Patent ID: 8222611

Claim:
A radiation imaging apparatus comprising: a sensor unit for acquiring an image signal from radiation, wherein said sensor unit includes a pixel having an MIS-type conversion element, and wherein said MIS-type conversion element includes a first electrode, a second electrode, a photoelectric conversion layer arranged between said first and second electrodes and an insulating layer arranged between said first electrode and said photoelectric conversion layer; a driving circuit unit for driving said sensor unit to perform a first operation such that the MIS-type conversion element generates an electron-hole pair according to incident radiation or light, a second operation for reading an electric signal based on an electron or a hole from said sensor unit, and a third operation for removing a part of the electrons or the holes accumulated at an interface between said photoelectric conversion layer and said insulating layer; a light source for emitting light onto said MIS-type conversion element; a power source for supplying a first voltage or a second voltage between said first and second electrodes, wherein the first voltage is supplied during the first and second operations, and the second voltage is supplied during the third operation; and a control unit for controlling said driving circuit unit, said light source and said power source, wherein before irradiating the radiation onto said sensor unit, said control unit controls said driving circuit unit, said light source and said power source so as to repeat, at least twice, a set of first and second operations with light being emitted from said light source onto said MIS-type conversion element, until a predetermined voltage is applied to the photoelectric conversion layer in a succeeding first operation after a performance of the third operation, and so as to perform the third operation after the second operation of the final set of the first and second operations.