Explanation

A materials that emits luminescence under the excitation of cathode rays. Also known as cathode ray phosphor. It has practical value. As a phosphor for CRT, it should have: ① high luminescence brightness and luminescence efficiency; ② Having certain radiation spectral characteristics; ③ There is a certain afterglow time; ④ There is a certain particle size. Generally, the average particle size is required to be within 0.220pm: ⑤ There is good stability and good adhesion of the screen glass. phosphor is evenly coated on the bottom of the electron beam tube. After focusing, the electron beam hits a certain point on the screen, and this point will luminescence. The current beam of the electron beam controls the brightness of the luminescence. The electron beam scans the entire screen. The brightness of each point on the screen changes with the light and dark parts of the pavilion image, and displays the image. Cathode ray luminescence can be divided into: black and white TV; Color television or color display tube: projection television; phosphor for flying spot scanning oscilloscope tube, etc. According to the length of afterglow, it is divided into: very long afterglow phosphor for radar display; Long afterglow phosphor, afterglow time (10%) 100ms, displayed by dry radar; Medium afterglow phosphor, afterglow time (10%) 110ms, for oscillographic display; Medium and short afterglow phosphor, afterglow time (10%), used for flying spot scanning tube. Cathode ray luminescence materials is a kind of luminescence materials whose output is only second to that of phosphor for lamps, and phosphor with larger output.

Classification