Television

[19] By the 1920s, when amplification made television practical, Scottish inventor John Logie Baird employed the Nipkow disk in his prototype video systems.

[29] On 25 December 1926, Kenjiro Takayanagi demonstrated a television system with a 40-line resolution that employed a Nipkow disk scanner and CRT display at Hamamatsu Industrial High School in Japan.

[55] On 25 December 1926, at Hamamatsu Industrial High School in Japan, Japanese inventor Kenjiro Takayanagi demonstrated a TV system with a 40-line resolution that employed a CRT display.

In September 1939, after losing an appeal in the courts and being determined to go forward with the commercial manufacturing of television equipment, RCA agreed to pay Farnsworth US$1 million over ten years, in addition to license payments, to use his patents.

[citation needed] However, Farnsworth had overcome his power issues with his Image Dissector through the invention of a completely unique "Multipactor" device that he began work on in 1930, and demonstrated in 1931.

[78][79] Philo Farnsworth gave the world's first public demonstration of an all-electronic television system, using a live camera, at the Franklin Institute of Philadelphia on 25 August 1934 and for ten days afterward.

[82] In Britain, the EMI engineering team led by Isaac Shoenberg applied in 1932 for a patent for a new device they called "the Emitron",[83][84] which formed the heart of the cameras they designed for the BBC.

On 2 November 1936, a 405-line broadcasting service employing the Emitron began at studios in Alexandra Palace and transmitted from a specially built mast atop one of the Victorian building's towers.

[85] The original U.S. iconoscope was noisy, had a high ratio of interference to signal, and ultimately gave disappointing results, especially compared to the high-definition mechanical scanning systems that became available.

[86][87] The EMI team, under the supervision of Isaac Shoenberg, analyzed how the iconoscope (or Emitron) produced an electronic signal and concluded that its real efficiency was only about 5% of the theoretical maximum.

[98][102] U.S. television broadcasting, at the time, consisted of a variety of markets in a wide range of sizes, each competing for programming and dominance with separate technology until deals were made and standards agreed upon in 1941.

[120] Polish inventor Jan Szczepanik patented a color television system in 1897, using a selenium photoelectric cell at the transmitter and an electromagnet controlling an oscillating mirror and a moving prism at the receiver.

One of the great technical challenges of introducing color broadcast television was the desire to conserve bandwidth, potentially three times that of the existing black-and-white standards, and not use an excessive amount of radio spectrum.

At first, terrestrial broadcasting was the only way television could be widely distributed, and because bandwidth was limited, i.e., there were only a small number of channels available, government regulation was the norm.

[171] In 1945, British science fiction writer Arthur C. Clarke proposed a worldwide communications system that would function by means of three satellites equally spaced apart in Earth orbit.

The transmissions were focused on the Indian subcontinent, but experimenters were able to receive the signal in Western Europe using home-constructed equipment that drew on UHF television design techniques already in use.

Traditional cable and satellite television providers began to offer services such as Sling TV, owned by Dish Network, which was unveiled in January 2015.

The CRT uses an evacuated glass envelope that is large, deep (i.e., long from front screen face to rear end), fairly heavy, and relatively fragile.

As a matter of safety, the face is typically made of thick lead glass so as to be highly shatter-resistant and to block most X-ray emissions, particularly if the CRT is used in a consumer product.

In television sets and computer monitors, the entire front area of the tube is scanned repetitively and systematically in a fixed pattern called a raster.

They are called "plasma" displays because the technology uses small cells containing electrically charged ionized gases, or what are in essence chambers more commonly known as fluorescent lamps.

Older programs with a 4:3 aspect ratio are shown in the United States as 4:3, with non-ATSC countries preferring to reduce the horizontal resolution by anamorphically scaling a pillarboxed image.

Reality television series "regular" people (i.e., not actors) facing unusual challenges or experiences ranging from arrest by police officers (COPS) to significant weight loss (The Biggest Loser).

Kristin Thompson argues that some of these television series exhibit traits also found in art films, such as psychological realism, narrative complexity, and ambiguous plotlines.

The first official, paid television advertisement was broadcast in the United States on 1 July 1941, over New York station WNBT (now WNBC) before a baseball game between the Brooklyn Dodgers and Philadelphia Phillies.

The announcement for Bulova watches, for which the company paid anywhere from $4.00 to $9.00 (reports vary), displayed a WNBT test pattern modified to look like a clock with the hands showing the time.

The first TV ad broadcast in Asia was on Nippon Television in Tokyo on 28 August 1953, advertising Seikosha (now Seiko), which also displayed a clock with the current time.

Many Traditional Catholic congregations such as the Society of Saint Pius X (SSPX), as with Laestadian Lutherans, and Conservative Anabaptists such as the Dunkard Brethren Church, oppose the presence of television in the household, teaching that it is an occasion of sin.

[250][252] A 2017 study in The Journal of Human Resources found that exposure to cable television reduced cognitive ability and high school graduation rates for boys.

[253] With high lead content in CRTs and the rapid diffusion of new flat-panel display technologies, some of which (LCDs) use lamps which contain mercury, there is growing concern about electronic waste from discarded televisions.