Patent Number: 052009866
Section: abstract

In an x-ray examination apparatus comprising. a frame (2) to which are connected an x-ray source (3) for emission of an x-ray beam and an x-ray detector (5) that is placed opposite the x-ray source, and PA0 filter means (31) that are placed between the x-ray source (3) and the x-ray detector (5) the filter means (31) comprising an x-ray absorbing filter body (33) and drive means for positioning the filter body in the x-ray beam, the drive means comprise two disk-shaped holding members between which the filter body is placed. The filter body is in a pivot-point pivotably fixed to one holding member and is provided with a pawl that engages a curved radial groove in the second holding member. By joint rotation of the holding members the filter body is translated in the x-ray beam whereas by rotation of one of the holding members only, the curved radial groove causes the filter body to rotate in the x-ray beam.