| 摘要 |
A shutter mechanism for collimating x-rays has two parallel drive shafts and two parallel guide shafts orthogonal to the drive shafts to define a rectangular aperture. Two flexible bands moving around a generally rectangular path about the aperture independently control the positions of each set of shutters. Two cams on the drive shafts control the positions of the flexible bands and shutters. A pair of transverse shutters made of an x-ray opaque material are held in sliding engagement between the drive shafts. One end of each transverse shutter is attached to the first flexible band adjacent to the drive shafts. Similarly, a pair of longitudinal shutters are held in sliding engagement between the drive shafts. One end of each longitudinal shutter is attached to the second flexible band adjacent to the guide shafts. |
