| 摘要 |
PCT No. PCT/SE83/00038 Sec. 371 Date Sep. 25, 1984 Sec. 102(e) Date Sep. 25, 1984 PCT Filed Feb. 3, 1983 PCT Pub. No. WO84/03033 PCT Pub. Date Aug. 16, 1984.A shutter arrangement for intra-oral radiographic X-ray apparatus comprises a substantially punctiform X-ray source (1), a radiation-screening and radiation-directing X-ray tube (3), a holder (10) for holding an object and an X-ray film or plate, the holder being located externally of the X-ray radiation exit orifice of the X-ray tube, and being adjustable in at least two positions in a direction transversely of the direction of radiation, for producing at least two pictures of the object in two mutually different positions relative to the radiation direction. The arrangement also includes a shutter (7c) which is arranged between the X-ray source (1) and the holder (10) and which has a shutter aperture which is adapted to the size of the X-ray film or plate used. The shutter (7c) comprises an apertured metal plate arranged in the exit orifice of the X-ray tube (3) for displacement in a slide-track arrangement (6), in a direction transversely to the direction of the radiation. The slide-track arrangement (6) and the metal plate (7c) are provided with mutually co-acting means (8), which define snap-in locations of the metal plate corresponding to selected positions of the holder (10).
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