As early as 194, some people had made exploratory experiments on color TV. In 1925, Adamian, an engineer from the former Soviet Union, developed a color TV system with almost all the performance of modern color TV.
in p>1928, Baird experimented with color TV sets at Bell Telephone Research Institute. On July 3rd, he made a public demonstration with three Pukov scanning discs with 3 holes with red, blue and green filters, and images such as bright red strawberries and blue ties appeared on the TV screen.
In p>1929, Gray of Bell Telephone Laboratory in the United States proposed the method of transmitting three primary color signals by three circuits, and the principle of this method became the basis of modern color TV. In the same year, Ives of Bell Laboratories broadcasted 5 lines of color TV images between new york and Washington, D.C..
In p>1938, Valency obtained a patent for color TV compatible with black and white TV system, which opened the way for solving the compatibility problem in the future.
In p>194, British Baird and Hungarian engineer Gardmark of American CBS explored in a similar way. They both demonstrated a field sequential color TV system which was incompatible with black and white TV. This system operated by the rotation of color filters of cameras and receivers. Before World War II, CBS also used this system for some experimental broadcasts. In 1951, the Federal Communications Commission of the United States approved the resumption of this service, but it was stopped soon because this system was quickly replaced by an all-electronic color system compatible with black-and-white television. In the same year, American inventor Loma began to develop color kinescope.
In p>1953, the National Television Standards Committee (NTSC) of the United States determined a color TV system compatible with black and white TV, which became the basis of the world color TV system.
the principle of p>NTSC system is to combine the transmission of two kinds of images, one is to transmit the information corresponding to the brightness (including the subtle details of TV scenery) of black and white TV sets, and the other is to transmit the color information with rough texture.
The reason why color TV sets combine the transmission of two kinds of image signals is that the luminance component of the color image has a high-definition visual effect, and the additional color information with rough texture does not change the definition of the generated color image, so that a clear color image can be seen.
American public television with NTSC system was launched in 1954. Japan also adopts this system. In 196, Japan officially broadcast NTSC color TV.
In p>1963, Bruck of German Telephony Company proposed to adopt PAL system, which made subtle and ingenious changes to NTSC.
The other system is the SECAM system, which is fundamentally different from the first two systems. It was put forward by Henry in Paris, France. SECAM system was adopted in France in 1966 and was officially broadcast in 1967.
In p>1969, Britain and the former Federal Republic of Germany began to use PAL to broadcast color TV. In the same year, France and the former Soviet Union decided to adopt the SECAM system. In the late 196s, most countries began to develop color TV broadcasting. In the 197s, all countries in the world adopted these three standards respectively. In 1973, China began to pilot color TV, using PAL system.
In p>195, American Radio Company developed the world's first color TV set. The sales boom of color TV sets began in the United States in 1964.
in the early 197s, most color TV cameras had 3-4 TV cameras. In a color TV set, there is a shadow mask, three electron guns and a cathode ray tube. Nowadays, color TV sets have become widely used household appliances, providing people with colorful moving images.
in p>1984, American radio company (RCA) developed a color TV camera with integrated circuit chip instead of camera tube.
with the wide application of LSI, microprocessor and digital technology, the function and structure of TV have changed greatly. In 198s, the new color TV set added many functions, such as remote channel selection; Display the channel number, volume and loudness on the screen; Pre-programmed to automatically start, shut down, change channels and play programs at a predetermined time; Multi-screen display; Receive multiple sound, stereo, etc. With the emergence of new TV broadcasting services, TV receivers are developing towards multifunction, digitalization and intelligence to meet various needs. Receivers with satellite TV receiving function and watching teletext, high-definition large-screen TVs, LCD projection TVs and flat-panel TVs have come out one after another. The TV receiver is also integrated with the videotex retrieval system and the home computer, and becomes the home information display terminal equipment to meet the needs of the information society.
in 199s, digital color TV came out. In 1997, Xi 'an developed the first generation of quasi-high-definition digital color TV set in China. Its definition was improved from 3 lines to 7 lines, and it can also be used as the display of computers or multimedia information terminals.