Filter arrangement for an x-ray apparatus

Claim 1

A filter arrangement for an X-ray apparatus having an X-ray source for emitting X-rays, and a collimator for forming a bundle from said X-rays and for directing said bundle of X-rays onto a target, said bundle of X-rays defining a center beam axis, comprising (a) a single filter plate having a first and a second end face which are opposed to each other, said filter plate being positioned in said bundle for passing said X-rays therethrough and for attenuation of said X-rays before their impingement on said target; (b) means for pivotally mounting said filter plate on a pivoting axis which is non-parallel to said center beam axis and for rotating said filter plate about said pivoting axis between a lower setting angle and an upper setting angle into a plurality of selected positions, wherein said two setting angles determine the setting range of said filter plate, such that in said whole setting range said first end face is always exposed to said entire bundle of X-rays, said entire bundle thereby passing through said filter plate and exiting through said second end face, thereby obtaining selected non-uniform radiation profiles of said X-rays transmitted to said target; and (c) means for locking said filter plate in a selected position within said setting range.