| 摘要 |
PURPOSE:To constitute a stop system semielectronically and obtain a constant image pickup output regardless of the intensity of incident light by using a charge transfer element which has a longitudinal overflow drain as an image pickup element, and controlling the potential applied to a semiconductor substrate on the basis of the level of the image pickup output. CONSTITUTION:The charge transfer element CCD10 which has the longitudinal overflow drain is used as the image pickup element to be used for a solid-state image pickup device. The optical image of an object 11 is projected upon this CCD10 through an optical system 12. The image pickup output converted into an electric signal by this CCD10 is applied to an encoder 14 including a processor, exponent converting circuit, etc., through a preamplifier 14. The mean level VA of the image pickup output of the amplifier 13 is detected by a mean level detecting circuit 17 and compared with a reference level V0 by a comparing circuit 18, which is applied the comparison output VD to a control circuit 19. The circuit 19 outputs a substrate potential VB to the semiconductor substrate of the CCD10 to output the constant image pickup output regardless of the intensity of incident light. |
