TELEVISION

DO U KNOW IT?




Television was invented by - J.L.Baird.

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 on electro mechanical systems was crucial in the development of fully electronic television.

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, 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.

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.

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.Using a Nipkow disk, Scottish inventor John Logie Baird succeeded in demonstrating the transmission of moving silhouette images in London in 1925,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. 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.

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. This was the first working example of a fully electronic television receiver. Takayanagi did not apply for a patent.

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

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

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.

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.

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. 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.

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.

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, and Texaco Star Theater, starring comedian Milton Berle, became television's first gigantic hit show. Since the 1950s, television has been the main medium for molding public opinion.

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.

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

Programming

Getting TV programming shown to the public can happen in many different ways. After production, the next step is to market and deliver the product to whatever markets are open to using it. This typically happens on two levels:

1. Original Run or First Run: a producer creates a program of one or multiple episodes and shows it on a station or network which has either paid for the production itself or to which a license has been granted by the television producers to do the same.
2. Broadcast syndication: this is the terminology rather broadly used to describe secondary programming usages (beyond original run). It includes secondary runs in the country of first issue, but also international usage which may not be managed by the originating producer. In many cases, other companies, TV stations or individuals are engaged to do the syndication work, in other words, to sell the product into the markets they are allowed to sell into by contract from the copyright holders, in most cases, the producers.

First run programming is increasing on subscription services outside the U.S., but few domestically produced programs are syndicated on domestic free-to-air (FTA) elsewhere. This practice is increasing however, generally on digital-only FTA channels, or with subscriber-only first-run material appearing on FTA.

Unlike the U.S., repeat FTA screenings of an FTA network program almost only occur on that network. Also, affiliates rarely buy or produce non-network programming that is not centred aroundlocal programming.