Patent Number: 051446472
Section: abstract

A radiation exposure field limiting apparatus which prevents leakage of X-rays through a gap between each adjacent ones of leaves of radiation shielding blocks and wherein each leaf of the radiation shielding blocks is simplified in sectional shape and can be produced at a reduced cost. The leaves of the apparatus are in the form of plates and are mounted for individual movement relative to each other with respect to a plane of a center axis of radiations generated from a point radiation source to define an exposure field of radiations having an approximated profile to that of an object to be irradiated by such radiations. A face of each of the radiation shielding members at which the radiation shielding member contacts with an adjacent one of the radiation shielding members makes part of a face of a circular cone having the apex at an imaginary radiation source which is imaginarily disposed at a point spaced by a significant distance from the point radiation source.