cathode ray tube




CRT(Cathode Ray Tube) is a vacuum tube used as a display screen in a computer monitor or TV. The viewing end of the tube is coated with phosphors, which emit light when struck by electrons.In the past, CRT was a popular term for the entire computer display terminal….
The cathode ray tube (CRT) is an evacuated glass envelope containing an electron gun (a source of electrons) and a fluorescent screen, usually with internal or external means to accelerate and deflect the electrons. When electrons strike the fluorescent screen, light is emitted.
The electron beam is deflected and modulated in a way which causes it to display an image on the screen. The image may represent electrical waveforms (oscilloscope), pictures (television, computer monitor), echoes of aircraft detected by radar, etc.
The single electron beam can be processed in such a way as to display moving pictures in natural colors.
The generation of an image on a CRT by deflecting an electron beam requires the use of an evacuated glass envelope which is large, deep, heavy, and relatively fragile (this has earned it the nickname “Fishbowl”). The development of imaging technologies without these disadvantages has caused CRTs to be largely displaced by flat plasma screens, liquid crystal displays, DLP, OLED displays, and other technologies.
An exception to the typical bowl-shaped CRT would be the flat CRTs used by Sony in their Watchman series (the FD-210 was introduced in 1982). One of the last flat-CRT models was the FD-10A. The CRT in these units was flat with the electron gun located roughly at right angles below the display surface thus requiring sophisticated electronics to create an undistorted picture free from effects such as keystoning.
CRT is a Abbreviation of cathode-ray tube, the technology used in most televisions and computer display screens.
A CRT works by moving an electron beam back and forth across the back of the screen. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby illuminating the active portions of the screen.
By drawing many such lines from the top to the bottom of the screen, it creates an entire screenful of images.