PHOTODETECTOR CIRCUIT AND SEMICONDUCTOR DEVICE

摘要

The present invention provides an optical detecting circuit capable of obtaining signals in different periods without being influenced by properties of a photoelectric conversion element. The optical detecting circuit has a structure in which the n numbers (n is a natural number of more than 2) of signal output circuits are connected to the photoelectric conversion element. The n numbers of the signal output circuits include (1) a transistor outputting a signal according to transposition of a gate and changing the transposition of the gate according to radiation intensity radiated to the photoelectric conversion element; (2) a first switching element maintaining the potential of the gate in the transistor; and (3) a second switching element controlling the output signal of the transistor. After the information according to the radiation intensity radiated to the photoelectric conversion element is maintained as the potential of the gate of the transistor in each signal output circuit, the second switching element is switched on so that signals in different periods can be obtained without an influence caused by the properties of the photoelectric conversion element.