Patent ID: 7514690

Claim:
A radiation image pickup apparatus comprising: a conversion circuit unit in which a plurality of pixels are two-dimensionally arranged on a substrate, each of the plurality of pixels including a conversion device for converting irradiated radiation into electrical signals, a source-follower-type first field-effect transistor for outputting the electrical signals generated by the conversion device, and a second field-effect transistor for resetting the conversion device, wherein the conversion is a MIS-type conversion device which has a first and second electrode arranged on the substrate, an insulating layer arranged between the first and second electrode, an intrinsic semiconductor layer arranged between the insulating layer and the second electrode, and an electric field is applied to the MIS-type conversion device in the direction for leading holes from the intrinsic semiconductor layer to the second electrode in a refresh mode; a readout circuit unit for reading signals from the conversion circuit unit; a bias power source for supplying a sensor bias to the conversion device for converting irradiated radiation into electrical signals; and a reset power source for supplying a reset bias to the conversion device, wherein at least either of the bias power source and the reset power source is set in the readout circuit unit, the bias power source has a first bias switching unit for switching a bias to be supplied to the second electrode between the sensor bias and a first refresh bias, and the reset power source has a second bias switching unit for switching a bias to be supplied to the first electrode between the reset bias and a second refresh bias.