| 摘要 |
PURPOSE:To reduce power consumption of a circuit, by commonly using a bias circuit determining a clamp voltage and characteristics of gamma correction section. CONSTITUTION:A video signal is inputted to a base of a transistor (TR) Q31 of a contrast amplifier 31. Resistors R36-R39 of a black level clamp and a gamma correction circuit 32 constitute a common use bias circuit. A positive video signal applied to the base of the TR Q31 is amplified at an amplifier 31 and supplied to a TR Q32 of a black level clamp and a gamma correction circuit 32 as a video signal of negative polarity from the collector of the TR Q31. The bias circuit consisting of the resistors R36-R39 determines the black level clamp voltage and the potential of a polygonal line of an input/output characteristic of the gamma correction circuit. |
