| 摘要 |
PURPOSE:To keep excellent control of signal integraion time at all times, by providing a circuit to the signal integrating time of a solidstate pickup element controlled with an integrating time control circuit to reset in a shorter integration time for a special case. CONSTITUTION:A dark current signal and a scanning signal including said signal are sequentially produced from a solidstate pickup element SP, and a pickup signal is obtained by subtracting the dark current signal from the scanning signal with a differential circuit OP1 and the image signal integrating time is controlled with the integration time control circuit so as to reduce the pickup signal level to a given leve. Further, in the state that the signal integration time is set to the longest integration time possible for control with the integration time control circuit, when the level of the pickup signal from the differential circuit is lower than the lower limit of the specified level range, a reset circuit is provided to reset the signal integration time to be set with the integration time control circuit to the shorter integration time. |
