| 摘要 |
PURPOSE:To reduce the power supply voltage and energy consumption of a vertical output means by supplying an amplitude limited vertical deflection current to a vertical deflection coil based on sawtooth signals through an amplitude limiting means. CONSTITUTION:A PWM(pulse width modulation) signal S11 for preparing sawtooth waves is passed through an integration circuit 12, turned to a sawtooth signal S12 upward to right and further outputted through an emitter follower circuit 13. In this case, a sawtooth wave upper part cut circuit 18 is provided between the output terminal of the emitter follower circuit 18 and the input terminal of an inverted amplifier circuit 14, and a sawtooth wave upper part cut circuit 19 is provided between the output terminal of the inverted amplifier circuit 14 and the input terminal of a vertical amplifier circuit 15. In the case of a zoom mode, the upper and lower parts of the sawtooth signal are cut and the amplitude is limited. Then, a sawtooth signal S15, which upper and lower parts are cut and amplitude is limited at a peak/peak value equal to that of a normal mode, is amplified by the vertical amplifier circuit 15 and passed through a vertical output circuit 16, and the vertical deflection current is supplied to the vertical deflection coil of a deflection yoke. |
