20-09-2012, 01:29 PM
Television Set
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Definition of Television Set
A television set (also called a television, TV set, or TV) is a device that combines a tuner, display, and speakers for the purpose of viewing television. Television sets became a popular consumer product after the Second World War, using vacuum tubes and cathode ray tube displays. The addition of color to broadcast television after 1953 further increased the popularity of television sets, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first generation of home computers.
Modern television sets incorporate liquid-crystal flat-screen displays, solid-state circuits, microprocessor controls and can interface with a variety of video signal sources, allowing the user to view broadcast and subscription cable TV signals or Satellite television, recorded material on DVD disks or VHS tape, or less common devices such as home security systems, and even over-the-air broadcasts received through an indoor or outdoor antenna.
Types of Television Set
There are various types of the television set from beginning to the present, it is listed at below.
Cathode Ray Tube (CRT)
Cathode Ray Tube televisions have been referred to by a number of names including direct-view, tube or CRT. CRT televisions have been around since the mid-1930s. CRTs are quickly being replaced by the newer flat-panel televisions even though CRTs still offer some of the best color, black levels and viewing angles of any type of set. CRTs are limited to a screen size of 40 inches.
Rear Projection
Rear projection screens are not as popular now as they once were. Rear projection screens are usually quite large in comparison to other television types. The video image is projected from inside the unit onto a mirror that reflects the image back to the screen. Rear projection screens are some of the largest one-piece TVs available with the typical
sizes ranging from 50 to 73 inches. There are many different types of rear projection screens including CRT (three separate CRT projectors), DLP (Digital Light Processing), 3LCD (three LCD projectors), LCoS (Liquid Crystal over Silicon) and the newest format Laser. In 2009, only one manufacturer still produces rear projection televisions. With the sizes of flat panel televisions getting bigger, the draw of rear projection is fading.
Front Projection
Front projection screens are highly popular in home theater installations or rooms with controlled lighting. Since the image is projected from an over-head projector, light needs to be minimized. Many newer projectors offer enough light output that they can be used in dim lighting; however, the darker the room, the better the picture quality. Screen sizes can vary greatly for home projectors from 40 inches to over 100 inches. The limiting factor of the size of the screen is how far the projector is placed from the wall or screen and how bright the picture needs to be.
Plasma
Plasma televisions are one of the two types of flat-panel televisions. Ranging from 42 to 56 inches on average, plasma televisions are generally only available in larger sizes. Plasma televisions are able to be mounted on a wall since they are only a few inches thick. Plasma televisions offer excellent color and black level performance like the CRT; however, plasma TVs tend to be much hotter, heavier and consume more power than LCD televisions of the same size. More manufacturers are moving away from plasma screens and replacing them with LCD televisions.
Liquid Crystal Display (LCD)
LCD televisions are by far the most common type of television sold in 2009. LCD televisions have a wide range of sizes from 15 to 55 inches. With lower costs and a wide array of sizes, LCDs have replaced CRT televisions as the standard home television. LCD televisions do not have the same color and black level performance of plasma and CRT sets; however, their low power consumption, cost and glare-free
visibility have given them an edge over the other sets. Like plasma televisions, LCD televisions are generally only 4 to 5 inches thick.
History of Television Set
In its early stages of development, television employed a combination of optical, mechanical and electronic technologies to capture, transmit and display a visual image. By the late 1920s, however, those employing only optical and electronic technologies were being explored. All modern television systems relied on the latter, although the knowledge gained from the work on electromechanical systems was crucial in the development of fully electronic television. Braun HF 1 television receiver, Germany, 1958
The first images transmitted electrically were sent by early mechanical fax machines, including the pantelegraph, developed in the late nineteenth century. The concept of electrically powered transmission of television images in motion was first sketched in 1878 as the telephonoscope, shortly after the invention of the telephone. At the time, it was imagined by early science fiction authors, that someday that light could be transmitted over copper wires, as sounds were.
[attachment=34159]
Definition of Television Set
A television set (also called a television, TV set, or TV) is a device that combines a tuner, display, and speakers for the purpose of viewing television. Television sets became a popular consumer product after the Second World War, using vacuum tubes and cathode ray tube displays. The addition of color to broadcast television after 1953 further increased the popularity of television sets, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first generation of home computers.
Modern television sets incorporate liquid-crystal flat-screen displays, solid-state circuits, microprocessor controls and can interface with a variety of video signal sources, allowing the user to view broadcast and subscription cable TV signals or Satellite television, recorded material on DVD disks or VHS tape, or less common devices such as home security systems, and even over-the-air broadcasts received through an indoor or outdoor antenna.
Types of Television Set
There are various types of the television set from beginning to the present, it is listed at below.
Cathode Ray Tube (CRT)
Cathode Ray Tube televisions have been referred to by a number of names including direct-view, tube or CRT. CRT televisions have been around since the mid-1930s. CRTs are quickly being replaced by the newer flat-panel televisions even though CRTs still offer some of the best color, black levels and viewing angles of any type of set. CRTs are limited to a screen size of 40 inches.
Rear Projection
Rear projection screens are not as popular now as they once were. Rear projection screens are usually quite large in comparison to other television types. The video image is projected from inside the unit onto a mirror that reflects the image back to the screen. Rear projection screens are some of the largest one-piece TVs available with the typical
sizes ranging from 50 to 73 inches. There are many different types of rear projection screens including CRT (three separate CRT projectors), DLP (Digital Light Processing), 3LCD (three LCD projectors), LCoS (Liquid Crystal over Silicon) and the newest format Laser. In 2009, only one manufacturer still produces rear projection televisions. With the sizes of flat panel televisions getting bigger, the draw of rear projection is fading.
Front Projection
Front projection screens are highly popular in home theater installations or rooms with controlled lighting. Since the image is projected from an over-head projector, light needs to be minimized. Many newer projectors offer enough light output that they can be used in dim lighting; however, the darker the room, the better the picture quality. Screen sizes can vary greatly for home projectors from 40 inches to over 100 inches. The limiting factor of the size of the screen is how far the projector is placed from the wall or screen and how bright the picture needs to be.
Plasma
Plasma televisions are one of the two types of flat-panel televisions. Ranging from 42 to 56 inches on average, plasma televisions are generally only available in larger sizes. Plasma televisions are able to be mounted on a wall since they are only a few inches thick. Plasma televisions offer excellent color and black level performance like the CRT; however, plasma TVs tend to be much hotter, heavier and consume more power than LCD televisions of the same size. More manufacturers are moving away from plasma screens and replacing them with LCD televisions.
Liquid Crystal Display (LCD)
LCD televisions are by far the most common type of television sold in 2009. LCD televisions have a wide range of sizes from 15 to 55 inches. With lower costs and a wide array of sizes, LCDs have replaced CRT televisions as the standard home television. LCD televisions do not have the same color and black level performance of plasma and CRT sets; however, their low power consumption, cost and glare-free
visibility have given them an edge over the other sets. Like plasma televisions, LCD televisions are generally only 4 to 5 inches thick.
History of Television Set
In its early stages of development, television employed a combination of optical, mechanical and electronic technologies to capture, transmit and display a visual image. By the late 1920s, however, those employing only optical and electronic technologies were being explored. All modern television systems relied on the latter, although the knowledge gained from the work on electromechanical systems was crucial in the development of fully electronic television. Braun HF 1 television receiver, Germany, 1958
The first images transmitted electrically were sent by early mechanical fax machines, including the pantelegraph, developed in the late nineteenth century. The concept of electrically powered transmission of television images in motion was first sketched in 1878 as the telephonoscope, shortly after the invention of the telephone. At the time, it was imagined by early science fiction authors, that someday that light could be transmitted over copper wires, as sounds were.