To eliminate flickers generated in one frame.

A light receiving element 12 measures the received luminous quantity lx for each horizontal period. A gain control circuit 14 calculates a corrected gain Kn on the basis of an electronic shutter control signal and the received luminous quantity lx for each horizontal period. A gain variable amplifier 13 uses the corrected gain Kn to amplify a video signal Pn from a CMOS sensor 11. Thus, flicker in the vertical direction in one frame generated in a picture based on a video output from the CMOS sensor 11 under a fluorescent light is eliminated by apparently matching the level of the fluorescent light luminous quantity for each horizontal line the same.