| 摘要 |
PURPOSE:To remove level variation of an input securely without deterioration the signal, by synthesizing the level variation of the input signal and the output signal of a clamping circuit. CONSTITUTION:A composite video signal supplied to a terminal 1 is applied to an extracting circuit 10 through a buffer amplifier 2, a diode clamping circuit 5, and a phase inverting amplifier 5. A level variation component outputted from the extracting circuit 10 is level-adjusted adequately and supplied to a differential amplifier 20 which operates as a synthesizer, and this differential amplifier 20 is supplied with the composite video signal after level adjustment, thereby synthesizing the both. At an output terminal 21, a composite video signal free of level variation appears. |
