Patent ID: 9423512
Filing Date: 2016-08-23
CPC Classification: G01T,H04N

Claim Text:
1. A radiation imaging apparatus comprising: a pixel array in which a plurality of pixels are arrayed, each of the plurality of pixels including a converter configured to accumulate charges corresponding to radiation; a bias line configured to apply a bias potential to the converters of the plurality of pixels; a detection circuit configured to detect a current flowing to the bias line; and a control unit configured to detect a start of radiation irradiation to the pixel array based on an output from the detection circuit and configured to control a charge accumulation operation of the plurality of pixels in accordance with the detection of the start of radiation irradiation, wherein the detection circuit includes a differential amplifier circuit and a feedback path and is configured to apply a potential corresponding to a reference bias potential to the bias line, the differential amplifier circuit includes a first input terminal to which the reference bias potential is applied, a second input terminal to which the bias line is connected, and an output terminal, and the feedback path connects the output terminal and the second input terminal, and an impedance of the feedback path in a detection operation of detecting radiation irradiation is higher than the impedance of the feedback path in a readout operation of a signal from the pixel array.