Television set


A television set or television receiver is an electronic device for viewing and hearing television broadcasts. It combines a tuner, display, and loudspeakers. Introduced in the late 1920s in mechanical form, television sets became a popular consumer product after World War II in electronic form, using cathode ray tube technology. The addition of color to broadcast television after 1953 further increased the popularity of television sets in the 1960s, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first recorded media for consumer use in the 1970s, such as Betamax, VHS; these were later succeeded by DVD. It has been used as a display device since the first generation of home computers and dedicated video game consoles in the 1980s. By the early 2010s, flat-panel television incorporating liquid-crystal display technology, especially LED-backlit LCD technology, largely replaced CRT and other display technologies. Modern flat-panel TVs are typically capable of high-definition display and are capable of playing content from multiple sources, such as a USB device or internet streaming services.

History

Early television

s were commercially sold from 1928 to 1934 in the United Kingdom, France, the United States, and the Soviet Union. The earliest commercially made televisions were radios with the addition of a television device consisting of a neon tube behind a mechanically spinning disk with a spiral of apertures that produced a red postage-stamp size image, enlarged to twice that size by a magnifying glass. The Baird "Televisor" is considered the first mass-produced television, selling about a thousand units.
Karl Ferdinand Braun was the first to conceive the use of a CRT as a display device in 1897. The "Braun tube" became the foundation of 20th century TV. In 1926, Kenjiro Takayanagi demonstrated the first TV system that employed a cathode ray tube display, at Hamamatsu Industrial High School in Japan. This was the first working example of a fully electronic television receiver. His research toward creating a production model was halted by the US after Japan lost World War II.
The first commercially made electronic televisions with CRTs were manufactured by Telefunken in Germany in 1934, followed by other makers in France, Britain, and US. The cheapest model with a screen was $445. An estimated 19,000 electronic televisions were manufactured in Britain, and about 1,600 in Germany, before World War II. About 7,000–8,000 electronic sets were made in the U.S. before the War Production Board halted manufacture in April 1942, production resuming in August 1945. Television usage in the western world skyrocketed after World War II with the lifting of the manufacturing freeze, war-related technological advances, the drop in television prices caused by mass production, increased leisure time, and additional disposable income. While only 0.5% of U.S. households had a television in 1946, 55.7% had one in 1954, and 90% by 1962. In Britain, there were 15,000 television households in 1947, 1.4 million in 1952, and 15.1 million by 1968.

Transistorized television

Early electronic television sets were large and bulky, with analog circuits made of vacuum tubes. As an example, the RCA CT-100 color TV set used 36 vacuum tubes. Following the invention of the first working transistor at Bell Labs, Sony founder Masaru Ibuka predicted in 1952 that the transition to electronic circuits made of transistors would lead to smaller and more portable television sets. The first fully transistorized, portable solid-state television set was the Sony TV8-301, developed in 1959 and released in 1960. By the 1970s, television manufacturers utilized this push for miniaturization to create small, console-styled sets which their salesmen could easily transport, pushing demand for television sets out into rural areas. However, the first fully transistorized color TV set, the HMV Colourmaster Model 2700, was released in 1967 by the British Radio Corporation. This began the transformation of television viewership from a communal viewing experience to a solitary viewing experience. By 1960, Sony had sold over 4million portable television sets worldwide.
By the late 1960s and early 1970s, color television had come into wide use. In Britain, BBC1, BBC2 and ITV were regularly broadcasting in color by 1969.
Late model CRT TVs used highly integrated electronics such as a Jungle chip which performs the functions of many transistors. This shift began in the 1980s.
In the 1980s, with the advent of video in the form of VCRs, some TVs began to come with an RCA jack input for composite video input. These were typically high end TVs for the time, a notable example being the Sony ProFeel line, and were called video monitors, without necessarily having a built in TV tuner, and for the first time could have at least 2 video inputs. On screen displays started to be introduced around this time. While in theory the dedicated composite input improved image quality by eliminating the need for an RF modulator connected to the antenna input when connecting devices such as VCRs and computers, there was no guarantee for higher image quality. The television stopped being used for broadcast television only, and molded plastic construction started to become common, closely surrounding the CRT tube inside, shifting away from cabinet construction in which the CRT tube was mounted inside a wooden box. RF modulators were used to connect a video source such as a VCR or a video game console to the TV by modulating it into a TV channel such as channel 3 or 4.

LCD television

at RCA developed the thin-film transistor in 1962, later the idea of a TFT-based liquid-crystal display was conceived by Bernard Lechner of RCA Laboratories in 1968. Lechner, F. J. Marlowe, E. O. Nester and J. Tults demonstrated the concept in 1968 with a dynamic scattering LCD that used standard discrete MOSFETs.
In 1973, T. Peter Brody, J. A. Asars and G. D. Dixon at Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display. Brody and Fang-Chen Luo demonstrated the first flat active-matrix liquid-crystal display in 1974.
By 1982, pocket LCD TVs based on AM LCD technology were developed in Japan. The Epson ET-10 was the first color LCD pocket TV, released in 1984. In 1988, a Sharp research team led by engineer T. Nagayasu demonstrated a full-color LCD, which convinced the electronics industry that LCD would eventually replace the CRT as the standard television display technology. The first wall-mountable TV was introduced by Sharp in 1992.
During the first decade of the 21st century, CRT "picture tube" display technology was almost entirely supplanted worldwide by flat-panel displays: first plasma displays around 1997, then LCDs. By the early 2010s, LCD TVs, which increasingly used LED-backlit LCDs, accounted for the overwhelming majority of television sets being manufactured.
In 2014, Curved OLED TVs were released to the market, which were intended to offer improved image quality but this effect was only visible at a certain position away from the TV.
Rollable OLED TVs were introduced in 2020, which allow the display panel of the TV to be hidden.
2023 saw the release of wireless TVs which connect to other devices solely through a transmitter box with an antenna that transmits information wirelessly to the TV. Demos of transparent TVs have also been made. There are TVs that are offered to users for free, but are paid for by showing ads to users and collecting user data.

TV sizes

Cambridge's Clive Sinclair created a mini TV in 1967 that could be held in the palm of a hand and was the world's smallest television at the time, though it never took off commercially because the design was complex. In 2019, Samsung launched the largest television to date at. The average size of TVs has grown over time.
In 2024, the sales of large-screen televisions significantly increased. Between January and September, approximately 38,000 televisions with a screen size of or larger were sold globally. This surge in popularity can be attributed to several factors, including technological advancements and decreasing prices.
The availability of larger screen sizes at more affordable prices has driven consumer demand. For example, Samsung, a leading electronics manufacturer, introduced its first television in 2019 with a price tag of $99,000. In 2024, the company will offer four models starting at $4,000. This trend is reflected in the overall market, with the average price of a television exceeding, declining from $6,662 in 2023 to $3,113 in 2024. As technology advances, even larger screen sizes, such as, are becoming increasingly accessible to consumers.

Display

Television sets may employ one of several available display technologies. As of mid-2019, LCDs overwhelmingly predominate in new merchandise, but OLED displays are claiming an increasing market share as they become more affordable and DLP technology continues to offer some advantages in projection systems. The production of plasma and CRT displays has been completely discontinued.
There are four primary competing TV technologies:
  • CRT
  • LCD
  • OLED
  • Plasma

    CRT

The cathode ray tube is a vacuum tube containing a so-called electron gun and a fluorescent screen where the television image is displayed. The electron gun accelerates electrons in a beam which is deflected in both the vertical and horizontal directions using varying electric or magnetic fields, in order to scan a raster image onto the fluorescent screen. The CRT requires an evacuated glass envelope, which is rather deep, fairly heavy, and breakable. As a matter of radiation safety, both the face and back were made of thick lead glass in order to reduce human exposure to harmful ionizing radiation produced when electrons accelerated using a high voltage strike the screen. By the early 1970s, most color TVs replaced leaded glass in the face panel with vitrified strontium oxide glass, which also blocked x-ray emissions but allowed better color visibility. This also eliminated the need for cadmium phosphors in earlier color televisions. Leaded glass, which is less expensive, continued to be used in the funnel glass, which is not visible to the consumer.
In television sets, the entire screen area is scanned repetitively in a fixed pattern called a raster. The image information is received in real time from a video signal which controls the electric current supplying the electron gun, or in color televisions each of the three electron guns whose beams land on phosphors of the three primary colors. Except in the very early days of television, magnetic deflection has been used to scan the image onto the face of the CRT; this involves a varying current applied to both the vertical and horizontal deflection coils placed around the neck of the tube just beyond the electron gun.