Patent ID: 7397059

Claim:
A radiation image reading system comprising: a radiation source for irradiating a radiation toward a subject, the radiation source having a size D; a radiation detector in which large number of detecting devices for detecting the radiation transmitted through the subject are arranged in an array form, for generating an image signal of the subject by detecting the radiation transmitted through the subject by each of the detecting devices, an aperture of each of the detecting devices having a size A; and a sampling section for sampling the image signal wherein the size A of the aperture fulfills a condition of B≦A≦2B, where B is a size of a penumbra on the radiation detector, and the size B of the penumbra is represented by B=Dx (R2/R1), where R1 is a distance from the radiation source to the subject and R2 is a distance from the subject to the radiation detector.