Cathodic ray television

In colored cathode ray tubes (CRTs), such as those used in televisions and computer terminals, three electron gun beams are focused on three different sets of phosphor dots on the front face of the tube. The dots are produced by using a compHcated photoHthography process. The phosphor dots are produced by settling the three different phosphors, each of which emits one of the primary saturated colors, red, green, or blue. Each phosphor is deposited separately and the three dots in each set are closely spaced so that the three primary colors are not resolved at normal viewing distances. Instead the viewer has the impression that there is only one color, the color achieved when the three primary colors are added together. 

Uses. The main appHcation for strontium is in the form of strontium compounds. The carbonate, used in cathode ray tubes (CRTs) for color televisions and color computer monitors, is used both in the manufacturing of the glass envelope of the CRT and in the phosphors which give the color. 

Cobalt is used as a blue phosphor in cathode ray tubes for television, in the coloration of polymers and leather goods, and as a pigment for oil and watercolor paints. Organic cobalt compounds that are used as colorants usually contain the azo (51) or formazon (52) chromophores. 

Donor and acceptor levels are the active centers in most phosphors, as in zinc sulfide [1314-98-3] ZnS, containing an activator such as Cu and various co-activators. Phosphors are coated onto the inside of fluorescent lamps to convert the intense ultraviolet and blue from the mercury emissions into lower energy light to provide a color balance closer to daylight as in Figure 11. Phosphors can also be stimulated directly by electricity as in the Destriau effect in electroluminescent panels and by an electron beam as in the cathodoluminescence used in television and cathode ray display tubes and in (usually blue) vacuum-fluorescence alphanumeric displays. 

Liquid crystal display systems have been increasingly used in electro-optical devices such as digital watches, calculators, televisions, instmment panels, and displays of various kinds of electronic equipment, ie, lap-top computers and word processors. The dominant reason for thek success is thek extremely low power consumption. Furthermore, the Hquid crystal display systems have been remarkably improved in recent years, and today they have high resolution (more than 300,000 pixels) and full color capabiUty almost equivalent to those of a cathode ray tube. 

Cathodoluminescence (CL), i.e., the emission of light as the result of electron-beam bombardment, was first reported in the middle of the nineteenth century in experiments in evacuated glass tubes. The tubes were found to emit light when an electron beam (cathode ray) struck the glass, and subsequendy this phenomenon led to the discovery of the electron. Currendy, cathodoluminescence is widely used in cathode-ray tube-based (CRT) instruments (e.g., oscilloscopes, television and computer terminals) and in electron microscope fluorescent screens. With the developments of electron microscopy techniques (see the articles on SEM, STEM and TEM) in the last several decades, CL microscopy and spectroscopy have emerged as powerfirl tools for the microcharacterization of the electronic propenies of luminescent materials, attaining spatial resolutions on the order of 1 pm and less. Major applications of CL analysis techniques include ... 

A television picture tube is a form of cathode-ray tube (Section 1.1) in which the beam of electrons is directed toward a screen that emits light where they strike it. Have you ever wondered what the pressure is inside the tube Estimate the pressure (in atmospheres), given that the volume of the tube is 5.0 L, its temperature is 23°C, and it contains 0.010 mg of nitrogen gas. 

Phosphors are inorganic materials which convert incident radiant energy to visible light within a device. The device chosen can be a cathode-ray tube, i.e.- a television tube, or a fluorescent lamp. A phosphor consists of a matrix modified by an additive chosen so that it becomes optically active within the matrix, or compound. This is an example of a substitutional impurity in a lattice wherein the additive, usualty Ccdled an "activator", introduces a lattice defect that is optically active. However, the added impurity still follows all of the rules found for defects in a lattice, as shown by the following example. 

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. 

Another name for a beam of electrons is a cathode ray. Cathode ray tubes, or CRT for short, are used extensively in video monitors and televisions. The electrons are ejected from the electron gun and directed at a screen coated with substances that glow different colors when struck with the electrons. The electron beam must strike different regions of the screen at different times and frequencies to create a clear... 

Lead (Pb) is used for many applications, for example in electronic goods such as cathode ray tube (CRT) televisions and as a stabilizer in PVC. Pb is one of the oldest known and most studied occupational and environmental toxins. Despite the many studies, there is still debate regarding the toxic effects caused by Pb [39]. 

Ba 2.8 0.5 7.6 200 26 36 100 271 Filler, extender, or weighting agent in paints, plastics, and rubber. Others aggregate in high-density concrete used for radiation shielding, contrast medium in medical X-rays, and ingredient in faceplate glass of cathode ray tubes used in televisions and computer monitors. 

While experimenting with cathode ray tubes (similar to television screens of the 1950s), Wilhelm Konrad Roentgen (1845-1923) discovered an unfamiliar type of radiation. He named these X-rays , using X to signify the unknown. ... 

Europium is used for the capture of thermal neutrons for nuclear control rods in atomic power stations. Thermal neutron absorption of the natural mixture of europium isotopes is 4,600 barns. While its salts are used in coatings for cathode ray tubes in color televisions, organoderivatives are used in NMR spectroscopy. 

Cathode ray tubes (CRTs) are almost universally used in colour televisions and still dominate in the display monitors of desktop computers. They are obviously not suitable for laptop PCs, because of bulk and weight, where currently liquid crystal displays are the systems of choice. Neither are they the most suitable technology for very large area displays, where other display techniques such as plasma panels and electroluminescent devices offer advantages. 

Recycling of computer monitor or television cathode ray tubes (CRT) or other lead-contaminated glass... 

Phosphors are solids which absorb energy and re-emit it as light. As in the lasers we have just described, the emitter is usually an impurity ion in a host lattice. However, for the uses to which phosphors are put it is not necessary to produce intense, coherent beams of light, and the emitting process is spontaneous instead of induced. Phosphors have many applications, for example, the colours of your television picture are produced by phosphors that are bombarded with electrons from a beam (cathode rays) or from a transistor (flat screen LCD displays). In terms of tonnage produced, one of the most important applications is the fluorescent light tube. 

Cathode rays A stream of electrons emitted by a cathode, or negative electrode, of a gas-discharge tube or by a hot filament in a vacuum tube, such as a television tube. 

Phosphors for cathode-ray tubes, television screens, monitor screens, radar screens, and oscilloscopes are tested under electron excitation. Electron energy and density should be similar to the conditions of the tube in which the screen will be used. The phosphors are sedimented or brushed onto light-permeable screens and coated with an evaporated aluminum coating to dissipate charge. The luminescence brightness and color of the emitted light are measured with optical instruments such as photomultipliers or spectrophotometers. 

The cathode ray—a stream of electrons—has found a great number of applications. Most notably, a traditional television set (not the modern, thin, LCD screens) is a cathode ray tube with one end widened out into a phosphor-coated screen. Signals from the television station cause electrically charged plates in the tube to control the direction of the ray such that images are traced onto the screen. 

Under regular light, it is difficult to see the waves traveling back and forth. For a better view, pluck the rubber band in front of a computer monitor or a television screen that uses a cathode ray tube. The light from these devices, which acts like a strobe light, makes the waves appear to slow down Vary the tension in the rubber band to see different effects. 

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