History Of The Tv
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Publicado: 27 de noviembre de 2012
Historia
he concept of television (distance vision) can be traced back to Galileo Galilei and his telescope. However, not until 1884, with the invention of Paul Nipkow disc Nipkow when made significant progress to create half. The change would bring the television as we know it today was invented by Vladimir Zworkyn iconoscope and Philo Taylor Farnsworth. This would lead to all-electronictelevision, which had a much better refresh rate, greater image definition and self-illumination.
On the origins of television exposed various mechanical solutions, as the Nipkow disk in 1910, but these mechanical systems were discarded in favor of fully electronic feedback systems today.
In 1925, Scottish inventor John Logie Baird made the first real experience using two discs, one in theemitter and the receiver, which were attached to the same shaft to spin off its synchronous and separated by 2 mm.
The first public television broadcasts of the BBC made in England in 1927, and CBS and NBC in the United States in 1930. In both studies used mechanical systems and programs will not be issued on a regular schedule.
The first station programming schedule was created in 1930 inBerlin by the local branch of the National Socialist German Workers Party but those responsible for Nazi propaganda were not aware of the possibilities of the medium and continued to use the radio.
Issues with programming began in England in 1936, and the United States on April 30, 1939, coinciding with the opening of the World Expo in New York. Scheduled broadcasts were interrupted during WorldWar II and resumed when finished.
[Edit] Television electronics
In 1937 began regular TV transmissions electronics in France and the United Kingdom. This led to a rapid development of the television industry and a rapid increase in viewers, although screen televisions were small and very expensive. These releases were made possible by the development of the following elements at each end of thechain: the cathode ray tube and iconoscope.
The iconoscope is based on the principle of photoelectric emission: the image is projected onto a mosaic of photoelectric cells that emit electrons that cause the picture signal. Was used in the United States between 1936 and 1946.
The vidicon tube is 2.2 cm in diameter and 13.3 cm in length based on the photoconductivity of some substances. Theoptical image is projected onto a conductive plate which in turn is scanned by the other side via a very thin electron beam.
The plumbicon is based on the same principle as a vidicon, however, the photoconductive plate consists of three layers: the first, in contact with the collector plate, and the third is formed by a semiconductor, the second lead oxide . Thus originates a diode which isreverse biased, as a result, the current through each elementary cell in the absence of light, is extremely low and the sensitivity of Plumbicon under these characteristics, very high.
[Edit] The video signal
Main article: Video signal.
The image signal transduced by the information it contains, but is necessary for restructuring, there is a perfect synchronization between scanning deflection anddeflection in representation.
Exploration of an image is done by decomposition, first frames to those who call boxes and then in lines, reading each box. To determine the number of frames that can be required to reconstruct a moving image and the number of lines for optimal playback quality and optimum color perception (in color television) were performed numerous empirical studies andscientific the human eye and the way they perceive. It was found that the number of frames must be at least 24 to the second (later used for other reasons 25 and 30) and that the number of lines must be above 300.
The video signal itself is composed image information corresponding to each line (in the 625-line PAL and NTSC 525 in each box) grouped into two groups, the odd and even lines of each...
he concept of television (distance vision) can be traced back to Galileo Galilei and his telescope. However, not until 1884, with the invention of Paul Nipkow disc Nipkow when made significant progress to create half. The change would bring the television as we know it today was invented by Vladimir Zworkyn iconoscope and Philo Taylor Farnsworth. This would lead to all-electronictelevision, which had a much better refresh rate, greater image definition and self-illumination.
On the origins of television exposed various mechanical solutions, as the Nipkow disk in 1910, but these mechanical systems were discarded in favor of fully electronic feedback systems today.
In 1925, Scottish inventor John Logie Baird made the first real experience using two discs, one in theemitter and the receiver, which were attached to the same shaft to spin off its synchronous and separated by 2 mm.
The first public television broadcasts of the BBC made in England in 1927, and CBS and NBC in the United States in 1930. In both studies used mechanical systems and programs will not be issued on a regular schedule.
The first station programming schedule was created in 1930 inBerlin by the local branch of the National Socialist German Workers Party but those responsible for Nazi propaganda were not aware of the possibilities of the medium and continued to use the radio.
Issues with programming began in England in 1936, and the United States on April 30, 1939, coinciding with the opening of the World Expo in New York. Scheduled broadcasts were interrupted during WorldWar II and resumed when finished.
[Edit] Television electronics
In 1937 began regular TV transmissions electronics in France and the United Kingdom. This led to a rapid development of the television industry and a rapid increase in viewers, although screen televisions were small and very expensive. These releases were made possible by the development of the following elements at each end of thechain: the cathode ray tube and iconoscope.
The iconoscope is based on the principle of photoelectric emission: the image is projected onto a mosaic of photoelectric cells that emit electrons that cause the picture signal. Was used in the United States between 1936 and 1946.
The vidicon tube is 2.2 cm in diameter and 13.3 cm in length based on the photoconductivity of some substances. Theoptical image is projected onto a conductive plate which in turn is scanned by the other side via a very thin electron beam.
The plumbicon is based on the same principle as a vidicon, however, the photoconductive plate consists of three layers: the first, in contact with the collector plate, and the third is formed by a semiconductor, the second lead oxide . Thus originates a diode which isreverse biased, as a result, the current through each elementary cell in the absence of light, is extremely low and the sensitivity of Plumbicon under these characteristics, very high.
[Edit] The video signal
Main article: Video signal.
The image signal transduced by the information it contains, but is necessary for restructuring, there is a perfect synchronization between scanning deflection anddeflection in representation.
Exploration of an image is done by decomposition, first frames to those who call boxes and then in lines, reading each box. To determine the number of frames that can be required to reconstruct a moving image and the number of lines for optimal playback quality and optimum color perception (in color television) were performed numerous empirical studies andscientific the human eye and the way they perceive. It was found that the number of frames must be at least 24 to the second (later used for other reasons 25 and 30) and that the number of lines must be above 300.
The video signal itself is composed image information corresponding to each line (in the 625-line PAL and NTSC 525 in each box) grouped into two groups, the odd and even lines of each...
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