Problem to be solved: to provide a technique for suppressing a decrease in accuracy of detecting an irradiation start of a radiation while suppressing an increase in power consumption in a radiation imaging apparatus which does not require the reception of a synchronizing signal between the radiation generating apparatus and the radiation generating apparatus.Solution includes a plurality of pixels including conversion elements for converting incident radiation into charge, a reading portion for reading signals from respective conversion elements of a plurality of pixels, a bias wiring for supplying a bias voltage to each of the conversion elements of a plurality of pixels, and a control section In a radiation imaging apparatus, the control section reads signals from the transducer elements to the readout section when the amount of change in the current of the bias wiring exceeds a predetermined amount, and irradiates the radiation from the transducer elementIf the determination of the start is made and it is determined that irradiation of the radiation is started, the imaging operation is started, and if it is determined that irradiation of the radiation is not started, the amount of change in the current of the bias wiring is monitored again.Diagram【課題】放射線発生装置との間で同期信号の授受を必要としない放射線撮像装置において、消費電力の増加を抑制しつつ、放射線の照射開始を検出する精度の低下を抑制する技術を提供する。【解決手段】入射する放射線を電荷に変換する変換素子をそれぞれ含む複数の画素と、複数の画素のそれぞれの変換素子から信号を読み出すための読出部と、複数の画素のそれぞれの変換素子にバイアス電圧を供給するためのバイアス配線と、制御部と、を含む放射線撮像装置であって、制御部は、バイアス配線の電流の変化量が所定の量を超えた場合、変換素子からの信号を読出部に読み出させ、変換素子からの信号に基づいて放射線の照射の開始の判定を行い、放射線の照射が開始されたと判定した場合、撮像動作を開始し、放射線の照射が開始されていないと判定した場合、再びバイアス配線の電流の変化量をモニタする。【選択図】図3
