| abstract |
The present invention focused on the fact that the distance between a phase grating 5 and an FPD 4 does not need to be the Talbot distance. The distance between the phase grating 5 and the FPD 4 can be more feely set. However, a self-image cannot be detected unless the phase grating 5 in the self-image is satisfactorily magnified. The degree to which the original phase grating 5 in the self-image is magnified on the FPD 4 is determined by a magnification factor X2/X1. Therefore, in the present invention, the magnification factor is set to be the same as the magnification factor in the conventional configuration. By doing so, even if the distance X2 between a radiation source 3 and the FPD 4 is decreased, a situation in which the self-image cannot be detected by the FPD 4 due to the minute size thereof does not occur. |