In 1890, Arthur Schuster demonstrated cathode rays could be deflected by electric fields, and William Crookes showed they could be deflected by magnetic fields.
Thomson succeeded in measuring the charge-mass-ratio of cathode rays, showing that they consisted of negatively charged particles smaller than atoms, the first "subatomic particles", which had already been named electrons by Irish physicist, George Johnstone Stoney in 1891.
The earliest version of the CRT was known as the "Braun tube", invented by the German physicist Ferdinand Braun in 1897.
Braun was the first to conceive the use of a CRT as a display device. In 1908 Alan Archibald Campbell-Swinton, fellow of the Royal Society (UK), published a letter in the scientific 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.
He expanded on his vision in a speech given in London in 1911 and reported in The Times and the Journal of the Röntgen Society. The first cathode-ray tube to use a [cathode] was developed by John Bertrand Johnson (who gave his name to the term Johnson noise) and Harry Weiner Weinhart of Western Electric, and became a commercial product in 1922.
He expanded on his vision in a speech given in London in 1911 and reported in The Times and the Journal of the Röntgen Society. The first cathode-ray tube to use a [cathode] was developed by John Bertrand Johnson (who gave his name to the term Johnson noise) and Harry Weiner Weinhart of Western Electric, and became a commercial product in 1922.
The introduction of hot cathodes allowed for lower acceleration anode voltages and higher electron beam currents, since the anode now only accelerated the electrons emitted by the hot cathode, and no longer had to have a very high voltage to induce electron emission from the cold cathode. In 1926, Kenjiro Takayanagi demonstrated a CRT television that received images with a 40-line resolution.
By 1927, he improved the resolution to 100 lines, which was unrivaled until 1931.
By 1928, he was the first to transmit human faces in half-tones on a CRT display.
By 1935, he had invented an early all-electronic CRT television. It was named in 1929 by inventor Vladimir K.
RCA was granted a trademark for the term (for its cathode-ray tube) in 1932; it voluntarily released the term to the public domain in 1950. In the 1930s, Allen B.
By 1927, he improved the resolution to 100 lines, which was unrivaled until 1931.
RCA was granted a trademark for the term (for its cathode-ray tube) in 1932; it voluntarily released the term to the public domain in 1950. In the 1930s, Allen B.
The first projection CRTs were made in 1933. Projector CRTs were available with electrostatic and electromagnetic focusing, the latter being more expensive.
By 1935, he had invented an early all-electronic CRT television. It was named in 1929 by inventor Vladimir K.
Eventually blue phosphors were replaced as well. The size of CRTs increased over time, from 19 inches in 1938, to 21 inches in 1955, 35 inches by 1985, and 43 inches by 1989.
However, experimental 31 inch CRTs were made as far back as 1938. In 1960 the Aiken tube was invented.
Usual deflection angles were 90° for computer monitor CRTs and small CRTs and 110° which was the standard in larger TV CRTs, with 120 or 125° being used in slim CRTs made since 2001-2005 in an attempt to compete with LCD TVs. Over time deflection angles increased as they became practical, from 50° in 1938 to 110° in 1959, and 125° in the 2000s.
It was used in computers of the 1940s as a random-access digital storage device.
RCA was granted a trademark for the term (for its cathode-ray tube) in 1932; it voluntarily released the term to the public domain in 1950. In the 1930s, Allen B.
Aluminum started being applied to CRTs in the 1950s, coating the inside of the CRT including the phosphors, which also increased image brightness since the aluminum reflected light (that would otherwise be lost inside the CRT) towards the outside of the CRT.
Electromagnetic focusing was much more stable over the lifetime of the CRT, retaining 95% of its sharpness by the end of life of the CRT. ===Beam-index tube=== Beam-index tubes, also known as Uniray, Apple CRT or Indextron, was an attempt in the 1950s by Philco to create a color CRT without a shadow mask, eliminating convergence and purity problems, and allowing for shallower CRTs with higher deflection angles.
While circular CRTs were the norm, European TV sets often blocked portions of the screen to make it appear somewhat rectangular while American sets often left the entire front of the CRT exposed or only blocked the upper and lower portions of the CRT. In 1954 RCA produced some of the first color CRTs, the 15GP22 CRTs used in the CT-100, the first color TV set to be mass produced.
The first rectangular color CRTs were also made in 1954.
Eventually blue phosphors were replaced as well. The size of CRTs increased over time, from 19 inches in 1938, to 21 inches in 1955, 35 inches by 1985, and 43 inches by 1989.
Unfocused and undeflected CRTs were used as grid-controlled stroboscope lamps since 1958.
Usual deflection angles were 90° for computer monitor CRTs and small CRTs and 110° which was the standard in larger TV CRTs, with 120 or 125° being used in slim CRTs made since 2001-2005 in an attempt to compete with LCD TVs. Over time deflection angles increased as they became practical, from 50° in 1938 to 110° in 1959, and 125° in the 2000s.
However, experimental 31 inch CRTs were made as far back as 1938. In 1960 the Aiken tube was invented.
Rebuilding was popular until the 1960s because CRTs were expensive and wore out quickly, making repair worth it.
Electron-stimulated luminescence (ESL) lamps, which use the same operating principle, were released in 2011. ===Print head CRT=== CRTs with an unphosphored front glass but with fine wires embedded in it were used as electrostatic print heads in the 1960s.
Headlines about "radioactive" TV sets continued until the end of the 1960s.
However, the first color rectangular CRTs to be offered to the public were made in 1963.
In 1965, brighter rare earth phosphors began replacing dimmer and cadmium-containing red and green phosphors.
However, since CRTs may stay on for several hours at a time, the amount of x-rays generated by the CRT may become significant, hence the importance of using materials to shield against x-rays, such as the thick leaded glass and barium-strontium glass used in CRTs. Concerns about x-rays emitted by CRTs began in 1967 when it was found that TV sets made by General Electric were emitting “X-radiation in excess of desirable levels”.
congressional committee, which later proposed a federal radiation regulation bill, which became the 1968 Radiation Control for Health and Safety Act.
Shadow masks may be pressed into a curved shape. ====Screen manufacture==== Early color CRTs did not have a black matrix, which was introduced by Zenith in 1969, and Panasonic in 1970.
Strontium oxide began being used in CRTs, its major application, in the 1970s. Some early CRTs used a metal funnel insulated with polyethylene instead of glass with conductive material.
X-rays may leak through the anode button, although that may not the case in newer CRTs starting from the late 1970s to early 1980s, thanks to a new button and clip design.
435 °C of the frit seal between the faceplate and the funnel of the CRT. Shadow masks were replaced in TVs by slot masks in the 1970s, since slot masks let more electrons through, increasing image brightness.
Shadow masks may be pressed into a curved shape. ====Screen manufacture==== Early color CRTs did not have a black matrix, which was introduced by Zenith in 1969, and Panasonic in 1970.
Since 1970, glass in the front panel (the viewable portion of the CRT) used strontium oxide rather than lead, though the rear of the CRT was still produced from leaded glass.
Black stripe CRTs were first made by Toshiba in 1972. Small CRTs below 3 inches were made for [television]s such as the MTV-1 and viewfinders in camcorders.
X-rays may leak through the anode button, although that may not the case in newer CRTs starting from the late 1970s to early 1980s, thanks to a new button and clip design.
It was revived by Sony in the 1980s as the Indextron but its adoption was limited, at least in part due to the development of LCD displays.
The first screen using this technology (called Diamond Vision by Mitsubishi Electric) was introduced by Mitsubishi Electric for the 1980 Major League Baseball All-Star Game.
Eventually blue phosphors were replaced as well. The size of CRTs increased over time, from 19 inches in 1938, to 21 inches in 1955, 35 inches by 1985, and 43 inches by 1989.
Such completely flat CRTs were first introduced by Zenith th 1986, and use flat tensioned shadow masks, where the shadow mask is held under tension, providing increased resistance to blooming. Flat CRTs have a number of challenges, like deflection.
By the time patent issues were solved RCA had already invested heavily in conventional CRTs. In 1987, flat screen CRTs were developed by Zenith for computer monitors, reducing reflections and helping increase image contrast and brightness.
Eventually blue phosphors were replaced as well. The size of CRTs increased over time, from 19 inches in 1938, to 21 inches in 1955, 35 inches by 1985, and 43 inches by 1989.
Attempts were made to produce flat screen CRTs using inexpensive and widely available float glass. In 1990, the first CRTs with HD resolution were released to the market by Sony. In the mid 1990s, some 160 million CRTs were made per year. Flat panel displays dropped in price and started significantly displacing cathode-ray tubes in the 2000s.
Only starting around the 1990s did sophisticated active dynamic convergence compensation circuits become available that made short-necked and flat-faced CRTs workable.
Electromagnetic focusing was introduced in the early 1990s and included an electromagnetic focusing coil in addition to the already existing focusing magnets.
The charged areas of the paper attract the ink and thus form the image. ===Zeus thin CRT display=== In the late 1990s and early 2000s Philips Research Laboratories experimented with a type of thin CRT known as the Zeus display which contained CRT-like functionality in a flat panel display.
CRTs make up most of the weight of CRT TVs and computer monitors. Since the late 2000s, CRTs have been superseded by flat-panel display technologies such as LCD, plasma display, and OLED displays which are cheaper to manufacture and run, as well as significantly lighter and less bulky.
Attempts were made to produce flat screen CRTs using inexpensive and widely available float glass. In 1990, the first CRTs with HD resolution were released to the market by Sony. In the mid 1990s, some 160 million CRTs were made per year. Flat panel displays dropped in price and started significantly displacing cathode-ray tubes in the 2000s.
After several predictions, LCD monitor sales began exceeding those of CRTs in 2003-2004 and LCD TV sales started exceeding those of CRTs in the US in 2005, in Japan in 2005-2006, in Europe in 2006, globally in 2007-2008, and in India in 2013. In the mid 2000s, Canon and Sony presented the Surface-conduction electron-emitter display and Field-emission displays, respectively.
The same occurred in Canada in 2018. ===Demise=== Worldwide sales of CRT computer monitors peaked in 2000, at 90 million units, while those of CRT TVs peaked in 2005 at 130 million units. Beginning in the late 90s to the early 2000s CRTs began to be replaced with LCDs, starting first with computer monitors smaller than 15 inches in size largely because of their lower bulk.
Demand for CRT screens dropped in the late 2000s.
(CRTs may need replacement due to wear as explained further below) Repairing CRTs, although possible, requires a high level of skill. === Current uses === While CRTs had declined dramatically in the late 2000s, they are still widely used by consumers and some industries.
Usual deflection angles were 90° for computer monitor CRTs and small CRTs and 110° which was the standard in larger TV CRTs, with 120 or 125° being used in slim CRTs made since 2001-2005 in an attempt to compete with LCD TVs. Over time deflection angles increased as they became practical, from 50° in 1938 to 110° in 1959, and 125° in the 2000s.
The charged areas of the paper attract the ink and thus form the image. ===Zeus thin CRT display=== In the late 1990s and early 2000s Philips Research Laboratories experimented with a type of thin CRT known as the Zeus display which contained CRT-like functionality in a flat panel display.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
Usual deflection angles were 90° for computer monitor CRTs and small CRTs and 110° which was the standard in larger TV CRTs, with 120 or 125° being used in slim CRTs made since 2001-2005 in an attempt to compete with LCD TVs. Over time deflection angles increased as they became practical, from 50° in 1938 to 110° in 1959, and 125° in the 2000s.
Such radiation of a potentially exploitable signal, however, occurs also with other display technologies and with electronics in general. == Recycling == Due to the toxins contained in CRT monitors the United States Environmental Protection Agency created rules (in October 2001) stating that CRTs must be brought to special e-waste recycling facilities.
In November 2002, the EPA began fining companies that disposed of CRTs through landfills or incineration.
After several predictions, LCD monitor sales began exceeding those of CRTs in 2003-2004 and LCD TV sales started exceeding those of CRTs in the US in 2005, in Japan in 2005-2006, in Europe in 2006, globally in 2007-2008, and in India in 2013. In the mid 2000s, Canon and Sony presented the Surface-conduction electron-emitter display and Field-emission displays, respectively.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
Matsushita Toshiba stopped in the US in 2004 due to losses of $109 million, and in Malaysia in 2006 due to losses that almost equaled their sales.
After several predictions, LCD monitor sales began exceeding those of CRTs in 2003-2004 and LCD TV sales started exceeding those of CRTs in the US in 2005, in Japan in 2005-2006, in Europe in 2006, globally in 2007-2008, and in India in 2013. In the mid 2000s, Canon and Sony presented the Surface-conduction electron-emitter display and Field-emission displays, respectively.
The same occurred in Canada in 2018. ===Demise=== Worldwide sales of CRT computer monitors peaked in 2000, at 90 million units, while those of CRT TVs peaked in 2005 at 130 million units. Beginning in the late 90s to the early 2000s CRTs began to be replaced with LCDs, starting first with computer monitors smaller than 15 inches in size largely because of their lower bulk.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
Ekranas in Lithuania and LG.Philips Displays went bankrupt in 2005 and 2006 respectively.
In 2005, Sony announced that they would stop the production of CRT computer displays.
After several predictions, LCD monitor sales began exceeding those of CRTs in 2003-2004 and LCD TV sales started exceeding those of CRTs in the US in 2005, in Japan in 2005-2006, in Europe in 2006, globally in 2007-2008, and in India in 2013. In the mid 2000s, Canon and Sony presented the Surface-conduction electron-emitter display and Field-emission displays, respectively.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
Ekranas in Lithuania and LG.Philips Displays went bankrupt in 2005 and 2006 respectively.
Matsushita Toshiba stopped in the US in 2004 due to losses of $109 million, and in Malaysia in 2006 due to losses that almost equaled their sales.
Dixons ceased selling CRT televisions in 2006. CRTs' demise has made maintaining arcade machines made before the wide adoption of flat panel displays difficult, due to a lack of spare replacement CRTs.
After several predictions, LCD monitor sales began exceeding those of CRTs in 2003-2004 and LCD TV sales started exceeding those of CRTs in the US in 2005, in Japan in 2005-2006, in Europe in 2006, globally in 2007-2008, and in India in 2013. In the mid 2000s, Canon and Sony presented the Surface-conduction electron-emitter display and Field-emission displays, respectively.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
The last CRT TVs at CES were shown by Samsung in 2007 and the last mass produced model was introduced by LG in 2008 for developing markets due to its low price.
In Canada and the United States, the sale and production of high-end CRT TVs ( screens) in these markets had all but ended by 2007.
The Food and Drug Administration regulations in are used to strictly limit, for instance, television receivers to 0.5 milliroentgens per hour (mR/h) (0.13 µC/(kg·h) or 36 pA/kg) at a distance of from any external surface; since 2007, most CRTs have emissions that fall well below this limit. The density of the x-rays that would be generated by a CRT is low because the raster scan of a typical CRT distributes the energy of the electron beam across the entire screen.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
The last CRT TVs at CES were shown by Samsung in 2007 and the last mass produced model was introduced by LG in 2008 for developing markets due to its low price.
Efforts from Samsung and LG to make CRTs competitive with their LCD and plasma counterparts, offering slimmer and cheaper models to compete with similarly sized and more expensive LCDs CRTs eventually became obsolete and were relegated to developing markets once LCDs fell in price, with their lower bulk, weight and ability to be wall mounted coming as pluses. Most high-end CRT production had ceased by around 2010, including high-end Sony and Panasonic product lines.
The last CRT rebuilder in the US closed in 2010, and the last in Europe, RACS, which was located in France, closed in 2013. ===Reactivation=== Also known as rejuvenation, the goal is to temporarily restore the brightness of a worn CRT.
Electron-stimulated luminescence (ESL) lamps, which use the same operating principle, were released in 2011. ===Print head CRT=== CRTs with an unphosphored front glass but with fine wires embedded in it were used as electrostatic print heads in the 1960s.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
After several predictions, LCD monitor sales began exceeding those of CRTs in 2003-2004 and LCD TV sales started exceeding those of CRTs in the US in 2005, in Japan in 2005-2006, in Europe in 2006, globally in 2007-2008, and in India in 2013. In the mid 2000s, Canon and Sony presented the Surface-conduction electron-emitter display and Field-emission displays, respectively.
The last CRT rebuilder in the US closed in 2010, and the last in Europe, RACS, which was located in France, closed in 2013. ===Reactivation=== Also known as rejuvenation, the goal is to temporarily restore the brightness of a worn CRT.
They were never put into mass production as LCD technology was significantly cheaper, eliminating the market for such displays. The last known manufacturer of (in this case, recycled) CRTs, Videocon, ceased in 2015.
CRT TVs stopped being made around the same time. In 2015, several CRT manufacturers were convicted in the US for price fixing.
Among the first manufacturers to stop CRT production was Hitachi, in 2001, followed by Sony in Japan in 2004, Thomson in the US in 2004, Matsushita Toshiba picture display in 2005 in the US, 2006 in Malaysia and 2007 in China, Sony in the US in 2006, Sony in Singapore and Malaysia for the Latin American and Asian markets in 2008, Samsung SDI in 2007 and 2012 and Cathode Ray Technology(formerly Philips) in 2012 and Videocon in 2015-16.
The same occurred in Canada in 2018. ===Demise=== Worldwide sales of CRT computer monitors peaked in 2000, at 90 million units, while those of CRT TVs peaked in 2005 at 130 million units. Beginning in the late 90s to the early 2000s CRTs began to be replaced with LCDs, starting first with computer monitors smaller than 15 inches in size largely because of their lower bulk.
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