Patent ID: 7969489

Claim:
A driving method of a device comprising a pixel comprising a transistor and a photoelectric conversion element, the driving method comprising: resetting the photoelectric conversion element by applying a first potential to an n-channel terminal of the photoelectric conversion element; flowing a first current corresponding to the first potential in the transistor; resetting the photoelectric conversion element by applying the first potential to the n-channel terminal of the photoelectric conversion element; flowing a second current corresponding to a second potential in the transistor when the n-channel terminal of the photoelectric conversion element has the second potential after an accumulation time T of the photoelectric conversion element; wherein the accumulation time T satisfies an expression T>(C×Vp)/Id, where C is a capacitance of the photoelectric conversion element, Vp is a voltage applied to both terminals of the photoelectric conversion element when the photoelectric conversion element is reset, and Id is a dark current flowing in the photoelectric conversion element, and wherein the first potential is almost the same as a potential obtained by reading a black calibration sheet, and the second potential is almost the same as a potential obtained by reading a white calibration sheet.