1. Introduction to television (write the history, function, and appearance of the television) is 500
Television uses electricity to transmit moving visual images in real time .Similar to movies, TV uses the visual residual effect of the human eye to display a frame-by-frame gradient of still images to form a visually moving image. The transmitter of the TV system converts each detailed part of the scene into electrical signals according to brightness and chromaticity. , transmitted sequentially. At the receiving end, the brightness and chromaticity of each minute part are displayed according to the corresponding geometric position to reproduce the entire original image. Its first appearance was on October 2, 1925. The Scotsman John Logie In an experiment in London, Baird "scanned the LCD TV and traced" the image of the puppet as a sign of the birth of television. He is called the "Father of Television". However, this view is controversial because, It was also that year that the American Sfrokin showed his television system to his bosses at Westinghouse. Although the time was the same, the television systems of John Logie Baird and Sfrogin were very different. The difference. Historically, John Logie Baird's television system was called mechanical television, while Sfrokin's system was called electronic television. This difference is mainly due to the difference in transmission and reception principles. Television The development of television is complicated. Many people are doing the same research at almost the same time. There are several sizes of TV sets - 5 inches, 14 inches, 18 inches, 21 inches, 25 inches, 29 inches, 34 inches, rear projection my country's first black-and-white TV set was born in 1958. During the Great Leap Forward boom, Tianjin 712 Factory's domestically produced electron tube heart part, a part of the Soviet Union's components, produced a Beijing-brand 14-inch black-and-white TV set. At that time, my country's TV development technology and Japan is basically on the same starting line. The development of television shows the rapid development of our country. This is really exciting. 2. What is the historical development process of television?
The origin of television: In 1934, Sun Mingjing, as Yang Jianchu’s assistant at the School of Science of Nanjing Central University, developed China’s first set of cameras that could record, transmit, receive and play TV prototype.
Yang Jianchu identified "TV" as the corresponding name of television in Chinese. In 1939, Sun Mingjing officially listed "Television" as the 13th subject in the Jinling University curriculum, and "Television" officially became a Chinese university curriculum.
System Structure Signal System The TV signal system includes three parts: public signal channel, sound channel and video amplifier final circuit. Their main function is to process the received high-frequency TV signal. Integrated circuit TV uses three integrated circuits (including image signals and accompanying sound signals) to amplify and process them, and finally reproduce the images on the fluorescent screen and restore the accompanying sounds in the speakers. It consists of three parts: high-frequency amplifier, mixer and local oscillator.
The function of the high-frequency amplifier is to select and amplify the high-frequency TV program signal received by the high-frequency tuner, and obtain the image mid-frequency signal and the audio mid-frequency signal through mixing processing. The role of the acoustic surface of the intermediate frequency (first intermediate frequency) signal is to form the amplitude-frequency characteristics of the image.
The function of pre-amplification: amplify small signals (20 dB amplifies a small amount) to compensate for the signal loss caused by the surface acoustic filter. . 3. History of TVs
The history of TVs has gone from tube TVs to transistor TVs to semi-integrated circuit TVs and later to large integrated circuit TVs and the current super integrated circuit TVs. In terms of performance, it has also evolved from simply watching TV to multimedia TVs and smart TVs capable of human-computer interaction.
At the end of the 19th century, a few pioneers began to research and design technology for transmitting images. In 1904, the British Bellwell and the German Cologne invented television technology that could telex one photo at a time. It took 10 minutes to send each photo. In 1924, British and German scientists almost simultaneously used mechanical scanning to successfully transmit still images. However, the distance and range of cable mechanical television transmission are very limited, and the images are also quite rough.
(1) In 1923, the Russian-American scientist Zvorykin applied for patents for photoelectric picture tubes, television transmitters and television receivers, and for the first time adopted a comprehensive "electronic television" sending and receiving system, becoming Pioneer of modern television technology.
The application of electronic technology in television brought television out of the laboratory and into public life. In 1925, British scientists successfully developed a television. In 1928, 31 radio stations in New York, USA, conducted the world's first television broadcast experiment. Since the picture tube technology had not yet fully passed the test, the entire experiment only lasted 30 minutes, and only a dozen TV sets were watched. The advent of television art for social welfare is an epoch-making event in the history of television development.
In 1929, American scientist Ives invented color television by broadcasting 50 lines of color television images between New York and Washington. In 1933, Zvorygin successfully developed a camera tube and a picture tube for television cameras. The process of completely electronicizing television photography and display was completed. At this point, the modern television system has basically taken shape. Today's imaging principles and equipment for television cameras and television reception are based on Eaves' invention.
(2) The development of television art in the United Kingdom and the United States: The textbook emphasizes that from the 1930s to the 1940s, television art developed significantly in the United Kingdom and the United States. It is recommended that teachers combine the teaching materials and supplement the information appropriately.
On November 2, 1936, the British Broadcasting Corporation broadcast a large-scale song and dance program at Alexandria Palace outside London, and launched a two-hour daily television broadcast for the first time. There were only more than 200 viewing television sets in London, but it marked the beginning of the world television industry. The coverage of the Berlin Olympics that year was a grand debut for the young television career. At that time, *** used 4 cameras to film the game. The most striking of these is the fully electronic camera. This machine is huge. Its 1.6-meter focal length lens weighs 45 kilograms and is 2.2 meters long. It is nicknamed a TV cannon. Since then, relatively expensive televisions have become more common in middle- and upper-class households in the UK. In 1937, when the company broadcast the coronation of King George V, 50,000 viewers in the UK were watching. In 1939, when World War II broke out, about 20,000 households in the UK had televisions.
On April 30, 1939, the American Radio Company transmitted the television programs of President Roosevelt delivering the opening speech at the World's Fair and the mayor of New York City leading the crowd to march through the transmitter on the roof of the Empire State Building. Thousands of people lined up in department stores to watch the spectacle. At the end of World War II, there were approximately 7,000 television sets in the United States. Before World War II, countries such as Germany, France, and Italy also started television. 4. The history of television
The first television set was invented by British electronic engineer John Baird in 1924. By 1928, the RCA TV station in the United States took the lead in broadcasting the first TV series " FelixTheCat", since then, television has begun to change human life, information dissemination and way of thinking.
Since then, mankind has entered the television era. ——From black and white to color, from analog to digital, from spherical to flat, my country’s color TV industry started in the mid-1970s and has gone through three historical periods, namely the introduction period from the mid-1970s to the early 1980s, and the introduction period from the mid-1980s to the early 1980s. The growth period in the early 1990s, and the maturity period in the mid-to-late 1990s.
my country’s first black-and-white TV was born in 1958. During the Great Leap Forward craze, Tianjin 712 Factory used domestically produced electronic tube components, which were part of the then Soviet Union, to produce a Beijing brand 14-inch black and white TV set.
At that time, my country's TV development technology was basically on the same starting line as Japan's. On December 26, 1970, my country's first color TV set was born at the same location, kicking off China's color TV production.
However, due to the restrictions of economic conditions at the time and the influence of the political situation, the development of color TV sets in my country was slow in the 1970s. Key components such as color TV picture tubes still needed to be imported. Production scale, output, performance, quality In other aspects, compared with Japan, which has entered rapid development during the same period, the gap has obviously widened. In the late 1970s and early 1980s, my country's color TV industry took advantage of the reform and opening up. On the basis of self-reliance, it followed the guideline of exchanging market for technology, cooperated with foreign countries, and used advanced technology and equipment to develop its own national color TV industry.
In 1978, the state approved the introduction of the first color TV production line, which was located at the former Shanghai TV Factory, now the Shanghai Radio and Television Group.
It was completed and put into production in October 1982. Then my country's color TV industry got rid of the stage of self-exploration and shortened the gap with foreign color TV technology.
Soon after, Xianyang Rainbow Factory, the first domestic color tube factory, was established. During this period, my country's color TV industry heated up rapidly and quickly formed a scale. More than 100 large and small color TV production lines were introduced across the country, and a large number of domestic brands such as Panda, Venus, Peony, and Feiyue emerged.
In 1985, my country's TV output reached 16.63 million units, surpassing the United States and becoming the world's second largest TV producer after Japan. During this period, domestic brands have made long-term progress in both technology and scale. Changhong's output alone has reached 1,500 per day per shift. However, due to the constraints of my country's TV market such as structure, price, consumption power, etc., the TV penetration rate is still Very low. The number of TV sets per 100 households in urban and rural areas is only 1,702 and 0.8 respectively.
By 1987, my country's TV output had reached 19.34 million units, surpassing Japan and becoming the world's largest TV producer. In the late 1980s, domestic color TV brands were limited by many factors such as technology, variety, function, quality, price, etc., and could not meet the growing domestic market demand. Therefore, foreign color TV companies relied on their technological and brand advantages to seize the opportunity. China's color TV market has resulted in the weakening of domestic brand development and product sales.
In order to break the situation of foreign brands attacking the Chinese color TV market, on August 9, 1989, Changhong, an old military industry enterprise in Sichuan, decided to reduce the price of Changhong color TVs across the country and give consumers a profit of 50 yuan per unit. At the same time, the state’s tax revenue will be guaranteed. Changhong's color TV price reduction set a precedent for a price war in the history of color TVs in my country. 50 days later, the country introduced a color TV price reduction policy.
This time Changhong’s first price reduction has produced at least two epoch-making impacts. First, domestic color TVs have escaped the shadow of the planned economy. Enterprises have truly gained the initiative in marketing their own products, which has provided a great opportunity for my country’s color TV industry. Marketization has laid the foundation. In addition, it is precisely because domestic brands have continuously distanced themselves from foreign brands through price advantages that they have created conditions for color TVs to finally enter the homes of ordinary people.
After entering the 1990s, my country's color TV market structure was turbulent. Some old color TV companies born in the planned economy era stopped production, switched production or even went bankrupt due to weak competitiveness. Changhong, Konka, and TCL were ruthlessly eliminated. A number of color TV companies with strong strength, advanced technology and strong competitiveness, such as Skyworth and Skyworth, have entered a period of great development and have become the backbone companies in China's color TV market. After the rapid improvement of domestic color TV technology and the continuous war between foreign brands, the market sales of foreign brands are evenly matched and are shrinking.
By the mid-1990s, there were 98 color TV companies in the country, and the annual output of domestic brand color TVs reached 35 million units, ranking first in the world and still today. At the same time, the continuous improvement in quality and high-tech content of domestic color TVs has laid the foundation for the development of the domestic market, and the price has the advantage of competing with foreign brands.
In 1996, the sales of domestic color TVs exceeded that of imported color TVs for the first time, achieving a historic victory. By 1998, my country's color TV industry entered a mature stage, and its output continued to rank first in the world. TV output reached 35.13 million units, including 26.43 million color TV sets. Color TV output increased 822 times compared with 1980.
In addition, compared with actual output, my country's potential TV production capacity is greater. According to statistics from the Ministry of Electronics, as of the end of 1997, my country's TV production capacity had reached 65.07 million units, of which color TV production capacity was 44.79 million units. Ten thousand units, nearly half of the production capacity is idle. The ownership of color TV sets among urban residents in our country has exceeded 100%, while the ownership of color TV sets in rural areas has also reached 32.5%. TV sets have become the most popular TV set in the past 20 years. 5. History of television
People usually regard the image of a puppet that was "scanned" by Scotsman John Logie Baird in an experiment in London on October 2, 1925. It is the symbol of the birth of television, and he is called the "Father of Television".
However, this view is controversial. Because, also in that year, the American Vladimir Zworykin showed his television system to his boss at Westinghouse.
Although the time was the same, the television systems of John Logie Baird and Vladimir Zworykin were very different. Historically, John Logie Baird's television system was called mechanical television, while Sfrokin's system was called electronic television.
This difference is mainly due to the difference in transmission and reception principles. The development of television has been complex.
Many people were doing the same research at almost the same time. RCA in the United States launched the world's first black-and-white television in 1939, set the national color television standard in 1953, and launched RCA color television in 1954. 6. Who knows the history and principles of the development of television? The more detailed the better.
Introduction to television Television uses electricity to transmit moving visual images in real time.
Similar to movies, television uses the visual residual effect of the human eye to display a frame-by-frame gradient of still images to form a visually moving image. The transmitting end of the television system converts each detailed part of the scene into electrical signals according to brightness and chroma, and then transmits them sequentially.
At the receiving end, the brightness and chromaticity of each minute part are displayed according to the corresponding geometric position to reproduce the entire original image. [Edit this paragraph] Working principle The sequential sampling, transmission and reproduction of TV signals from point to surface are accomplished by scanning.
TV scanning formats vary from country to country. In China, it is 25 frames per second and 625 lines per frame. Each line is scanned from left to right, and each frame is divided into two odd-numbered lines and even-numbered lines from top to bottom to reduce the flicker feeling.
Transmit image information during scanning. When the scanning electron beam returns from the end of the previous line to the line reverse retrace line before the starting point of the next line, and when each field is scanned from top to bottom, the reverse retrace line returning to the upper field should be blanked. .
During the horizontal and vertical blanking period, the horizontal and vertical synchronization signals are transmitted to synchronize the receiving and transmitting scans to accurately reproduce the original image. Television photography focuses the light image of the scene on the photosensitive (or light guide) target surface of the camera tube. The excitation of photoelectrons or changes in photoconductivity at each point on the target surface vary with the brightness of each point in the light image.
When the electron beam is used to scan the target surface, an electrical signal is generated whose amplitude is proportional to the brightness of the scene light image at each point. The scanning electron beam sent to the television receiver causes the picture tube screen to change with the strength of the input signal.
When scanning simultaneously with the sending end, the original image sent will appear on the screen of the picture tube. The process of TV signal transmission and distribution, taking live broadcasts in other cities as an example, generally starts from cameras, TV centers or broadcast trucks, then through microwave relay lines, transmitting stations, and finally to user TV receivers.
In addition, television broadcast satellite and cable television are also effective means of national and urban regional television transmission distribution. TV signal scanning formats and channel bandwidths in various countries are not exactly the same, and Latin letters are used to distinguish them according to the recommendations of the International Radio Consultative Committee (CCIR).
For example, M represents 30 frames per second, 525 lines per frame, video bandwidth 4.2 MHz, plus the residual lower sideband of FM audio and AM video, the total high-frequency bandwidth is 6 MHz; D and K represent each 25 frames per second, 625 lines per frame, video bandwidth 6 MHz, high frequency bandwidth 8 MHz. The full TV signal of the video baseband together with the audio signal is modulated to the very high frequency (VHF) or ultra high frequency (UHF) frequency band for broadcast transmission.
Internationally, the frequency bands allocated for television broadcasting include bands I and III in the VHF, and bands IV and V in the UHF. A TV channel is the nominal channel position occupied by the frequency of a certain TV broadcast.
Countries adopt different television standards and channel divisions. In China, the frequency band I is 48.5~92 MHz and is divided into channels 1~5; the frequency band III is 167~233 MHz and is divided into channels 6~12 (Table 1).
Band IV is 470~566 MHz, divided into channels 13~24; Band V is 606~958 MHz, divided into channels 25~68. The frequency interval occupied by each channel is fixed.
China’s 625-line 25-frame D and K format standards are shown in Figure 1. The image signal modulates the image carrier frequency fp in the form of residual sidebands in order to maintain the low-frequency phase characteristics.
The frequency band of the image signal after partial suppression of the lower sideband is -0.75~+6 MHz relative to fp. The audio signal modulates the audio carrier frequency fs. The audio carrier frequency is fixedly 6.5MHz higher than the image carrier frequency. The frequency range of the modulated audio signal is relatively at fs is ±0.25 MHz.
In this way, each TV channel occupies a maximum frequency range of 8 MHz. In addition to the same scanning and channel content as black and white TV, which are distinguished by Latin letters (Table 2), the color TV system also forms different color TV systems based on the different encoding and decoding methods of the three primary color signals at the transmitter and receiver. .
The broadcast color TV standard requires compatibility with black and white TV, that is, a black and white TV can receive color TV broadcasts, and a color TV can also receive black and white TV broadcasts, but all the images and sounds received are black and white. For this reason, color TV is based on the principle that a certain proportion of the three primary colors of light can be mixed into various colors of light including white light in the additive color mixing method. At the same time, in order to be compatible with and compress the transmission band, red (R), green (G) are generally , blue (B) three primary color signals constitute the brightness signal (Y) and two color difference signals (B-Y), (R-Y) of blue and red. The brightness signal can be used to transmit black and white images, and the combination of the color difference signal and the brightness signal can restore Three primary color signals of red, green and blue.
Therefore, in addition to transmitting the same brightness signals and sound signals as black and white TVs, compatible color TVs also transmit chrominance signals within the same video frequency band. The chrominance signal is formed by modulating the color subcarrier at the high-frequency end of the video band with two color difference signals.
In order to prevent the modulation overload of the color difference signal, the blue and red difference signals (B-Y) and (R-Y) are compressed. The compressed blue and red difference signals are represented by U and V. 1. NTSC system A compatible color television system officially broadcast in the United States in 1954 and also used in Canada, Japan and other countries.
NTSC is the abbreviation of the National Television System Mittee. This system uses the color difference signals Q and red between blue and magenta based on the visual characteristics that the human eye has the weakest ability to distinguish color details between blue and magenta, while the ability to distinguish color details between red and yellow is strongest. The color difference signal I between , and yellow replaces the blue and red difference signals U and V.
Use Q and I color difference signals to perform orthogonal balanced amplitude modulation on two same-frequency color subcarriers with initial phase angles of 33° and 123° respectively, so as to facilitate decoding, separation and suppression of subcarriers. The modulated The two color difference signals are mixed to form a chrominance signal. In order to detect the chrominance signal synchronously at the receiving end, the color synchronization signal must be sent during the horizontal blanking period at the transmitting end.
This format is characterized by simple decoding circuitry and low cost. 2. PAL system: A system developed by the Federal Republic of Germany in 1963 to reduce the phase sensitivity of the NTSC system. It was officially broadcast in 1967 and is also used in countries such as the United Kingdom and China.
PAL is the abbreviation of Phase Alternation Line. This system uses U and V color difference signals to perform orthogonal balanced amplitude modulation on two same-frequency color subcarriers with initial phases of 0° and 90° respectively, and inverts the V component color difference signal line by line.
This. 7. Does anyone know the history of television?
The origin of the invention of television. Television was not invented by any one person.
It is the culmination of a large group of people from different historical periods and countries. As early as the 19th century, people began to discuss and explore methods of converting images into electronic signals.
In 1900, the word "television" had already appeared. People usually regard the image of the puppet "scanned" by the Scotsman John Logie Baird in an experiment in London on October 2, 1925 as a sign of the birth of television. father".
However, this view is controversial. Because, also in that year, the American Vladimir Zworykin showed his television system to his boss at Westinghouse.
Although the time was the same, the television systems of John Logie Baird and Vladimir Zworykin were very different. Historically, John Logie Baird's television system was called mechanical television, while Sfrokin's system was called electronic television.
This difference is mainly due to the difference in transmission and reception principles. The development of television has been complex.
Many people were doing the same research at almost the same time. RCA in the United States launched the world's first black-and-white television in 1939, set the national color television standard in 1953, and launched RCA color television in 1954.
The Development of Television On Christmas Day 1883, the German electrical engineer Nipkov used the "Nipkov Disk" he invented to conduct the first experiment of emitting images using a mechanical scanning method. Each frame has 24 lines, and the image is quite blurry.
In 1908, Kemper Swinton of the United Kingdom and Roshenk of Russia proposed the principle of electronic scanning, laying the theoretical foundation for modern electrical technology. In 1923, the Soviet-American Zvarikin invented the electrostatic accumulation camera tube.
Invented the electronic scanning picture tube in 1998, which was the pioneer of modern television photography. In 1925, British John Lodge Baird conducted new research work based on the "Nipkow Disc" and invented a mechanical scanning television camera and receiver.
At that time, the screen resolution was only 30 lines, the scanner could only scan the scanning area 5 times per second, and the screen itself was only 2 inches high and one inch wide. A performance was given to the public in a large London store.
In 1926, Baird gave a broadcast and reception performance to the British press. 1927-1929 Baird conducted the first trial of electromechanical television through telephone cables; the first shortwave television trial; the British Broadcasting Corporation began to broadcast television programs continuously for a long time.
In 1930, simultaneous broadcast of television images and sounds was achieved. In 1931, the film was put on the television screen for the first time.
——People watched the live broadcast of the famous British local horse racing meeting on TV in London. ——The United States invented a tube television device that can project 25 images per second.
In 1936, the British Broadcasting Corporation adopted Baird's electromechanical television broadcast, broadcasting television images with higher definition for the first time and entering the practical stage. 1939 RCA begins broadcasting all-electronic television.
Swiss Philippe invented the first black and white TV projector. In 1940, Gulmar, the United States, developed an electromechanical color television system.
On December 17, 1949, the first television cable was put into use between London and Sudden Kelfield, England. In 1951, H. Low of the United States invented a three-gun shadow mask color picture tube, and Lorenzo invented a single-gun color picture tube.
In 1954, the Texas Instrument Company of the United States developed the first all-transistor television receiver. In 1966, Radio Corporation of America developed an integrated circuit television.
Three years later, a color television receiver with an electronic adjustment device was produced. In 1972, Japan developed a color TV projector.
In 1973, digital technology was used in television broadcasting, and experiments proved that digital television could be used in satellite communications. In 1976, the UK completed the research on the "TV Library" system, allowing users to check news, books, newspapers or magazines directly on the TV.
In 1977, the UK developed the first portable televisions. In 1979, the world's first "cable TV" was opened in London.
It was invented by the British Post Office. It can transmit information from the computer through ordinary telephone lines and display it on the user's TV screen.
In 1981, Japan's Sony Corporation developed a pocket-sized black and white TV with an LCD screen of only 2.5 inches and powered by a battery. In 1984, Panasonic Corporation of Japan launched "Cosmic TV".
The system's screen is 3.6 meters wide and 4.62 meters high, equivalent to 210 inches. It can be placed on a large truck and played in places where needed such as streets and squares.
The system uses the "high-brightness color light-emitting tube" exclusively developed by Panasonic, which can produce colorful and bright images even during the day outdoors.
On March 17, 1985, at the Tsukuba Science and Technology Exposition held in Japan, a large-screen color TV wall built by Sony was unveiled. It is located on the central square, 40 meters long, 25 meters high, covering an area of ??1,000 square meters. The entire building is as high as a 14-story building.
Equivalent to an 1857-inch color TV. The ultra-large screen is composed of 36 large-scale luminous screens, each weighing 1 ton and 1.8 meters thick. There are 4 rows and 9 works with 450,000 color luminescent elements.
Through the camera installed on the top, various activities at the venue can be displayed at any time, and various advertising videos of Sony can be played. 1985 British Telecom (BT) launches an integrated digital communications network.
It provides users with voice, fast transmission of graphics, fax, slow-scan TV terminals, etc. On November 25, 1991, Japan's Sony Corporation's high-definition TV began trial broadcasting: its scanning lines were 1125, twice as many as the current 525, and the image quality was improved by 100%; the aspect ratio of the screen was changed to the traditional 9:12 to 9:16, enhancing the viewer’s sense of presence; the flat-screen viewing angle has been expanded from 10 degrees to 30 degrees, giving the image a greater sense of depth; the number of “pixels” in the TV image has increased from 280,000 to 1.27 million per unit area. The amount of information has increased nearly 4 times in one fell swoop... Therefore, the viewing distance of high-definition TV is not 7 times but 3 times that of the previous screen height, and the accompanying sound is lifelike, using 4-channel high-fidelity stereo sound, which is full of appeal.
In 1995, Japan's Sony Corporation launched an ultra-miniature color TV receiver (ie, palm-type color TV), which was only the size of a palm and weighed 280 grams. It has speakers and a headphone jack, and the LCD screen is about 5.5 cm. 8. Introduce the television (write the history, function, and appearance of the television)
Television uses electricity to transmit moving visual images in real time. Similar to movies, television uses the visual residual effect of the human eye to display still images that gradually change frame by frame, forming a visually moving image. The transmitting end of the television system converts each detailed part of the scene into electrical signals according to brightness and chroma, and then transmits them sequentially. At the receiving end, the brightness and chromaticity of each minute part are displayed according to the corresponding geometric position to reproduce the entire original image.
Its first appearance was on October 2, 1925. Scotsman John Logie Baird "scanned" the image of a puppet on an LCD TV during an experiment in London as a sign of the birth of television. He is called the "Father of Television." However, this view is controversial. Because, also in that year, the American Sfrokin showed his television system to his boss at Westinghouse.
Although the time was the same, John Logie Baird's and Sfrokin's television systems were very different. Historically, John Logie Baird's television system has been called mechanical television, while Sfrokin's system has been called electronic television. This difference is mainly due to the difference in transmission and reception principles.
The development of television is complex. Many people were doing the same research at almost the same time.
There are several sizes of TV sets - 5 inches, 14 inches, 18 inches, 21 inches, 25 inches, 29 inches, 34 inches, rear projection,
my country's first Black and white television was born in 1958. During the Great Leap Forward craze, Tianjin 712 Factory used domestically produced electronic tube components, which were part of the then Soviet Union, to produce a Beijing brand 14-inch black and white TV set. At that time, my country's TV development technology was basically on the same starting line as Japan's.
The development of television shows the rapid development of our country. This is so exciting