| 摘要 |
PURPOSE:To eliminate the backward current from an optical signal, by providing a well layer of an MOS transistor switch for horizontal reading with a distance to the well layer of a photodiode. CONSTITUTION:A solid state image pickup element 13 consists of a well 13a of a photodiode, a well 13b of an MOS transistor which switches the electric charge of the photodiode, and a well 13c of an MOS transistor for horizontal reading. An optical signal is supplied to a differential system 16 via a signal processing system 14; while a current flowing by a charge pump phenomenon is supplied to the system 16 via a signal processing system 15. The system 16 performs a differential process. With the differential process of the system 16, a signal cancelling the backward current of the element 13 is obtained from the output of the system 16. |
