| 摘要 |
PURPOSE:To decrease the influence due to the fluctuation of the storage time. CONSTITUTION:A waveform shaping circuit 120 waveform-shapes a flyback pulse corresponding to a horizontal deflection cycle A differentiating circuit 121 differentiates a horizontal driving pulse. From the output of the waveform shaping circuit 120 and the differentiating circuit 121, a charging discharging control signal generating circuit 122 (comparator 91) generates a charging discharging control signal. The charging discharging control signal controls the charging discharging of a charging discharging circuit 123. The saw-tooth-wave generated by the charging discharging circuit 123 is inputted to a comparing circuit 124, compared with a reference signal level changed by the vertical deflection cycle and a PWM signal as a switch driving signal is generated. The output of the charging discharging circuit 123 supplied to a comparator 99 is clamped by a clamping circuit 127. |
