| 摘要 |
PURPOSE:To eliminate the effect due to a dark current by producing a noise signal component and storing it due to the dark current under the same condition as the image pickup condition previously the image pickup and subtracting the said noise component from a picture signal obtained at the image pickup. CONSTITUTION:When a shutter button 16 is depressed, an electric charge in the solid-state image pickup element is discharged externally at first. Then the noise of electric charge stored in each picture element is read for Tsec at a point of time elapsed by the same time (Tsec) as the shutter time and stored in a memory 13 via switches 7, 8, a differential amplifier 11 and an A/D converter 12. After the operation, a shutter 4 is opened and the signal charge from an object is stored in each picture element. When the shutter 4 is closed after Tsec, the stored electric charge is read and written in the memory 13. In this case, the dark current data written at first is read and fed to the differential amplifier 11, where an electric charge corresponding to the dark current is subtracted from the signal charge. |
