Radiation imaging apparatus and radiation imaging system

摘要

A radiation imaging apparatus includes a pixel array having pixels, a bias line applying a bias potential to converters of the pixels, a detection circuit which detects a current flowing to the bias line, and a control unit which detects a start of radiation irradiation to the pixel array based on an output from the detection circuit and controls a charge accumulation operation of the pixels in accordance with the detection. The detection circuit includes a differential amplifier circuit and a feedback path, and applies a potential corresponding to a reference bias potential to the bias line. The differential amplifier circuit includes a first input terminal receiving the reference bias potential, a second input terminal connected to the bias line, and an output terminal, and the feedback path connects the output terminal and the second input terminal.