| 摘要 |
PURPOSE:To eliminate useless power consumption and to prevent the deterioration of contrast, by making the width of a blanking pulse longer than the flyback time of a deflection circuit. CONSTITUTION:When a vertical pulse inputs to a terminal 16, pulse counters 12, 13 are set with leading of the vertical pulse. Thus, signals 12a, 13a are at L level. When the 33rd horizontal pulse is applied to a terminal 15, the output 12a of the counter 12 is at H level. Thus, RS-FF14 is reset and the F output 17 is at L level. When the 250th H horizontal pulse is applied to the terminal 15, the output 13a of the counter 13 changes to H level and the F output 17 of the FF14 is at H level. Thus, since the blanking pulse width is a length between the 250th and the 33rd H, the scanning electron beam of the overscanning section is cut off. |
