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Picture tube, color television

A television picture tube is a form of cathode ray tube in which the beam of j electrons is directed toward colored phosphors on the screen. A very low pressure is required to minimize the collisions between the electrons in the = beam and the gas molecules. Collisions and the resulting deflections of the j electrons would give a blurred, dim picture. [Pg.306]

Luminescent Pigments. This group of pigments covers a number of technologies and markets ranging from color television picture tubes to glow-in-the-dark ... [Pg.97]

Figure 3 shows the SPD of the old (A) and new (B) cool-white lamps. The new triphosphor lamp, based on phosphors developed for television picture tubes is much better at rendering color than the old monofluorophosphor (12). From their SPDs, one could hardly call them equivalent. They do however meet the criteria of color rendition, to "fool the eye", very well. [Pg.102]

The name comes from the town of Strontian in Scotland and was given to the element by Thomas Hope (1766-1844). There are many claims for the original discovery of strontium. William Cruikshank, in 1787, and Adair Crawford, in 1790, both examined strontianite (SrC03) and recognized that it had unique properties. Thomas Hope noted an unknown earth in 1791. Martin Klaproth presented a paper on a number of strontium compounds in 1793 and 1794. Richard Kirwan (1733-1812) examined a number of strontium compounds and presented his findings in 1794. It was Davy who isolated strontium metal, in 1808. Strontium does not occur in pure form in nature but is found in small quantities in many places. Some forms of strontium are radioactive, particularly 90Sr, which has been found in nuclear fallout. It can also be used in SNAP devices (Systems for Nuclear Auxiliary Power) as a power source. The main commercial use of strontium is in the glass of color television picture tubes. [Pg.126]

Compounds of europium and ytterbium are used in the picture tubes of color televisions. Neodymium is used in some high-power lasers. [Pg.107]

In a color television tube the luminescent screen consists of a regular array of three kinds of phosphor dots red-emitting dots, green-emitting dots and blue-emitting dots. There is an electron gun for the red dots giving a red picture, a gun for the green dots and one for the blue dots. [Pg.134]

Color television s RGB system (Ernst Alexanderson) The RGB system uses three image tubes to scan scenes through colored filters and three electron guns in the picture tube to reconstruct scenes. [Pg.2065]

Blacker, A. et al. 1966. A new form of extended field lens for use in color television picture tube guns. IEEE Trans. Consumer Eke. (Aug.) 238 246. [Pg.450]

Morrell, A. et al. 1971. Color Television Picture Tubes. Academic, New York. [Pg.451]

The use of consumer products that contain radioactive sources can contribute to nonoccupational exposures (320). Examples of consumer products incorporating radioactive materials are radioluminescent indicators (timepieces, signs, instrument dials), ionization smoke detectors, anti-static devices, dentistry porcelains, pottery glazes, incandescent gas mantles, and tobacco products. Low levels of radiation are also generated by such sources as color television tubes, but emissions are well controlled and the glass of the picture tube is sufficiently thick to absorb most of this radiation. [Pg.193]

A television picture tube or computer monitor is also fundamentally a cathode ray tube. In this case the electrons are directed onto a screen containing chemical compounds that glow when struck by fast-moving electrons. The use of various compounds that emit different colors when they are struck by the electrons makes color pictures possible on the screens of these CRTs. [Pg.93]

Thomsons picture of the atom emerged from his work with cathode ray tubes. It was a milestone on the road to understanding atomic structure. But it was not the only major advance to come out of cathode ray experiments. Almost every television set in existence today is a cathode ray tube. The electrons stream from the cathode and are deflected by electromagnetic coils guided by signals from the television station. When an electron hits the televisions screen, which is coated with a phosphorescent material, it produces a dot of color. The dots form the picture you see on the screen. [Pg.9]

The color tube of the television that we use at our home is simply a vacuum tube, or cathode ray tube (CRT). CRT s are frequently used in televisions, computer monitors or anywhere where it is necessary to produce a picture. [Pg.9]

The cathode ray tubes are scanned in a raster like a television picture. Each scan line is modulated into a series of dots called picture elements (abbreviated to pixels or pels) and each character is built up from these pixels. It soon became possible to manipulate the pixels individually so that as well as characters, dots, lines and shapes could be displayed on the screen. Microcomputers are now available with graphics capabilities rivalling those found on mainframe systems, but at a fraction of the cost. Clearly, more memory locations have to be put aside for graphics displays. For example, compare the text (character) display of the IBM Color/Graphics display with its high-resolution monochrome graphics mode. The 80-character mode puts 25 rows of 80 characters on the screen. Each character is stored in two bytes - one for the character itself and one for its attributes , that is, colour. [Pg.327]

Since we are dealing with a vacuum tube, the upper limit of the screen which can be reached by present-day technology is about 73 cm. Piaures with a 2 m diameter can be obtained in projection television (PTV). For each of the three colors a small (monochrome) cathode-ray tube is used. Their images are optically projected and superimposed on a projection screen using a lens system. In such a way a composite picture in full color is shown on the screen (Fig. 7.3). In order to obtain high illumination levels on the large screen, much higher current densities have to be used in PTV than in direct-view cathode-ray tubes. [Pg.135]


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See also in sourсe #XX -- [ Pg.177 , Pg.178 ]




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