A television is an electronic facility for receiving and reproducing television signals. Usually consists of a display and controls or controls. The word comes from the Greek tele (τῆλε; away) and Latin viewfinder (agent videre 'see'). It was created on January 26, 1926 by John Logie Baird.
Its operation is based on the phenomenon of photoelectricity, which is responsible for converting light into electricity in a camera that can transmit high frequency waves to the receiving antennas and is reproduced on the screen of our television . The TV is one of the most everyday appliances.
Its operation is based on the phenomenon of photoelectricity, which is responsible for converting light into electricity in a camera that can transmit high frequency waves to the receiving antennas and is reproduced on the screen of our television . The TV is one of the most everyday appliances.
-Elements of a television
Screen Thanks to advances in display technology, there are now several classes in modern TVs:
Cathode ray tube or CRT: The most common displays are direct-view tubes are achieved with up to 37 inches diagonal. Until 2007, are still the least expensive, and it is a mature technology that can deliver a great picture. Since we do not have a fixed resolution, although a minimum resolution, given the separation between points, can display fonts in various resolutions with the best possible image quality. The frame rate of NTSC TV is 29.97 Hz and 25 Hz in the case of the PAL standard TVs. Visible vertical resolution of the TV is 480 lines NTSC, PAL and the 575-lines. Cathode ray tubes were quite bulky and heavy, are currently being replaced by formats Plasma, LCD and more recently LED. Projection: They are large-screen TVs up to 100 diagonal inches or more. Uses three types of projection systems: CRT, LCD and DLP (chip micromirror device). Rear-projection TVs have existed since the 70's, but at that time had no common definition of a television cathode ray. Current models are much improved, and offer a large price. Projection screens do not give good results in the light of day or in brightly lit rooms, making them more suitable for darkened areas. Liquid crystal display and plasma: The current developments allow the manufacture of flat panel TVs using liquid crystal technology for active matrix (LCD) or plasma. They are ready for high definition (1920x1080) pixels, although some have less resolution. These televisions can have only a couple of inches wide, and can be hung on a wall like a painting or be put on base. Some models can also be used as computer monitors. LCD flat screens can have narrow viewing angles, and are less suitable for the home, although this is being addressed in most current computers. LED Matrix has become one of the options for video outdoors and in stadiums, since the advent of light emitting diodes and their respective circuits ultraluminous. The LED displays allow you to create scalable ultragrandes currently existing technologies that can not igualar.Recientemente has taken the initiative to apply this technology to the domestic TV. They take on different characteristics to other types of display. Lower power consumption compared to LCD screens, improved durability, reduced thickness of the same and higher contrast are examples of these features. The pioneer in this field was Korea's Samsung commercial. [Edit] Resolution Resolution in pixels is the number of individual dots called pixels in a given screen. A typical resolution of 720x480 means that the TV has 720 horizontal pixels and 480 pixels on the vertical axis, the resolution affects the sharpness of the image, higher resolution screen, the greater its clarity. The first resolution had 48 lines and each of the factories used different systems. The standardization of these systems began in July 1941 when he won the NTSC system, valid for all states of the United States, 325 lines. Europe achieved a 625 line at the end of the war, France had a proper 819 lines and England maintained their 405-line. Subsequently the NTSC system was improved.
[Edit] Controls Contrast ratio is a measure of the interval between light and dark points of the screen. The higher the contrast the better the image looks in their richness, depth and shadow detail. The contrast control of a television actually controls the image intensity or brightness [1]. The brightness of an image measures the overall brightness of the screen. It is measured in cd / m2 equivalent to the amount of candles required to form the image. The brightness control shifts the "black point" or shadow level, affecting the contrast ratio or gamma of the image [1]. During the years immediately following World War II experiments were conducted with several different television systems in some European countries, including France and the Netherlands, but it was the USSR, which began regular broadcasts in Moscow in 1948, the first country in the operate in the public service. About 98% of households in the USSR (3.2 people per recipient) and France (2.5) has TV, the percentage of 94 in Italy (3.9) and 93 households now part of Germany the reunified Federal Republic of Germany (2.7).
Cathode ray tube or CRT: The most common displays are direct-view tubes are achieved with up to 37 inches diagonal. Until 2007, are still the least expensive, and it is a mature technology that can deliver a great picture. Since we do not have a fixed resolution, although a minimum resolution, given the separation between points, can display fonts in various resolutions with the best possible image quality. The frame rate of NTSC TV is 29.97 Hz and 25 Hz in the case of the PAL standard TVs. Visible vertical resolution of the TV is 480 lines NTSC, PAL and the 575-lines. Cathode ray tubes were quite bulky and heavy, are currently being replaced by formats Plasma, LCD and more recently LED. Projection: They are large-screen TVs up to 100 diagonal inches or more. Uses three types of projection systems: CRT, LCD and DLP (chip micromirror device). Rear-projection TVs have existed since the 70's, but at that time had no common definition of a television cathode ray. Current models are much improved, and offer a large price. Projection screens do not give good results in the light of day or in brightly lit rooms, making them more suitable for darkened areas. Liquid crystal display and plasma: The current developments allow the manufacture of flat panel TVs using liquid crystal technology for active matrix (LCD) or plasma. They are ready for high definition (1920x1080) pixels, although some have less resolution. These televisions can have only a couple of inches wide, and can be hung on a wall like a painting or be put on base. Some models can also be used as computer monitors. LCD flat screens can have narrow viewing angles, and are less suitable for the home, although this is being addressed in most current computers. LED Matrix has become one of the options for video outdoors and in stadiums, since the advent of light emitting diodes and their respective circuits ultraluminous. The LED displays allow you to create scalable ultragrandes currently existing technologies that can not igualar.Recientemente has taken the initiative to apply this technology to the domestic TV. They take on different characteristics to other types of display. Lower power consumption compared to LCD screens, improved durability, reduced thickness of the same and higher contrast are examples of these features. The pioneer in this field was Korea's Samsung commercial. [Edit] Resolution Resolution in pixels is the number of individual dots called pixels in a given screen. A typical resolution of 720x480 means that the TV has 720 horizontal pixels and 480 pixels on the vertical axis, the resolution affects the sharpness of the image, higher resolution screen, the greater its clarity. The first resolution had 48 lines and each of the factories used different systems. The standardization of these systems began in July 1941 when he won the NTSC system, valid for all states of the United States, 325 lines. Europe achieved a 625 line at the end of the war, France had a proper 819 lines and England maintained their 405-line. Subsequently the NTSC system was improved.
[Edit] Controls Contrast ratio is a measure of the interval between light and dark points of the screen. The higher the contrast the better the image looks in their richness, depth and shadow detail. The contrast control of a television actually controls the image intensity or brightness [1]. The brightness of an image measures the overall brightness of the screen. It is measured in cd / m2 equivalent to the amount of candles required to form the image. The brightness control shifts the "black point" or shadow level, affecting the contrast ratio or gamma of the image [1]. During the years immediately following World War II experiments were conducted with several different television systems in some European countries, including France and the Netherlands, but it was the USSR, which began regular broadcasts in Moscow in 1948, the first country in the operate in the public service. About 98% of households in the USSR (3.2 people per recipient) and France (2.5) has TV, the percentage of 94 in Italy (3.9) and 93 households now part of Germany the reunified Federal Republic of Germany (2.7).
