Full Form of CRT :
Cathode Ray Tube
CRT Full Form is Cathode Ray Tube. It is a specialized tube with vacuum, which produces images when a beam of electron strikes it. It has a surface or screen made of a phosphorescent material. CRTs are used mostly in desktop computers. This is almost same as the picture tube present in televisions. CRT has many components such as a coil, electron gun, anodes, phosphor-coated screen, and more. Johann Hittorf was the genius who discovered CRT in 1869. Much later, in 1907 a Russian scientist named Boris Rosing, used CRT as a receiver of a video signal experiment. He was successful in displaying geometrical shapes on the screen. It was supposedly the first use of CRT in such video technology. Later in 1934, the first commercial television set with CRT was made by Telefunken.
CRT Full Form – Additional Information
The Cathode Ray Tube, which shall hereinafter be referred to as CRT, is basically a vacuum tube which contains a phosphorescent screen that is used for the purposes of viewing images and at least one electron gun. The CRT tube has a mechanism to cause acceleration and deflection of electron beams onto the screen for creating the images. These images produced may represent picture (in computer screens or television), electrical waveforms (as in oscilloscope), radar targets among many others. The application of these tubes has been found in the form of memory devices. In case of a memory device, the visible light which the fluorescent material emits does not give any significant meaning to an observer. CRT is an essential instrument and therefore there are other things about it that must be discussed. Here are three points about CRT you should know:
History behind the invention and development of CRT tubes
Johann Hittorf discovered the cathode rays in the year 1869 in archaic Crookes tubes. His states in his observations that certain unknown rays would emit from the negative electrode—which is called cathode—and cast a shadow on the tube’s wall, indicating that the direction of the rays was in a straight line. In the year 1890, Arthur Schuster showed that electric fields could deflect cathode rays and William Crookes showed deflection by magnetic fields. In the year 1897, J.J. Thomas successfully measured the mass of the cathode rays, which showed that they comprised of negatively charged particles, later known as electrons.
Ferdinand Braun, a German physicist, came up with the first ever CRT under the name Braun tube. It was invented in the year 1897. Braun tube, a cold cathode diode, was a modification of the Crookes tube but with a coating of phosphor on the screen. It was only in the year 1907 that Boris Rosing, a Russian scientist, came with an experimented use of CRT which eventually went to be known as television. The first ever hot cathode use in CRT was made by John B. Johnson.
Color tubes make use of three distinct phosphors, emitting blue, green, and red light respectively. These are packed in the form of stripes or clusters popularly known as triads. A Color CRT uses three electron guns, one for every primary color arranged in an equilateral triangular configuration or in a straight line. There is also a shadow mask used for the purposes of ensuring that the illumination of correct phosphors on the tube’s face. The holes in the shadow mask tube are tapered so as to ensure reflection of electrons if not absorbed.
A CRT tube makes use of an evacuated glass envelope that is large, heavy, deep, and fragile. For the purposes of safety, the face of the tube is made of a thick lead glass in order to ensure high shatter-resistance and blocking of X-ray emissions, especially in cases where the CRT tube is used in a consumer appliance. Lately, the use of newer forms of display technologies such as plasma display, LCD, OELD has become more than that of CRT. This is due to the latter’s low power consumption, bulk, weight, and manufacturing cost.
In computer screens and television, the whole front area of the CRT tube is repetitively scanned in a pattern called raster. Thereafter, an image is produced by means of control on the intensity of every one of the three electron beams with a video signal used as a reference. In modern day CRT televisions and monitors, the electron beams are bent by means of magnetic deflection, although in oscilloscopes electrostatic deflection is commonly found.
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