| 摘要 |
PURPOSE:To eliminate the need for erasure of blanking line and to prevent flicker by superimposing a horizontal period pulse on a sawtooth wave of vertical scanning period and superimposing a vertical blanking period pulse whose trailing edge is shifted from a clamp pulse on a sawtooth wave of the horizontal scanning period. CONSTITUTION:A horizontal drive pulse 4 is superimposed on an output of a vertical sawtooth wave generating section 2 by an adder 10 and a vertical drive pulse 1 whose pulse width is changed by a pulse width adjusting section 9 is superimposed on an output of a horizontal sawtooth wave generating section 5 by an adder 11. Thus both the clamp pulses of the 1st and 2nd fields are shifted by a 1/4 of horizontal period, and since DC regeneration is applied by a signal of an optical black level normal from the start to both the 1st and the 2nd field, the luminance difference at each field is eliminated and generation of flicker is prevented. |
