The working principle of television briefly. Types of modern television. Where did television begin?

Terrestrial television distributes the signal using terrestrial repeater stations.

This type of television is most common in Russia today.

Advertising on terrestrial television today reaches such a number of potential buyers that no other medium reaches - neither radio, nor newspapers and magazines, nor the Internet, nor street advertising, etc.

The number of people watching television is in the millions.

Digital terrestrial television has high quality picture and sound. Increasing the number of transmitted channels in the same frequency range (when transmitting an image, not every frame is transmitted (this is the operating principle of analog television), but only those elements of the frame that have changed their characteristics (color, brightness, etc.) in relation to the previous frame As a result, instead of one analog channel, you can use 5-7 digital channels. The third feature of digital television is the availability of related services.

Television is a field of science, technology and culture associated with the transmission of visual information (moving images) over a distance by radio-electronic means; the actual method of such transfer. Along with radio broadcasting, television is one of the most widespread means of disseminating information and one of the main means of communication, used for scientific, organizational, technical and other applied purposes. The final link in a television transmission is the human eye, so television systems are built taking into account the peculiarities of vision. The real world is perceived by a person visually in colors, objects - in relief, located in the volume of some space, and events in dynamics, movement: therefore, an ideal television system should provide the ability to reproduce these properties of the material world. In modern television, the problems of transmitting motion and color have been successfully solved. Television systems capable of reproducing the relief of objects and the depth of space are at the testing stage.

Television reception with a kinescope The television has a magnetically controlled cathode ray, called a kinescope. In a kinescope, an electron gun creates an electron beam that is focused on a screen covered with crystals that can glow when struck by fast-moving electrons. On their way to the screen, the electrons fly through the magnetic fields of two pairs of coils located outside the tube. The transmission of television signals to any point in our country is provided with the help of relay artificial Earth satellites in the Orbit system.

The antenna of the television receiver receives ultrashort waves emitted by the antenna of the television transmitter, modulated by the signals of the transmitted image. To receive stronger signals in the receiver and reduce various interferences, as a rule, a special receiving television antenna is made. In the simplest case, it is a so-called half-wave vibrator, or dipole, i.e. a metal rod with a length slightly less than half the wavelength, located horizontally at right angles to the direction of the telecenter. The received signals are amplified, detected, and amplified again in the same way as conventional receivers for receiving audio broadcasts. A feature of a television receiver, which can be direct amplification or superheterodyne type, is that it is designed to receive ultrashort waves. The voltage and current of the image signals obtained as a result of amplification after the detector repeat all changes in the current that modulated the television transmitter. In other words, the image signal at the receiver accurately reflects the sequential transmission of individual elements of the transmitted object, repeated 25 times per second. The image signals affect the television receiving tube, which is the main part of the television. How does television reception work?

The use of a cathode ray tube for receiving television images was proposed by B. L. Rosing, a professor at the St. Petersburg Institute of Technology, back in 1907 and ensured the further development of high-quality television. It was Boris Lvovich Rosing who laid the foundations of modern television with his works.

Kinescope A kinescope is a cathode-ray device that converts electrical signals into light. Main parts: 1) electron gun, designed to form an electron beam, in color picture tubes and multi-beam oscillographic tubes they are combined into an electron-optical spotlight; 2) a screen coated with a phosphor substance that glows when a beam of electrons hits it; 3) deflection system, controls the beam in such a way that it forms the required image.

Historically, television has evolved from transmitting only the brightness characteristics of each image element. In a black-and-white TV, the brightness signal at the output of the transmitting tube is amplified and converted. The communication channel is a radio channel or a cable channel. In the receiving device, the received signals are converted into a single-beam kinescope, the screen of which is covered with a white phosphor.

1) Electron guns 2) Electron beams 3) Focusing coil 4) Deflection coils 5) Anode 6) Mask, thanks to which the red beam hits the red phosphor, etc. 7) Red, green and blue phosphor grains 8) Mask and phosphor grains (enlarged). Color kinescope device

Red blue green Transmission and reception of color images require the use of more complex television systems. Instead of one falling tube, three tubes are required, transmitting signals of three single-color images - red, blue and green. red green blue blue red green The kinescope screen of a color TV is covered with three types of phosphor crystals. These crystals are located in separate cells on the screen in a strict order. On a color TV screen, three beams simultaneously create three images of red, green, and blue. The overlay of these images, consisting of small luminous areas, is perceived by the human eye as a multi-color image with all shades of colors. At the same time, the glow of crystals in one place in blue, red and green is perceived by the eye as white, so black and white images can also be obtained on a color TV screen.

(TK-1) The first TV for individual use KVN-49 Teleradiola "Belarus-5" Color TVs "Minsk" and "Rainbow"

Conclusion In conclusion, I would like to say that a fairly large amount of popular science literature, as well as encyclopedias and reference books, was studied. The principle of radio communication, the processes of amplitude modulation and detection were studied in detail. Based on what has been studied, the following conclusions can be drawn: Radio played a huge role in the life of mankind in the 20th century. It occupies an important place in the economy of any country. Thanks to the invention of radio in the 20th century, various means of communication received enormous development. Scientists around the world, including Russian and Soviet ones, continue to improve modern means of communication. And without the invention of radio this would hardly have been possible. By 2014, information transfer via digital communications will be introduced in our country.

References 1. I.V.Brenev "Invention of radio by A.S. Popov" MOSCOW "Soviet radio" B.B. Bukhovtsev, G.Ya. Myakishev "Physics. Textbook for 11th grade of educational institutions" Moscow "Enlightenment" edition 3. V.S. Virginsky, V.F. Khoteenkov "Essays on the history and science of technology." MOSCOW "Enlightenment" F.M. Dyagilev "From the history of physics and the lives of its creators" MOSCOW "Enlightenment" O.F. Kabardin, A.A. Pinsky "Physics 11th grade. Textbook for educational institutions and schools with in-depth study of physics" Moscow "Enlightenment" edition 6. V.P. Orekhov "Oscillations and waves in a high school physics course" Moscow "Enlightenment" 1977 7. Popov V.I. Basics of cellular communications of the GSM standard ("Engineering Encyclopedia of the Fuel and Energy Complex"). M., "Eco-Trends", 2005

And the words “vision”), an area of ​​science, technology, culture associated with the transmission over a distance of images of objects and sound (speech, music) using radio signals (terrestrial television) or electrical signals transmitted through wires (cable television). The principle of television is to sequentially transform image elements into electrical signals over time (image analysis), transmit these signals through communication channels to a receiving point, and convert them back into a visible image (image synthesis). The origins of television date back to the beginning of the 20th century. However, the practical development of television began in the early 1930s. after the invention of the transmitting television tube and kinescope.

Historically, television has developed from transmitting only the brightness characteristics of each image element (black and white television). By the beginning of the 50s. Electronic color television systems were developed in the USA, Russia and then in other countries. In modern standard color television systems (for example, SECAM, PAL), compatible with black and white, 2 types of signals are transmitted simultaneously: a brightness signal, which carries information about the brightness of the transmitted scene; a chrominance signal (formed by two so-called chromaticity signals), carrying information about its color. In Russia, television broadcasting is carried out in the range of meter (12 television channels) and decimeter (over 40 television channels) waves; Television programs are almost entirely transmitted in color. At the end of the 80s. High-definition television systems have been developed (over 1000 lines instead of the usual 625); Digital television systems are being developed in which the transmitted television signal is a sequence of code (digital) combinations of electrical pulses.. 2000 .

Synonyms

See what "TV" is in other dictionaries: A television …

Spelling dictionary-reference book This is when people who have nothing to do look at people who don't know how to do anything. Fred Allen Television is proof that people will watch anything to avoid looking at each other. Ann Landers Television... ...

Consolidated encyclopedia of aphorisms Big Encyclopedic Dictionary

An area of ​​science, technology and culture associated with the transmission over a distance of images of moving and stationary objects using electrical signals propagating through a communication channel. Television is a means of disseminating political... Financial Dictionary

A television- (from television... and the word “vision”), a field of science, technology, culture associated with the transmission over a distance of images of objects and sound (speech, music) using radio signals (terrestrial television) or electrical signals,... ... Illustrated Encyclopedic Dictionary

An area in science and technology associated with the transmission over a distance of images of stationary and moving objects and using radio-electronic devices. The transmission of images is a sequence of three physical. processes:… … Physical encyclopedia

Television, televidka, blue screen, television, television garbage chute, electronic press, television, television broadcasting Dictionary of Russian synonyms. television blue screen Dictionary of synonyms of the Russian language. Practical guide. M.: Russian language. Z.E.... ... Synonym dictionary

TV- Transmission and reception at a distance of images of moving or stationary objects by electrical means with or without sound. [GOST 21879 88] Topics: television, radio broadcasting, video General terms, terms and... ... Technical Translator's Guide

TELEVISION, a system that transmits and receives visual images using RADIO WAVES or CABLE. A television camera converts light rays (coming from an object) into electrical signals. The basis of most television cameras is orthikon,... ... Scientific and technical encyclopedic dictionary

TELEVISION, television, many. no, cf. (neol. tech.). Vision at a distance using electrical methods of communication via wires or radio. see tele…. Ushakov's explanatory dictionary. D.N. Ushakov. 1935 1940 ... Ushakov's Explanatory Dictionary

Books

• Television, N.K. Ignatiev. Moscow, 1958. State publishing house of literature on communications and radio. Publisher's binding. The condition is good. The publication is a textbook for technical schools…

It is difficult for us to imagine our life without television. Even if we don't watch it, it is still a vital part of our culture. Meanwhile, this invention is just over 100 years old. Television, whose history of origin and development fits into such a short period by the standards of history, has radically changed our communication, attitude to information, our states and culture.

Invention

The history of the invention of television lasts almost 100 years. Unlike radio, which was discovered simultaneously by two people in different parts of the world, television is a complex, step-by-step creation of technology. Each country has its own version of the history of the discovery of television, which emphasizes the participation of its scientists in this process. This is explained by the fact that the technology was created by entire teams in the form of solving individual technical problems. In order not to go into technical details, we will name the main engineers involved in this event.

At the origins is Willoughby Smith, who invented the photoelectric effect in selenium. The next stage of the discovery is associated with the name of a Russian scientist who patented an electrical method for transmitting images. Also, contributions to the discovery were made by P. Nipkov, D. Baird, J. Jenkins, I. Adamyan, L. Termen, who independently create transmitters for broadcasting images in different countries. The next round of technology development is associated with the advent of electronic television. M. Dickmann and G. Glage documented the creation of a tube for transmitting images. But the first patent for the technology, which is still used in televisions today, was received by Boris Rosing in 1907. Then a whole galaxy of scientists worked to improve the technology. And in 1931, engineer V. Zvorykin creates an iconoscope, which is considered the first television. Based on this invention, F. Farnsworth creates a kinescope. This is how the history of the creation of television briefly looks like.

Work principles

In 1928, with the beginning of regular broadcasting, the real history of the emergence of television begins. Ulysses Sanabria was the first to use radio waves to transmit images and sound. The principle of operation of television is a special projection of the image onto a photosensitive plate in a cathode ray tube. For a long time, the history of television was associated with the improvement of this tube, which led to improved picture quality and an increase in screen surface. But with the advent of digital broadcasting, the principle changed; now a kinescope with a ray tube is no longer needed. It uses a completely different way of transmitting images. It is encoded and transmitted using digital channels and Internet systems.

Types of television

The long history of the development of television has led to the formation of numerous types. Firstly, it is divided into black and white and color. Until 1950, all televisions showed only black and white pictures. Two color television standards: NTSC and SECAM are still in use throughout the world. Television can also be divided into paid and free. In every country there is a set of channels that anyone with a TV can watch. But there are also channels whose signal can only be seen for money. Forms of payment may be different, but the share of such television steadily remains at 30% of the entire market.

Based on the method of signal transmission, television can be divided into:

• terrestrial, in this case the television receiver receives a signal from a television tower, this is the most familiar and widespread method of broadcasting;
• cable, in this case the signal comes from the transmitter via a cable connected to the TV;
• satellite - the signal is transmitted from a satellite and is picked up by a special antenna, which transmits the image to a special set-top box connected to the TV;
• Internet television, in this case the signal is transmitted via the Internet.

Based on the method of encoding information, television is divided into analog and digital. The second is of higher quality thanks to the latest encoding and transmission standards.

Television functions

Television has long been an important social phenomenon; it has many significant functions. Due to its enormous reach, accessibility and persuasiveness, television is the most important. Television is an effective tool for disseminating information to a large part of the population.

Thus, the history of television can be briefly described by the word “informing”. The second most important function is that it is not in vain that politicians and advertising are so eager to get on TV; it is this channel that allows you to convince a person of the correctness of a particular point of view and influence his behavior. Television also performs a cultural and educational function. It also transmits values, disseminates socially approved standards, it conveys knowledge to a person, and forms in him criteria for evaluating events and phenomena. Television is also capable of performing an integrative function, as it can unite people into certain communities. Like all media, television performs an educational function: it talks about what is good and evil, sets moral norms and values. And, of course, television performs an entertainment function; it helps a person relax and enjoy watching a TV show.

Types of television programs

The entire history of television is a path of searching for new formats of television programs. Channels are fighting for viewers and therefore are forced to create more and more new varieties. Modern television content can be divided into the following types:

• Entertainment programs. Television is the main means of leisure for many people, so channels try to offer a variety of entertainment programs for different groups of viewers.
• Information broadcasts. The history of the emergence of television is associated primarily with the need to disseminate information, and many people still turn on the TV in order to find out the news and gain additional information about phenomena and facts.
• Infotainment programs. The combination of two important functions makes it possible to interest a larger number of viewers, and therefore producers are trying to combine the two formats in one type of program.
• Educational programs. These programs are aimed at deepening and expanding knowledge on any issue. They provide viewers with useful information, allow them to learn something new and expand their horizons.
• Socially activating programs. This content is aimed at mobilizing viewers, involving them in some socially significant activity, for example, elections.

The emergence and development of television broadcasting in the world

In 1928, the first television station began operating. Ulysses Sanabria first began transmitting images and sound over the frequencies of his radio station. But they were unable to begin regular broadcasting due to the Great Depression. The widespread history of television with regular broadcasting begins in 1934 in Germany. For the first time in history, the German television company RRG broadcast the Berlin Olympics on a television channel. In 1936, regular broadcasting was established in Great Britain. A little later, television companies appeared in the USA and the USSR.

In 1950, the United States introduced a new color television standard for the first time, and almost instantly this trend was picked up in all developed countries. In 1967, Europe and the USSR introduced their own color television standard. A television culture is gradually being formed, a system of genres is being developed, archives of programs are being created, and professional television journalists and presenters are appearing. In the second half of the 20th century, television became widespread; it existed in almost every home on Earth.

The history of television can be briefly described as a quest for world domination. Television has always competed with cinema, theater, and mass entertainment, but in the end it occupied its niche in modern culture, neither winning nor losing the competition.

The arrival of television in Russia

The history of the development of television in Russia begins late compared to other developed countries. This was prevented by the Second World War, which posed other, more pressing tasks for the state. Regular broadcasting began in 1931, when a medium wave broadcaster was launched. At first, only 30 mechanical televisions accept it; later, Russian craftsmen begin making homemade receivers. In 1933, production of attachments for the B-2 radio receiver began to be produced for receiving domestic television signals. In 1949, serial production of domestic KVN televisions began. In 1951, the Central Television of the USSR State Television and Radio was created. In 1959, experiments were carried out to launch color broadcasting. In 1965, the USSR launched the first satellite, which made it possible to broadcast a television signal throughout the country.

The massive history of television in Russia begins in 1951, when the central studio began operating. The Soviet government took the creation of the television company very seriously, understanding its enormous potential to influence the minds of the country's population. Therefore, the government took a thorough approach to organizing the work of the studio; it opened several thematic editorial offices: socio-political, for children and youth, music, literary and dramatic. A year later, the Leningrad Television Studio appeared. Both television studios are subordinate to the USSR Ministry of Culture.

Until 1965, broadcasting was carried out only in Moscow and Leningrad. In the second half of the 50s, television studios appeared in many regions; they filmed stories for the central studio. At the end of the 60s, broadcasting began to spread to European territory, and since 1965 - to the entire country. New editions are gradually appearing: “Latest news”, “First program”, “Moscow program”, “Educational program”, etc. The broadcasting time is expanding, and new channels appear over time. There is a division by numbers: the Central Studio broadcasts on the first number, and local programs on the second. In the early 80s, republican television studios appeared. Central Television begins to launch several takes for different regions.

New television of Russia

With perestroika, approaches to the work of television are changing, and the possibility of organizing independent television companies appears. The history of the creation of a new format of television begins with the emergence of the VID television company. It is organized by young journalists V. Listyev, A. Lyubimov, A. Razbash, D. Zakharov. The broadcaster begins to create various products and sells them to new broadcasters. In 1989, the corporatization of existing television studios began, new organizations appeared: Ostankino, VGTRK, Petersburg - Channel 5. The main frequencies are distributed between them, and small television companies begin to film various programs for them. In 1996, the rapid growth of new television companies of various sizes began, from large ones, such as NTV and Ren-TV, to the smallest, city level. This diversity leads to the fact that many programs of various types appear on the air: from political to entertainment. The number of television professionals is growing in the country, television is becoming an economically profitable field of activity.

Since 2006, a clear division into state and commercial television has begun, between which there is intense competition for viewers. Today in Russia there are about 3,200 television companies that create products for all groups of viewers.

Commercial television in Russia

The history of Russian television repeats the history of the entire country. Therefore, when the USSR collapsed and a state emerged with new economic and political principles, television was also forced to change. Thus, commercial television appears, which, in addition to the previously listed functions, pursues the goal of generating economic profit. The commercialization of television leads to the emergence of advertising, which is a source of finance. The pay television segment is also emerging, which includes cable, satellite and Internet television.

In Russia, this process is extremely slow, the majority of the population is not ready to pay for a television product, and commercial channels cannot offer much unique content that would compete with free television. The development of pay television has been further complicated by the Internet, where Russians can get almost any information for free. However, it can be seen that Russian residents are gradually getting used to services such as cable and satellite television, which bring a large number of channels into the home for a small amount of money.

With great difficulty, but purely commercial television is being formed, which exists only through the sale of its television product. Such an example is, for example, the independent television company Dozhd, which exists by selling subscriptions to its channel and attracts viewers with unique original programs. The history of the creation of pay television in the West has a much more successful history. In Russia, however, commercial television is still trying to exist at the expense of advertisers, attracting a large number of viewers for free.

Digital television

The entire history of television is connected with the development of technological progress. It influences changes in image transmission technology and determines the emergence of new types of television. Thus, with the emergence of digital technologies, corresponding television appears. There are several options for transmitting a digital signal: cable, satellite and terrestrial. The latest technologies allow television receivers with a special decoder to receive digital signals along with analogue ones. Digital technology allows you to quickly broadcast high-definition images over any distance. Depending on the type of encoding, there are several world standards: European, Japanese and American. The main advantages of digital television over analogue are as follows:

• reduction of interference during signal transmission;
• increase in transmitted programs in one frequency range;
• improving the quality of transmitted images and sound;
• the possibility of interactive interaction with the viewer, he can choose the viewing time, review programs, order certain content;
• the ability to transmit additional information, except television programs.

Today, all over the world, analogue transmitters are rapidly being replaced by digital ones. Russia has also adopted a program to replace analogue broadcasting with digital; today all main channels transmit two types of signals, but the number of analogue channels will gradually decrease. Over time, when all viewers replace the television receivers in their homes with modern ones, it will come to naught.

Modern trends in the development of television in the world

From television it changes its vector. Today, every major television company creates an electronic version of the channel, where you can watch TV shows, leave comments, and make some requests. Television is changing the model of interaction with viewers; now channels are constantly striving to involve viewers in communication. And obviously, this trend will only develop. Viewers already have the opportunity to leave comments, vote, and ask questions to the program characters. Apparently, in the near future the broadcast grid will lose its relevance; each viewer will create his own grid upon request. The modern viewer is increasingly becoming a consumer, and his interests will continue to determine the form of information presented on television. The trend of integrating television with electronic media will apparently only increase. The TV will become not only a receiver of television content, but also a multifunctional device.

Prospects for the development of television in Russia

Modern television is moving in the same direction as global television. In 2004, access to the fiber-optic method of transmitting a television signal was achieved for the first time in Russia. Thus opened a new era of Internet television. Today, television companies are under strong pressure from electronic media, which attract viewers, especially young people. Therefore, it is obvious that the history of television in Russia will develop in competition and cooperation with the Internet. Today, 99% of households are covered by television broadcasting, but there is an emerging trend of abandoning televisions, especially in young families in the capital region. Apparently, the existing diversity of television companies will decrease slightly due to those migrating to the Internet, the specialization of companies will increase, and the division into broadcasting and production companies will become more intense.

In a cathode ray video camera mosaic screen 1 is formed by several million isolated from each other silver grains coated with cesium. They are located on a mica plate 2, glued to a metal plate 3. Light 5 falling on the grains is capable of “knocking out” electrons from them, which “flow down” through the collector 4.
Depending on the brightness of the light, each grain acquires a greater or lesser positive charge. The charges of all the grains of the mosaic “describe” the image. The elements at the bottom left of the video camera create scanning electron beam. Consistently hitting the grains, the beam gives up its electrons in place of those knocked out by light. “Recharging” occurs - the grains change charges from “+” to “-”. Note that the grains, together with the metal plate 3, form a variety of microscopic capacitors. When they are sequentially recharged, a varying current—a video signal—appears in the external circuit between the metal plate 3 and the collector 4.
In a cathode ray video monitor An electron beam is also used to convert the video signal into an image. Its intensity (the flow of flying electrons) changes in accordance with the video signal. Getting on a mosaic screen consisting of grains of the phosphor substance, electrons cause them to glow. It lasts for some time while the beam “runs around” other grains on the screen, which we perceive as a video image.
In these devices electron beams scan the screens synchronously with a frequency of 25 Hz, that is, they run through them simultaneously 25 times per second (line by line, like reading a book). This allows you to transmit and receive rapidly changing images.
In a semiconductor video camera The mosaic screen (matrix) is formed by several million “electronic pockets” in a p-type silicon wafer, above which control electrodes are located. If a positive charge is applied to them, then a pocket in the silicon wafer under the electrode “opens” and electrons released under the influence of light accumulate in it. Accordingly, holes formed at the sites where electrons are released are pushed by the electric field into the thickness of the plate. The number of electrons accumulated in the pocket depends on the brightness of the image fragment falling on it. The charges of all pockets together “describe” the image.

Under the influence of control signals from a special microprocessor, a sequential “reading” of the charge of the pockets is carried out. As shown in the figure, at the moment of “capturing” the image, there is a charge only on the first electrode. This charge is then switched to the next electrode and the electrons move to the adjacent pocket. And so on, to the edge of the screen, where additional electrodes are located, to which the video signal “flows.”
In a semiconductor video monitor A layer of “liquid crystals” is used to convert the video signal into a light image. It is enclosed between special translucent films with a mosaic grid of control electrodes. The microprocessor sequentially distributes the video signal to all mosaic elements. Electric fields generated between the electrodes cause the crystals of each piece of the mosaic to rotate differently in the liquid layer. Depending on this, the amount of light transmitted by each mosaic element changes. As a result, we see an image made up of individual points - pixels.
By the end of the 20th century, black and white television was replaced by color television. His the basic principles remain the same: mosaic screen in the transmitter and receiver, sequential scanning of mosaic elements by an electron beam or microprocessor to form a video signal or light image, transmission of a video signal by radio waves. Only the mosaic of screens became more complicated: each of its elements was replaced with a red-green-blue triad of elements capable of transmitting all shades of colors.