| 摘要 |
PURPOSE:To suppress variation in dark current by equalizing a dark current component of a horizontal signal line to those of a photodiode and a vertical signal line, and subtracting the dark current component from a signal component. CONSTITUTION:The moment a switch 53 is turned on, a dark current component stored in a horizontal signal line is read out in a spike shape. The output signal of a preamplifier 54 is applied to a clamping circuit 55 for dark current detection and a clamping circuit 56 for signal detection. The output of the clamping circuit 55 is inputted through a sample holding circuit 57 to a differential amplifier 58, and a reference level is inputted to the differential amplifier 58. The output of the amplifier 58 is applied to the clamping circuit 56 to clamp an image pickup signal. |
