| 摘要 |
PURPOSE:To automatically correct directional picture distortion. CONSTITUTION:Two photodiodes 1, 2 are horizontally arranged on the right and left end parts of an invalid screen on a CRT screen. A direction detection/ correction control circuit 30 judges which out of the photodidoes 1, 2 senses an electron beam at first based upon their output signals. Consequently whether the CRT screen is directed to the north or the south is judged, a correction circuit 40 is controlled in accordance with the judged direction and DC voltage to be impressed from the circuit 40 to a vertical deflection coil 50 is continuously increased until both the diodes 1, 2 simultaneously sense the electron beam. |
