Patent attributes
An entire area of an FPD on which an alignment marker provided in a screen is projected is set in advance as a fixed overlapping area (Ctop to Cbottom) according to the long length imaging area and/or the X-ray source position. When determining a plurality of field-of-view area areas for dividing an imaging area for long length imaging into a plurality of areas and taking images, the field-of-view areas (FOVNT to FOVNB) and the FPD positions PN corresponding to the respective field-of-view areas are determined so that adjacent field-of-view areas overlap each other at the set fixed overlapping area. The X-ray source height, the X-ray irradiation direction, the collimator aperture angle and the FPD position are controlled so as to apply an X-ray only to each of the determined field-of-view areas.