PROBLEM TO BE SOLVED: To provide a radiation imaging device capable of detecting the start of irradiation of radiation with high immediacy and high accuracy.SOLUTION: A radiation imaging device includes: a pixel array 101 that includes a plurality of pixels 110 arranged in matrix, each of which including a conversion element S and a switching element T bias wiring Vs that supplies voltage to the conversion elements S a power source unit 107 that supplies voltage to the bias wiring and a detection unit that detects the start of irradiation of the pixel array 101 with radiation. The detection unit includes a detection circuit 108b that detects the start of irradiation of the pixel array 101 with radiation on the basis of a comparison result of calculation and comparison of currents flowing through at least two lines of the bias wiring of the plurality of lines of bias wiring Vs.COPYRIGHT: (C)2014,JPO&INPIT【課題】 放射線の照射の開始を高い即時性で且つ高い精度で検知可能な放射線撮像装置を提供する。【解決手段】 変換素子Sとスイッチ素子Tとを含む画素110が行列状に複数配置された画素アレイ101と、電圧を変換素子Sに供給するバイアス配線Vsと、バイアス配線に電圧を供給する電源部107と、画素アレイ101への放射線の照射の開始を検知する検知部と、を含む放射線撮像装置であって、検知部が、複数のバイアス配線Vsのうち少なくとも2つのバイアス配線を流れる電流を演算して比較した比較結果に基づいて画素アレイ101への放射線の照射の開始を検知する検知回路108bを含む。【選択図】 図1
