VIDEO SIGNAL PROCESSOR

摘要

PROBLEM TO BE SOLVED: To suppress flickers appearing in video signals by the cyclic fluctuation of the light quantity of a fluorescent lamp in terms of a circuit and to enlarge an automatic light quantity control range at the time of automatically controlling the light quantity by using electronic shutter control and automatic gain control together in an image pickup device provided with a solid-state image pickup element. SOLUTION: An average value detection circuit 4 detects an average value of the video signals outputted from an A/D converter 3 and supplies it to an automatic light quantity control circuit 5. The automatic light quantity control circuit 5 selects the electronic shutter speed of an image pickup element 1 stepwise so as not to make the flickers appear in the video signals and to turn the average value of the video signals to an optimum value and also control the gain of an AGC gain circuit 2 together with the change of the electronic shutter speed.