My stories in crayons: September 2013

T.V
TELEVISION

Television (TV) is a telecommunication medium for transmitting and receiving moving images that can be monochrome (black-and-white) or colored, with or without accompanying sound. "Television" may also refer specifically to a television set, television program, or television transmission.

The etymology of the word has a mixed Latin and Greek origin, meaning "far sight": Greek tele (τῆλε), far, and Latin visio, sight (from video, vis- to see, or to view in the first person).

Commercially available since the late 1920s, the television set has become commonplace in homes, businesses and institutions, particularly as a vehicle for advertising, a source of entertainment, and news. Since the 1950s, television has been the main medium for molding public opinion.^[1] Since the 1970s, the availability of video cassettes, laserdiscs, DVDs and now Blu-ray Discs have resulted in the television set frequently being used for viewing recorded as well as broadcast material. In recent years, Internet television has seen the rise of television available via the Internet through services such as iPlayer and Hulu.

In 2009 78 percent of the world's households owned at least one television set, an increase of 5% over 2003.^[2]

Although other forms such as closed-circuit television (CCTV) are in use, the most common usage of the medium is for broadcast television, which was modeled on the existing radio broadcasting systems developed in the 1920s, and uses high-powered radio-frequency transmitters to broadcast the television signal to individual TV receivers.

HISTORY

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 onelectromechanical 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.

The idea of using scanning to transmit images was put to actual practical use in 1881 in the pantelegraph, through the use of a pendulum-based scanning mechanism. From this period forward, scanning in one form or another has been used in nearly every image transmission technology to date, including television. This is the concept of "rasterization", the process of converting a visual image into a stream of electrical pulses.

In 1884, Paul Gottlieb Nipkow, a 23-year-old university student in Germany,^[5] patented the first electromechanical television system which employed ascanning disk, a spinning disk with a series of holes spiraling toward the center, for rasterization. The holes were spaced at equal angular intervals such that, in a single rotation, the disk would allow light to pass through each hole and onto a light-sensitive selenium sensor which produced the electrical pulses. As an image was focused on the rotating disk, each hole captured a horizontal "slice" of the whole image.^[6]

Nipkow's design would not be practical until advances in amplifier tube technology became available. Later designs would use a rotating mirror-drum scanner to capture the image and a cathode ray tube (CRT) as a display device, but moving images were still not possible, due to the poor sensitivity of the selenium sensors. In 1907, Russian scientist Boris Rosing became the first inventor to use a CRT in the receiver of an experimental television system. He used mirror-drum scanning to transmit simple geometric shapes to the CRT.^[7]

Vladimir Zworykindemonstrates electronic television (1929).

Using a Nipkow disk, Scottish inventor John Logie Baird succeeded in demonstrating the transmission of moving silhouette images in London in 1925,^[8]and of moving, monochromatic images in 1926. Baird's scanning disk produced an image of 30 lines resolution, just enough to discern a human face, from a double spiral of Photographic lenses.^[9] This demonstration by Baird is generally agreed to be the world's first true demonstration of television, albeit a mechanical form of television no longer in use. Remarkably, in 1927, Baird also invented the world's first video recording system, "Phonovision": by modulating the output signal of his TV camera down to the audio range, he was able to capture the signal on a 10-inch wax audio disc using conventional audio recording technology. A handful of Baird's 'Phonovision' recordings survive and these were finally decoded and rendered into viewable images in the 1990s using modern digital signal-processing technology.^[10]

In 1926, Hungarian engineer Kálmán Tihanyi designed a television system utilizing fully electronic scanning and display elements, and employing the principle of "charge storage" within the scanning (or "camera") tube.^[11]^[12]^[13]^[14]

On 25 December 1926, Kenjiro Takayanagi demonstrated a television system with a 40-line resolution that employed a CRT display at Hamamatsu Industrial High School in Japan.^[15] This was the first working example of a fully electronic television receiver. Takayanagi did not apply for a patent.^[16]

By 1927, Russian inventor Léon Theremin developed a mirror-drum-based television system which used interlacing to achieve an image resolution of 100 lines.^[17]

Philo Farnsworth

In 1927, Philo Farnsworth made the world's first working television system with electronic scanning of both the pickup and display devices,^[18] which he first demonstrated to the press on 1 September 1928.^[18]^[19]

WRGB claims to be the world's oldest television station, tracing its roots to an experimental station founded on 13 January 1928, broadcasting from the General Electric factory in Schenectady, NY, under the call letters W2XB.^[20] It was popularly known as "WGY Television" after its sister radio station. Later in 1928, General Electric started a second facility, this one in New York City, which had the call letters W2XBS, and which today is known as WNBC. The two stations were experimental in nature and had no regular programming, as receivers were operated by engineers within the company. The image of a Felix the Cat doll, rotating on a turntable, was broadcast for 2 hours every day for several years, as new technology was being tested by the engineers.

At the Berlin Radio Show in August 1931, Manfred von Ardenne gave the world's first public demonstration of a television system using a cathode ray tube for both transmission and reception. The world's first electronically scanned television service then started in Berlin in 1935. In August 1936, the Olympic Games in Berlin were carried by cable to television stations in Berlin and Leipzig where the public could view the games live.^[21]

In 1935, the German firm of Fernseh A.G. and the United States firm Farnsworth Television owned by Philo Farnsworth signed an agreement to exchange their television patents and technology to speed development of television transmitters and stations in their respective countries.^[22]

On 2 November 1936, the BBC began transmitting the world's first public regular high-definition service from the Victorian Alexandra Palace in north London.^[23] It therefore claims to be the birthplace of television broadcasting as we know it today.

In 1936, Kálmán Tihanyi described the principle of plasma display, the first flat panel display system.^[24]^[25]

Mexican inventor Guillermo González Camarena also played an important role in early television. His experiments with television (known as telectroescopía at first) began in 1931 and led to a patent for the "trichromatic field sequential system" color television in 1940.^[26]

Although television became more familiar in the United States with the general public at the 1939 World's Fair, the outbreak of World War II prevented it from being manufactured on a large scale until after the end of the war. True regular commercial television network programming did not begin in the U.S. until 1948. During that year, legendary conductor Arturo Toscanini made his first of ten TV appearances conducting the NBC Symphony Orchestra,^[27] and Texaco Star Theater, starring comedian Milton Berle, became television's first gigantic hit show.^[28] Since the 1950s, television has been the main medium for molding public opinion.^[1]

Amateur television (ham TV or ATV) was developed for non-commercial experimentation, pleasure and public service events by amateur radio operators. Ham TV stations were on the air in many cities before commercial TV stations came on the air.^[29]

In 2012, it was reported that television revenue was growing faster than film for major media companies.^[30]

MODELS

1.OLD AGE

2. MODERN AGE

differences

The way the television is made has changed drastically since the first model was made. The first telecsion was made on March 28, 1928 by John L. Baird, a scientist from Britain. He first called it a sight machine (Wilt). He pioneered the way electronics are built into making televisions today. The earlier models had a black and white resolution showing through a very small screen. They had speakers already built in and were framed with wood casings. Only a few stations would be available. Since then the innovations companies such as sony, rca, panasonic and others have made have changed the entire aspect of the way the television is made and watched. Cable was introduced to widen the variety of channels to watch. The models of televisions began getting thinner and screens began getting larger. The quality of the picture has evolved from black and white to color, and from color to and even more vivid picture when lcd screens and now even led screens were introduced. There has also been accessories put onto televisions to enhance the picture and sounds, such as high definition and surround sound systems. We have exposed in the world, plasma tvs, lcd and led tvs. Plasma screen televisions use a sheet of individual plasma cells that generates a picture when electric charge is applied ("The Skinny Behind LED Flat Screens"). LCD tvs use a liquid crystal compressed between two glass plates. an image is created when electricity is applied to the crystals. LED tvs are made the same way except they use a blacklight instead of using flourescent lamps. As of this moment the most popular televisions out in circulation are LED televisions ("The Skinny Behind LED Flat Screens"). They are so versatile and can be put anywhere because they are so thin and dont take up any space. These tvs also have a spectacular picture because they allow brighter contrast and deeper blacks than flourescent LCD televisions.

1 loss

1. television rays were attack to brain

1 profit

1. television is away of entertainment

photos

this post is writtern by sarthak sharma.

T.V

My stories in crayons

Sunday, 8 September 2013

amazing video

TELEVISION

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