| 摘要 |
PROBLEM TO BE SOLVED: To provide an image pickup device which can improve its S/N by increasing the charge accumulation time of an image pickup element with a simple constitution and in accordance with the signal level of image data. SOLUTION: An image pickup element 11 performs photoelectric conversion of an optical image that is formed on an image pickup screen and accumulates the electric charge. A drive circuit 13 generates drive signals by means of the clock signals generated by a 1st oscillator 14 and drives the element 11. The oscillator 14 generates clock signals of frequency accordant with the input voltage. A processing circuit 15 performs the image processing to the image signals which are outputted from the element 11. The image data that undergo the image processing are converted into analog video signals by a D/A converter 20 via a multiplier 201 and a scan converter 17. A control part 16 varies the control voltage to the oscillator 14 to increase the value of image data when this value is lower than the standard signal level. When the oscillator 14 lowers its oscillation frequency in response to the control voltage, the time span of drive signal generated by the circuit 13 is expanded and the charge accumulation time of the element 11 is increased.
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