervision.
Transmissions from the spacecraft Vostok 3 and Vostok 4 in 1962 marked the beginning of space television. A third educational program of the Central Television Studio was established in 1965, the same year in which television programs were exchanged between Moscow and Vladivostok via the artificial satellite Molniia 1. In 1966 a color television program was transmitted for the first time from Paris to Moscow, and the country has enjoyed regular color programming since 1967.
A system of informative, journalistic programming was inaugurated in the 1960’s. The programs included daily installments of Television News (since 1960), the program Time (since 1968), and a series of broadcasts devoted to specific topics. The artistic organization Telefil’m was founded in 1961 at the motion-picture studio Mosfil’m, and the first artistic television serial, entitled We Draw the Fire on Ourselves, was shown in 1965. National television film festivals, the first of which was broadcast in Kiev, have been held since 1966.
The further development of television led to the establishment of the 50th Anniversary of the October Revolution Television Technical Center in Moscow (1967–70). An important achievement in motion-picture documentaries was the serialized documentary television film entitled Chronicle of a Half Century, which was devoted to the 50th anniversary of the October Revolution of 1917. The creative possibilities of television broadcasting were used extensively in preparing the cycles of programs In Lenin’s Footsteps (1969–70) and V. I. Lenin: A Chronicle of His Life and Work, which included approximately 40 artistic and documentary motion pictures and television films.
The CPSU and the Soviet government give constant consideration to television, including its development, the growth of its material and technical resources, the raising of the ideological and artistic level of broadcasting, and the role played by television in the shaping of the communist world view, the ideological struggle with the capitalist world, and the education of Soviet citizens to the new, communist attitude to labor. In the decree The Future Development of Soviet Television, issued by the Central Committee of the CPSU in January 1960, it was noted that television played an increasingly important role in the ideological work of the party and in the political and cultural education of the masses, and specific measures were cited for the further improvement of television broadcasting. The important role of television in the educational work of party, government, and public organizations has been underscored in the Program of the CPSU.
In 1970 the Committee for Radio Broadcasting and Television of the Council of Ministers of the USSR became a Union-republic body—the State Committee of the Council of Ministers of the USSR for Television and Radio.
The Soviet television system comprises Central Television and broadcasting services on the republic and local (krai and oblast) level. Central Television broadcasts six programs, two of which are for remote areas of the country.
Program 1—the main program—carries news, sociopolitical, artistic, and general information broadcasts for the entire Soviet Union. The average daily amount of broadcasting is 13 hours. It includes programs on important events in the political, economic, and cultural life of the USSR and abroad, coverage of holiday and ceremonial events, demonstrations, workers’ rallies, government meetings and other major political events, and broadcasts from space. The principal programs include News, Time, Lenin’s University of the Millions, Journal of Socialist Emulation, The Rural Hour, Heroic Deed, I Serve the Soviet Union, Science Today, A Word to the Scholar, Man and Law, and The Soviet Union Through the Eyes of Foreign Guests. Talks by political commentators are broadcast regularly, and international programs are discussed on the programs Cooperation and International Panorama. Popular general information series include Motion-Picture Travel Club, In the Animal World, The Obvious and the Incredible, Man, Earth, and Universe, Health, Motion-Picture Panorama, and Talks About Literature.
Television popularizes various types of music and art, produces festivals of Soviet songs, and cooperates with artistic societies to organize programs devoted to individual composers. A considerable portion of the programming is assigned to motion pictures and television films, broadcasts of theatrical and television performances, recitals by major artists, performances by amateur groups, and variety and comedy broadcasts, such as The Thirteen Chairs and Blue Light. Children’s programs include Meetings With Famous People, Campfire, and Alarm Clock, as well as special shows and animated cartoons. Test Yourself is a popular program for young people. Sports competitions are also broadcast.
A second Program 1, entitled East, is prepared for broadcasting
|Table 1. Distribution of television receivers in 1974 (millions)|
|1 Including the USSR|
|2 Including North Africa|
|3 Including Japan|
|4 Including the USA|
|Western Europe ...............||398.4||88.5|
|Eastern Europe1 ...............||355.7||63.5|
|Middle East2 ...............||158.9||3.5|
|North America4 ...............||231.0||106.3|
|Latin America ...............||282.1||18.2|
Program 2 provides broadcasts of news and artistic performances; it is received in many areas in the European part of the USSR. Daily programming averages 6 hours. Program 2 also includes broadcasts concerning workers in Moscow and Moscow Oblast.
Program 3 offers educational and popular-science broadcasts for students in primary schools, students in specialized secondary and vocational-technical educational institutions, and students and specialists within the national economy. It is received in many areas in the European part of the USSR. Daily programming averages 6.2 hours. Broadcasts for students on literature, geography, history, the principles of Soviet law, physics, and other subjects are intended for use during lessons and for individual review. Lessons in philosophy, the history of the CPSU, scientific communism, and mathematics are broadcast for students in correspondence courses. As part of a system for improving the qualifications of specialists within the national economy, Program 3 offers a series of broadcasts devoted to problems in economics, the scientific organization of labor, and production control; there are also special broadcasts for teachers, doctors, those studying foreign languages independently, including English, German, French, and Spanish, and those preparing to enter higher educational institutions. Participating in the program are research workers of the Academy of Sciences of the USSR, the academies of the Union republics, and branch academies, as well as instructors in the leading higher educational institutions, public figures, writers, major artists, teachers, and production specialists.
Program 4 offers broadcasts of artistic performances. Daily programming averages 3½ hours and is chiefly composed of re-broadcasts from Program 1.
In 1975, republic and local (krai and oblast) television broadcasting was conducted from 130 television program centers (78 in the RSFSR and 52 in other Union republics), with total daily programming averaging over 2,000 hours. The programs deal with local issues for the most part, and they are coordinated thematically and in format with the programs of Central Television, which they supplement. All Union and autonomous republics receive programs in the native language together with Central Television broadcasts. Programs on the life of the republics, krais, and oblasts are prepared regularly for Central Television. Two or more programs are available for viewing in the capitals of the Union republics and in ten major cities—Leningrad, Volgograd, Sverdlovsk, Novosibirsk, Gorky, Saratov, Cheliabinsk, Petrozavodsk, Vladivostok, and Perm’. Color programs are broadcast regularly in Moscow, Leningrad, Kiev, Tashkent, Tbilisi, Yerevan, Baku, Tallinn, Vilnius, and Riga, averaging 200 hours of broadcasting per week.
The receiving and transmitting television network consists of more than 1,800 repeater stations, more than 70,000 km of radio-relay links, and approximately 70 receiving stations for the Orbita space communications system. In areas where reception is reliable, there are, on the average, 98 television receivers per 100 families. In 1975 the population owned a total of 60 million television receivers, including more than 1 million color receivers.
Central Television prepares and broadcasts programs through its Main Editorial Office, its Main Programming Board, and the 50th Anniversary of the October Revolution Television Technical Center. Television films are produced through artistic cooperation between television studios and major motion-picture studios. The foremost television studio is the Ekran studio of the State Committee of the Council of Ministers of the USSR for Television and Radio. Central Television received approximately 2 million letters in 1975.
Abroad, regular television broadcasting began in 1936 in Great Britain and Germany and in 1941 in the USA. It became widespread in Europe in the 1950’s and throughout the developing nations in the 1960’s. The distribution of television receivers in various areas of the world in 1974 is shown in Table 1 on page 485.
In the other socialist countries, television is a government enterprise and is generally available to the entire population. Two programs and color broadcasting are available daily. Statistics on the number of television receivers owned in some socialist countries are given in Table 2. The television organizations of the socialist countries cooperate with each other to exchange broadcasts, produce joint programs, and coordinate plans. There is also cooperation within the framework of Intervision.
Both government-operated and commercial television exist in the developed capitalist countries. The leading television organizations include the Columbia Broadcasting System (CBS), National Broadcasting Company (NBC), and American Broadcasting Company (ABC) in the USA; the British Broadcasting Corporation (BBC) and Independent Broadcasting Authority (ITV) in Great Britain; Radiotelevisione Italiana (RAI) in Italy; Nippon Hoso Kyokai (NHK) in Japan; and Arbeitsgemeinschaft der öffentlichrechtlichen Rundfunkanstalten der Bundesrepublik Deutschland (ARD) and Zweites Deutsches Fernsehen (ZDF) in the Federal Republic of Germany. These countries have two or more programs, and daily broadcasts with multiple programming average from 150 to 200 hours.
|Table 2. Number of television receivers and extent of weekly programming in selected socialist countries (Jan. 1,1975)|
|Receivers (millions)||Programming (hr per week)|
|German Democratic Republic ...............||4.8||120|
Television in the developing countries is usually a state enterprise. It is second to radio broadcasting as a mass medium of information, education, and entertainment. Much importance is attached to the teaching and educational functions of national television. There is usually one program offered during the evening. Group viewing in clubs is the usual practice because there are not enough television receivers for individual viewing.
World and regional television organizations and unions are concerned with the technical, programming, and legal aspects of television within the framework of multilateral international cooperation. The allocation of wavelengths is subject to the authority of the International Telecommunication Union. International exchange of television programs takes place through Intervision and Eurovision, the Asian Broadcasting Union (founded 1964), the Union of National Radio and Television Organizations of Africa (1962), the Inter-American Association of Broadcasters (1946), and the Arab Telecommunications Union (1958). Television broadcasts are also exchanged via satellites—Intersputnik (1971), which is part of the international space communications system for the socialist countries, and Intelsat (1964), which links the USA, the European countries, and several other countries.
REFERENCESLenin, V. I. Poln. sobr. soch., 5th ed., vol. 52.
KPSS v rezoliutsiiakh i resheniiakh s”ezdov, konferentsii i plenumov TsK, 8th ed., vol. 7 (1955–59). Moscow, 1971.
Voprosy ideologicheskoi raboty: Sb. vazhneishikh reshenii KPSS (1954–1961). Moscow, 1962.
Sb. vazhneishikh reshenii KPSS (1965–1973), 2nd ed. Moscow, 1973.
O partiinoi i sovetsskoi pechati, radioveshchanii i televidenii: Sb. dokumentov i materialov. Moscow, 1972.
Materialy XXVs”ezda KPSS. Moscow, 1976.
Il’in, R. N. lzobrazitel’nye resursy ekrana. Moscow, 1973.
Iurovskii, A. Ia. Televidenie—poiski i resheniia. Moscow, 1975.
Sappak, V. S. Televidenie i my. Moscow, 1963.
Kravchenko, L. P. Tainy golubogo ekrana. Moscow, 1974.
Davis, D. Azbuka televideniia. Moscow, 1962. (Translated from English.)
S. G. LAPIN