I. Mechanical TV
As early as 1884, Russian-born German scientist PaulGottliebNipkow put forward and applied for the world's first patent for mechanical television system. At that time, he was only 23 years old and still studying in Germany. After research, he found that if the image is divided into a single image point, it is very possible to transmit the image of a person or scene to a far place. Soon, an instrument called "TV telescope" came out. This is a photoelectric mechanical scanning disk. It looks clumsy, but it is very creative.
1884165438+1October 6th, Pukov declared his invention to the Royal Patent Office in Berlin. On the first page of his patent application, he wrote: "The instrument described here can make objects in place A visible everywhere in place B." A year later, the patent was approved. The Ni Pukov CD in this patent is also considered as the world's first TV image rasterizer. However, Pukov himself has never made a model to prove his design. It was not until 1907 that the progress of amplifier technology proved the feasibility of his system.
1897, German physicist karl braun invented a cathode ray tube with a fluorescent screen. When the electron beam collides, the fluorescent screen will glow. At that time, Braun's assistant proposed to use cathode-ray tube as TV monitor, but stubborn Braun thought it was impossible.
The word TV was coined by Constantine Perski in a paper submitted to the 1900 Paris World Expo. Posky's paper evaluates the status of electromechanical technology at that time and mentions the contribution of Pukov and others. [3]? 1906, two assistants of German physicist karl braun made an image receiver with this cathode ray tube to reproduce the image. But their equipment reproduces still pictures, which should be regarded as a fax system rather than a TV system.
From 1907 to 19 10, BorisRosing and his student VladimirZworykin verified the TV system with a fast rotating mirror scanning device in the transmitter and a cathode ray tube in the receiver.
Boris Rossing left people's sight in the "October Revolution" in 19 17. Zworykin later went to the United States to work in theRadioCorporationofAmerica. He set up a pure electronic TV system there. However, his system was finally considered to infringe PhiloTaylorFarnsworth's patent.
Second, electronic television.
19 1 1 year, engineer AlanArchibaldCampbell-Swinton gave a speech in London, which was also reported by Time magazine. He described the details of how to use cathode ray tubes to transmit TV signals at transmitters and receivers. In his speech, he also supplemented the electronic TV transmission mode first described in the article of Nature written by 1908, which is still in use today. At that time, others also completed the experiment of using cathode ray tube as receiver, but the concept of using another cathode ray tube as transmitter was the first.
In the late 1920s of 19, when mechanical TV was still widely used, inventors Ferro farnsworth and Vladimir Zolikin were already studying all-electronic transmission tubes.
Russian-American scientist VladimirZworykin (Zvorykin initiated the era of electronic television. Zvorykin was originally an electrical engineer at St. Petersburg Institute of Technology in Russia. As early as 19 12, he began to study electronic camera technology. 19 19 Zvorykin immigrated to the United States and worked for Westinghouse Electric Company.
1923, a friend of Scottish inventor JohnLogieBaird told him: "Since Marconi can transmit and receive radio waves from a long distance, he should be able to transmit images." This greatly encouraged him. Baird is determined to complete the image transmission through electronic signals. He sold his few possessions, collected a lot of information, and devoted all his time to the development of TV, thus completing the design of TV. Baird successfully used electrical signals to display images on the screen.
Russian-American scientist VladimirZworykin (Zvorykin) is also experimenting with cathode ray tubes to generate and display images. During his work in Westinghouse Electric Company from 65438 to 0923, he developed an electronic camera tube. However, in the process of 1925 demonstration, the image is blurred, the contrast is very low, the resolution is poor, and the image is still.
This camera tube has not passed the experimental stage, but RCA (patent of Westinghouse Electric Company) thinks that the patent conditions of Farnsworth 1927 image decomposer are too broad, which will crowd out other forms of electronic imaging technology. Therefore, RCA filed a patent conflict lawsuit against Farnsworth after obtaining the patent application of Sforokin in 1923. The prosecutor of the United States Patent Office rejected the resolution of 1935, and gave priority to farnsworth's invention.
1939 10, RCA lost the case, but they still hope to further produce commercial TV equipment. RCA agreed to pay Farnsworth $1million (equivalent to $1380,000 in 2006). In the following 10 years, the use of farnsworth's patents required extra fees. 1929, Zvorykin introduced an improved model, and the result was still unsatisfactory.
The American ARC Company finally invested 50 million dollars 193 1 year, and Zvorykin finally manufactured the camera picture tube. In the same year, the photoelectric camera tube system was completely tested in the field. In this experiment, an image consisting of 240 scanning lines was transmitted to a TV set four miles away (the image of a 9-inch picture tube was reflected in front of the TV set by a mirror), and the TV camera and imaging mode were successfully digitized.
192510.2, Scottish JohnLogieBaird "scanned" the first semi-mechanical analog TV system in an experiment in London, which was regarded as the symbol of the birth of TV. He is called "the father of television". Later, his system was adopted by the BBC. Later, at 1937, the British Broadcasting Corporation (BBC) stopped using this technology. Because electronic TV systems were more popular at that time.
The decisive solution-the basic principle of television is based on the principle of electron flow accumulation and storage of secondary electrons released continuously during the whole scanning period-was first discovered by the Hungarian inventor KálmánTihanyi in 1926, and the technology was perfected in 1928.
1927, 1927 On February 7th, 2007, PhiloFarnsworth transmitted the first image: a simple straight line, in his laboratory at 202 Green Street, San Francisco. 1928, farnsworth developed a complete system to demonstrate to the media, and an animated video was transmitted through TV.
1929, this system is further optimized, and the motor generator is removed. Now his TV system has no moving parts. In the same year, farnsworth used his TV system to transmit the first living human image: a 3.5-inch moving image of his wife Pam with her eyes closed (probably because the light was too bright).
1928, the 5th German Broadcasting Expo opened in Berlin. Television was first shown as a public product at the exhibition. The transmission distance and range of cable mechanical TV signals are very limited, and the images are quite rough, so it is impossible to display fine pictures.
Because only a small part of the light can pass through the small hole of Nye Pukov disk, in order to get the ideal light, the small hole must be enlarged, and the picture will be very rough. In order to improve the clarity of the image, it is necessary to increase the number of holes. But as the hole becomes smaller, the light that can penetrate will decrease and the image will be blurred. This defect of mechanical TV led to the elimination of this technology.
1929, the British Broadcasting Corporation (BBC) allowed Baird to provide public television broadcasting services. After 1930s, Baird turned to the research of color TV. Through the continuous improvement of equipment and technology, the TV effect developed by Baird is getting better and better, which has caused a great sensation. Later, Baird TV Development Company was established. With the continuous improvement of technology and equipment, the transmission distance of Baird TV has been greatly improved.
During the period of 1933, Russian-American scientist VladimirZworykin (Zvorykin) successfully developed a camera tube and kinescope for TV camera shooting. The process of making TV camera and imaging completely electronic has been completed, and so far, the modern TV system has basically taken shape. Today, the imaging principle and equipment of TV cameras and TV receivers are improved according to his invention.
1934 On August 25th, farnsworth showed the whole electronic TV system to the world for the first time at Franklin Institute in Philadelphia, Pennsylvania. Other inventors have only demonstrated some functions of similar systems before, or demonstrated electronic systems using still images or moving pictures and movies. But Farnsworth is the first system that integrates electronic scanning TV camera and electronic scanning TV receiver, which can provide live, dynamic and black-and-white images. Unfortunately, his camera needed strong light, so his work had to be interrupted.
In Britain, IsaacShoenberg developed Marconi -EMI's own electronic camera tube using the idea of Sforokin. This design forms the core part of the camera made for BBC. Using this camera tube, the 405-line service was set up in the studio of Alexandria Palace on June 5438+0936+065438+1October 2, and broadcast through the special mast antenna installed at the top of Victoria Building.
It is temporarily relayed to the Baird mechanical television system next door, but it is more reliable and has better definition. Mast antenna has been used to this day. This program, broadcast entirely by electronic TV system, left a deep impression on people. In the report of the Olympic Games held in Berlin, Germany in the same year, * * * used four cameras to shoot the game. The all-electronic camera invented by Zorkin is huge. The lens with a focal length of 1.6 meters weighs 45 kilograms and is 2.2 meters long. It is called TV cannon.
The image signals of these four cameras are transmitted to the Imperial Post Center through cables, where they are mixed and transmitted through the TV tower. During the Berlin Olympic Games, the game was broadcast live on TV for 8 hours every day, and more than 6.5438+0.6 million people watched the Olympic Games on TV.
1939, about 20,000 families in Britain owned TV sets, and the TV set of American Radio Company also made its debut at the new york World Expo, and began the first regular TV program broadcast. The outbreak of World War II stopped the development of newly developed TV 10 years. After the war, the television industry flourished again, and television became popular rapidly.
1946, the BBC resumed fixed TV programs, and the US government also lifted the ban on making new TVs. The television industry is developing rapidly. In the United States, from 1949 to 195 1, not only TV programs are broadcast all over the country, but also the number of TV sets has increased from 1 10,000 to 1 10,000, and many TV stations have been established. Humorous plays, easy songs and dances, cartoons, entertainment programs and Hollywood movies are often shown on TV.
German scientist Carolus has also made achievements in TV development. 1942, Carolus's team (including two scientists, a mechanic and a carpenter) built a device. The equipment uses two NiPukov disks with the diameter of 1m as the two ends for transmitting and receiving signals. Each disk has 48 holes with a diameter of 1.5mm and can scan 48 lines. The two disks are connected by a synchronous motor, and rotate synchronously 10 pictures every second, and the images are projected onto another receiver.
They call this machine a big TV. The effect of this big TV is much clearer than Baird's TV. But they have never been publicly displayed, so their inventions are little known.
1956, the ModollVRllo video recorder designed by Ginsburg and Anderson came out, and the electrical technology took a big step forward. Because there are two ways to do TV programs at first. One is to shoot programs with TV film, print them out and broadcast them through electronic scanning. One of the biggest disadvantages of this method is that it is impossible to broadcast TV programs live. The other is to spread the signal directly with the camera. Although this meets the needs of those who want to witness the scene, it cannot be replayed. The appearance of video recorder changed this situation.
1972, Sony Corporation of Japan introduced 3/4 inch cassette tape, which fundamentally changed the recording method of TV programs. Is the world's first professional color video projection system using cassette tape.
Extended data:
Television (English: television) is referred to as household appliances for short. Moreover, this word has different connotations and extensions. For example, it refers to the technology of converting dynamic images and sounds into electronic signals, transmitting electronic signals through different channels, and then restoring electronic signals into images and sounds, that is, the technology of transmitting and receiving TV signals; And equipment that can receive electronic signals and restore them to dynamic images and sounds, commonly known as TV sets; Television has no single inventor.
But scientists from different countries have studied the same results. As early as the19th century, people began to study the method of converting images into electronic signals. Television is also a social and cultural phenomenon and commercial activity, especially the process of information exchange and information dissemination by people using television as a communication carrier, such as TV program production, TV signal transmission, TV signal reception and audience's evaluation and feedback on TV program content.
screen size
The screen size of TV is a parameter to measure the smallest possible display picture of TV. It is measured by the diagonal length of the TV screen, usually in inches.
The size of LCD TV screen is the size marked in the strict product manual, because the LCD screen is not covered by the frame.
The size of some products sold in the market is not true, mainly because they are smaller than the marked standard size by 1-2 cm, that is, the distance is less than 1 inch.