The world's first mechanical television
In 1880, the Frenchman Leblanc proposed to make a mirror vibrate at different speeds on two different axes to form a back-and-forth linear scan, thus Decompose and reproduce images.
In 1883, the German Nipkov proposed the disk scanning method;
In 1897, the German Braun invented the cathode ray tube to display rapidly changing electrical signals;
In 1904, the British Bellwell and the German Cologne invented television technology that telexed one photo at a time. Each photo took 10 minutes to transmit.
Electronic tube television
In 1923, the Russian-American scientist Zvorykin applied for a patent for the photoelectric picture tube, television transmitter and television receiver. He was the first to use a comprehensive "electronic "TV" transmitting and receiving system, becoming the pioneer of modern television technology. The application of electronic technology in television has brought television out of the laboratory and into public life.
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.
The picture in the TV set
In 1925, Baird of Scotland publicly demonstrated a machine he built, which successfully transmitted human facial movements with a resolution of 30 lines. , with a repetition rate of 5 frames per second. From then on, television began its magical development process.
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 or so TV sets were watched. Taiwan, this move announced the advent of television art as a social public undertaking, and was an epoch-making event in the history of television development.
In 1929, American scientist Eaves broadcast 50 lines of color television images between New York and Washington, and invented color television.
In 1933, Zvorykin successfully developed it Camera tubes and picture tubes 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. The imaging principles and equipment of today's television cameras and television reception were improved based on his invention.
In 1935, Baird cooperated with a German company to establish the first television station, which broadcast programs three times a week. In 1936, the United Kingdom broadcast the clearest public television program in the world;
In 1939, the United States broadcast a fixed television program. People's lives have since had a profound and complex connection with television. In 1938, the German Fletcher Siegel proposed the idea of ??a three-gun and three-beam color picture tube; in 1949, the United States developed the world's first three-gun and three-beam color picture tube for the first time; in 1957, it developed an all-glass shell color picture tube; in 1964 In 1969, an all-glass rectangular picture tube was developed; in 1969, a black-bottom picture tube was developed to double the brightness; in 1968, Sony Corporation of Japan developed a three-beam color picture tube; in 1972, the United States successfully developed a color picture tube that automatically corrects the convergence error. Tube. At this point, the development of color TV has entered a mature stage.
With the rapid development of modern science and technology, the development trend of modern TV technology will have the following ten characteristics:
1. Polarization. One is miniaturization. The screen size of a microcomputer with an LCD display screen is 3.8 cm to 3.9 cm, and the screen size of a microcomputer with a cathode ray tube display is less than 14 cm. The second is large-scale. Such as wall-mounted thin flat-panel TVs, cathode ray imaging large-screen TVs and projection large-screen TVs, etc.
2． Decoration. With its exquisite shape and decoration, the TV will become a beautiful decoration in the room arrangement and can replace things such as wall paintings or mirror cabinets.
3． Digitization. Televisions that use digital integrated circuits to convert analog quantities into discrete digital quantities appear.
4. Serialization. It is a technical means to strengthen quality management, improve labor productivity, ensure product quality and facilitate after-sales service in design work.
5. High definition. The 625 scanning lines of the original TV screen will be increased to 1250, and the picture quality can be improved by 100%.
6． stereophonic. The TV has a two-channel sound effect, and the sound quality is comparable to that of a compact disc.
7. Multi-channel. Can receive more than 10 or even hundreds of TV station programs.
8. Satelliteization. Through specially installed outdoor antennas, several, dozens, or even global television programs transmitted by satellites can be received.
9. Day visualization. With improved color filters and display screens, you can still watch bright TV images even during the day or in the sun.
10． New materials. The materials of various parts and components in TV sets will be updated, and new alternative materials with lower costs and better performance will be developed and applied.
The period from 1930 to 1940 was the era when television took shape. In addition to significant improvements in broadcast engineering technology, television has begun to gradually become a mass media. However, due to the outbreak of World War II, the research and development of television in various countries was greatly affected and almost interrupted. It was not until the end of World War II that television began to flourish in the United States and other countries.
In 1940, the American Gurmar developed an electromechanical color television system. On December 17, 1949, the first television cable between London and Sudden Kelfield was put into use. In 1951, H. Lowe of the United States invented a three-gun shadow mask color picture tube, and Lawrence invented a single-gun color picture tube.