PROBLEM TO BE SOLVED: To easily detect the placement error of the imaging plane of a radiographic image detector.SOLUTION: The radiographic image detector D includes the imaging plane 102 formed by disposing pixel sections in a two-dimensional matrix, which pixel sections stores a charge according to the irradiation amount when irradiated with radiation 104. In the radiographic image detector D used to receive the irradiation of the radiation 104 transmitted through the same subject each time its position is changed by moving along a predetermined movement axis H, the inclination of the two-dimensional matrix relative to the movement axis H is detected. For that, the position is changed by the movement and the radiation is irradiated two times to the radiation image detector D so that common markers M1 and M2 are imaged during each radiation irradiation. A reading operation is performed after each radiation irradiation to acquire image data representing the radiation image information of the markers M1 and M2, and the inclination is detected based on the positional relationship of marker images represented by the image data, respectively.COPYRIGHT: (C)2010,JPO&INPIT【課題】放射線画像検出器の撮像面の設置誤差を簡単に検出する。【解決手段】放射線104の照射を受けてその照射量に応じた電荷を蓄積する画素部を2次元マトリクス状に配置してなる撮像面102を有する放射線画像検出器Dであって、所定の移動軸Hに沿って移動して位置を変える毎に同一被写体を透過した放射線104の照射を受けるように使用される放射線画像検出器Dにおける、2次元マトリクスの移動軸Hに対する傾きを検出する。そのために放射線画像検出器Dに対して、各回の放射線照射で共通のマーカーM1、M2が撮像されるように、前記移動により位置を変えて2回の放射線照射を行う。各回の放射線照射後に読取操作を行ってマーカーM1、M2の放射線画像情報を示す画像データを得、それらの画像データが各々示すマーカー像の位置関係に基づいて、前記傾きを検出する。【選択図】図10
