PROBLEM TO BE SOLVED: To provide a technique advantageous to achieve high accuracy in AEC (automatic exposure control).SOLUTION: A radiation imaging apparatus includes multiple sensors, a driving section, a reading section, and a control section. The control section performs three kinds of control: a first control for reading a signal of the first sensor by the reading section while driving the first sensor among the multiple sensors by the driving section after the start of irradiation of a radiation ray, monitoring the signal, and cumulatively adding the monitored signals a second control for terminating the irradiation of the radiation ray in accordance with a fact that an arithmetic value obtained by the cumulative addition reaches a target value and a third control for reading the respective signals by the reading section while driving each one of the multiple sensors by the driving section after the termination of the irradiation of the radiation ray. The control section changes the period of the monitoring in the first control on the basis of the target value and a passage time after the start of the irradiation of the radiation ray.SELECTED DRAWING: Figure 5COPYRIGHT: (C)2017,JPO&INPIT【課題】AECを高精度化するのに有利な技術を提供する。【解決手段】複数のセンサと駆動部と読出部と制御部とを備える放射線撮像装置であって、前記制御部は、放射線の照射の開始後、前記複数のセンサのうちの第1センサを前記駆動部により駆動しながら前記第1センサの信号を前記読出部により読み出して該信号をモニタし、該モニタされた信号を累積加算する第1制御と、該累積加算により得られた演算値が目標値に達したことに応じて前記放射線の照射を終了させる第2制御と、前記放射線の照射が終了された後、前記複数のセンサのそれぞれを前記駆動部により駆動しながら該それぞれの信号を前記読出部により読み出す第3制御とを行い、前記制御部は、前記第1制御での前記モニタの周期を、前記目標値および前記放射線の照射が開始されてからの経過時間に基づいて変更する。【選択図】図5
