Patent ID: 7746977

Claim:
A radiation image radiographing system, comprising: an X-ray tube, having a focal point, to irradiate a radiographic subject with X-rays; and a digital detector, having a minimum control unit, to detect X-rays having passed through the radiographic subject based on the minimum control unit, wherein respective positions of the X-ray tube, the radiographic subject, and the digital detector are arranged to perform a phase contrast radiography, and wherein when D (μm) represents a focal point size of the X-ray tube, S (μm) represents the minimum control unit of the digital detector, R 1 (m) represents a distance from the focal point of the X-ray tube to the radiographic subject, R 2 (m) represents a distance from the radiographic subject to the digital detector, M represents an enlargement ratio obtained by the formula (M =(R 1 +R 2 )/R 1 ), and E represents an edge enhancement caused by the phase contrast radiography, the digital radiation image radiographing system satisfies the formula (D≧(2S−E)/(M−1)).