由于 CRT 彩色显示管内部的荫罩、栅网及外部屏蔽罩等均由金属材料制成,当其受到地磁场或外部磁场作用时,显示管及其附件极易被磁化,使得电子束扫描运动的轨迹发生偏移,不能准确地击中对应的荧光粉粒,从而导致荧光屏四周出现色斑等故障现象。为此,彩色显示管均设置了显示管消磁电路。在彩色显示器中消磁电路有自动消磁电路、受控消磁电路等两种类型。 Since the shadow mask inside the CRT color display tube, the grid and the outer shield are made of a metal material, the display tube and its accessories can easily be magnetized when subjected to a magnetic field or an external magnetic field, so that the electron beam scanning motion Of the track offset, can not accurately hit the corresponding phosphor particles, resulting in fluorescent stains around the phenomenon of failure. To this end, color display tubes are set to display tube degaussing circuit. In the color display degaussing circuit has automatic degaussing circuit, controlled degaussing circuit, and other two types.