Patent ID: 9424958
Filing Date: 2016-08-23
CPC Classification: G01N,G21K,H01J

Claim Text:
1. An X-ray tube for generating multiple-energy X-ray radiation, with: an anode; and a directional filter; wherein the anode comprises at least a first and a second focal spot position, which are offset from each other in an offset direction transverse to an X-ray radiation projection direction; wherein the directional filter comprises a first plurality of first portions with first filtering characteristics for X-ray radiation and a second plurality of second portions with second filtering characteristics for X-ray radiation; wherein the filter is a directional filter adapted in a such a way that at least a first part of a first X-ray beam emanating from the first focal spot position passes through the directional filter unit via the first portions; and at least a second part of a second X-ray beam emanating from the second focal spot position passes the second portions when passing through the filter unit; the directional filter has through-holes or slots, the through-holes or slots being transmissive to first X-ray beam from the first focal spot and pointing at the first focal spot and has separators which are less transmissive to X-rays, the separators being oriented such that the first X-ray beam from the first focal spot passes between the separators through the through-holes or slots and a second X-ray beam from the second focal spot passes obliquely through one or more separators; wherein at least a portion of the first X-ray beam and at least a portion of the second X-ray beam pass through a common area of the filter.