Motor-controlled parallel plate collimator for x-ray apparatus, has position measurement potentiometer fitted to each plate

摘要

The position measurement device fitted to each plate (4), comprising a sliding measurement component, is hinged directly to the associated plate. The connection is a peg (26) entering a matching mounting (36), held by a catch formation. The position measurement unit has a measurement plate (34) and a plate holder. The measurement plate (34) has a guide (42) along it, for guidance on the corresponding plate holder. There are at least two opposite guides (42) across the measurement plate. The position measurement unit is a potentiometer. The measurement plate includes a contact assembly (46). This is held by a fastening (44) to the measurement plate. The plate holder, and the associated measurement plate which is held and guided by it, is located above an upper transverse side or below a lower transverse side of the plate in the beam direction (12). The measurement plate is made from plastic. Position measurement units of adjacent plates, are arranged in alternation on opposite sides of the plates. Beam therapy apparatus with a corresponding parallel plate collimator is also claimed.