PROBLEM TO BE SOLVED: To execute ACE (Automatic Exposure Control) in the proper processing time corresponding to an imaging portion.SOLUTION: A bit width setting change part 65 sets the bit width of an A/D converter (A/D) 52 to a relatively small value when an imaging portion has relatively small thickness to an incident direction of X-ray, and sets it to a relatively large value when the imaging portion has relatively large thickness. A division number setting change part 66 sets the number of divided regions for which an AEC part 60 calculates an integrated value of radiation dosage detection signals of detection elements 41b to a relatively small value when the imaging portion has a relatively large occupancy area to an imaging region 40, and sets it to a relatively large value when the imaging portion has a relatively small occupancy area.COPYRIGHT: (C)2014,JPO&INPIT【課題】撮影部位に応じた適切な処理時間でAEC(Automatic Exposure Control,自動露出制御)を行う。【解決手段】ビット幅設定変更部65は、X線の入射方向に対する厚みが比較的薄い撮影部位の場合、A/D変換器(A/D)52のビット幅を比較的小さい値に設定し、厚みが比較的厚い撮影部位の場合は比較的大きい値に設定する。分割数設定変更部66は、撮像領域40に対する占有面積が比較的大きい撮影部位の場合、AEC部60で検出画素41bの線量検出信号の積算値を計算する分割領域の分割数を比較的少なく設定し、占有面積が比較的小さい撮影部位の場合は比較的多く設定する。【選択図】図4
