| 摘要 |
PURPOSE: To improve a coloring phenomenon, to optimize γ-correction owing to a circuit configuration and to prevent the deterioration of a contrast by adjusting to equalize the black level of a clamp level and that held in a post- stage circuit so as to absorb also the dispersed portion of the post-stage circuit. CONSTITUTION: The clamp circuit 4 of a chrominance signal R is provided with a clamp voltage generating circuit 42 for generating a clamp voltage CR which is controlled in response to the supply of individual control signal QR and makes the black level in the input/output characteristic of a γ-conversion circuit 7 coincide with the black level in a clamp color signal RC and a clamp operation part 41 for receiving the supply of the clamp voltage CR and adding the clamp voltage CR to a pedestal level in the prescribed timing of the chrominance signal R in response to the supply of the control signal PR. In this case, the clamp voltage generating circuit 42 can be provided with a D/A converting circuit for executing the digital/analog(D/A) conversion of a digital data signal which is included in the first control signal and for outputting an analog voltage signal and a buffer circuit for buffer-amplifying the analog voltage signal and outputting the clamp voltage.
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