Abstract: A dynamic scanning X-ray machine has a detector with an array of crystals which respond to X-rays and a circuit made of semiconductor material, both of which deteriorate when exposed to X-rays. A pair of blinder plates which are opaque to X-rays normally cover the detector and semiconductor material to prevent their deterioration by the X-rays. The blinder plates are separated from each other by an adjustable distance to form a gap which enables the X-rays to reach the detector. An object under study and the blinders move in synchronism through the X-ray field so that a part of the X-ray field forming the shadow of the object passes through the gap formed by the separation between the blinder plates and falls upon the detector, while the detector crystals and semiconductor material are shielded from the remainder of the X-ray field. The shielding of the detector crystals and semiconductor material does not have any effect upon the image of the object under study.

Abstract: A dynamic focusing device is provided for an X-ray scanner, the device comprising at least one detector module located in a position to receive, be illuminated by, and respond to X-ray. A source of X-rays is movable toward or away from the detector module. The module comprises a plurality of crystals each having a scintillation surface located in a common plane, with a plurality of septa separating the crystals. The septa have a height which is upstanding above the surfaces of the crystals far enough to reduce lateral X-ray scatter and to cast a shadow upon the surfaces of the crystals responsive to an illumination thereof from said X-ray source. The invention dynamically positions the detector module relative to the distance between the detector module and the source of X-rays in order to reduce substantially to a minimum any shadow in the X-rays cast by the septa upon the surfaces of the crystals.