| 摘要 |
In an apparatus for slit radiography a body (1) to be irradiated is scanned at least twice by means of a planar, fan X-ray beam (4) emitted from an X-ray source (1) via a slit diaphragm (2), the hardness of which beam increases with each next scanning motion. …<??>An X-ray detector (6) mounted behind the body collects the radiation passed, and sections of detection means (10) juxtaposed in the longitudinal direction of the X-ray detector, produce electrical signals depending upon the radiation collected by the respective X-ray detector sections, which signals are sampled during each scanning motion and are stored in a memory (13). The diaphragm (2) includes controllable elements (22) juxtaposed in the longitudinal direction of the slit in a number corresponding to that of the sections of the detection means. The controllable elements are each operative to locally block the slit diaphragm during a next scanning motion if a stored signal produced by the corresponding section of the detection means during a preceding scanning motion exceeds a predetermined value. |
