| 摘要 |
PURPOSE:To prevent the display of an abnormal image on a picture plane by blanking a video output signal during a reset period immediately after turning on a power supply. CONSTITUTION:A positive fly-back pulse generated from a horizontal flyback pulse generator 1 is divided by resistors 8, 9, shaped at its waveform by a TR7 and inverted and the inverted output executes blanking operation. On the other hand, an output from a pulse generator 11 turns on a diode 16 and the TR7, so that the collector of the TR7 is turned to low potential similarly to the application of the horizontal fly-back pulse and blanking is held also in the reset period. In a period other than the reset period, a positive pulse is outputted from the circuit 11, a TR14 is turned on and the collector is turned to low potential, so that the diode is cut off and normal horizontal blanking operation is not influenced. |
