Editing Television (section)

==History==
{{main|History of television}}

===Mechanical===
{{main|Mechanical television}}
[[File:Nipkow disk.svg|right|upright=0.9|thumb|The [[Nipkow disk]]. This schematic shows the circular paths traced by the holes that may also be square for greater precision. The area of the disk outlined in black displays the region scanned.]]
[[Facsimile transmission]] systems for still photographs pioneered methods of mechanical scanning of images in the early 19th century. [[Alexander Bain (inventor)|Alexander Bain]] introduced the facsimile machine between 1843 and 1846. [[Frederick Bakewell]] demonstrated a working laboratory version in 1851.{{Citation needed|date=May 2015}} [[Willoughby Smith]] discovered the [[photoconductivity]] of the element [[selenium]] in 1873. As a 23-year-old German university student, [[Paul Gottlieb Nipkow|Paul Julius Gottlieb Nipkow]] proposed and patented the [[Nipkow disk]] in 1884 in [[Berlin]].<ref>Shiers, George and May (1997), ''Early Television: A Bibliographic Guide to 1940''. Taylor & Francis, pp. 13, 22. {{ISBN|978-0-8240-7782-2}}.</ref> This was a spinning disk with a spiral pattern of holes, 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 "[[rasterizer|image rasterizer]]" became exceedingly common.<ref>Shiers & Shiers, p. 13, 22.</ref> [[Constantin Perskyi]] had coined the word ''television'' in a paper read to the International Electricity Congress at the [[Exposition Universelle (1900)|International World Fair]] in Paris on 24 August 1900. Perskyi's paper reviewed the existing electromechanical technologies, mentioning the work of Nipkow and others.<ref>{{cite web|author=Constantin PERSKYI|url=https://www.histv.net/perskyi-1900|title=Télévision au moyen de l'électricité|agency=Congrès Inographs by Telegraph|work=The New York Times Sunday Magazine|date=20 September 1907|page=7}}</ref> 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.<ref name="Sending Photographs by Telegraph">[https://query.nytimes.com/gst/abstract.html?res=9A07E4DA1331E733A25757C2A9649C946697D6CF "Sending Photographs by Telegraph"], ''The New York Times'', Sunday Magazine, 20 September 1907, p. 7.</ref>

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]] cells, individually wired to a mechanical [[commutator (electric)|commutator]], served as an electronic [[retina]]. In the receiver, a type of [[Kerr effect|Kerr cell]] 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]] 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.<ref>Henry de Varigny, "[http://histv2.free.fr/rignoux/rignoux1909.htm La vision à distance] {{Webarchive|url=https://web.archive.org/web/20160303231305/http://histv2.free.fr/rignoux/rignoux1909.htm |date=3 March 2016 }}", ''L'Illustration'', Paris, 11 December 1909, p. 451.</ref>

In 1911, [[Boris Rosing]] and his student [[Vladimir K. Zworykin|Vladimir Zworykin]] created a system that used a mechanical mirror-drum scanner to transmit, in Zworykin's words, "very crude images" over wires to the "[[Karl Ferdinand Braun|Braun]] 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".<ref>[https://books.google.com/books?id=gZcwhVyiMqsC&q=zworykin+rosing+selenium R. W. Burns, ''Television: An International History of the Formative Years''], IET, 1998, p. 119. {{ISBN|0-85296-914-7}}.</ref>

In 1921, [[Édouard Belin]] sent the first image via radio waves with his [[belinograph]].<ref name="Corporation1921">{{cite magazine|url=https://books.google.com/books?id=aSoDAAAAMBAJ&pg=PA21|author=Wilfred S. Ogden|date=December 1921|publisher=Bonnier Corporation|pages=21–22|title=How the World's First Wireless News-Picture Was Flashed Across the Atlantic Ocean, Paris get President Harding's portrait in twenty minutes|magazine=The Popular Science Monthly|issn=0161-7370|access-date=2 July 2014}}</ref>

[[File:John Logie Baird and Stooky Bill.png|thumb|[[John Logie Baird|Baird]] in 1925 with his televisor equipment and dummies "James" and "Stooky Bill" ''(right)'']]

By the 1920s, when amplification made television practical, Scottish inventor [[John Logie Baird]] employed the Nipkow disk in his prototype video systems. On 25 March 1925, Baird gave the first public demonstration of televised [[silhouette]] images in motion at [[Selfridges]]'s department store in [[London]].<ref>{{cite journal |title=Current Topics and Events |journal=Nature |volume=115 |issue=2892 |pages=504–508 |year=1925 |bibcode=1925Natur.115..504. |doi=10.1038/115504a0 |doi-access=free|issn=0028-0836 }}</ref> 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 before members of the Royal Institution the transmission of an image of a face in motion by radio. This is widely regarded as the world's first true public television demonstration, exhibiting light, shade, and detail.<ref>Television 1873–1927,''Television: The Official Organ Of The Television Society'', Vo1, No1, March 1928, Television Press Ltd, London, p11.</ref> 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 that swept images across a static photocell. The [[thallium sulfide]] (thalofide) cell, developed by [[Theodore Case]] 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]] 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.<ref>"The 'Televisor' – Successful test of a new apparatus," The Times (London), 28 January 1926, p. 9. "First on a receiver in the same room and then on a portable receiver in another room, the visitors were shown recognizable reception of the movements of the dummy head and of a person speaking."</ref> In 1927, Baird transmitted a signal over {{convert|438|mi|km}} of telephone line between London and [[Glasgow]].<ref>{{cite web |title=John Logie Baird (1888–1946) |url=http://www.bbc.co.uk/history/historic_figures/baird_logie.shtml#:~:text=On%2026%20January%201926%20he,the%20Baird%20Television%20Development%20Company. |publisher=[[BBC]] |access-date=7 April 2021}}</ref> Baird's original 'televisor' now resides in the Science Museum, South Kensington.

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-[[John Logie Baird|Baird]]-Natan. In 1931, he made the first outdoor remote broadcast of [[Epsom Derby|The Derby]].<ref>Baird, J.L., "[http://www.bairdtelevision.com/1932.html Television in 1932]", ''BBC Annual Report'', 1933.</ref> In 1932, he demonstrated [[ultra-short wave]] television. Baird's mechanical system reached a peak of 240 lines of resolution on [[BBC]] telecasts in 1936, though the mechanical system did not scan the televised scene directly. Instead, a [[17.5 mm film]] was shot, rapidly developed, and then scanned while the film was still wet. {{Citation needed|date=August 2019}}

A U.S. inventor, [[Charles Francis Jenkins]], 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&nbsp;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.<ref>"Radio Shows Far Away Objects in Motion", ''The New York Times'', 14 June 1925, p. 1.</ref><ref name="glinsky">{{cite book |last=Glinsky |first=Albert |title=Theremin: Ether Music and Espionage |url=https://archive.org/details/thereminethermus00glin |url-access=registration |publisher=University of Illinois Press |location=Urbana, IL |year=2000 |pages=[https://archive.org/details/thereminethermus00glin/page/41 41]–45 |isbn=978-0-252-02582-2}}</ref> He was granted [[United States Patent and Trademark Office|U.S. Patent]] No. 1,544,156 (Transmitting Pictures over Wireless) on 30 June 1925 (filed 13 March 1922).<ref>{{cite web |title=Case Files: Francis Jenkins (Phantoscope) |url=https://www.fi.edu/case-files/francis-jenkins-phantoscope |website=[[The Franklin Institute]] |date=27 May 2016 |access-date=28 March 2020 |archive-date=28 March 2020 |archive-url=https://web.archive.org/web/20200328180825/https://www.fi.edu/case-files/francis-jenkins-phantoscope |url-status=dead }}</ref>

[[Herbert E. Ives]] and [[Frank Gray (researcher)|Frank Gray]] of [[Bell Labs|Bell Telephone Laboratories]] 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&nbsp;cm). The large receiver had a screen 24&nbsp;inches wide by 30&nbsp;inches high (60 by 75&nbsp;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]] link from Washington to New York City, then a radio link from [[Whippany, New Jersey]]. Comparing the two transmission methods, viewers noted no difference in quality. Subjects of the telecast included [[Secretary of Commerce]] [[Herbert Hoover]]. A [[flying-spot scanner]] 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 [[millisecond]]s. (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."<ref>Abramson, Albert, ''The History of Television, 1880 to 1941'', McFarland & Co., Inc., 1987, p. 101. {{ISBN|978-0-89950-284-7}}.</ref>

In 1928, [[WRGB]], then W2XB, was started as the world's first television station. It broadcast from the [[General Electric]] facility in [[Schenectady, NY]]. It was popularly known as "[[WGY (AM)|WGY]] Television." Meanwhile, in the [[Soviet Union]], [[Leon Theremin]] had been developing a mirror drum-based television, starting with 16 lines resolution in 1925, then 32 lines, and eventually 64 using [[interlaced video|interlacing]] in 1926. As part of his thesis, on 7 May 1926, he electrically transmitted and then projected near-simultaneous moving images on a {{convert|5|ft2|adj=on}} screen.<ref name="glinsky"/>

By 1927 Theremin had achieved an image of 100 lines, a resolution that was not surpassed until May 1932 by RCA, with 120 lines.<ref>{{cite web | url=http://www.earlytelevision.org/rca_story_brewster.html | title=Early Electronic Television RCA TV Development: 1929–1949 | publisher=Early Television Museum | access-date=20 February 2016 | author=Brewster, Richard}}</ref>

On 25 December 1926, [[Kenjiro Takayanagi]] demonstrated a television system with a 40-line resolution that employed a Nipkow disk scanner and CRT display at Hamamatsu Industrial High School in Japan. This prototype is still on display at the Takayanagi Memorial Museum in [[Shizuoka University]], Hamamatsu Campus. His research in creating a production model was halted by the [[Supreme Commander for the Allied Powers|SCAP]] after [[World War II]].<ref name="nhk.or.jp">[http://www.nhk.or.jp/strl/aboutstrl/evolution-of-tv-en/p05/ ''Kenjiro Takayanagi: The Father of Japanese Television''] {{webarchive|url=https://web.archive.org/web/20160101180643/http://www.nhk.or.jp/strl/aboutstrl/evolution-of-tv-en/p05/ |date=1 January 2016 }}, NHK (Japan Broadcasting Corporation), 2002. Retrieved 23 May 2009.</ref>

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.<ref>{{cite book |last1=McLean |first1=Donald F. |title=Restoring Baird's Image |date=2000 |publisher=IET |isbn=978-0-85296-795-9 |page=184 |url=https://books.google.com/books?id=1ISFkhG6cZQC&pg=PA184 |language=en}}</ref> 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.]] started in 1935 at station VE9AK in [[Montreal]].<ref>{{cite web|url=http://www.earlytelevision.org/ve9ak.html |title=VE9AK entry at |publisher=Earlytelevision.org |access-date=2 March 2010}}</ref><ref>{{cite web|title=Peck Television Corporation Console Receiver and Camera|url=http://www.earlytelevision.org/peck.html|publisher=Early Television Museum|access-date=18 February 2012}}</ref> The advancement of all-electronic television (including [[Video camera tube#Image dissector|image dissectors]] and other camera tubes and [[cathode-ray tube]]s 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===
{{Further|Video camera tube}}
[[File:Ferdinand_Braun.jpg|thumb|upright=.8|[[Ferdinand Braun]]]]
In 1897, English [[physicist]] [[J. J. Thomson]] 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]] in 1897 and is also known as the "Braun" tube.<ref>Ferdinand Braun (1897) [https://archive.today/20141217172841/http://babel.hathitrust.org/cgi/pt?id=wu.89048352892;view=1up;seq=568 "Ueber ein Verfahren zur Demonstration und zum Studium des zeitlichen Verlaufs variabler Ströme"] (On a process for the display and study of the course in time of variable currents), ''Annalen der Physik und Chemie'', 3rd series, '''60''' : 552–59.</ref> It was a [[cold cathode|cold-cathode]] [[diode]], a modification of the [[Crookes tube]], with a [[phosphor]]-coated screen. Braun was the first to conceive the use of a CRT as a display device.<ref>{{cite book|last1=Lehrer |first1=Norman H. |title=Flat-Panel Displays and CRTS |chapter=The Challenge of the Cathode-Ray Tube|editor-first=Lawrence E. Jr. |editor-last=Tannas|doi=10.1007/978-94-011-7062-8_6|isbn=978-94-011-7062-8 |pages=138–76 |publisher=[[Van Nostrand Reinhold|Van Nostrand Reinhold Company Inc.]]|location=New York|date=1985}}</ref> The ''Braun tube'' became the foundation of 20th century television.<ref>{{Cite web|url=https://www.lindahall.org/about/news/scientist-of-the-day/karl-ferdinand-braun|title=Karl Ferdinand Braun|website=The Linda Hall Library}}</ref> In 1906 the Germans Max Dieckmann and Gustav Glage produced [[Raster scan|raster images]] for the first time in a CRT.<ref>{{cite web|url=http://www.televisionheaven.co.uk/television_timeline_1.htm|title=Television Timeline 1812–1923 – Television Heaven|first=Laurence|last=Marcus|access-date=11 November 2016|archive-date=17 October 2018|archive-url=https://web.archive.org/web/20181017014615/http://www.televisionheaven.co.uk/television_timeline_1.htm|url-status=dead}}</ref> In 1907, Russian scientist [[Boris Rosing]] used a CRT in the receiving end of an experimental [[video signal]] to form a picture. He managed to display simple geometric shapes onto the screen.<ref name="crthistory">{{cite web |url=http://inventors.about.com/od/cstartinventions/a/CathodeRayTube.htm |archive-url=https://archive.today/20120709164537/http://inventors.about.com/od/cstartinventions/a/CathodeRayTube.htm |url-status=dead |archive-date=9 July 2012 |title=History of the Cathode Ray Tube |access-date=4 October 2009 |work=About.com }}</ref>

In 1908, [[Alan Archibald Campbell-Swinton]], a fellow of the [[Royal Society]] (UK), published a letter in the scientific journal ''[[Nature (journal)|Nature]]'' 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,<ref name="Swinton_DEV1">
{{cite journal
 | author = Campbell-Swinton, A. A.
 | title = Distant Electric Vision (first paragraph)
 | journal = Nature
 | volume = 78
 | issue = 2016
 | page = 151
 | date = 18 June 1908
| doi=10.1038/078151a0| bibcode = 1908Natur..78..151S
 | s2cid = 3956737
 | url = https://zenodo.org/record/1429503
 | doi-access = free
 }}
</ref><ref name="Swinton_DEV2">
{{cite journal
 | url = http://www.nature.com/nature/journal/v78/n2016/pdf/078151a0.pdf
 | author = Campbell-Swinton, A. A.
 | title = Distant Electric Vision
 | journal = Nature
 | volume = 78
 | page = 151
 | date = 18 June 1908
| issue=2016
| doi=10.1038/078151a0| bibcode = 1908Natur..78..151S
 | s2cid = 3956737
 | doi-access = free
 }}
</ref> he expanded on his vision in a speech given in London in 1911 and reported in ''[[The Times]]''<ref>"Distant Electric Vision", ''The Times'' (London), 15 November 1911, p. 24b.</ref> and the Journal of the Röntgen Society.<ref name="Swinton_Braid">
{{cite web
 | url = http://www.bairdtelevision.com/swinton.html
 | title = Alan Archivald Campbell-Swinton (1863–1930)
 | author = Bairdtelevision
 | work = Biography
 | access-date = 10 May 2010}}
</ref><ref name="Swinton-Rontgen">{{Cite book|url=https://books.google.com/books?id=OlXsZdT8HUQC&q=swinton+rontgen|title=Early Television: A Bibliographic Guide to 1940|first=May|last=Shiers|date=29 December 1997|page=56|publisher=Taylor & Francis|isbn=978-0-8240-7782-2 |via=Google Books}}</ref> In a letter to ''[[Nature (journal)|Nature]]'' 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]] beam.<ref name="Swinton_ET1">
{{cite journal
 | author = Campbell-Swinton, A. A.
 | title = Electric Television (abstract)
 | journal = Nature
 | volume = 118
 | issue = 2973
 | page = 590
 | date = 23 October 1926
| doi=10.1038/118590a0| bibcode = 1926Natur.118..590S
 | s2cid = 4081053
 | doi-access = free
 }}
</ref><ref name="Burns-Swinton">{{cite book
 | title = Television: An International History of the Formative Years
 | author = Burns, R W.
 | publisher = The Institute of Electrical Engineers (IEE) (History of Technology Series 22) in association with [ The Science Museum (UK)]
 | year = 1998
 | isbn = 978-0-85296-914-4
 | page = 123
 | url = https://books.google.com/books?id=gZcwhVyiMqsC&q=swinton+minchin+stanton+1903
 }}</ref> These experiments were conducted before March 1914, when Minchin died,<ref name="Minchin">
{{cite journal |author=G. |first=R. A. |date=2 April 1914 |title=Prof. G.M. Minchin, F.R.S |journal=[[Nature (journal)|Nature]] |volume=93 |issue=2318 |pages=115–16 |bibcode=1914Natur..93..115R |doi=10.1038/093115a0 |doi-access=free}}
</ref> but they were later repeated by two different teams in 1937, by H. Miller and J. W. Strange from [[EMI]],<ref name="Miller-Strange">
{{cite journal
 | doi = 10.1088/0959-5309/50/3/307
 |author1=Miller, H. |author2=Strange. J. W.
 |name-list-style=amp | title = The electrical reproduction of images by the photoconductive effect
 | journal = Proceedings of the Physical Society
 | volume = 50
 | issue = 3
 | pages = 374–84
 | date = 2 May 1938| bibcode = 1938PPS....50..374M
 }}
</ref> and by H. Iams and A. Rose from [[RCA]].<ref name="Iams-Rose-1937">
{{cite journal
 | doi = 10.1109/JRPROC.1937.228423
 |author1=Iams, H. |author2=Rose, A.
 |name-list-style=amp | title = Television Pickup Tubes with Cathode-Ray Beam Scanning
 | journal = Proceedings of the Institute of Radio Engineers
 | volume = 25
 | issue = 8
 | pages = 1048–70
 | date = August 1937|s2cid=51668505 }}
</ref> Both teams successfully transmitted "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.<ref>Abramson, Albert, ''Zworykin, Pioneer of Television'', p. 16.</ref> The first cathode-ray tube to use a [[hot cathode]] was developed by [[John Bertrand Johnson|John B. Johnson]] (who gave his name to the term [[Johnson–Nyquist noise|Johnson noise]]) and Harry Weiner Weinhart of [[Western Electric]], and became a commercial product in 1922.{{citation needed|date=January 2011}}

In 1926, Hungarian engineer [[Kálmán Tihanyi]] designed a television system using fully electronic scanning and display elements and employing the principle of "charge storage" within the scanning (or "camera") tube.<ref name="Radioskop" /><ref name=US2133123>United States Patent Office, Patent No. 2,133,123, 11 October 1938.</ref><ref name=US2158259>United States Patent Office, Patent No. 2,158,259, 16 May 1939</ref><ref>{{cite web|url=http://www.bairdtelevision.com/zworykin.html |title=Vladimir Kosma Zworykin, 1889–1982 |publisher=Bairdtelevision.com |access-date=17 April 2009}}</ref> 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.<ref name="IEC_Tihanyi">[http://www.iec.ch/about/history/techline/swf/temp.xml] {{Webarchive|url=https://web.archive.org/web/20150924033236/http://www.iec.ch/about/history/techline/swf/temp.xml|date=24 September 2015}} "Kálmán Tihanyi (1897–1947)", ''IEC Techline'', International Electrotechnical Commission (IEC), 15 July 2009.</ref> 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]] in March 1926 for a television system he called "Radioskop".<ref name="Radioskop">{{Cite web |url=https://www.unesco.org/en/memory-world/kalman-tihanyis-1926-patent-application-radioskop |title=Kálmán Tihanyi's 1926 Patent Application Radioskop |publisher=UNESCO Memory of the World Programme| access-date=2025-04-22}}</ref> After further refinements included in a 1928 patent application,<ref name="IEC_Tihanyi"/> Tihanyi's patent was declared void in Great Britain in 1930,<ref name="abstract1928">[http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_V3&FT=D&date=19301111&CC=GB&NR=313456A&KC=A Tihanyi, Koloman, ''Improvements in television apparatus''] {{Webarchive|url=https://web.archive.org/web/20221204171044/https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_EP&FT=D&date=19301111&CC=GB&NR=313456A&KC=A |date=4 December 2022 }}. European Patent Office, Patent No. GB313456. Convention date UK application: 1928-06-11, declared void and published: 11 November 1930. Retrieved 25 April 2013.</ref> so he applied for patents in the United States. Although his breakthrough would be incorporated into the design of [[RCA]]'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.<ref name=autogenerated1>{{cite web|url=https://patents.google.com/patent/US2133123|title=Patent US2133123 – Television apparatus|access-date=22 March 2015}}</ref><ref name=autogenerated2>{{cite web|url=https://patents.google.com/patent/US2158259|title=Patent US2158259 – Television apparatus|access-date=22 March 2015}}</ref> Charge storage remains a basic principle in the design of imaging devices for television to the present day.<ref name="Radioskop"/> On 25 December 1926, at Hamamatsu Industrial High School in Japan, Japanese inventor [[Kenjiro Takayanagi]] demonstrated a TV system with a 40-line resolution that employed a CRT display.<ref name="nhk.or.jp"/> This was the first working example of a fully electronic television receiver and Takayanagi's team later made improvements to this system parallel to other television developments.<ref>{{Cite journal |date=June 1932 |title=The Editor—to You |journal=Radio News |volume=13 |issue=12 |pages=979}}</ref> Takayanagi did not apply for a patent.<ref>{{cite web|url=http://www.ieeeghn.org/wiki/index.php/Milestones:Development_of_Electronic_Television,_1924-1941|title=Milestones:Development of Electronic Television, 1924–1941|access-date=22 March 2015}}</ref>

In the 1930s, [[Allen B. DuMont]] made the first CRTs to last 1,000 hours of use, one of the factors that led to the widespread adoption of television.<ref>Hart, Hugh (28 January 2010). [https://www.wired.com/2010/01/jan-29-1901-dumont-will-make-tv-work-2/ "Jan. 29, 1901: DuMont Will Make TV Work."] ''[[Wired (magazine)|Wired]]''. Retrieved 21 May 2021.</ref>

On 7 September 1927, U.S. inventor [[Philo Farnsworth]]'s [[image dissector]] camera tube transmitted its first image, a simple straight line, at his laboratory at 202 Green Street in San Francisco.<ref name="Postman">[https://web.archive.org/web/20000531100005/http://www.time.com/time/time100/scientist/profile/farnsworth.html Postman, Neil, "Philo Farnsworth"], ''The TIME 100: Scientists & Thinkers'', ''Time'', 29 March 1999. Retrieved 28 July 2009.</ref><ref name="sfmuseum">[http://www.sfmuseum.org/hist10/philo.html "Philo Taylor Farnsworth (1906–1971)"] {{webarchive|url=https://web.archive.org/web/20110622033654/http://www.sfmuseum.org/hist10/philo.html |date=22 June 2011 }}, ''The Virtual Museum of the City of San Francisco''. Retrieved 15 July 2009.</ref> 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.<ref name="sfmuseum"/> In 1929, the system was improved further by eliminating a motor generator so that his television system had no mechanical parts.<ref>Abramson, Albert, ''Zworykin, Pioneer of Television'', p. 226.</ref> 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).<ref>{{cite web |url = http://db3-sql.staff.library.utah.edu/lucene/Manuscripts/null/Ms0648.xml/complete |title = The Philo T. and Elma G. Farnsworth Papers |archive-url=https://web.archive.org/web/20080422211543/http://db3-sql.staff.library.utah.edu/lucene/Manuscripts/null/Ms0648.xml/complete |archive-date=22 April 2008 |url-status=dead}}</ref>

[[File:Zworykin kinescope 1929.jpg|thumb|upright=0.75|[[Vladimir Zworykin]] demonstrates electronic television (1929).]]
Meanwhile, Vladimir Zworykin also experimented with the cathode-ray tube to create and show images. While working for [[Westinghouse Electric (1886)|Westinghouse Electric]] in 1923, he began to develop an electronic camera tube. However, in a 1925 demonstration, the image was dim, had low contrast and poor definition, and was stationary.<ref>Abramson, Albert, ''Zworykin, Pioneer of Television'', University of Illinois Press, 1995, p. 51. {{ISBN|0-252-02104-5}}.</ref> Zworykin's imaging tube never got beyond the laboratory stage. However, 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, based on Zworykin's 1923 patent application, RCA filed a [[patent interference]] suit against Farnsworth. The [[United States Patent and Trademark Office|U.S. Patent Office]] examiner disagreed in a 1935 decision, finding priority of invention for Farnsworth against Zworykin. Farnsworth claimed that Zworykin's 1923 system could not 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.<ref name=US1691324>[https://www.google.com/patents/about?id=mZ9KAAAAEBAJ Zworykin, Vladimir K., Television System] {{Webarchive|url=https://web.archive.org/web/20140131053220/http://www.google.com/patents/about?id=mZ9KAAAAEBAJ |date=31 January 2014 }}. Patent No. 1691324, U.S. Patent Office. Filed 1925-07-13, issued 13 November 1928. Retrieved 28 July 2009</ref> He also divided his original application in 1931.<ref name="US2022450">[https://www.google.com/patents?id=tQt-AAAAEBAJ Zworykin, Vladimir K., Television System] {{Webarchive|url=https://web.archive.org/web/20130518183522/http://www.google.com/patents?id=tQt-AAAAEBAJ |date=18 May 2013 }}. Patent No. 2022450, U.S. Patent Office. Filed 1923-12-29, issued 26 November 1935. Retrieved 10 May 2010.</ref> 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 being determined to go forward with the commercial manufacturing of television equipment, RCA agreed to pay Farnsworth US$1&nbsp;million over ten years, in addition to license payments, to use his patents.<ref>Stashower, Daniel, ''The Boy Genius and the Mogul: The Untold Story of Television'', Broadway Books, 2002, pp. 243–44. {{ISBN|978-0-7679-0759-0}}.</ref><ref name="Everson">Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. {{ISBN|978-0-405-06042-7}}, 266 pp.</ref>

In 1933, RCA introduced an improved camera tube that relied on Tihanyi's charge storage principle.<ref name="NewYorkTimes">{{cite news |author=Lawrence, Williams L. |title=Human-like eye made by engineers to televise images|quote= 'Iconoscope' converts scenes into electrical energy for radio transmission. Fast as a movie camera. Three million tiny photocells 'memorize,' then pass out pictures. Step to home television. Developed in ten years of work by Dr. V.K. Zworykin, who describes it in Chicago. |url=https://books.google.com/books?id=OlXsZdT8HUQC&q=3971+zworykin+N.Y.T | work=The New York Times |date=27 June 1933 |access-date=10 January 2010 |isbn=978-0-8240-7782-2}}</ref> 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.{{Citation needed|date=July 2009}} However, Farnsworth had overcome his power issues with his Image Dissector through the invention of a completely unique "[[multipactor effect|Multipactor]]" device that he began work on in 1930, and demonstrated in 1931.<ref name="TheHistoryofTV1">Abramson, Albert (1987), ''The History of Television, 1880 to 1941''. Jefferson, NC: Albert Abramson. p. 148. {{ISBN|0-89950-284-9}}.</ref><ref name="Everson1">Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. {{ISBN|978-0-405-06042-7}}, pp. 137–41.</ref> This small tube could amplify a signal reportedly to the 60th power or better<ref name="Everson2">Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. {{ISBN|978-0-405-06042-7}}, p. 139.</ref> and showed great promise in all fields of electronics. Unfortunately, an issue with the multipactor was that it wore out at an unsatisfactory rate.<ref name="Everson3">Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. {{ISBN|978-0-405-06042-7}}, p. 141.</ref>

[[File:Bundesarchiv Bild 183-K0917-501, Prof. Manfred v. Ardenne.jpg|thumb|right|upright=0.75|[[Manfred von Ardenne]] in 1933]]
At the [[Berlin Radio Show]] in August 1931 in [[Berlin]], [[Manfred von Ardenne]] gave a public demonstration of a television system using a CRT for both transmission and reception, the first completely electronic television transmission.<ref>{{Cite web|url=https://www.vonardenne.biz/ja/company/history/manfred-von-ardenne/|title=Manfred von Ardenne|website=VON ARDENNE Website}}</ref> However, Ardenne had not developed a camera tube, using the CRT instead as a [[flying-spot scanner]] to scan slides and film.<ref>Albert Abramson, ''Zworykin: Pioneer of Television'', University of Illinois Press, 1995, p. 111.</ref> Ardenne achieved his first transmission of television pictures on 24 December 1933, followed by test runs for a public television service in 1934. The world's first electronically scanned television service then started in Berlin in 1935, the [[Fernsehsender Paul Nipkow]], culminating in the live broadcast of the [[1936 Summer Olympic Games]] from Berlin to public places all over Germany.<ref name="dw">{{cite web|title=22.3.1935: Erstes Fernsehprogramm der Welt|url=http://www.kalenderblatt.de/index.php?what=thmanu&lang=de&manu_id=1737&sdt=20090322&maca=de-podcast_kalenderblatt-1086-xml-mrss|publisher=[[Deutsche Welle]]|accessdate=27 July 2015}}</ref><ref name="computer">{{cite web|title=Es begann in der Fernsehstube: TV wird 80 Jahre alt|url=http://www.computerbild.de/artikel/avf-News-Fernseher-Es-begann-in-der-Fernsehstube-TV-wird-80-Jahre-alt-11525963.html|publisher=Computer Bild|date=22 March 2015|accessdate=28 April 2017|archive-date=21 January 2019|archive-url=https://web.archive.org/web/20190121012410/https://www.computerbild.de/artikel/avf-News-Fernseher-Es-begann-in-der-Fernsehstube-TV-wird-80-Jahre-alt-11525963.html|url-status=dead}}</ref>

Philo Farnsworth gave the world's first public demonstration of an all-electronic television system, using a live camera, at the [[Franklin Institute]] of [[Philadelphia]] on 25 August 1934 and for ten days afterward.<ref>"[https://books.google.com/books?id=yt8DAAAAMBAJ&pg=PA838 New Television System Uses 'Magnetic Lens']", ''Popular Mechanics'', Dec. 1934, pp. 838–39.</ref><ref name="Burns370">Burns, R.W. ''Television: An international history of the formative years''. (1998). IEE History of Technology Series, 22. London: IEE, p. 370. {{ISBN|9780852969144}}.</ref> Mexican inventor [[Guillermo González Camarena]] also played an important role in early television. His experiments with television (known as telectroescopía at first) began in 1931 and led to a patent for the "trichromatic field sequential system" [[color television]] in 1940.<ref>{{cite web|url=https://patents.google.com/patent/US2296019|title=Patent US2296019 – Chromoscopic adapter for television equipment|access-date=22 March 2015}}</ref> In Britain, the [[EMI]] engineering team led by [[Isaac Shoenberg]] applied in 1932 for a patent for a new device they called "the Emitron",<ref name="GB406353">{{cite web |author1=EMI LTD |author2=Tedham, William F. |author3=McGee, James D. |name-list-style=amp |title=Improvements in or relating to cathode ray tubes and the like |url=http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_V3&FT=D&date=19340226&CC=GB&NR=406353A&KC=A |work=Patent No. GB 406,353 (filed May 1932, patented 1934) |publisher=United Kingdom Intellectual Property Office |access-date=22 February 2010 |archive-date=22 November 2021 |archive-url=https://web.archive.org/web/20211122002108/https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_EP&FT=D&date=19340226&CC=GB&NR=406353A&KC=A |url-status=dead }}</ref><ref name="US2077442">
{{cite web
 |author1=Tedham, William F. |author2=McGee, James D.
 |name-list-style=amp | title=Cathode Ray Tube
 | url=https://www.google.com/patents/about?id=BYNaAAAAEBAJ
 | archive-url=https://web.archive.org/web/20130523212804/http://www.google.com/patents/about?id=BYNaAAAAEBAJ
 | url-status=dead
 | archive-date=23 May 2013
 | work=Patent No. 2,077,422 (filed in Great Britain 1932, filed in USA 1933, patented 1937)
 | publisher=United States Patent Office
 | access-date=10 January 2010
}}</ref> which formed the heart of the cameras they designed for the BBC. On 2 November 1936, a [[405-line television system|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 briefly 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.<ref name="Burns576">Burns, R.W., ''Television: An international history of the formative years''. (1998). IEE History of Technology Series, 22. London: IEE, p. 576. {{ISBN|0-85296-914-7}}.</ref>

The original U.S. iconoscope was noisy, had a high ratio of interference to signal, and ultimately gave disappointing results, especially compared to the high-definition mechanical scanning systems that became available.<ref name="Winstor-media">{{cite book
| title = Misunderstanding media
| author = Winston, Brian
| publisher = Harvard University Press
| year = 1986
| isbn = 978-0-674-57663-6
| pages = 60–61
| url = https://books.google.com/books?id=K_RpAAAAIAAJ&q=%22american+iconoscope%22+noisy
| access-date = 9 March 2010
}}</ref><ref name="Winstor-history">{{cite book
| title = Media technology and society. A history: from the telegraph to the Internet
| author = Winston, Brian
| publisher = Routledge
| year = 1998
| isbn = 978-0-415-14230-4
| page = 105
| url = https://books.google.com/books?id=TZOF_1GZRmYC&q=american+iconoscope+noisy
| access-date = 9 March 2010
}}</ref> The [[EMI]] team, under the supervision of [[Isaac Shoenberg]], analyzed how the iconoscope (or Emitron) produced an electronic signal and concluded that its real efficiency was only about 5% of the theoretical maximum.<ref name="Alexander">
{{cite book
| title=The inventor of stereo: the life and works of Alan Dower Blumlein
| author=Alexander, Robert Charles
| publisher=Focal Press
| year=2000
| isbn=978-0-240-51628-8
| pages=217–19
| url=https://books.google.com/books?id=qRhx3UmYBz0C&q=super+emitron
| access-date=10 January 2010
}}</ref><ref name="Burns-Blumlein">
{{cite book
| title=The life and times of A.D. Blumlein
| author=Burns, R.W.
| publisher=IET
| year=2000
| isbn=978-0-85296-773-7
| page=181
| url=https://books.google.com/books?id=B2z2ONO7nBQC&q=blumlein+mcgee+cps+emitron+decelerating+zero
| access-date=5 March 2010
}}</ref> They solved this problem by developing and patenting in 1934 two new camera tubes dubbed [[Video camera tube#Super-Emitron and image iconoscope|super-Emitron]] and [[Video camera tube#Orthicon and CPS Emitron|CPS Emitron]].<ref name="GB442666">{{cite web
 | author1 = Lubszynski, Hans Gerhard
 | author2 = Rodda, Sydney
 | name-list-style = amp
 | title = Improvements in or relating to television
 | url = http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_V3&FT=D&date=19360212&CC=GB&NR=442666A&KC=A
 | work = Patent No. GB 442,666 (filed May 1934, patented 1936)
 | publisher = United Kingdom Intellectual Property Office
 | access-date = 15 January 2010
 | archive-date = 22 November 2021
 | archive-url = https://web.archive.org/web/20211122010440/https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_EP&FT=D&date=19360212&CC=GB&NR=442666A&KC=A
 | url-status = dead
 }}</ref><ref name="GB446661">{{cite web
 | author1 = Blumlein, Alan Dower
 | author2 = McGee, James Dwyer
 | name-list-style = amp
 | title = Improvements in or relating to television transmitting systems
 | url = http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_V3&FT=D&date=19360504&CC=GB&NR=446661A&KC=A
 | work = Patent No. GB 446,661 (filed August 1934, patented 1936)
 | publisher = United Kingdom Intellectual Property Office
 | access-date = 9 March 2010
 | archive-date = 22 November 2021
 | archive-url = https://web.archive.org/web/20211122012740/https://v3.espacenet.com/errorpages/error403.htm?reason=RequestBlacklisted&ip=207.241.229.151
 | url-status = dead
 }}</ref><ref name="GB446664">{{cite web
 | author = McGee, James Dwyer
 | title = Improvements in or relating to television transmitting systems
 | url = http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_V3&FT=D&date=19360505&CC=GB&NR=446664A&KC=A
 | work = Patent No. GB 446,664 (filed September 1934, patented 1936)
 | publisher = United Kingdom Intellectual Property Office
 | access-date = 9 March 2010
 | archive-date = 22 November 2021
 | archive-url = https://web.archive.org/web/20211122020916/https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_EP&FT=D&date=19360505&CC=GB&NR=446664A&KC=A
 | url-status = dead
 }}</ref> 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.<ref name="Alexander"/> It was used for [[outside broadcasting]] by the BBC, for the first time, on [[Armistice Day]] 1937, when the general public could watch on a television set as the King laid a wreath at the Cenotaph.<ref name="Alexander2">
{{cite book
| title=The inventor of stereo: the life and works of Alan Dower Blumlein
| author=Alexander, Robert Charles
| publisher=Focal Press
| year=2000
| isbn=978-0-240-51628-8
| page=216
| url=https://books.google.com/books?id=qRhx3UmYBz0C&q=emitron+cenotaph+armistice
| access-date=10 January 2010
}}</ref> 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]].
[[File:1939 RCA Television Advertisement.jpg|left|thumb|Ad for the beginning of experimental television broadcasting in New York City by RCA in 1939]]
[[File:RCA Indian Head test pattern.JPG|thumb|right|[[Indian-head test pattern]] used during the black-and-white era before 1970. It was displayed when a television station first signed on every day.]]
On the other hand, in 1934, Zworykin shared some patent rights with the German licensee company Telefunken.<ref name="Inglis">{{cite book
 | title = Behind the tube: a history of broadcasting technology and business
 | author = Inglis, Andrew F.
 | publisher = Focal Press
 | year = 1990
 | isbn = 978-0-240-80043-1
 | page = 172
 | url = https://books.google.com/books?id=xiu4AAAAIAAJ&q=image-iconoscope+telefunken
 | access-date = 15 January 2010
}}</ref> The "image iconoscope" ("Superikonoskop" in Germany) was produced as a result of the collaboration. This tube is essentially identical to the super-Emitron.{{Citation needed|date=May 2010}} The production and commercialization of the super-Emitron and image iconoscope in Europe were not affected by the [[patent war]] 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,<ref name="DE450187">{{cite web
 | author1 = Dieckmann, Max
 | author2 = Rudolf Hell
 | name-list-style = amp
 | title = Lichtelektrische Bildzerlegerröehre für Fernseher
 | url = http://v3.espacenet.com/publicationDetails/originalDocument?CC=DE&NR=450187C&KC=C&FT=D&date=19271003&DB=EPODOC&locale=en_V3
 | work = Patent No. DE 450,187 (filed 1925, patented 1927)
 | publisher = Deutsches Reich Reichspatentamt
 | access-date = 28 July 2009
 | archive-date = 22 November 2021
 | archive-url = https://web.archive.org/web/20211122022403/https://v3.espacenet.com/errorpages/error403.htm?reason=RequestBlacklisted&ip=207.241.231.164
 | url-status = dead
 }}</ref> two years before Farnsworth did the same in the United States.<ref name="US1773980">
{{cite web
 | author = Farnsworth, Philo T.
 | title = Television System
 | url=https://www.google.com/patents/about?id=HRd5AAAAEBAJ
 | archive-url=https://web.archive.org/web/20130523192021/http://www.google.com/patents/about?id=HRd5AAAAEBAJ
 | url-status=dead
 | archive-date=23 May 2013
 | work = Patent No. 1,773,980 (filed 1927, patented 1930)
 | publisher = United States Patent Office
 | access-date = 28 July 2009
}}</ref> The image iconoscope (Superikonoskop) became the industrial standard for public broadcasting in Europe from 1936 until 1960, when it was replaced by the [[Video camera tube|vidicon]] and [[Video camera tube|plumbicon]] tubes. Indeed, it represented the European tradition in electronic tubes competing against the American tradition represented by the image orthicon.<ref name="Vries">{{cite book
 | title = Design methodology and relationships with science, Número 71 de NATO ASI series
 |author1=de Vries, M.J. |author2=de Vries, Marc |author3=Cross, Nigel |author4=Grant, Donald P. |name-list-style=amp | publisher = Springer
 | year = 1993
 | isbn = 978-0-7923-2191-0
 | page = 222
 | url = https://books.google.com/books?id=4T8U_J1h7noC&q=image-iconoscope+image-orthicon+telefunken
 | access-date = 15 January 2010
}}</ref><ref name="Multicon">
{{cite web
 | author = Smith, Harry
 | title = Multicon – A new TV camera tube
 | url = http://www.earlytelevision.org/multicon.html
 | archive-url = https://web.archive.org/web/20100318011743/http://www.earlytelevision.org/multicon.html
 | archive-date = 18 March 2010
| work = newspaper article
 | date = July 1953
 | publisher = Early Television Foundation and Museum
 | access-date = 15 January 2010
}}</ref> The German company Heimann produced the Superikonoskop for the 1936 Berlin Olympic Games,<ref name="Heimann1">
{{cite web
| author=Gittel, Joachim
| title=Spezialröhren
| url=http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Spezialroehren/Spezialroehren.htm
| work=photographic album
| date=11 October 2008
| publisher=Jogis Röhrenbude
| access-date=15 January 2010
}}</ref><ref name="ETM">
{{cite web
 | author = Early Television Museum
 | title = TV Camera Tubes, German "Super Iconoscope" (1936)
 | url = http://www.earlytelevision.org/prewar_camera_tubes.html
 | archive-url = https://web.archive.org/web/20110617080126/http://www.earlytelevision.org/prewar_camera_tubes.html
 | archive-date = 17 June 2011
| work = photographic album
 | publisher = Early Television Foundation and Museum
 | access-date = 15 January 2010
}}</ref> later Heimann also produced and commercialized it from 1940 to 1955;<ref name="Heimann2">
{{cite web
| author=Gittel, Joachim
| title=FAR-Röhren der Firma Heimann
| url=http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Spezialroehren/Ikonoskop_Heimann/Heimann.htm
| work=photographic album
| date=11 October 2008
| publisher=Jogis Röhrenbude
| access-date=15 January 2010
}}</ref> finally the Dutch company [[Philips]] produced and commercialized the image iconoscope and multicon from 1952 to 1958.<ref name="Multicon"/><ref name="Philips">
{{cite book
 | author = Philips
 | chapter = 5854, Image Iconoscope, Philips
 | url = http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Spezialroehren/Ikonoskop_Heimann/5854_Philips_Iconoscop-1958.pdf
 | title = electronic tube handbook
 | year = 1958
 | publisher = Philips
 | access-date = 15 January 2010
 | archive-url = https://web.archive.org/web/20060903223404/http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Spezialroehren/Ikonoskop_Heimann/5854_Philips_Iconoscop-1958.pdf
 | archive-date = 3 September 2006
 | url-status = live
}}</ref>

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.<ref name="Everson4">Everson, George (1949), ''The Story of Television, The Life of Philo T. Farnsworth'' New York: W.W. Norton & Co,. {{ISBN|978-0-405-06042-7}}, p. 248.</ref> RCA, for example, used only Iconoscopes in the New York area, but Farnsworth Image Dissectors in Philadelphia and San Francisco.<ref name="TheHistoryofTV2">Abramson, Albert (1987), ''The History of Television, 1880 to 1941''. Jefferson, NC: Albert Abramson. p. 254. {{ISBN|0-89950-284-9}}.</ref> 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.<ref name="Schatzkin187-8">Schatzkin, Paul (2002), ''The Boy Who Invented Television''. Silver Spring, Maryland: Teamcom Books, pp. 187–88. {{ISBN|1-928791-30-1}}.</ref> With this historic agreement in place, RCA integrated much of what was best about the Farnsworth Technology into their systems.<ref name="TheHistoryofTV2"/> In 1941, the United States implemented 525-line television.<ref>"Go-Ahead Signal Due for Television", ''The New York Times'', 25 April 1941, p. 7.</ref><ref>"An Auspicious Beginning", ''The New York Times'', 3 August 1941, p. X10.</ref> Electrical engineer [[Benjamin Adler]] played a prominent role in the development of television.<ref>{{cite web|url=https://www.nytimes.com/1990/04/18/obituaries/benjamin-adler-86-an-early-advocate-of-uhf-television.html|title=Benjamin Adler, 86, An Early Advocate of UHF Television|date=18 April 1990|work=The New York Times}}</ref><ref>{{cite web|url=http://archive.poly.edu/poly_ebriefs/archives/Feb03.htm|title=ePoly Briefs Home|access-date=11 October 2016|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304225948/http://archive.poly.edu/poly_ebriefs/archives/Feb03.htm|url-status=dead}}</ref>

The world's first 625-line television standard was designed in the Soviet Union in 1944 and became a national standard in 1946.<ref name="60TH_ANNIVERSARY_OF_625">[http://625.625-net.ru/files/587/511/h_665921be9883776271895912fb8bb262 "On the beginning of broadcast in 625 lines 60 years ago"], ''625'' magazine (in Russian). {{webarchive|url=https://web.archive.org/web/20160304131236/http://625.625-net.ru/files/587/511/h_665921be9883776271895912fb8bb262 |date=4 March 2016 }}</ref> The first broadcast in 625-line standard occurred in Moscow in 1948.<ref>[https://web.archive.org/web/20041230091501/http://www.ebu.ch/en/technical/trev/trev_255-portrait.pdf "M.I. Krivocheev – an engineer's engineer"], ''EBU Technical Review'', Spring 1993.</ref> The concept of 625 lines per frame was subsequently implemented in the European [[Comité consultatif international pour la radio|CCIR]] standard.<ref>{{cite web |url = http://cra.ir/FTD/Static/RRC/RRCFile10.pdf |title = "In the Vanguard of Television Broadcasting". |archive-url=https://web.archive.org/web/20070221210300/http://cra.ir/FTD/Static/RRC/RRCFile10.pdf |archive-date=21 February 2007 |url-status=dead}}</ref> In 1936, [[Kálmán Tihanyi]] described the principle of [[plasma display]], the first [[flat-panel display]] system.<ref>[https://ewh.ieee.org/r2/johnstown/downloads/20090217_IEEE_JST_Trivia_Answers.pdf]</ref><ref>[http://www.scitech.mtesz.hu/52tihanyi/flat-panel_tv_en.pdf] {{webarchive|url=https://web.archive.org/web/20120314070853/http://www.scitech.mtesz.hu/52tihanyi/flat-panel_tv_en.pdf|date=14 March 2012}}</ref>

Early electronic [[television sets]] were large and bulky, with [[analog circuits]] made of [[vacuum tubes]]. Following the invention of the first working [[transistor]] at [[Bell Labs]], [[Sony]] founder [[Masaru Ibuka]] predicted in 1952 that the transition to [[electronic circuits]] made of transistors would lead to smaller and more portable television sets.<ref>{{cite book |last1=Childs |first1=William R. |last2=Martin |first2=Scott B. |last3=Stitt-Gohdes |first3=Wanda |title=Business and Industry: Savings and investment options to telecommuting |date=2004 |publisher=[[Marshall Cavendish]] |isbn=9780761474395 |page=1217 |url=https://books.google.com/books?id=nCwYAAAAIAAJ |quote=In 1952 Ibuka toured AT&T's Bell Laboratories in the United States and saw the newly invented transistor. He realized that replacing the large, clumsy vacuum tube with the transistor would make possible smaller, more portable radios and TVs.}}</ref> The first fully transistorized, portable [[solid-state electronics|solid-state]] television set was the 8-inch [[Sony TV8-301]], developed in 1959 and released in 1960.<ref>{{cite journal |title=Sony Founder Masaru Ibuka's New Year's Dream Comes True: The Launch of Sony's TV Business |journal=Time Capsule |date=17 November 2009 |volume=21 |publisher=[[Sony]] |url=https://www.sony.net/SonyInfo/CorporateInfo/History/capsule/21/index.html |access-date=1 October 2019}}</ref><ref>{{cite book |last=Sparke |first=Penny |title=Japanese Design |date=2009 |publisher=[[The Museum of Modern Art]] |isbn=9780870707391 |page=18 |url=https://books.google.com/books?id=WaIQf2gV8pEC&pg=PA18}}</ref> This began the transformation of television viewership from a communal viewing experience to a solitary viewing experience.<ref>{{cite book |last=Lucie-Smith |first=Edward |author-link=Edward Lucie-Smith |title=A History of Industrial Design |date=1983 |publisher=[[Phaidon Press]] |isbn=9780714822815 |page=208 |url=https://books.google.com/books?id=fMsfAQAAIAAJ |quote=The first all-transistor television set was introduced by Sony in 1959 (fig. 386), only four years after their all-transistor radio, and started the transformation of television from something used for communal viewing, as the radio in the 30s had been a focus for communal listening, into an object of solitary contemplation.}}</ref> By 1960, Sony had sold over 4{{nbsp}}million portable television sets worldwide.<ref>{{cite book |last1=Chang |first1=Yoon Seok |last2=Makatsoris |first2=Harris C. |last3=Richards |first3=Howard D. |title=Evolution of Supply Chain Management: Symbiosis of Adaptive Value Networks and ICT |date=2007 |publisher=[[Springer Science & Business Media]] |isbn=9780306486968 |url=https://books.google.com/books?id=5Y3wBwAAQBAJ&pg=PA48}}</ref>
{{clear}}

===Color===
{{main|Color television}}
[[File:Samsung LED TV.jpg|thumb|right|Samsung LED TV]]
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.<ref>M. Le Blanc, "Etude sur la transmission électrique des impressions lumineuses", ''La Lumière Electrique'', vol. 11, 1 December 1880, pp. 477–81.</ref> Polish inventor [[Jan Szczepanik]] patented a color television system in 1897, using a [[selenium]] photoelectric cell at the transmitter and an electromagnet controlling an oscillating mirror and a moving prism at the receiver. 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.<ref>R.W. Burns, ''Television: An International History of the Formative Years'', IET, 1998, p. 98. {{ISBN|0-85296-914-7}}.</ref> Another inventor, [[Hovannes Adamian]], also experimented with color television as early as 1907. The first color television project is claimed by him,<ref>Western technology and Soviet economic development: 1945 to 1965, by Antony C. Sutton, Business & Economics – 1973, p. 330</ref> and was patented in Germany on 31 March 1908, patent No. 197183, then in Britain, on 1 April 1908, patent No. 7219,<ref>The History of Television, 1880–1941, by Albert Abramson, 1987, p. 27</ref> in France (patent No. 390326) and in Russia in 1910 (patent No. 17912).<ref name="tvmuseum.ru">{{Cite web|url=http://www.tvmuseum.ru/attach.asp?a_no=1018|archiveurl=https://web.archive.org/web/20130424162531/http://www.tvmuseum.ru/attach.asp?a_no=1018|url-status=usurped|title=A. Rokhlin, Tak rozhdalos' dal'novidenie (in Russian)|archivedate=24 April 2013}}</ref>

Scottish inventor [[John Logie Baird]] 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 (electric)|commutator]] to alternate their illumination.<ref>John Logie Baird, [https://www.google.com/patents?id=JRVAAAAAEBAJ Television Apparatus and the Like] {{Webarchive|url=https://web.archive.org/web/20130518084511/http://www.google.com/patents?id=JRVAAAAAEBAJ |date=18 May 2013 }}, U.S. patent, filed in U.K. in 1928.</ref> Baird also made the world's first color broadcast on 4 February 1938, sending a mechanically scanned 120-line image from Baird's [[The Crystal Palace|Crystal Palace]] studios to a projection screen at London's [[Dominion Theatre]].<ref>Baird Television: [http://www.bairdtelevision.com/crystalpalace.html Crystal Palace Television Studios]. Previous color television demonstrations in the U.K. and U.S. had been via closed circuit.</ref> Mechanically scanned color television was also demonstrated by [[Bell Laboratories]] in June 1929 using three complete systems of [[Solar cell|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.<ref>{{cite web|url=http://www.bairdtelevision.com/colour.html|title=The World's First High Definition Colour Television System|access-date=22 March 2015}}</ref> 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]] introduced an electro-mechanical system while at [[CBS]], 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.<ref>Peter C. Goldmark, assignor to Columbia Broadcasting System, "Color Television", [https://patents.google.com/patent/US2480571 U.S. Patent 2,480,571], filed 7 September 1940.</ref> The system was first demonstrated to the [[Federal Communications Commission]] (FCC) on 29 August 1940 and shown to the press on 4 September.<ref>Current Broadcasting 1940</ref><ref name=ColorTVSuccess>"Color Television Success in Test", ''The New York Times'', 30 August 1940, p. 21.</ref><ref>"Color Television Achieves Realism", ''The New York Times'', 5 September 1940, p. 18.</ref><ref>"[https://books.google.com/books?id=JScDAAAAMBAJ&pg=PA120 New Television System Transmits Images in Full Color]", ''Popular Science'', December 1940, p. 120.</ref>

CBS began experimental color field tests using film as early as 28 August 1940 and live cameras by 12 November.<ref name="ColorTVSuccess" /><ref>"CBS Demonstrates Full-Color Television," ''The Wall Street Journal'', 5 September 1940, p. 1. "Television Hearing Set," ''The New York Times'', 13 November 1940, p. 26.</ref> [[NBC]] (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.<ref>Ed Reitan, [http://colortelevision.info/rca-nbc_firsts.html RCA-NBC Color Firsts in Television (commented)] {{Webarchive|url=https://web.archive.org/web/20150204092411/http://colortelevision.info/rca-nbc_firsts.html |date=4 February 2015 }}.</ref> These color systems were not compatible with existing black-and-white [[television sets]], 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]] 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.<ref>"Making of Radios and Phonographs to End April 22", ''The New York Times'', 8 March 1942, p. 1. "Radio Production Curbs Cover All Combinations," ''The Wall Street Journal,'' 3 June 1942, p. 4. "WPB Cancels 210 Controls; Radios, Trucks in Full Output", ''New York Times'', 21 August 1945, p. 1.</ref><ref>Bob Cooper, "[http://www.earlytelevision.org/color_tv_cooper.html Television: The Technology That Changed Our Lives]", Early Television Foundation.</ref>

As early as 1940, Baird had started work on a fully electronic system he called [[Telechrome]]. 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 "[[Stereoscopy|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 the development of the Telechrome system.<ref>Albert Abramson, ''The History of Television, 1942 to 2000'', McFarland & Company, 2003, pp. 13–14. {{ISBN|0-7864-1220-8}}</ref><ref>Baird Television: [http://www.bairdtelevision.com/colour.html The World's First High Definition Colour Television System].</ref>
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]] 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]] 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]] 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 (signal processing)|bandwidth]], potentially three times that of the existing [[black-and-white]] standards, and not use an excessive amount of [[radio spectrum]]. In the United States, after considerable research, the [[NTSC|National Television Systems Committee]]<ref name=name>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.:54021386 [http://catalog.loc.gov/cgi-bin/Pwebrecon.cgi?DB=local&PAGE=First Library of Congress Online Catalog]</ref> approved an all-electronic system developed by [[RCA]], which encoded the color information separately from the brightness information and significantly 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 [backwards] "compatible." ("Compatible Color," featured in RCA advertisements of the period, is mentioned in the song "[[America (West Side Story song)|America]]," of [[West Side Story]], 1957.) The brightness image remained compatible with existing black-and-white television sets at slightly reduced resolution. In contrast, 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 significant technical achievement.

[[File:SMPTE Color Bars.svg|thumb|left|Color bars used in a [[test pattern]], sometimes used when no program material is available]]
The first color broadcast (the first episode of the live program ''[[The Marriage (American TV series)|The Marriage]]'') occurred on 8 July 1954. However, during the following ten years, most network broadcasts and nearly all local programming continued to be 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. [[General Electric|GE]]'s relatively compact and lightweight [[Porta-Color]] set was introduced in the spring of 1966. It used a [[transistor]]-based [[UHF television broadcasting|UHF tuner]].<ref>{{cite web |title=GE Portacolor |url=http://www.earlytelevision.org/ge_portacolor.html |website=[[Early Television Museum]] |access-date=2 October 2019}}</ref> The first fully transistorized color television in the United States was the [[Quasar (brand)|Quasar]] television introduced in 1967.<ref>{{cite book |last1=Tyson |first1=Kirk |title=Competition in the 21st Century |date=1996 |publisher=[[CRC Press]] |isbn=9781574440324 |page=[https://archive.org/details/competitionin21s00tyso/page/253 253] |url=https://archive.org/details/competitionin21s00tyso|url-access=registration }}</ref> These developments made watching color television a more flexible and convenient proposition.

In 1972, sales of color sets finally surpassed sales of black-and-white sets. Color broadcasting in Europe was not standardized on the [[PAL]] 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. 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]] screens in lower-cost consumer equipment. By the late 1980s, even these last holdout niche B&W environments had inevitably shifted to color sets.

===Digital===
{{main|Digital television}}
{{see also|Digital television transition}}

Digital television (DTV) is the transmission of audio and video by digitally processed and multiplexed signals, in contrast to the analog and channel-separated signals used by [[analog television]]. Due to [[data compression]], digital television can support more than one program on the same channel bandwidth.<ref>{{cite web | url=http://www.disabled-world.com/artman/publish/digital-hdtv.shtml | title=HDTV Set Top Boxes and Digital TV Broadcast Information | access-date=28 June 2014 | url-status=dead | archive-url=http://arquivo.pt/wayback/20160522191336/http://www.disabled%2Dworld.com/artman/publish/digital%2Dhdtv.shtml | archive-date=22 May 2016 | df=dmy-all }}</ref> It is an innovative service that represents the most significant evolution in television broadcast technology since color television emerged in the 1950s.<ref>{{cite book |last1=Kruger |first1=Lennard G. |last2=Guerrero |first2=Peter F. |title=Digital Television: An Overview |date=2002 |publisher=[[Nova Publishers]] |isbn=9781590335024 |page=1 |url=https://books.google.com/books?id=BIAfWq2V3wgC&pg=PA1 |location=Hauppauge, New York}}</ref> 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.<ref>{{cite web|url=http://www.benton.org/initiatives/obligations/charting_the_digital_broadcasting_future/sec1|title=The Origins and Future Prospects of Digital Television|date=22 December 2008|access-date=22 March 2015}}</ref> Digital television was previously not practically possible due to the impractically high [[Bandwidth (computing)|bandwidth]] requirements of [[uncompressed video|uncompressed]] [[digital video]],<ref name="Lea">{{cite book |last1=Lea |first1=William |title=Video on demand: Research Paper 94/68 |date=1994 |publisher=[[House of Commons Library]] |url=https://researchbriefings.parliament.uk/ResearchBriefing/Summary/RP94-68 |access-date=20 September 2019}}</ref><ref name="Barbero">{{cite journal |last1=Barbero |first1=M. |last2=Hofmann |first2=H. |last3=Wells |first3=N. D. |title=DCT source coding and current implementations for HDTV |journal=EBU Technical Review |date=14 November 1991 |issue=251 |pages=22–33 |publisher=[[European Broadcasting Union]] |url=https://tech.ebu.ch/publications/trev_251-barbero |access-date=4 November 2019}}</ref> requiring around 200{{nbsp}}[[Mbit/s]] for a [[standard-definition television]] (SDTV) signal,<ref name="Lea"/> and over 1{{nbsp}}[[Gbit/s]] for [[high-definition television]] (HDTV).<ref name="Barbero"/>

A digital television service was proposed in 1986 by [[Nippon Telegraph and Telephone]] (NTT) and the [[Ministry of Posts and Telecommunications (Japan)|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 implement such a digital television service practically until the adoption of DCT video compression technology made it possible in the early 1990s.<ref name="Lea" />

In the mid-1980s, as Japanese [[consumer electronics]] firms forged ahead with the development of [[High-definition television|HDTV]] technology, the [[Multiple sub-Nyquist sampling encoding|MUSE]] analog format proposed by [[NHK]], 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 [[Federal Communications Commission|FCC]] 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 several 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]]" 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]] 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]] industry (joined by some broadcasters) and the [[computer industry]] (joined by the [[film industry]] 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.<ref name="bambooav.com">{{cite web|url=http://www.bambooav.com/information-about-interlaced-and-progressive-scan-signals.html |archive-url=https://web.archive.org/web/20090816184950/http://www.bambooav.com/information-about-interlaced-and-progressive-scan-signals.html |url-status=dead |archive-date=16 August 2009 |title=Information about interlaced and progressive scan signals |access-date=22 March 2015 }}</ref> Interlaced scanning, which had been specifically designed for older analog CRT display technologies, scans even-numbered lines first, then odd-numbered ones. Interlaced scanning can be regarded as the first video compression model. It was partly developed in the 1940s to double the image resolution to exceed the limitations of 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.<ref>{{cite web|url=http://www.isfforum.com/FAQs/view/All-About-HDTV/What-s-the-Difference-between-Interlaced-and-Progressive-Video/33.html|title=What's the Difference between "Interlaced" and "Progressive" Video? – ISF Forum}}</ref> However, interlaced scanning does not work as efficiently on newer display devices such as [[liquid-crystal display]] (LCD), for example, which are better suited to a more frequent progressive refresh rate.<ref name="bambooav.com"/>

[[Progressive scanning]], 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]] 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.<ref>{{cite web |url=http://www.cinemasource.com/articles/hist_politics_dtv.pdf|title=The history and politics of DTV|page=13|archive-url=https://web.archive.org/web/20030322131735/http://www.cinemasource.com/articles/hist_politics_dtv.pdf|archive-date=22 March 2003|url-status=live}}</ref>

[[Digital television transition]] started in the late 2000s. All governments across the world set the deadline for analog shutdown by the 2010s. Initially, the adoption rate was low, as the first digital tuner-equipped television sets were costly. However, as the price of digital-capable television sets dropped, more and more households started converting to digital television sets. The transition is expected to be completed worldwide by the mid to late 2010s.

===Smart television===
{{main|Smart television}}
{{Distinguish|Internet television|Internet Protocol television|Web television}}
[[File:LG smart TV.jpg|thumb|right|upright=0.9|A smart TV]]
The advent of digital television allowed innovations like smart television sets. A smart television sometimes referred to as a "connected TV" or "hybrid TV," is a television set or [[set-top box]] with integrated Internet and [[Web 2.0]] features and is an example of [[technological convergence]] 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]], [[over-the-top content]], as well as [[video on demand|on-demand]] [[streaming media]], and [[home network]]ing access. These TVs come pre-loaded with an operating system.<ref name="Techcrunch.com"/><ref name="businessinsider1">{{cite web|author=Steve Kovach | url=http://www.businessinsider.com/what-is-a-smart-tv-2010-12 |title=What Is A Smart TV? |work=Business Insider |date=8 December 2010 |access-date=17 January 2012}}</ref><ref>{{cite news|author=Carmi Levy Special to the Star |url=https://www.thestar.com/business/media/article/876278--future-of-television-is-online-and-on-demand |title=Future of television is online and on-demand |work=Toronto Star |date=15 October 2010 |access-date=17 January 2012}}</ref><ref>{{cite web|first=Jeremy |last=Toeman |url=http://mashable.com/2010/10/20/connected-tv-content-not-apps/ |title=Why Connected TVs Will Be About the Content, Not the Apps |publisher=Mashable |date=20 October 2010 |access-date=7 October 2024}}</ref>

Smart TV is not to be confused with [[Internet TV]], [[Internet Protocol television]] (IPTV), or with [[Web TV]]. [[Internet television]] refers to receiving television content over the Internet instead of through traditional systems—terrestrial, cable, and satellite. IPTV is one of the emerging Internet television technology standards for television networks. [[Web television]] (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<ref>{{cite web |url=http://worldwide.espacenet.com/publicationDetails/originalDocument?FT=D&date=19960510&DB=EPODOC&locale=en_EP&CC=FR&NR=2726670A1&KC=A1&ND=3 |title=espacenet&nbsp;– Original document |publisher=Worldwide.espacenet.com |access-date=17 January 2012 |archive-date=24 February 2021 |archive-url=https://web.archive.org/web/20210224135932/https://worldwide.espacenet.com/publicationDetails/originalDocument?FT=D&date=19960510&DB=EPODOC&locale=en_EP&CC=FR&NR=2726670A1&KC=A1&ND=3 |url-status=dead }}</ref> (and extended the following year)<ref>{{cite web |url=http://worldwide.espacenet.com/publicationDetails/biblio?CC=US&NR=5905521A&KC=A&FT=D&ND=7&date=19990518&DB=EPODOC |title=espacenet&nbsp;– Bibliographic data |publisher=Worldwide.espacenet.com |access-date=17 January 2012 |archive-date=4 September 2015 |archive-url=https://web.archive.org/web/20150904022930/http://worldwide.espacenet.com/publicationDetails/biblio?CC=US&NR=5905521A&KC=A&FT=D&ND=7&date=19990518&DB=EPODOC |url-status=dead }}</ref> for an "intelligent" television system, linked with data processing systems, using 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 announced the production of smart TVs only for middle-end and high-end TVs in 2015.<ref name="theverge.com"/><ref name="techtimes.com"/><ref name="cnet.com"/> Smart TVs have gotten more affordable compared to when they were first introduced, with 46 million U.S. households having at least one as of 2019.<ref>Kats, Rimma (15 November 2018). [https://www.emarketer.com/content/how-many-households-own-a-smart-tv "How Many Households Own a Smart TV?"] ''[[eMarketer]]''. Retrieved 21 May 2021.</ref>

===3D===
{{main|3D television}}
3D television conveys [[depth perception]] to the viewer by employing techniques such as [[stereoscopy|stereoscopic]] display, [[free viewpoint television|multi-view]] display, [[2D-plus-depth]], or any other form of [[3D display]]. Most modern 3D [[television set]]s use an [[active shutter 3D system]] or a [[polarized 3D system]], and some are [[Autostereoscopy|autostereoscopic]] without the need for glasses. Stereoscopic 3D television was demonstrated for the first time on 10 August 1928, by [[John Logie Baird]] in his company's premises at 133 Long Acre, London.<ref>{{cite web |url=http://www.bairdtelevision.com/stereo.html |title=How Stereoscopic Television is Shown |publisher=Baird Television website|access-date=18 September 2010| archive-url= https://web.archive.org/web/20101019045734/http://www.bairdtelevision.com/stereo.html| archive-date= 19 October 2010 | url-status=live}}</ref> 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. As a result, many 3D television channels that started in the early 2010s were shut down by the mid-2010s. According to DisplaySearch 3D television shipments totaled 41.45&nbsp;million units in 2012, compared with 24.14 in 2011 and 2.26 in 2010.<ref>{{cite news|title=3D TV-sales growth |url=http://www.globalpost.com/dispatch/news/yonhap-news-agency/130318/3d-tv-sales-growth |newspaper=globalpost.com |date=18 March 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130724082049/http://www.globalpost.com/dispatch/news/yonhap-news-agency/130318/3d-tv-sales-growth |archive-date=24 July 2013 }}</ref> As of late 2013, the number of 3D TV viewers started to decline.<ref>{{cite news|title=Future looks flat for 3D TV|url=https://www.smh.com.au/digital-life/digital-life-news/future-looks-flat-for-3d-tv-20130814-2rv1q.html|newspaper=The Sydney Morning Herald|date=15 August 2013}}</ref><ref>{{cite news|title=Is 3D TV dead? ESPN 3D to shut down by end of 2013|url=https://www.theverge.com/2013/6/12/4422874/espn-3d-to-shut-down-by-end-of-2013|author=Chris Welch|newspaper=The Verge|date=12 June 2013}}</ref><ref>{{cite news|title=Why 3D TV is such a turn-off|url=http://www.iol.co.za/scitech/technology/software/why-3d-tv-is-such-a-turn-off-1.1755980|publisher=Iol Scitech|author=Guy Walters|date=25 September 2014}}</ref><ref>{{cite news|title=Is 3D dead…again?|url=http://techday.com/netguide/news/is-3d-deadagain/192995/|publisher=Techday|author=Donovan Jackson|date=29 September 2014}}</ref><ref>{{cite news|title=3D TV falls further out of favour as Sky omits Premier League matches from schedule|url=https://www.telegraph.co.uk/culture/tvandradio/11102038/3D-TV-falls-further-out-of-favour-as-Sky-omits-Premier-League-matches-from-schedule.html |archive-url=https://ghostarchive.org/archive/20220110/https://www.telegraph.co.uk/culture/tvandradio/11102038/3D-TV-falls-further-out-of-favour-as-Sky-omits-Premier-League-matches-from-schedule.html |archive-date=10 January 2022 |url-access=subscription |url-status=live|work=The Telegraph|author=Hannah Furness|date=17 September 2014}}{{cbignore}}</ref>