| 摘要 |
PURPOSE:To improve the responsiveness at the time of still picture image pickup and to improve the stability at the time of movie image pickup by operating with an open loop at the time of still-picture image pickup and with a closed loop at the other time. CONSTITUTION:The gain of a color output signal from an image pickup means is control led by a gain control means 4. At the time of open loop control mode, outputs from the means 4 are integrated by field integrating and holding means 16-18 during the duration of a first timing signal from a timing control circuit 49, and based on the output of said integration, an arithmetic operation is achieved by a counter 24 and a D/A converter 21, of which output is supplied to the gain control means 4. Also, in the closed loop control mode, outputs from the means 4 are integrated through the updated integrating actions by the field integrating and holding means 16-18 based on a second timing signal from the timing control means 49, and the above-said arithmetic operation is executed based on the output of this integration, accordingly, the gain control means 4 is controlled by means of the output of this arithmetic operation.
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