发明授权
- 专利标题: Automatic peak beam current leveler system
- 专利标题(中): 自动峰值电流调整系统
-
申请号: US102685申请日: 1979-12-12
-
公开(公告)号: US4298886A公开(公告)日: 1981-11-03
- 发明人: Geoffrey W. Perkins
- 申请人: Geoffrey W. Perkins
- 申请人地址: IL Schaumburg
- 专利权人: Motorola Inc.
- 当前专利权人: Motorola Inc.
- 当前专利权人地址: IL Schaumburg
- 主分类号: H04N5/59
- IPC分类号: H04N5/59 ; H04N5/14 ; H04N5/68
摘要:
A peak beam current leveler for use in a television receiver system which is responsive to the magnitude of the beam current supplied to the cathode of the cathode ray tube (CRT) exceeding a predetermined peak level to adjust the cathode peak beam current accordingly. The cathode beam current is supplied by a gain controlled video amplifier to the cathode through the base-emitter junction of a transistor. The collector electrode of the transistor is connected with a resistor for providing a voltage level proportional to the peak beam cathode current. A comparator circuit is utilized to provide a gain control signal that controls the gain of the gain controlled video amplifier such that the higher the beam current the more gain reduction that occurs. Thus, the level of the peak current is automatically reduced to maintain good focusing of the display on the CRT.
公开/授权文献
信息查询