| 摘要 |
PURPOSE:To suppress a video and a synchronous level separately by performing the DC fixation of a pedestal position for the limitation of the synchronous level by clamping a white level by a pedestal clamping circuit after clamping the peak of the synchronous level of a TV signal. CONSTITUTION:A chip clamping circuit 1 clamps the synchronous peak of a TV signal stably by a clamping pulse from the 1st synchronous separating circuit 2, and a nonlinear amplifier 3 expands the signal in a synchronous level direction and compresses it in a white level direction to send outputs to circuits 4 and 5. The pedestal clamping circuit 4 clamps the pedestal of the TV signal by a clamping pulse from the 2nd synchronous separating circuit 5 to limit the maximum value of the white level through a white clipping circuit 6. After the value is suppressed to a prescribed value by a synchronous level limiting circuit 7, the resulting signal is outputted from a distributing amplifying circuit 8 by being distributed. Thus, the operation is stabilized to ITV signals differing in level and distortion condition, and the video level and synchronous level are suppressed to prescribed values independently. |
