In older video cameras, before the 1990s, a video camera tube or pickup tube was used instead of a charge-coupled device (CCD). Several types were in use from the 1930s to the 1980s. These tubes are a type of cathode ray tube. A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. ... Germans dancing on the Berlin Wall in late 1989, the symbol of the cold war divide falls down as the world unites in the 1990s. ... A specially developed CCD used for ultraviolet imaging in a wire bonded package. ... This article or section does not cite its references or sources. ... The 1980s refers to the years of 1980 to 1989. ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT Electron guns Electron beams Focusing coils Deflection coils Anode connection Mask for separating beams for red, green, and blue part of displayed image Phosphor layer with red, green, and blue zones Close-up of the phosphor...

Some clarification of terminology is in order. Any vacuum tube which operates using a focused beam of electrons is called a cathode ray tube or CRT. However, in the popular lexicon CRT is usually used to refer to the type of tube used as a television or computer monitor picture tube. The proper term for these display tubes is actually kinescope. Kinescopes are simply one of many types of cathode ray tubes. Others include the types of display tubes used in oscilloscopes, radar displays, and the camera pickup tubes described in this article. (In the interest of avoiding further confusion it will be noted that the word "kinescope" has an alternate meaning as it has become the popular name for a television film recording made by focusing a motion picture film camera onto the face of a kinescope cathode ray tube as was commonly done before the invention of video tape recording.) The term kinescope originally referred to the cathode ray tube used in television monitors. ... This long range RADAR antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll[1]. RADAR is a system that uses radio waves to determine and map the location, direction, and/or speed...

Image dissector

The image dissector was invented by Philo Farnsworth, one of the pioneers of electronic television, in 1927. It is a type of cathode ray tube occasionally employed as a camera in industrial television systems. The image dissector had very poor light sensitivity, and was useful only where scene illumination exceeded 685 cd/m², but it was ideal for high light levels such as when engineers wanted to monitor the bright, hot interior of an industrial furnace. Owing to its lack of sensitivity, the image dissector was mainly used only to scan film and other transparencies in TV broadcasting. It was, however, the beginning of the electronic TV age. Philo Taylor Farnsworth (August 19, 1906 – March 11, 1971) was an American inventor. ... 1927 (MCMXXVII) was a common year starting on Saturday (link will take you to calendar). ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT Electron guns Electron beams Focusing coils Deflection coils Anode connection Mask for separating beams for red, green, and blue part of displayed image Phosphor layer with red, green, and blue zones Close-up of the phosphor... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength[1]. The elementary particle that defines light is the photon. ... The candela (symbol: cd) is the SI base unit of luminous intensity (that is, power emitted by a light source in a particular direction, with wavelengths weighted by the luminosity function, a standardized model of the sensitivity of the human eye). ... A square metre (US spelling: square meter) is by definition the area enclosed by a square with sides each 1 metre long. ...

The image dissector sees the outside world through a glass lens, which focuses an image through the clear glass wall of the tube onto a special plate which is coated with a layer of caesium oxide. When light strikes caesium oxide, the material emits electrons, somewhat like a mirror that reflects an image made of electrons, rather than light (see photoelectric effect). These electrons are aimed and accelerated by electric and magnetic fields onto the dissector's single electron detector so that only a small portion of the electron image hits the detector at any given moment. As time passes the electron image is deflected back and forth and up and down so that the entire image, portion by portion, can be read by the detector. The output from the detector is an electric current whose magnitude is a measure of brightness at a specific point on the image. Electrons that do not hit the single detector are wasted, rather than stored on the target as in the image orthicon (described below) which accounts in part for its low sensitivity (approximately 3000 lux). It has no "storage characteristic". The photoelectric effect is the emission of electrons from matter upon the absorption of electromagnetic radiation, such as ultraviolet radiation or x-rays. ... The lux (symbol: lx) is the SI derived unit of illuminance or illumination. ...

The iconoscope

Vladimir Zworykin patented the idea, in May 1931, of projecting an image on a special plate which was covered with a chemical photoemissive mosaic consisting of granules of material, a pattern comparable to the receptors of the human eye. Emission of photoelectrons from each granule in proportion to the amount of light resulted in a charge image being formed on the mosaic. Each granule, together with the conductive plate behind the mosaic, formed a small capacitor, all of these having a common plate. An electron beam was then swept across the face of the plate from an electron gun, discharging the capacitors in succession; the resulting changes in potential at the metal plate constituted the picture signal. Unlike the image dissector the Zworykin model was much more sensitive, to about 75 000 lux. It was also easier to manufacture and produced a very clear image. Vladimir Kosma Zworykin (Russian: (July 30, 1889 - July 29, 1982) was a pioneer of television technology. ... Year 1931 (MCMXXXI) was a common year starting on Thursday (link is to a full 1931 calendar). ... The human eye. ... Capacitors: SMD ceramic at top left; SMD tantalum at bottom left; through-hole tantalum at top right; through-hole electrolytic at bottom right. ... A charged particle beam is a group of electrically charged particles that have approximately the same kinetic energy and move in approximately the same direction. ... Electron gun from a cathode ray tube An electron gun is a component that produces an electron stream that has a precise kinetic energy, being used in all TVs and monitors which use cathode ray tube technology, and in other instruments, eg. ...

Image Orthicon

Schematic of image orthicon tube.

The image orthicon tube (often abbreviated as IO) was common until the 1960s. A combination of Farnsworth's image dissector and RCA's orthicon technologies, it replaced the iconoscope/orthicon, which required a great deal of light to work adequately. While the iconoscope and the intermediate orthicon used capacitance between a multitude of small but discrete light sensitive collectors and an isolated signal plate for reading video information, the IO employed direct charge readings off of a continuous electronically charged collector. The resultant signal was immune to most extraneous signal "crosstalk" from other parts of the target, and could yield extremely detailed images. For instance, IO cameras were used for capturing Apollo/Saturn rockets nearing orbit long after the networks had phased them out, as only they could provide sufficient detail. The image orthicon is another type of video camera tube which uses a photoemissive sensitive element. ... The image orthicon is another type of video camera tube which uses a photoemissive sensitive element. ... The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... Philo Taylor Farnsworth (August 19, 1906 – March 11, 1971) was an American inventor. ... In older video cameras, prior to the 1990s, a video camera tube or pickup tube was used instead of a charge-coupled device (CCD). ... RCA, formerly an initialism for the Radio Corporation of America, is now a trademark used by two companies for products descended from that common ancestor: Thomson Consumer Electronics, which manufactures RCA-branded televisions, DVD players, video cassette recorders, direct broadcast satellite decoders, camcorders, audio equipment, telephones, and related accessories; and... In older video cameras, before the 1990s, a video camera tube or pickup tube was used instead of a charge-coupled device (CCD). ... The iconoscope was invented by Vladimir Zworykin in 1923, essencially a tube for television transmission used in the first cameras. ... In older video cameras, before the 1990s, a video camera tube or pickup tube was used instead of a charge-coupled device (CCD). ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength[1]. The elementary particle that defines light is the photon. ... The iconoscope was invented by Vladimir Zworykin in 1923, essencially a tube for television transmission used in the first cameras. ... In older video cameras, before the 1990s, a video camera tube or pickup tube was used instead of a charge-coupled device (CCD). ...

A properly constructed image orthicon could take television pictures by candlelight owing to the more ordered light-sensitive area and the presence of an electron multiplier at the base of the tube, which operated as a high-efficiency amplifier. It also had a logarithmic light sensitivity curve similar to the human eye, so the picture looked more natural. Its defect was that it tended to flare if a shiny object in the studio caught a reflection of a light, generating a dark halo around the object on the picture. Image orthicons were used extensively in the early color television cameras, where their increased sensitivity was essential to overcome their very inefficient optical system. A logarithmic scale is a scale of measurement that uses the logarithm of a physical quantity instead of the quantity itself. ... This article refers to the sight organ. ... Photograph of NASA lunar lander containing lens flare. ...

An engineer's nickname for the tube was the "immy", which later was feminized to become the "Emmy". An Emmy Award. ...

Summary of IO Operation: An IO consists of three parts: an image store ("target"), a scanner that reads this image (an electron gun), and a multiplicative amplifier. In the image store, light falls upon a photosensitive plate, and is converted into an electron image (borrowed from Farnsworth's image dissector). These electrons ("rain") are then accelerated towards the target, causing a "splash" of electrons to be discharged (secondary electrons). Each image electron ejects, on average, more than one "splash" electron, and these excess electrons are soaked up by a positively-charged mesh very near and parallel to the target (the image electrons also pass through this mesh, whose positive charge also helps to accelerate the image electrons). The result is an image painted in positive charge, with the brightest portions having the largest positive charge. Secondary electrons are electrons generated as ionization products. ...

A sharply focused beam of electrons (a cathode ray) is then scanned over the back side of the target. The electrons are slowed down just before reaching the target so that they are absorbed without ejecting more electrons. This adds negative charge to the positive charge until the region being scanned reaches some threshold negative charge, at which point the scanning electrons are reflected rather than absorbed. These reflected electrons return down the cathode ray tube toward an electron detector (multiplicative amplifier) surrounding the electron gun. The number of reflected electrons is a measure of the target's original positive charge, which, in turn, is a measure of brightness. In analogy with the image dissector, this beam of electrons is scanned around the target so that the image is read one small portion at a time.

Multiplicative amplification is also performed via the splashing of electrons: a stack of charged pinwheel-like disks surround the electron gun. As the returning electron beam hits the first pinwheel, it ejects electrons exactly like the target. These loose electrons are then drawn toward the next pinwheel back, where the splashing continues for a number of steps. Consider a single, highly-energized electron hiting the first stage of the amplifier, causing 2 electrons to be emitted and drawn towards the next pinwheel. Each of these might then cause two each to be emitted. Thus, by the start of the third stage, you would have four electrons to the original one.

What causes the dark halo? The mysterious "dark halo" around bright objects in an IO-captured image is based in the very fact that the IO relies on the splashing caused by highly energized electrons. When a very bright point of light (and therefore very strong electron stream emitted by the photosensitive plate) is captured, a great preponderance of electrons is ejected from the image target. So many are ejected that the corresponding point on the collection mesh can no longer soak them up, and thus they fall back to nearby spots on the target much as splashing water when a rock is thrown in forms a ring. Since the resultant splashed electrons do not contain sufficient energy to eject enough electrons where they land, they will instead neutralize any positive charge in that region. Since darker images result in less positive charge on the target, the excess electrons deposited by the splash will be read as a dark region by the scanning electron beam.

This effect was actually "cultivated" by tube manufacturers to a certain extent, as a small, carefully-controlled amount of the dark halo has the effect of "crispening" the viewed image. (That is, giving the illusion of being more sharply-focussed that it actually is). The later Vidicon tube and its decendants (see below) do not exhibit this effect, and so could not be used for broadcast purposes until special "detail correction" circuitry could be developed.

Vidicon

A vidicon tube (sometimes called a hivicon tube) is a video camera tube in which the target material is made of antimony trisulfide (Sb₂S₃). Stibnite, sometimes also called antimonite, is a sulfide mineral. ... General Name, Symbol, Number antimony, Sb, 51 Chemical series metalloids Group, Period, Block 15, 5, p Appearance silvery lustrous grey Atomic mass 121. ... This article is about the chemical element. ...

The terms vidicon tube and vidicon camera are often used indiscriminately to refer to video cameras of any type. The principle of operation of the vidicon camera is typical of other types of video camera tubes.

Schematic of vidicon tube.

The vidicon is a storage-type camera tube in which a charge-density pattern is formed by the imaged scene radiation on a photoconductive surface which is then scanned by a beam of low-velocity electrons. The fluctuating voltage coupled out to a video amplifier can be used to reproduce the scene being imaged. The electrical charge produced by an image will remain in the face plate until it is scanned or until the charge dissipates. Schematic of vidicon image tube. ... Schematic of vidicon image tube. ... A photoresistor is an electronic component whose resistance decreases with increasing incident light intensity. ... The electron is a fundamental subatomic particle that carries an electric charge. ... Generally, an amplifier is any device that uses a small amount of energy to control a larger amount of energy. ...

Pyroelectric photocathodes can be used to produce a vidicon sensitive over a broad portion of the infrared spectrum. Pyroelectricity is the electrical potential created in certain materials when they are heated. ... In an electron tube, a negatively charged electrode coated with a photosensitive compound. ... Image of two girls in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. ...

Vidicon tubes are notable for a particular type of interference they suffered from, known as vidicon microphony. Since the sensing surface is quite thin, it is possible to bend it with loud noises. The artifact is characterized by a series of many horizontal bars evident in any footage (mostly pre 1990) in an environment where loud noise was present at the time of recording or broadcast. A studio where a loud rock band was performing or even gunshots or explosions would create this artifact.

Plumbicon

Plumbicon is a registered trademark of Philips. Mostly used in broadcast camera applications. These tubes have low output, but a high signal-to-noise ratio. They had excellent resolution compared to Image Orthicons, but lacked the artificially sharp edges of IO tubes, which caused some of the viewing audience to perceive them as softer. CBS Labs invented the first outboard edge enhancement circuits to sharpen the edges of Plumbicon generated images. Philips HQ in Amsterdam Koninklijke Philips Electronics N.V. (Royal Philips Electronics N.V.), usually known as Philips, (Euronext: PHIA, NYSE: PHG) is one of the largest electronics companies in the world. ... Signal-to-noise ratio (often abbreviated SNR or S/N) is an electrical engineering concept defined as the ratio of a given transmitted signal to the background noise of the transmission medium. ...

Compared to Saticons, Plumbicons had much higher resistance to burn in, and coma and trailing artifacts from bright lights in the shot. Saticons though, usually had slightly higher resolution. After 1980, and the introduction of the diode gun plumbicon tube, the resolution of both types was so high, compared to the maximum limits of the broadcasting standard, that the Saticon's resolution advantage became moot.

surface: PbO Lead Oxide

Saticon

Saticon is a registered trademark of Hitachi also produced by Thomson and Sony. Its surface is comprised of SeAsTe — Selenium Arsenic Tellurium Hitachi may refer to: Hitachi (train) trains in Melbourne, Australia. ... Thomson has several meanings: Thomson SA, formerly known as Thomson Multimedia, a French electronics manufacturer and media services provider. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Pasecon

Pasecon is a registered trademark of Heimann. Its surface is comprised of CdSe — Cadmium selenide Heimann, Heymann refers to: Alexander Heimann, see German article Diana Heimann Friedrich Heimann, see List of World War II aces from Germany Ernst Heymann (1870 - 1946), German jurist Klaus Heymann, founder of the Naxos Lida Gustava Heymann Mendel Heymann, father of Moses Mendelssohn Werner R. Heymann (Werner Richard Heymann, Werner...

Newvicon

Newvicon is a registered trademark of Matsushita. The Newvicon tubes were characterized by high light sensitivity. Its surface is comprised of ZnSe, ZnCdTe — Zinc Selenide, Zinc Cadmium Telluride Logo for the Panasonic brand Matsushita Electric Industrial Co. ...

Trinicon

Trinicon is a registered trademark of Sony. Used a vertical stripe filter. To meet Wikipedias quality standards, this article or section may require cleanup. ...

See also

Monoscope The Indian Head test pattern A monoscope was a special form of cathode ray tube that was used to generate, rather than display, a video signal. ...

External links

• Orthicon brief history, description and diagram
• The Cathode Ray Tube site
• A brief technical guide to camera tubes