VIDEO SIGNAL PROCESSING CIRCUIT AND CAMERA SYSTEM

PROBLEM TO BE SOLVED: To provide a video signal processing circuit by which desired clamp characteristics are achieved in a simple circuit configuration. SOLUTION: The video signal processing circuit is provided with a differential amplifier 102, in one input terminal of which an analog video signal is inputted and in which the gain is controlled by a control signal, an A/D converter 103 to convert the analog video signal outputted from the differential amplifier into a digital video signal, a subtracter 105 to calculate difference between a level of a prescribed part other than a valid signal part in an output signal of the A/D converter and a reference value and to output the difference as a digital error signal, comparison operation parts 107, 108 to compare a level of the digital error signal with a threshold and to switch coefficients to be multiplied by the digital error signal according to a comparison result and a D/A converter 111 to convert the digital error signal outputted from the comparison operation parts into an analog error signal and to supply it to the other input terminal of the differential amplifier.