CRT (Cathode ray tube)
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The document discusses cathode ray tubes (CRTs), which were the primary output devices in graphical systems and video monitors. CRTs display images using an electron beam that scans across phosphorescent screen coatings. There are two types of display methods: raster scan and random scan. Color CRTs use three electron guns and phosphors to produce red, green, and blue light, and require convergence calibration. CRTs were used in televisions, computer monitors, radar displays, and oscilloscopes. They can produce bright, high quality images but also have disadvantages like health hazards from radiation emission and potential overheating issues.
CRT (Cathode ray tube)
- 3. What is CRT? The primary output device in a graphical system is the video monitor. The main element of a video monitor is the Cathode Ray Tube (CRT), shown in the following illustration.
- 4. Display There are two ways by which we can display an object on the screen. 1. Raster scan display 2. Random scan display
- 5. Color CRTs Two basic techniques for producing color is given below: 1. Beam-Penetration Method 2.Shadow-Mask Method
- 6. Color CRTs • Color tubes use three different phosphors which emit red, green, and blue light respectively. • Color CRTs have three electron guns, one for each primary color, arranged either in a straight line or in a triangular configuration . • The three beams in color CRTs would not strike the screen at the same point without convergence calibration.
- 7. Application of CRT • In televisions • In computer monitors • As a display device in radar • In cathode ray oscilloscope
- 8. Advantages of CRT • The cathode rayed tube can easily increase the monitor’s brightness by reflecting the light. • Can produce more colors. • The quality of the image displayed on a CRT monitors is superior to the LCD and Plasma monitors. • The color features of the cathode ray tube monitor are considered highly excellent.
- 9. Disadvantages of CRT • Monitors causes a health hazard to the functioning of living cells. • CRTs emit a small amount of X-ray radiation which can result in a health hazard. • Constant refreshing of CRT monitors can result a headache. • CRTs operate at very high voltage which can overheat system or result in an implosion.
- 11. Thank You!