Patent Number: 062529390
Section: abstract

The X-ray examination apparatus includes an X-ray source, an X-ray detector and an X-ray filter which is located between the X-ray source and the X-ray detector. The X-ray filter includes elements, notably capillary tubes, and the X-ray absorptivity of separate filter elements is adjustable by adjustment of a quantity of X-ray absorbing liquid in the respective filter elements. The quantity of X-ray absorbing liquid in the individual filter elements is adjusted by way of electric voltages applied to the individual filter elements. A control system is provided to apply the electric voltages selectively to the individual filter elements. The control system includes voltage lines and switching elements which electrically couple the filter elements to an electric voltage source. The filter elements are formed by spaces between corrugated plates or parallel plates provided with separating members, such as protrusions which extend transversely of the plates. The voltage lines are disposed on the plates. Preferably, the plates are formed from a stack of extendable wall foils and separating foils are provided partially between the wall foils so as to adapt the spacing of the voltage lines to the spacing of the switching elements.