TV Shutel on:  
[Wikipedia]  
[Google]  
[Amazon]
![Cptvdisplay](https://upload.wikimedia.org/wikipedia/commons/4/40/Cptvdisplay.jpg)
Television, sometimes shortened to TV, is a telecommunication
medium
Medium may refer to:
Science and technology
Aviation
*Medium bomber, a class of war plane
*Tecma Medium, a French hang glider design
Communication
* Media (communication), tools used to store and deliver information or data
* Medium of ...
for
transmitting
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to th ...
moving images and sound. The term can refer to a
television set
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
, or the medium of
television transmission. Television is a
mass medium
Mass media refers to a diverse array of media technologies that reach a large audience via mass communication. The technologies through which this communication takes place include a variety of outlets.
Broadcast media transmit information ...
for advertising, entertainment, news, and sports.
Television became available in crude experimental forms in the late 1920s, but only after several years of further development was the new technology marketed to consumers. After
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
, an improved form of black-and-white television broadcasting became popular in the United Kingdom and the United States, and television sets became commonplace in homes, businesses, and institutions. During the 1950s, television was the primary medium for influencing
public opinion
Public opinion is the collective opinion on a specific topic or voting intention relevant to a society. It is the people's views on matters affecting them.
Etymology
The term "public opinion" was derived from the French ', which was first use ...
.
[Diggs-Brown, Barbara (2011]
''Strategic Public Relations: Audience Focused Practice''
p. 48 In the mid-1960s, color broadcasting was introduced in the U.S. and most other developed countries.
The availability of various types of archival storage media such as
Betamax and
VHS tapes,
LaserDiscs, high-capacity
hard disk drives,
CDs
The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in Octo ...
,
DVD
The DVD (common abbreviation for Digital Video Disc or Digital Versatile Disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any kind ...
s,
flash drives
A flash drive is a portable computer drive that uses flash memory. Flash drives are the larger memory modules consisting of a number of flash chips. A flash chip is used to read the contents of a single cell, but it can write entire block of cell ...
, high-definition
HD DVD
HD DVD (short for High Definition Digital Versatile Disc) is an obsolete high-density optical disc format for storing data and playback of high-definition video. Supported principally by Toshiba, HD DVD was envisioned to be the successor to the ...
s and
Blu-ray Discs, and cloud
digital video recorders
A digital video recorder (DVR) is an electronic device that records video in a digital format to a disk drive, USB flash drive, SD memory card, SSD or other local or networked mass storage device. The term includes set-top boxes with direct to d ...
has enabled viewers to watch pre-recorded material—such as movies—at home on their own time schedule. For many reasons, especially the convenience of remote retrieval, the storage of television and video programming now also occurs on
the cloud (such as the video-on-demand service by
Netflix
Netflix, Inc. is an American subscription video on-demand over-the-top streaming service and production company based in Los Gatos, California. Founded in 1997 by Reed Hastings and Marc Randolph in Scotts Valley, California, it offers a fi ...
). At the end of the first decade of the 2000s,
digital television
Digital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative adva ...
transmissions greatly increased in popularity. Another development was the move from
standard-definition television (SDTV) (
576i
576i is a standard-definition digital video mode, originally used for digitizing analog television in most countries of the world where the utility frequency for electric power distribution is 50 Hz. Because of its close association with ...
, with 576
interlaced
Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. This ...
lines of resolution and
480i
480i is the video mode used for standard-definition digital television in the Caribbean, Japan, South Korea, Taiwan, Philippines, Laos, Western Sahara, and most of the Americas (with the exception of Argentina, Paraguay, and Uruguay). The ...
) to
high-definition television
High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the g ...
(HDTV), which provides a
resolution
Resolution(s) may refer to:
Common meanings
* Resolution (debate), the statement which is debated in policy debate
* Resolution (law), a written motion adopted by a deliberative body
* New Year's resolution, a commitment that an individual mak ...
that is substantially higher. HDTV may be transmitted in different formats:
1080p
1080p (1920×1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the screen ve ...
,
1080i
1080i (also known as Full HD or BT.709) is a combination of frame resolution and scan type. 1080i is used in high-definition television (HDTV) and high-definition video. The number "1080" refers to the number of horizontal lines on the scre ...
and
720p
720p (1280×720 px; also called HD ready, standard HD or just HD) is a progressive HDTV signal format with 720 horizontal lines/1280 columns and an aspect ratio (AR) of 16:9, normally known as widescreen HDTV (1.78:1). All major HDTV broadcast ...
. Since 2010, with the invention of
smart television
A smart TV, also known as a connected TV (CTV), is a traditional television set with integrated Internet and interactive Web 2.0 features, which allows users to stream music and videos, browse the internet, and view photos. Smart TVs are a techno ...
,
Internet television
Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming television stands in contrast to dedicated terrestrial television delivered by over-the-air a ...
has increased the availability of television programs and movies via the Internet through
streaming video services such as Netflix,
Amazon Prime Video,
iPlayer
BBC iPlayer (stylised as iPLAYER or BBC iPLAYER) is a video on demand service from the BBC. The service is available on a wide range of devices, including mobile phones and tablets, personal computers and smart televisions. iPlayer services de ...
and
Hulu.
In 2013, 79% of the world's
households owned a television set. The replacement of earlier
cathode-ray tube (CRT) screen displays with compact, energy-efficient, flat-panel alternative technologies such as
LCDs (both
fluorescent-backlit and
LED),
OLED
An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light i ...
displays, and
plasma display
A plasma display panel (PDP) is a type of flat panel display that uses small cells containing plasma: ionized gas that responds to electric fields. Plasma televisions were the first large (over 32 inches diagonal) flat panel displays to be releas ...
s was a hardware revolution that began with computer monitors in the late 1990s. Most television sets sold in the 2000s were flat-panel, mainly LEDs. Major manufacturers announced the discontinuation of CRT,
Digital Light Processing
Digital Light Processing (DLP) is a set of chipsets based on optical micro-electro-mechanical technology that uses a digital micromirror device. It was originally developed in 1987 by Larry Hornbeck of Texas Instruments. While the DLP imagin ...
(DLP), plasma, and even fluorescent-backlit LCDs by the mid-2010s.
In the near future, LEDs are expected to be gradually replaced by OLEDs.
Also, major manufacturers have announced that they will increasingly produce smart TVs in the mid-2010s.
Smart TVs with integrated Internet and
Web 2.0
Web 2.0 (also known as participative (or participatory) web and social web) refers to websites that emphasize user-generated content, ease of use, participatory culture and interoperability (i.e., compatibility with other products, systems, and ...
functions became the dominant form of television by the late 2010s.
Television signals were initially distributed only as terrestrial television using high-powered
radio-frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upp ...
television transmitter
A television transmitter is a transmitter that is used for terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, along with a synchronized ...
s to
broadcast the signal to individual television receivers. Alternatively television signals are distributed by
coaxial cable or optical fiber,
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...
systems and, since the 2000s via the Internet. Until the early 2000s, these were transmitted as
analog
Analog or analogue may refer to:
Computing and electronics
* Analog signal, in which information is encoded in a continuous variable
** Analog device, an apparatus that operates on analog signals
*** Analog electronics, circuits which use analog ...
signals, but a
transition to digital television was expected to be completed worldwide by the late 2010s. A standard television set consists of multiple internal
electronic circuits, including a tuner for
receiving and decoding broadcast signals. A visual
display device which lacks a
tuner is correctly called a
video monitor
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal the ...
rather than a television.
Etymology
The word ''television'' comes . The first documented usage of the term dates back to 1900, when the Russian scientist
Constantin Perskyi used it in a paper that he presented in French at the first International Congress of Electricity, which ran from 18 to 25 August 1900 during the
International World Fair in Paris.
The
anglicised version of the term is first attested in 1907, when it was still "...a theoretical system to transmit moving images over
telegraph
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas p ...
or
telephone wire
A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or ot ...
s".
It was "...formed in English or borrowed from French ."
In the 19th century and early 20th century, other "...proposals for the name of a then-hypothetical technology for sending pictures over distance were telephote (1880) and televista (1904)."
The abbreviation ''TV'' is from 1948. The use of the term to mean "a
television set
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
" dates from 1941.
The use of the term to mean "television as a medium" dates from 1927.
The slang term ''telly'' is more common in the UK. The slang term "the tube" or the "boob tube" derives from the bulky
cathode-ray tube used on most TVs until the advent of
flat-screen TVs. Another slang term for the TV is "idiot box".
Also, in the 1940s and throughout the 1950s, during the early rapid growth of television programming and television set ownership in the United States, another slang term became widely used in that period and continues to be used today to distinguish productions originally created for broadcast on television from films developed for presentation in movie theaters.
[Johnson, Richard (2018)]
“Big movie stars are not making the cut on the small screen”
p. 6, ''The New York Post
The ''New York Post'' (''NY Post'') is a conservative daily tabloid newspaper published in New York City. The ''Post'' also operates NYPost.com, the celebrity gossip site PageSix.com, and the entertainment site Decider.com.
It was established ...
'', 11 October 2018. Retrieved 24 November 2018. The "small screen", as both a compound adjective and noun, became specific references to television, while the "
big screen" was used to identify productions made for theatrical release.
History
Mechanical
Facsimile transmission
Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer o ...
systems for still photographs pioneered methods of mechanical scanning of images in the early 19th century.
Alexander Bain introduced the facsimile machine between 1843 and 1846.
Frederick Bakewell
Frederick Collier Bakewell (29 September 1800 – 26 September 1869) was an English physicist who improved on the concept of the facsimile machine introduced by Alexander Bain in 1842 and demonstrated a working laboratory version at the 1 ...
demonstrated a working laboratory version in 1851.
Willoughby Smith
Willoughby Smith (6 April 1828, in Great Yarmouth, Norfolk – 17 July 1891, in Eastbourne, Sussex) was an English electrical engineer who discovered the photoconductivity of the element selenium. This discovery led to the invention of photoele ...
discovered the
photoconductivity
Photoconductivity is an optical and electrical phenomenon in which a material becomes more electrically conductive due to the absorption of electromagnetic radiation such as visible light, ultraviolet light, infrared light, or gamma radiation ...
of the element
selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...
in 1873. As a 23-year-old German university student,
Paul Julius Gottlieb Nipkow proposed and patented the
Nipkow disk
A Nipkow disk (sometimes Anglicized as Nipkov disk; patented in 1884), also known as scanning disk, is a mechanical, rotating, geometrically operating image scanning device, patented in 1885 by Paul Gottlieb Nipkow. This scanning disk was a funda ...
in 1884. This was a spinning disk with a spiral pattern of holes in it, so each hole scanned a line of the image. Although he never built a working model of the system, variations of Nipkow's spinning-disk "
image rasterizer" became exceedingly common.
Constantin Perskyi had coined the word ''television'' in a paper read to the International Electricity Congress at the
International World Fair in Paris on 24 August 1900. Perskyi's paper reviewed the existing electromechanical technologies, mentioning the work of Nipkow and others. However, it was not until 1907 that developments in amplification tube technology by
Lee de Forest and
Arthur Korn, among others, made the design practical.
["Sending Photographs by Telegraph"](_blank)
''The New York Times'', Sunday Magazine, 20 September 1907, p. 7.
The first demonstration of the live transmission of images was by Georges Rignoux and A. Fournier in Paris in 1909. A matrix of 64
selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...
cells, individually wired to a mechanical
commutator, served as an electronic
retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...
. In the receiver, a type of
Kerr cell
The Kerr effect, also called the quadratic electro-optic (QEO) effect, is a change in the refractive index of a material in response to an applied electric field. The Kerr effect is distinct from the Pockels effect in that the induced index chan ...
modulated the light and a series of differently angled mirrors attached to the edge of a rotating disc scanned the modulated beam onto the display screen. A separate circuit regulated synchronization. The 8x8
pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device.
In most digital display devices, pixels are the ...
resolution in this proof-of-concept demonstration was just sufficient to clearly transmit individual letters of the alphabet. An updated image was transmitted "several times" each second.
In 1911,
Boris Rosing and his student
Vladimir Zworykin
Vladimir Kosma Zworykin; or with the patronymic as ''Kosmich''; or russian: Кузьмич, translit=Kuz'mich, label=none. Zworykin anglicized his name to ''Vladimir Kosma Zworykin'', replacing the patronymic with the name ''Kosma'' as a middle ...
created a system that used a mechanical mirror-drum scanner to transmit, in Zworykin's words, "very crude images" over wires to the "
Braun
Braun is a common surname, originating from the German word for the color brown. The name is the 22nd most common family name in Germany. Many German emigrants to the United States also changed their name to ''Brown'' (''see Brown (surname)'') ...
tube" (
cathode-ray tube or "CRT") in the receiver. Moving images were not possible because, in the scanner: "the sensitivity was not enough and the selenium cell was very laggy".
In 1921,
Edouard Belin sent the first image via radio waves with his
belinograph.
![John Logie Baird and Stooky Bill](https://upload.wikimedia.org/wikipedia/commons/b/b2/John_Logie_Baird_and_Stooky_Bill.png)
By the 1920s, when amplification made television practical, Scottish inventor
John Logie Baird
John Logie Baird FRSE (; 13 August 188814 June 1946) was a Scottish inventor, electrical engineer, and innovator who demonstrated the world's first live working television system on 26 January 1926. He went on to invent the first publicly dem ...
employed the Nipkow disk in his prototype video systems. On 25 March 1925, Baird gave the first public demonstration of televised
silhouette
A silhouette ( , ) is the image of a person, animal, object or scene represented as a solid shape of a single colour, usually black, with its edges matching the outline of the subject. The interior of a silhouette is featureless, and the silhou ...
images in motion, at
Selfridges
Selfridges, also known as Selfridges & Co., is a chain of high-end department stores in the United Kingdom that is operated by Selfridges Retail Limited, part of the Selfridges Group of department stores. It was founded by Harry Gordon Selfridg ...
's department store in London. Since human faces had inadequate contrast to show up on his primitive system, he televised a ventriloquist's dummy named "Stooky Bill", whose painted face had higher contrast, talking and moving. By 26 January 1926, he had demonstrated the transmission of an image of a face in motion by radio. This is widely regarded as the world's first public television demonstration. Baird's system used the Nipkow disk for both scanning the image and displaying it. A brightly illuminated subject was placed in front of a spinning Nipkow disk set with lenses which swept images across a static photocell. The thallium sulphide (Thalofide) cell, developed by
Theodore Case
Theodore Willard Case (December 12, 1888 – May 13, 1944) was an American chemist and inventor known for the invention of the Movietone sound-on-film system.
Early life and education
Theodore Willard Case was born in 1888 in Auburn, New Yo ...
in the U.S., detected the light reflected from the subject and converted it into a proportional electrical signal. This was transmitted by AM radio waves to a receiver unit, where the video signal was applied to a neon light behind a second Nipkow disk rotating synchronized with the first. The brightness of the neon lamp was varied in proportion to the brightness of each spot on the image. As each hole in the disk passed by, one
scan line
A scan line (also scanline) is one line, or row, in a raster scanning pattern, such as a line of video on a cathode ray tube (CRT) display of a television set or computer monitor.
On CRT screens the horizontal scan lines are visually discernible ...
of the image was reproduced. Baird's disk had 30 holes, producing an image with only 30 scan lines, just enough to recognize a human face. In 1927, Baird transmitted a signal over of telephone line between London and
Glasgow
Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...
.
In 1928, Baird's company (Baird Television Development Company/Cinema Television) broadcast the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. In 1929, he became involved in the first experimental mechanical television service in Germany. In November of the same year, Baird and
Bernard Natan of
Pathé established France's first television company, Télévision-
Baird-Natan. In 1931, he made the first outdoor remote broadcast, of
The Derby. In 1932, he demonstrated
ultra-short wave
Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves ( radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter.
Frequencies immediately below V ...
television. Baird's mechanical system reached a peak of 240-lines of resolution on
BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...
...
telecasts in 1936, though the mechanical system did not scan the televised scene directly. Instead a
17.5 mm film
17.5 mm film was a film gauge for as many of eight types of motion picture film stock, generally created by splitting unperforated 35 mm film.
History
17.5 mm film was first documented in 1898 with the creation of the Birtac camera ...
was shot, rapidly developed and then scanned while the film was still wet.
A U.S. inventor,
Charles Francis Jenkins
Charles Francis Jenkins (August 22, 1867 – June 6, 1934) was an American engineer who was a pioneer of early cinema and one of the inventors of television, though he used mechanical rather than electronic technologies. His businesses incl ...
, also pioneered the television. He published an article on "Motion Pictures by Wireless" in 1913; transmitted moving silhouette images for witnesses in December 1923; and on 13 June 1925 publicly demonstrated synchronized transmission of silhouette pictures. In 1925 Jenkins used the Nipkow disk and transmitted the silhouette image of a toy windmill in motion, over a distance of 5 miles (8 km), from a naval radio station in Maryland to his laboratory in Washington, D.C., using a lensed disk scanner with a 48-line resolution.
He was granted
U.S. Patent No. 1,544,156 (Transmitting Pictures over Wireless) on 30 June 1925 (filed 13 March 1922).
Herbert E. Ives
Herbert Eugene Ives (July 31, 1882 – November 13, 1953) was a scientist and engineer who headed the development of facsimile and television systems at AT&T in the first half of the twentieth century. He is best known for the 1938 Ives–Stilwel ...
and
Frank Gray
Francis Tierney Gray (born 27 October 1954) is a Scottish football manager and former player. He played for Leeds United, Nottingham Forest, Sunderland and Darlington, while he also represented Scotland 32 times.
Gray has managed Darlington, ...
of
Bell Telephone Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial research and scientific development company owned by mult ...
gave a dramatic demonstration of mechanical television on 7 April 1927. Their reflected-light television system included both small and large viewing screens. The small receiver had a 2-inch-wide by 2.5-inch-high screen (5 by 6 cm). The large receiver had a screen 24 inches wide by 30 inches high (60 by 75 cm). Both sets could reproduce reasonably accurate, monochromatic, moving images. Along with the pictures, the sets received synchronized sound. The system transmitted images over two paths: first, a
copper wire
Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s. The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor.
Copper is the electri ...
link from Washington to New York City, then a radio link from
Whippany, New Jersey
Whippany is a Local government in New Jersey#Unincorporated communities, unincorporated community located within Hanover Township, New Jersey, Hanover Township in Morris County, New Jersey, Morris County, New Jersey, United States. Whippany's na ...
. Comparing the two transmission methods, viewers noted no difference in quality. Subjects of the telecast included
Secretary of Commerce Herbert Hoover
Herbert Clark Hoover (August 10, 1874 – October 20, 1964) was an American politician who served as the 31st president of the United States from 1929 to 1933 and a member of the Republican Party, holding office during the onset of the Gr ...
. A
flying-spot scanner
A flying-spot scanner (FSS) uses a scanning source of a spot of light, such as a high-resolution, high-light-output, low-persistence cathode ray tube (CRT), to scan an image. Usually the image to be scanned is on photographic film, such as motion ...
beam illuminated these subjects. The scanner that produced the beam had a 50-aperture disk. The disc revolved at a rate of 18 frames per second, capturing one frame about every 56
milliseconds. (Today's systems typically transmit 30 or 60 frames per second, or one frame every 33.3 or 16.7 milliseconds respectively.) Television historian Albert Abramson underscored the significance of the Bell Labs demonstration: "It was in fact the best demonstration of a mechanical television system ever made to this time. It would be several years before any other system could even begin to compare with it in picture quality."
In 1928,
WRGB
WRGB (channel 6) is a television station licensed to Schenectady, New York, United States, serving the Capital District as an affiliate of CBS. It is owned by Sinclair Broadcast Group alongside CW affiliate WCWN (channel 45, also licensed to Sc ...
, then W2XB, was started as the world's first television station. It broadcast from the
General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable en ...
facility in
Schenectady, NY
Schenectady () is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2020 census, the city's population of 67,047 made it the state's ninth-largest city by population. The city is in eastern New Y ...
. It was popularly known as "
WGY Television". Meanwhile, in the
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
,
Léon Theremin
Leon Theremin (born Lev Sergeyevich Termen rus, Лев Сергеевич Термéн, p=ˈlʲef sʲɪrˈɡʲejɪvʲɪtɕ tɨrˈmʲen; – 3 November 1993) was a Russian and Soviet inventor, most famous for his invention of the theremin, one o ...
had been developing a mirror drum-based television, starting with 16 lines resolution in 1925, then 32 lines and eventually 64 using
interlacing in 1926. As part of his thesis, on 7 May 1926, he electrically transmitted, and then projected, near-simultaneous moving images on a screen.
By 1927 Theremin had achieved an image of 100 lines, a resolution that was not surpassed until May 1932 by RCA, with 120 lines.
On 25 December 1926
Kenjiro Takayanagi
was a Japanese engineer and a pioneer in the development of television. Although he failed to gain much recognition in the West, he built the world's first all-electronic television receiver, and is referred to as "the father of Japanese televisi ...
demonstrated a television system with 40-line resolution that employed a Nipkow disk scanner and CRT display at Hamamatsu Industrial High School in Japan. This prototype is still on display at the Takayanagi Memorial Museum in
Shizuoka University
is a List of national universities in Japan, national university in Shizuoka Prefecture, Japan.
Shizuoka University is well known in the field of engineering, in creative innovation, and in the invention of next generation technology, with ...
, Hamamatsu Campus. His research in creating a production model was halted by the
SCAP after
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
.
[''Kenjiro Takayanagi: The Father of Japanese Television''](_blank)
, NHK (Japan Broadcasting Corporation), 2002. Retrieved 23 May 2009.
Because only a limited number of holes could be made in the disks, and disks beyond a certain diameter became impractical, image resolution on mechanical television broadcasts was relatively low, ranging from about 30 lines up to 120 or so. Nevertheless, the image quality of 30-line transmissions steadily improved with technical advances, and by 1933 the UK broadcasts using the Baird system were remarkably clear. A few systems ranging into the 200-line region also went on the air. Two of these were the 180-line system that Compagnie des Compteurs (CDC) installed in Paris in 1935, and the 180-line system that
Peck Television Corp. Peck Television Corp. was a private company headquartered in Montreal, Canada that was a pioneer in television. William Hoyt Peck developed a mechanical television
Mechanical television or mechanical scan television is a television system that ...
started in 1935 at station VE9AK in
Montreal
Montreal ( ; officially Montréal, ) is the second-most populous city in Canada and most populous city in the Canadian province of Quebec. Founded in 1642 as '' Ville-Marie'', or "City of Mary", it is named after Mount Royal, the triple ...
. The advancement of all-electronic television (including
image dissectors and other camera tubes and
cathode-ray tubes for the reproducer) marked the start of the end for mechanical systems as the dominant form of television. Mechanical television, despite its inferior image quality and generally smaller picture, would remain the primary television technology until the 1930s. The last mechanical telecasts ended in 1939 at stations run by a lot of public universities in the United States.
Electronic
In 1897, English
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.
Physicists generally are interested in the root or ultimate cau ...
J. J. Thomson
Sir Joseph John Thomson (18 December 1856 – 30 August 1940) was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered.
In 1897, Thomson showed that ...
was able, in his three well-known experiments, to deflect cathode rays, a fundamental function of the modern
cathode-ray tube (CRT). The earliest version of the CRT was invented by the German physicist
Ferdinand Braun
Karl Ferdinand Braun (; 6 June 1850 – 20 April 1918) was a German electrical engineer, inventor, physicist and Nobel laureate in physics. Braun contributed significantly to the development of radio and television technology: he shared the ...
in 1897 and is also known as the "Braun" tube. It was a
cold-cathode
A cold cathode is a cathode that is not electrically heated by a filament.A negatively charged electrode emits electrons or is the positively charged terminal. For more, see field emission. A cathode may be considered "cold" if it emits more ele ...
diode, a modification of the
Crookes tube
A Crookes tube (also Crookes–Hittorf tube) is an early experimental electrical discharge tube, with partial vacuum, invented by English physicist William Crookes and others around 1869-1875, in which cathode rays, streams of electrons, were ...
, with a
phosphor-coated screen. Braun was the first to conceive the use of a CRT as a display device. In 1906 the Germans Max Dieckmann and Gustav Glage produced
raster images
upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for ...
for the first time in a CRT. In 1907, Russian scientist
Boris Rosing used a CRT in the receiving end of an experimental
video signal
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) sy ...
to form a picture. He managed to display simple geometric shapes onto the screen.
In 1908,
Alan Archibald Campbell-Swinton
Alan Archibald Campbell-Swinton FRS (18 October 1863 – 19 February 1930) was a Scottish consulting electrical engineer, who provided the theoretical basis for the electronic television, two decades before the technology existed to implement ...
, fellow of the
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
(UK), published a letter in the scientific journal ''
Nature
Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...
'' in which he described how "distant electric vision" could be achieved by using a cathode-ray tube, or Braun tube, as both a transmitting and receiving device,
[
][
] He expanded on his vision in a speech given in London in 1911 and reported in ''
The Times
''The Times'' is a British daily national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its sister paper '' The Sunday Times'' (f ...
'' and the Journal of the Röntgen Society.
[
][Shiers, George and May (1997), ''Early television: a bibliographic guide to 1940''](_blank)
New York: Garland, p. 56. Retrieved 13 June 2010.
In a letter to ''
Nature
Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...
'' published in October 1926, Campbell-Swinton also announced the results of some "not very successful experiments" he had conducted with G. M. Minchin and J. C. M. Stanton. They had attempted to generate an electrical signal by projecting an image onto a selenium-coated metal plate that was simultaneously scanned by a
cathode ray
Cathode rays or electron beam (e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to el ...
beam.
[
] These experiments were conducted before March 1914, when Minchin died,
[
] but they were later repeated by two different teams in 1937, by H. Miller and J. W. Strange from
EMI
EMI Group Limited (originally an initialism for Electric and Musical Industries, also referred to as EMI Records Ltd. or simply EMI) was a British Transnational corporation, transnational Conglomerate (company), conglomerate founded in March 1 ...
,
[
] and by H. Iams and A. Rose from
RCA
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
.
[
] Both teams succeeded in transmitting "very faint" images with the original Campbell-Swinton's selenium-coated plate. Although others had experimented with using a cathode-ray tube as a receiver, the concept of using one as a transmitter was novel. The first cathode-ray tube to use a
hot cathode
In vacuum tubes and gas-filled tubes, a hot cathode or thermionic cathode is a cathode electrode which is heated to make it emit electrons due to thermionic emission. This is in contrast to a cold cathode, which does not have a heating elemen ...
was developed by
John B. Johnson (who gave his name to the term
Johnson noise) and Harry Weiner Weinhart of
Western Electric, and became a commercial product in 1922.
In 1926, Hungarian engineer
Kálmán Tihanyi
Kálmán Tihanyi or in English language technical literature often mentioned as Coloman Tihanyi or Koloman Tihanyi (28 April 1897 – 26 February 1947) was a Hungarian physicist, electrical engineer and inventor. One of the early pioneers ...
designed a television system using fully electronic scanning and display elements and employing the principle of "charge storage" within the scanning (or "camera") tube.
[United States Patent Office, Patent No. 2,133,123, 11 October 1938.][United States Patent Office, Patent No. 2,158,259, 16 May 1939] The problem of low sensitivity to light resulting in low electrical output from transmitting or "camera" tubes would be solved with the introduction of charge-storage technology by Kálmán Tihanyi beginning in 1924.
"Kálmán Tihanyi (1897–1947)", ''IEC Techline'', International Electrotechnical Commission (IEC), 15 July 2009. His solution was a camera tube that accumulated and stored electrical charges ("photoelectrons") within the tube throughout each scanning cycle. The device was first described in a patent application he filed in
Hungary
Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the ...
in March 1926 for a television system he called "Radioskop".
["Kálmán Tihanyi's 1926 Patent Application 'Radioskop'"](_blank)
''Memory of the World'', United Nations Educational, Scientific and Cultural Organization (UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
), 2005. Retrieved 29 January 2009. After further refinements included in a 1928 patent application,
Tihanyi's patent was declared void in Great Britain in 1930,
[Tihanyi, Koloman, ''Improvements in television apparatus''](_blank)
European Patent Office, Patent No. GB313456. Convention date UK application: 1928-06-11, declared void and published: 11 November 1930. Retrieved 25 April 2013. so he applied for patents in the United States. Although his breakthrough would be incorporated into the design of
RCA
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
's "
iconoscope" in 1931, the U.S. patent for Tihanyi's transmitting tube would not be granted until May 1939. The patent for his receiving tube had been granted the previous October. Both patents had been purchased by RCA prior to their approval.
Charge storage remains a basic principle in the design of imaging devices for television to the present day.
On 25 December 1926, at Hamamatsu Industrial High School in Japan, Japanese inventor
Kenjiro Takayanagi
was a Japanese engineer and a pioneer in the development of television. Although he failed to gain much recognition in the West, he built the world's first all-electronic television receiver, and is referred to as "the father of Japanese televisi ...
demonstrated a TV system with a 40-line resolution that employed a CRT display.
This was the first working example of a fully electronic television receiver. Takayanagi did not apply for a patent.
In the 1930s,
Allen B. DuMont
Allen Balcom DuMont, also spelled Du Mont, (January 29, 1901 – November 14, 1965) was an American electronics engineer, scientist and invention, inventor best known for improvements to the cathode ray tube in 1931 for use in television receive ...
made the first CRTs to last 1,000 hours of use, which was one of the factors that led to the widespread adoption of television.
On 7 September 1927, U.S. inventor
Philo Farnsworth
Philo Taylor Farnsworth (August 19, 1906 – March 11, 1971) was an American inventor and television pioneer. He made many crucial contributions to the early development of all-electronic television. He is best known for his 1927 invention of t ...
's
image dissector
An image dissector, also called a dissector tube, is a video camera tube in which photocathode emissions create an "electron image" which is then swept up, down and across an anode to produce an electrical signal representing the visual image. It e ...
camera tube transmitted its first image, a simple straight line, at his laboratory at 202 Green Street in San Francisco.
[Postman, Neil, "Philo Farnsworth"](_blank)
''The TIME 100: Scientists & Thinkers'', ''Time'', 29 March 1999. Retrieved 28 July 2009.
, ''The Virtual Museum of the City of San Francisco''. Retrieved 15 July 2009. By 3 September 1928, Farnsworth had developed the system sufficiently to hold a demonstration for the press. This is widely regarded as the first electronic television demonstration.
In 1929, the system was improved further by the elimination of a motor generator, so that his television system now had no mechanical parts. That year, Farnsworth transmitted the first live human images with his system, including a three and a half-inch image of his wife Elma ("Pem") with her eyes closed (possibly due to the bright lighting required).
![Zworykin kinescope 1929](https://upload.wikimedia.org/wikipedia/commons/8/85/Zworykin_kinescope_1929.jpg)
Meanwhile, Vladimir Zworykin was also experimenting with the cathode-ray tube to create and show images. While working for
Westinghouse Electric
The Westinghouse Electric Corporation was an American manufacturing company founded in 1886 by George Westinghouse. It was originally named "Westinghouse Electric & Manufacturing Company" and was renamed "Westinghouse Electric Corporation" in ...
in 1923, he began to develop an electronic camera tube. But in a 1925 demonstration, the image was dim, had low contrast, and poor definition, and was stationary. Zworykin's imaging tube never got beyond the laboratory stage. But RCA, which acquired the Westinghouse patent, asserted that the patent for Farnsworth's 1927 image dissector was written so broadly that it would exclude any other electronic imaging device. Thus RCA, on the basis of Zworykin's 1923 patent application, filed a
patent interference
An interference proceeding, also known as a priority contest, is an inter partes proceeding to determine the priority issues of multiple patent applications. It is a proceeding unique to the patent law of the United States. Unlike in most other co ...
suit against Farnsworth. The
U.S. Patent Office
The United States Patent and Trademark Office (USPTO) is an agency in the U.S. Department of Commerce that serves as the national patent office and trademark registration authority for the United States. The USPTO's headquarters are in Alexa ...
examiner disagreed in a 1935 decision, finding priority of invention for Farnsworth against Zworykin. Farnsworth claimed that Zworykin's 1923 system would be unable to produce an electrical image of the type to challenge his patent. Zworykin received a patent in 1928 for a color transmission version of his 1923 patent application;
[Zworykin, Vladimir K., Television System]
. Patent No. 1691324, U.S. Patent Office. Filed 1925-07-13, issued 13 November 1928. Retrieved 28 July 2009 he also divided his original application in 1931.
[Zworykin, Vladimir K., Television System](_blank)
. Patent No. 2022450, U.S. Patent Office. Filed 1923-12-29, issued 26 November 1935. Retrieved 10 May 2010. Zworykin was unable or unwilling to introduce evidence of a working model of his tube that was based on his 1923 patent application. In September 1939, after losing an appeal in the courts, and determined to go forward with the commercial manufacturing of television equipment, RCA agreed to pay Farnsworth US$1 million over a ten-year period, in addition to license payments, to use his patents.
[Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. , 266 pp.]
In 1933, RCA introduced an improved camera tube that relied on Tihanyi's charge storage principle.
Called the "Iconoscope" by Zworykin, the new tube had a light sensitivity of about 75,000
lux, and thus was claimed to be much more sensitive than Farnsworth's image dissector. 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.
[Abramson, Albert (1987), ''The History of Television, 1880 to 1941''. Jefferson, NC: Albert Abramson. p. 148. .][Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. , pp. 137–141.] This small tube could amplify a signal reportedly to the 60th power or better
[Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. , p. 139.] and showed great promise in all fields of electronics. Unfortunately, an issue with the multipactor was that it wore out at an unsatisfactory rate.
[Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. , p. 141.]
At the
Berlin Radio Show
The IFA ( ) or Internationale Funkausstellung Berlin (International radio exhibition Berlin, a.k.a. 'Berlin Radio Show') is one of the oldest industrial exhibitions in Germany. Between 1924 and 1939 it was an annual event, but from 1950 it was ...
in August 1931,
Manfred von Ardenne
Manfred von Ardenne (20 January 1907 – 26 May 1997) was a German researcher and applied physicist and inventor. He took out approximately 600 patents in fields including electron microscopy, medical technology, nuclear technology, plasma physics ...
gave a public demonstration of a television system using a CRT for both transmission and reception. However, Ardenne had not developed a camera tube, using the CRT instead as a
flying-spot scanner
A flying-spot scanner (FSS) uses a scanning source of a spot of light, such as a high-resolution, high-light-output, low-persistence cathode ray tube (CRT), to scan an image. Usually the image to be scanned is on photographic film, such as motion ...
to scan slides and film. Philo Farnsworth gave the world's first public demonstration of an all-electronic television system, using a live camera, at the
Franklin Institute
The Franklin Institute is a science museum and the center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and statesman Benjamin Franklin. It houses the Benjamin Franklin National Memori ...
of
Philadelphia
Philadelphia, often called Philly, is the List of municipalities in Pennsylvania#Municipalities, largest city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, the List of United States cities by population, sixth-largest city i ...
on 25 August 1934, and for ten days afterwards.
[Burns, R.W. ''Television: An international history of the formative years''. (1998). IEE History of Technology Series, 22. London: IEE, p. 370. .] Mexican inventor
Guillermo González Camarena
Guillermo González Camarena (17 February 1917 – 18 April 1965) was a Mexican electrical engineer who was the inventor of a color-wheel type of color television.
Early life
González Camarena was born in Guadalajara, Mexico. He was the younge ...
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. In Britain, the
EMI
EMI Group Limited (originally an initialism for Electric and Musical Industries, also referred to as EMI Records Ltd. or simply EMI) was a British Transnational corporation, transnational Conglomerate (company), conglomerate founded in March 1 ...
engineering team led by
Isaac Shoenberg
Sir Isaac Shoenberg (1 March 1880 – 25 January 1963) was a British electronic engineer born in Belarus who was best known for his role in the history of television. He was the head of the EMI research team that developed the 405-line (Marconi-EM ...
applied in 1932 for a patent for a new device they called "the Emitron",
[
][
] 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. It alternated for a short time with Baird's mechanical system in adjoining studios, but was more reliable and visibly superior. This was the world's first regular "high-definition" television service.
[Burns, R.W., ''Television: An international history of the formative years''. (1998). IEE History of Technology Series, 22. London: IEE, p. 576. .]
The original U.S. iconoscope was noisy, had a high ratio of interference to signal, and ultimately gave disappointing results, especially when compared to the high definition mechanical scanning systems then becoming available.
The
EMI
EMI Group Limited (originally an initialism for Electric and Musical Industries, also referred to as EMI Records Ltd. or simply EMI) was a British Transnational corporation, transnational Conglomerate (company), conglomerate founded in March 1 ...
team, under the supervision of
Isaac Shoenberg
Sir Isaac Shoenberg (1 March 1880 – 25 January 1963) was a British electronic engineer born in Belarus who was best known for his role in the history of television. He was the head of the EMI research team that developed the 405-line (Marconi-EM ...
, analyzed how the iconoscope (or Emitron) produces an electronic signal and concluded that its real efficiency was only about 5% of the theoretical maximum.
[
][
] They solved this problem by developing, and patenting in 1934, two new camera tubes dubbed
super-Emitron and
CPS Emitron.
[
][
][
] The super-Emitron was between ten and fifteen times more sensitive than the original Emitron and iconoscope tubes and, in some cases, this ratio was considerably greater.
It was used for
outside broadcasting
Outside broadcasting (OB) is the electronic field production (EFP) of television or radio programmes (typically to cover television news and sports television events) from a mobile remote broadcast television studio. Professional video camera ...
by the BBC, for the first time, on
Armistice Day
Armistice Day, later known as Remembrance Day in the Commonwealth and Veterans Day in the United States, is commemorated every year on 11 November to mark the armistice signed between the Allies of World War I and Germany at Compiègne, Fran ...
1937, when the general public could watch on a television set as the King laid a wreath at the Cenotaph.
[
] This was the first time that anyone had broadcast a live street scene from cameras installed on the roof of neighboring buildings, because neither Farnsworth nor RCA would do the same until the
1939 New York World's Fair.
![RCA Indian Head test pattern](https://upload.wikimedia.org/wikipedia/commons/1/1b/RCA_Indian_Head_test_pattern.JPG)
On the other hand, in 1934, Zworykin shared some patent rights with the German licensee company Telefunken.
The "image iconoscope" ("Superikonoskop" in Germany) was produced as a result of the collaboration. This tube is essentially identical to the super-Emitron. The production and commercialization of the super-Emitron and image iconoscope in Europe were not affected by the
patent war
A patent war is a "battle" between corporations or individuals to secure patents for litigation, whether offensively or defensively. There are ongoing patent wars between the world's largest technology and software corporations. Contemporary pat ...
between Zworykin and Farnsworth, because Dieckmann and Hell had priority in Germany for the invention of the image dissector, having submitted a patent application for their ''Lichtelektrische Bildzerlegerröhre für Fernseher'' (''Photoelectric Image Dissector Tube for Television'') in Germany in 1925,
[
] two years before Farnsworth did the same in the United States.
[
] The image iconoscope (Superikonoskop) became the industrial standard for public broadcasting in Europe from 1936 until 1960, when it was replaced by the
vidicon
Video camera tubes were devices based on the cathode ray tube that were used in television cameras to capture television images, prior to the introduction of charge-coupled device (CCD) image sensors in the 1980s. Several different types of tubes ...
and
plumbicon
Video camera tubes were devices based on the cathode ray tube that were used in television cameras to capture television images, prior to the introduction of charge-coupled device (CCD) image sensors in the 1980s. Several different types of tubes ...
tubes. Indeed, it was the representative of the European tradition in electronic tubes competing against the American tradition represented by the image orthicon.
[
] The German company Heimann produced the Superikonoskop for the 1936 Berlin Olympic Games,
[
][
] later Heimann also produced and commercialized it from 1940 to 1955;
[
] finally the Dutch company
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...
produced and commercialized the image iconoscope and multicon from 1952 to 1958.
[
]
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.
[Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. , p. 248.] RCA, for example, used only Iconoscopes in the New York area, but Farnsworth Image Dissectors in Philadelphia and San Francisco.
[Abramson, Albert (1987), ''The History of Television, 1880 to 1941''. Jefferson, NC: Albert Abramson. p. 254. .] In September 1939, RCA agreed to pay the Farnsworth Television and Radio Corporation royalties over the next ten years for access to Farnsworth's patents.
[Schatzkin, Paul (2002), ''The Boy Who Invented Television''. Silver Spring, Maryland: Teamcom Books, pp. 187–88. .] With this historic agreement in place, RCA integrated much of what was best about the Farnsworth Technology into their systems.
In 1941, the United States implemented 525-line television. Electrical engineer
Benjamin Adler
Benjamin Adler (10 November 1903 – 16 April 1990) was an American electrical engineer and inventor who helped develop the first commercial television set. He was born in New York City to Romanian Jewish immigrants. He graduated from the-now New ...
played a prominent role in the development of television.
The world's first 625-line television standard was designed in the Soviet Union in 1944 and became a national standard in 1946.
["On the beginning of broadcast in 625 lines 60 years ago"](_blank)
''625'' magazine (in Russian). The first broadcast in 625-line standard occurred in Moscow in 1948. The concept of 625 lines per frame was subsequently implemented in the European
CCIR standard. In 1936,
Kálmán Tihanyi
Kálmán Tihanyi or in English language technical literature often mentioned as Coloman Tihanyi or Koloman Tihanyi (28 April 1897 – 26 February 1947) was a Hungarian physicist, electrical engineer and inventor. One of the early pioneers ...
described the principle of
plasma display
A plasma display panel (PDP) is a type of flat panel display that uses small cells containing plasma: ionized gas that responds to electric fields. Plasma televisions were the first large (over 32 inches diagonal) flat panel displays to be releas ...
, the first
flat panel display
A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment.
Flat-panel displays are thin, lightweight, provide better l ...
system.
Early electronic
television sets
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
were large and bulky, with
analog circuits
Analogue electronics ( en-US, analog electronics) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels. The term "analogue" describes the proportional relati ...
made of
vacuum tubes
A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
The type known as a ...
. Following the invention of the first working
transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
at
Bell Labs
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial Research and development, research and scientific developm ...
,
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...
founder
Masaru Ibuka
Masaru Ibuka (井深 大 ''Ibuka Masaru''; April 11, 1908 – December 19, 1997) was a Japanese electronics industrialist and co-founder of Sony, along with Akio Morita.Kirkup, James"Obituary: Masaru Ibuka,"''Independent'' (London). December 2 ...
predicted in 1952 that the transition to
electronic circuits
An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electrical ...
made of transistors would lead to smaller and more portable television sets. The first fully transistorized, portable
solid-state
Solid state, or solid matter, is one of the four fundamental states of matter.
Solid state may also refer to:
Electronics
* Solid-state electronics, circuits built of solid materials
* Solid state ionics, study of ionic conductors and their use ...
television set was the 8-inch
Sony TV8-301 The TV8-301 was a small black and white television made by Sony. It is notable for being the world's first non- projection type all-transistor television. It had an eight-inch screen. It was also portable, having a bay in the back for two 6 vo ...
, developed in 1959 and released in 1960. 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.
Color
![Samsung LED TV](https://upload.wikimedia.org/wikipedia/commons/1/1d/Samsung_LED_TV.jpg)
The basic idea of using three monochrome images to produce a color image had been experimented with almost as soon as black-and-white televisions had first been built. Although he gave no practical details, among the earliest published proposals for television was one by Maurice Le Blanc, in 1880, for a color system, including the first mentions in television literature of line and frame scanning. Polish inventor
Jan Szczepanik
Jan Szczepanik (June 13, 1872 – April 18, 1926) was a Polish inventor, with several hundred patents and over 50 discoveries to his name, many of which are still applied today, especially in the motion picture industry, as well as in photography ...
patented a color television system in 1897, using a
selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...
photoelectric cell at the transmitter and an electromagnet controlling an oscillating mirror and a moving prism at the receiver. But his system contained no means of analyzing the spectrum of colors at the transmitting end, and could not have worked as he described it. Another inventor,
Hovannes Adamian
Hovhannes (Ivan) Abgari Adamian (5 February 1879 – 12 September 1932) was an Armenian engineer, an author of more than 20 inventions. The first experimental color television was shown in London in 1928 based on Adamian's tricolor principle, and h ...
, also experimented with color television as early as 1907. The first color television project is claimed by him, and was patented in Germany on 31 March 1908, patent No. 197183, then in Britain, on 1 April 1908, patent No. 7219, in France (patent No. 390326) and in Russia in 1910 (patent No. 17912).
[A. Rokhlin, Tak rozhdalos' dal'novidenie (in Russian)](_blank)
Scottish inventor
John Logie Baird
John Logie Baird FRSE (; 13 August 188814 June 1946) was a Scottish inventor, electrical engineer, and innovator who demonstrated the world's first live working television system on 26 January 1926. He went on to invent the first publicly dem ...
demonstrated the world's first color transmission on 3 July 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with filters of a different primary color; and three light sources at the receiving end, with a
commutator to alternate their illumination. Baird also made the world's first color broadcast on 4 February 1938, sending a mechanically scanned 120-line image from Baird's
Crystal Palace
Crystal Palace may refer to:
Places Canada
* Crystal Palace Complex (Dieppe), a former amusement park now a shopping complex in Dieppe, New Brunswick
* Crystal Palace Barracks, London, Ontario
* Crystal Palace (Montreal), an exhibition building ...
studios to a projection screen at London's
Dominion Theatre
The Dominion Theatre is a West End theatre and former cinema on Tottenham Court Road, close to St Giles Circus and Centre Point, in the London Borough of Camden. Planned as primarily a musical theatre, it opened in 1929, but the following year ...
. Mechanically scanned color television was also demonstrated by
Bell Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial research and scientific development company owned by mult ...
in June 1929 using three complete systems of
photoelectric cells, amplifiers, glow-tubes, and color filters, with a series of mirrors to superimpose the red, green, and blue images into one full color image.
The first practical hybrid system was again pioneered by John Logie Baird. In 1940 he publicly demonstrated a color television combining a traditional black-and-white display with a rotating colored disk. This device was very "deep", but was later improved with a mirror folding the light path into an entirely practical device resembling a large conventional console. However, Baird was unhappy with the design, and, as early as 1944, had commented to a British government committee that a fully electronic device would be better.
In 1939, Hungarian engineer
Peter Carl Goldmark
Peter Carl Goldmark (born Péter Károly Goldmark; December 2, 1906 – December 7, 1977) was a Hungarian-American engineer who, during his time with Columbia Records, was instrumental in developing the long-playing microgroove 33 rpm phonogr ...
introduced an electro-mechanical system while at
CBS
CBS Broadcasting Inc., commonly shortened to CBS, the abbreviation of its former legal name Columbia Broadcasting System, is an American commercial broadcast television and radio network serving as the flagship property of the CBS Entertainm ...
, which contained an
Iconoscope sensor. The CBS field-sequential color system was partly mechanical, with a disc made of red, blue, and green filters spinning inside the television camera at 1,200 rpm, and a similar disc spinning in synchronization in front of the cathode-ray tube inside the receiver set. The system was first demonstrated to the
Federal Communications Commission
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdicti ...
(FCC) on 29 August 1940, and shown to the press on 4 September.
["Color Television Success in Test", ''The New York Times'', 30 August 1940, p. 21.]
CBS began experimental color field tests using film as early as 28 August 1940, and live cameras by 12 November.
NBC
The National Broadcasting Company (NBC) is an American English-language commercial broadcast television and radio network. The flagship property of the NBC Entertainment division of NBCUniversal, a division of Comcast, its headquarters are l ...
(owned by RCA) made its first field test of color television on 20 February 1941. CBS began daily color field tests on 1 June 1941. These color systems were not compatible with existing black-and-white
television sets
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
, and, as no color television sets were available to the public at this time, viewing of the color field tests was restricted to RCA and CBS engineers and the invited press. The
War Production Board
The War Production Board (WPB) was an agency of the United States government that supervised war production during World War II. President Franklin D. Roosevelt established it in January 1942, with Executive Order 9024. The WPB replaced the Su ...
halted the manufacture of television and radio equipment for civilian use from 22 April 1942, to 20 August 1945, limiting any opportunity to introduce color television to the general public.
As early as 1940, Baird had started work on a fully electronic system he called
Telechrome Telechrome was the first all-electronic single-tube color television system. It was invented by well-known Scottish television engineer, John Logie Baird, who had previously made the first public television broadcast, as well as the first color broa ...
. Early Telechrome devices used two electron guns aimed at either side of a phosphor plate. The phosphor was patterned so the electrons from the guns only fell on one side of the patterning or the other. Using cyan and magenta phosphors, a reasonable limited-color image could be obtained. He also demonstrated the same system using monochrome signals to produce a 3D image (called "
stereoscopic" at the time). A demonstration on 16 August 1944 was the first example of a practical color television system. Work on the Telechrome continued and plans were made to introduce a three-gun version for full color. However, Baird's untimely death in 1946 ended development of the Telechrome system.
Similar concepts were common through the 1940s and 1950s, differing primarily in the way they re-combined the colors generated by the three guns. The
Geer tube
Geer (; wa, Djer) is a Municipalities of Belgium, municipality of Wallonia located in the Liège Province, province of Liège, Belgium.
On January 1, 2006, Geer had a total population of 2,854. The total area is 23.62 km² which gives a p ...
was similar to Baird's concept, but used small pyramids with the phosphors deposited on their outside faces, instead of Baird's 3D patterning on a flat surface. The
Penetron The penetron, short for penetration tube, is a type of limited-color television used in some military applications. Unlike a conventional color television, the penetron produces a limited color gamut, typically two colors and their combination. Pene ...
used three layers of phosphor on top of each other and increased the power of the beam to reach the upper layers when drawing those colors. The
Chromatron
The Chromatron is a color television cathode ray tube design invented by Nobel prize-winner Ernest Lawrence and developed commercially by Paramount Pictures, Sony, Litton Industries and others. The Chromatron offered brighter images than convention ...
used a set of focusing wires to select the colored phosphors arranged in vertical stripes on the tube.
One of the great technical challenges of introducing color
broadcast television was the desire to conserve
bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
, potentially three times that of the existing
black-and-white
Black-and-white (B&W or B/W) images combine black and white in a continuous spectrum, producing a range of shades of grey.
Media
The history of various visual media began with black and white, and as technology improved, altered to color. ...
standards, and not use an excessive amount of
radio spectrum
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 0 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particula ...
. In the United States, after considerable research, the
National Television Systems Committee[National Television System Committee (1951–1953), [Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplementary references cited in the Reports, and the Petition for adoption of transmission standards for color television before the Federal Communications Commission, n.p., 1953], 17 v. illus., diagrams., tables. 28 cm. LC Control No.:5402138]
Library of Congress Online Catalog
/ref> approved an all-electronic system developed by RCA
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
, which encoded the color information separately from the brightness information and greatly reduced the resolution of the color information to conserve bandwidth. As black-and-white televisions could receive the same transmission and display it in black-and-white, the color system adopted is ackwards"compatible". ("Compatible Color", featured in RCA advertisements of the period, is mentioned in the song " America", of West Side Story
''West Side Story'' is a musical conceived by Jerome Robbins with music by Leonard Bernstein, lyrics by Stephen Sondheim, and a book by Arthur Laurents.
Inspired by William Shakespeare's play '' Romeo and Juliet'', the story is set in the mid ...
, 1957.) The brightness image remained compatible with existing black-and-white television sets at slightly reduced resolution, while color televisions could decode the extra information in the signal and produce a limited-resolution color display. The higher resolution black-and-white and lower resolution color images combine in the brain to produce a seemingly high-resolution color image. The NTSC standard represented a major technical achievement.
The first color broadcast (the first episode of the live program '' The Marriage'') occurred on 8 July 1954, but during the following ten years most network broadcasts, and nearly all local programming, continued to be in black-and-white. It was not until the mid-1960s that color sets started selling in large numbers, due in part to the color transition of 1965 in which it was announced that over half of all network prime-time programming would be broadcast in color that fall. The first all-color prime-time season came just one year later. In 1972, the last holdout among daytime network programs converted to color, resulting in the first completely all-color network season.
Early color sets were either floor-standing console models or tabletop versions nearly as bulky and heavy, so in practice they remained firmly anchored in one place. GE's relatively compact and lightweight Porta-Color
General Electric's Porta-Color was the first "portable" color television introduced in the United States in 1966.
The Porta-Color set introduced a new variation of the shadow mask display tube. It had the electron guns arranged in an in-line confi ...
set was introduced in the spring of 1966. It used a transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
-based UHF tuner. The first fully transistorized color television in the United States was the Quasar television introduced in 1967. These developments made watching color television a more flexible and convenient proposition.
The MOSFET (metal-oxide-semiconductor field-effect transistor, or MOS transistor) was invented by Mohamed M. Atalla
Mohamed M. Atalla ( ar, محمد عطاالله; August 4, 1924 – December 30, 2009) was an Egyptian-American engineer, physicist, cryptographer, inventor and entrepreneur. He was a semiconductor pioneer who made important contributions to ...
and Dawon Kahng
Dawon Kahng ( ko, 강대원; May 4, 1931 – May 13, 1992) was a Korean-American electrical engineer and inventor, known for his work in solid-state electronics. He is best known for inventing the MOSFET (metal–oxide–semiconductor field-effe ...
at Bell Labs
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial Research and development, research and scientific developm ...
in 1959, and presented in 1960. By the mid-1960s, RCA
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
were using MOSFETs in their consumer television products. RCA Laboratories
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
researchers W.M. Austin, J.A. Dean, D.M. Griswold and O.P. Hart in 1966 described the use of the MOSFET in television circuits, including RF amplifier
A radio-frequency power amplifier (RF power amplifier) is a type of electronic amplifier that converts a low-power radio-frequency signal into a higher-power signal. Typically, RF power amplifiers drive the antenna of a transmitter. Design goa ...
, low-level video, chroma and AGC circuits. The power MOSFET was later widely adopted for television receiver
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
circuits.
In 1972, sales of color sets finally surpassed sales of black-and-white sets. Color broadcasting in Europe was not standardized on the PAL
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
format until the 1960s, and broadcasts did not start until 1967. By this point many of the technical issues in the early sets had been worked out, and the spread of color sets in Europe was fairly rapid. By the mid-1970s, the only stations broadcasting in black-and-white were a few high-numbered UHF stations in small markets, and a handful of low-power repeater stations in even smaller markets such as vacation spots. By 1979, even the last of these had converted to color and, by the early 1980s, B&W sets had been pushed into niche markets, notably low-power uses, small portable sets, or for use as video monitor
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal the ...
screens in lower-cost consumer equipment. By the late 1980s even these areas switched to color sets.
Digital
Digital television (DTV) is the transmission of audio and video by digitally processed and multiplexed signals, in contrast to the totally analog and channel separated signals used by analog television. Due to data compression
In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compressio ...
, digital television can support more than one program in the same channel bandwidth. It is an innovative service that represents the most significant evolution in television broadcast technology since color television emerged in the 1950s. Digital television's roots have been tied very closely to the availability of inexpensive, high performance computers. It was not until the 1990s that digital television became possible. Digital television was previously not practically possible due to the impractically high bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
requirements of uncompressed digital video, requiring around 200Mbit/s
In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...
for a standard-definition television (SDTV) signal, and over 1Gbit/s
In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...
for high-definition television
High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the g ...
(HDTV).
A digital television service was proposed in 1986 by Nippon Telegraph and Telephone
, commonly known as NTT, is a Japanese telecommunications company headquartered in Tokyo, Japan. Ranked 55th in ''Fortune'' Global 500, NTT is the fourth largest telecommunications company in the world in terms of revenue, as well as the third la ...
(NTT) and the Ministry of Posts and Telecommunication (MPT) in Japan, where there were plans to develop an "Integrated Network System" service. However, it was not possible to practically implement such a digital television service until the adoption of DCT video compression technology made it possible in the early 1990s.
In the mid-1980s, as Japanese consumer electronics
Consumer electronics or home electronics are electronic ( analog or digital) equipment intended for everyday use, typically in private homes. Consumer electronics include devices used for entertainment, communications and recreation. Usuall ...
firms forged ahead with the development of HDTV
High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the g ...
technology, the MUSE
In ancient Greek religion and mythology, the Muses ( grc, Μοῦσαι, Moûsai, el, Μούσες, Múses) are the inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the ...
analog format proposed by NHK
, also known as NHK, is a Japanese public broadcaster. NHK, which has always been known by this romanized initialism in Japanese, is a statutory corporation funded by viewers' payments of a television license fee.
NHK operates two terrestr ...
, a Japanese company, was seen as a pacesetter that threatened to eclipse U.S. electronics companies' technologies. Until June 1990, the Japanese MUSE standard, based on an analog system, was the front-runner among the more than 23 other technical concepts under consideration. Then, a U.S. company, General Instrument, demonstrated the possibility of a digital television signal. This breakthrough was of such significance that the FCC
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdictio ...
was persuaded to delay its decision on an ATV standard until a digitally-based standard could be developed.
In March 1990, when it became clear that a digital standard was possible, the FCC made a number of critical decisions. First, the Commission declared that the new ATV standard must be more than an enhanced analog signal, but be able to provide a genuine HDTV signal with at least twice the resolution of existing television images.(7) Then, to ensure that viewers who did not wish to buy a new digital television set could continue to receive conventional television broadcasts, it dictated that the new ATV standard must be capable of being "simulcast
Simulcast (a portmanteau of simultaneous broadcast) is the broadcasting of programmes/programs or events across more than one resolution, bitrate or medium, or more than one service on the same medium, at exactly the same time (that is, simulta ...
" on different channels.(8)The new ATV standard also allowed the new DTV signal to be based on entirely new design principles. Although incompatible with the existing NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
standard, the new DTV standard would be able to incorporate many improvements.
The last standards adopted by the FCC did not require a single standard for scanning formats, aspect ratios, or lines of resolution. This compromise resulted from a dispute between the consumer electronics
Consumer electronics or home electronics are electronic ( analog or digital) equipment intended for everyday use, typically in private homes. Consumer electronics include devices used for entertainment, communications and recreation. Usuall ...
industry (joined by some broadcasters) and the computer industry (joined by the film industry
The film industry or motion picture industry comprises the technological and commercial institutions of filmmaking, i.e., film production companies, film studios, cinematography, animation, film production, screenwriting, pre-production, p ...
and some public interest groups) over which of the two scanning processes—interlaced or progressive—would be best suited for the newer digital HDTV compatible display devices. Interlaced scanning, which had been specifically designed for older analogue CRT display technologies, scans even-numbered lines first, then odd-numbered ones. In fact, interlaced scanning can be looked at as the first video compression model as it was partly designed in the 1940s to double the image resolution to exceed the limitations of the television broadcast bandwidth. Another reason for its adoption was to limit the flickering on early CRT screens whose phosphor coated screens could only retain the image from the electron scanning gun for a relatively short duration. However interlaced scanning does not work as efficiently on newer display devices such as Liquid-crystal (LCD), for example, which are better suited to a more frequent progressive refresh rate.
Progressive scanning
Progressive scanning (alternatively referred to as noninterlaced scanning) is a format of displaying, storing, or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to interlaced video used ...
, the format that the computer industry had long adopted for computer display monitors, scans every line in sequence, from top to bottom. Progressive scanning in effect doubles the amount of data generated for every full screen displayed in comparison to interlaced scanning by painting the screen in one pass in 1/60-second, instead of two passes in 1/30-second. The computer industry argued that progressive scanning is superior because it does not "flicker" on the new standard of display devices in the manner of interlaced scanning. It also argued that progressive scanning enables easier connections with the Internet, and is more cheaply converted to interlaced formats than vice versa. The film industry also supported progressive scanning because it offered a more efficient means of converting filmed programming into digital formats. For their part, the consumer electronics industry and broadcasters argued that interlaced scanning was the only technology that could transmit the highest quality pictures then (and currently) feasible, i.e., 1,080 lines per picture and 1,920 pixels per line. Broadcasters also favored interlaced scanning because their vast archive of interlaced programming is not readily compatible with a progressive format. William F. Schreiber, who was director of the Advanced Television Research Program at the Massachusetts Institute of Technology
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...
from 1983 until his retirement in 1990, thought that the continued advocacy of interlaced equipment originated from consumer electronics companies that were trying to get back the substantial investments they made in the interlaced technology.
Digital television transition started in late 2000s. All governments across the world set the deadline for analog shutdown by 2010s. Initially, the adoption rate was low, as the first digital tuner-equipped television sets were costly. But soon, as the price of digital-capable television sets dropped, more and more households were converting to digital television sets. The transition is expected to be completed worldwide by mid to late 2010s.
Smart television
The advent of digital television allowed innovations like smart television sets. A smart television, sometimes referred to as connected TV or hybrid TV, is a television set or set-top box
A set-top box (STB), also colloquially known as a cable box and historically television decoder, is an information appliance device that generally contains a TV-tuner input and displays output to a television set and an external source of sign ...
with integrated Internet and Web 2.0
Web 2.0 (also known as participative (or participatory) web and social web) refers to websites that emphasize user-generated content, ease of use, participatory culture and interoperability (i.e., compatibility with other products, systems, and ...
features, and is an example of technological convergence
Technological convergence is the tendency for technologies that were originally unrelated to become more closely integrated and even unified as they develop and advance. For example, watches, telephones, television, computers, and social media ...
between computers, television sets and set-top boxes. Besides the traditional functions of television sets and set-top boxes provided through traditional Broadcasting media, these devices can also provide Internet TV, online interactive media
Interactive media normally refers to products and services on digital computer-based systems which respond to the user's actions by presenting content such as text, moving image, animation, video and audio. Since its early conception, various f ...
, over-the-top content, as well as on-demand streaming media, and home networking access. These TVs come pre-loaded with an operating system.
Smart TV should not to be confused with Internet TV
Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming television stands in contrast to dedicated terrestrial television delivered by over-the-air aer ...
, Internet Protocol television (IPTV) or with Web TV
Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming television stands in contrast to dedicated terrestrial television delivered by over-the-air ae ...
. Internet television
Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming television stands in contrast to dedicated terrestrial television delivered by over-the-air a ...
refers to the receiving of television content over the Internet instead of by traditional systems—terrestrial, cable and satellite (although Internet itself is received by these methods). IPTV is one of the emerging Internet television technology standards for use by television networks. Web television
Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming television stands in contrast to dedicated terrestrial television delivered by over-the-air ae ...
(WebTV) is a term used for programs created by a wide variety of companies and individuals for broadcast on Internet TV. A first patent was filed in 1994 (and extended the following year) for an "intelligent" television system, linked with data processing systems, by means of a digital or analog network. Apart from being linked to data networks, one key point is its ability to automatically download necessary software routines, according to a user's demand, and process their needs. Major TV manufacturers have announced production of smart TVs only, for middle-end and high-end TVs in 2015. Smart TVs have gotten more affordable compared to when they were first introduced, with 46 million of U.S. households having at least one as of 2019.
3D
3D television conveys depth perception to the viewer by employing techniques such as stereoscopic display, multi-view display, 2D-plus-depth
2D-plus-Depth is a stereoscopic video coding format that is used for 3D displays, such as Philips WOWvx. Philips discontinued work on the WOWvx line in 2009, citing "current market developments". Currently, this Philips technology is used by See ...
, or any other form of 3D display
A 3D display is a display device capable of conveying depth to the viewer. Many 3D displays are stereoscopic displays, which produce a basic 3D effect by means of stereopsis, but can cause eye strain and visual fatigue. Newer 3D displays such ...
. Most modern 3D television set
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
s use an active shutter 3D system or a polarized 3D system
A polarized 3D system uses polarization glasses to create the illusion of three-dimensional images by restricting the light that reaches each eye (an example of stereoscopy).
To present stereoscopic images and films, two images are projected s ...
, and some are autostereoscopic without the need of glasses. Stereoscopic 3D television was demonstrated for the first time on 10 August 1928, by John Logie Baird
John Logie Baird FRSE (; 13 August 188814 June 1946) was a Scottish inventor, electrical engineer, and innovator who demonstrated the world's first live working television system on 26 January 1926. He went on to invent the first publicly dem ...
in his company's premises at 133 Long Acre, London. Baird pioneered a variety of 3D television systems using electromechanical and cathode-ray tube techniques. The first 3D television was produced in 1935. The advent of digital television in the 2000s greatly improved 3D television sets. Although 3D television sets are quite popular for watching 3D home media such as on Blu-ray discs, 3D programming has largely failed to make inroads with the public. Many 3D television channels which started in the early 2010s were shut down by the mid-2010s. According to DisplaySearch 3D televisions shipments totaled 41.45 million units in 2012, compared with 24.14 in 2011 and 2.26 in 2010. As of late 2013, the number of 3D TV viewers started to decline.
Broadcast systems
Terrestrial television
Programming is broadcast by television stations, sometimes called "channels", as stations are licensed
A license (or licence) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit).
A license is granted by a party (licensor) to another party (licensee) as an element of an agreeme ...
by their governments to broadcast only over assigned channels
Channel, channels, channeling, etc., may refer to:
Geography
* Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water.
Australia
* Channel Country, region of outback Austral ...
in the television band
Band or BAND may refer to:
Places
*Bánd, a village in Hungary
*Band, Iran, a village in Urmia County, West Azerbaijan Province, Iran
* Band, Mureș, a commune in Romania
*Band-e Majid Khan, a village in Bukan County, West Azerbaijan Province, I ...
. At first, terrestrial broadcasting was the only way television could be widely distributed, and because bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
was limited, i.e., there were only a small number of channels
Channel, channels, channeling, etc., may refer to:
Geography
* Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water.
Australia
* Channel Country, region of outback Austral ...
available, government regulation was the norm. In the U.S., the Federal Communications Commission
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdicti ...
(FCC) allowed stations to broadcast advertisements beginning in July 1941, but required public service programming commitments as a requirement for a license. By contrast, the United Kingdom chose a different route, imposing a television license
A television licence or broadcast receiving licence is a payment required in many countries for the reception of television broadcasts, or the possession of a television set where some broadcasts are funded in full or in part by the licence f ...
fee on owners of television reception equipment to fund the British Broadcasting Corporation #REDIRECT BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board ex ...
(BBC), which had public service as part of its Royal Charter
A royal charter is a formal grant issued by a monarch under royal prerogative as letters patent. Historically, they have been used to promulgate public laws, the most famous example being the English Magna Carta (great charter) of 1215, but s ...
.
WRGB
WRGB (channel 6) is a television station licensed to Schenectady, New York, United States, serving the Capital District as an affiliate of CBS. It is owned by Sinclair Broadcast Group alongside CW affiliate WCWN (channel 45, also licensed to Sc ...
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
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable en ...
factory in Schenectady, NY
Schenectady () is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2020 census, the city's population of 67,047 made it the state's ninth-largest city by population. The city is in eastern New Y ...
, 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
WNBC (channel 4) is a television station in New York City, serving as the flagship of the NBC network. It is owned and operated by the network's NBC Owned Television Stations division alongside Linden, New Jersey–licensed Telemundo station W ...
and which today is known as WNBC
WNBC (channel 4) is a television station in New York City, serving as the flagship of the NBC network. It is owned and operated by the network's NBC Owned Television Stations division alongside Linden, New Jersey–licensed Telemundo stati ...
. 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
Felix the Cat is a cartoon character created in 1919 by Pat Sullivan and Otto Messmer during the silent film era. An anthropomorphic black cat with white eyes, a black body, and a giant grin, he was one of the most recognized cartoon characte ...
doll rotating on a turntable was broadcast for 2 hours every day for several years as new technology was being tested by the engineers. On 2 November 1936, the BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...
...
began transmitting the world's first public regular high-definition service from the Victorian