| 摘要 |
PURPOSE:To reduce the influence of a dark current at the titled element by a method wherein the period to hold pictorial charge in the image pick-up element of CCD, etc., is reduced as much as possible. CONSTITUTION:A one frame counter 22 starts counting action corresponding to the amount of one frame (one picture) of the CCD image sensor 40 to generate a charge extraction gate signal E22 of logic ''1'' for the period corresponding to the amount of one frame. The gate signal E22 is applied to a CCD control circuit 38. The control circuit 38 performs scanning by the amount of one frame of the CCD image sensor 40 according to the signal E22, destructive reading of charge in the respective cells of the CCD image sensor 40 is performed, and residual charge of the CCD image sensor 40 is removed (the respective cells are emptied). During destructive reading thereof, because no optical image is applied to the CCD image sensor 40, content of a picture signal E40 read from the CCD image sensor 40 corresponds to dead darkness. When destructive reading thereof is completed, the gate signal E22 returns to logic ''0''. |
