| 摘要 |
<p>In order to perform stereoradiography, an X-ray apparatus utilizes an X-ray tube (2) having a pair of X-ray focal points (FR, Fb). The X-ray beams alternately irradiated from the focal points toward an image intensifier (3) through a patient (P) are limited by an X-ray beam limiting device (10, 11, 12, 13). The device shapes the irradiated X-ray beams onto a circular detection surface of the image intensifier (3) into a polygon such as octagon, which looks like an approximate circular. The X-ray irradiation field on the detection surface can be circumscribed to a circular input window (i.e. effective input area), preventing the field from going out of the surface. Thus, direct X-ray leaking over the image intensifier is avoidable. <IMAGE></p> |
