PROBLEM TO BE SOLVED: To enable detection of irradiation start of radiation with high accuracy even when noise is generated due to disturbance factor or the like.SOLUTION: A radiation imaging device includes: a plurality of pixels each of which has a sensor part of generating electric charge according to irradiated radiation and a switching element of reading the electric charge from the sensor part on the basis of a control signal to output it to a signal line a radiation detection unit which outputs an electric signal according to the irradiated radiation a start detection unit which detects irradiation start of the radiation on the basis of the electric signal outputted from the radiation detection unit during a detection period a determination unit which determines whether or not the start detection unit erroneously detects the irradiation start of the radiation on the basis of the electric signal outputted from the radiation detection unit during an imaging period of the radiation image after the start detection unit detects the irradiation start of the radiation and a transition part which immediately performs transition from the imaging period to the detection period when the determination unit determines the erroneous detection.COPYRIGHT: (C)2015,JPO&INPIT【課題】外乱要因等に起因してノイズが発生した場合でも、精度よく放射線の照射開始を検知することができる。【解決手段】照射された放射線に応じた電荷を発生するセンサ部、及び制御信号に基づいてセンサ部から電荷を読み出して信号線に出力するスイッチング素子を各々備えた複数の画素と、照射された放射線に応じた電気信号を出力する放射線検知部と、検知期間中に放射線検知部から出力される電気信号に基づいて、放射線の照射開始を検知する開始検知部と、開始検知部が放射線の照射開始を検知した後の放射線画像の撮影期間に、放射線検知部から出力された電気信号に基づいて、開始検知部が放射線の照射開始を誤検知したか否かを判断する判断部と、判断部が誤検知と判断した場合に、撮影期間から、すぐに検知期間に遷移させる遷移部と、を備えた放射線画像撮影装置。【選択図】図8
