PROBLEM TO BE SOLVED: To provide a filter capable of adjusting spectrum in multiple stages and that capable of attaining the reduction of size, as well as an X-ray imaging system having such a filter.SOLUTION: The filter, which is for adjusting the spectrum of passing radiation, comprises a support plate (104, 204) having an aperture (102, 202) for passage therethrough of radiation, plural filter plates (110, 120, 130, 210, 220, 230) supported by the support plate and having mutually different filter characteristics, and a moving device for moving the plural filter plates selectively to a position to close the aperture and a position to open the aperture.COPYRIGHT: (C)2010,JPO&INPIT【課題】多段階のスペクトル調節ができしかも小型化が可能なフィルタ、および、そのようなフィルタを備えたX線撮影装置を実現する。【解決手段】通過する放射線のスペクトルを調節するフィルタは、放射線通過用の開口(102,202)を有する支持板(104,204)と、前記支持板に、支持されており、互いにフィルタ特性の異なる複数のフィルタプレート(110,120,130,210,220,230)と、前記複数のフィルタプレートを、前記開口を塞ぐ位置と前記開口を開放する位置とに、それぞれ選択的に移動させる移動手段とを具備する。【選択図】図4
