The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 31, 2001
Filed:
Jan. 13, 2000
Martin J. Powell, Horley, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
An X-ray examination apparatus comprises an X-ray source, an X-ray detector (,) and an X-ray filter arranged between the X-ray source and the X-ray detector. The X-ray filter comprises a plurality of filter elements each comprising a vessel containing an X-ray absorbing liquid, the liquid level in each vessel determining the X-ray absorptivity of the respective filter element. Control means is provided for applying electric voltages to the individual filter elements to change the liquid levels within an adjust time period. The control means is arranged to apply a respective control voltage to each individual filter element a repeat number of times within the adjust time period, the repeat number being selected so as substantially to maximize the rate of change of liquid level of the filter elements. This enables patient examination times to be reduced, by reducing the times between sequential images.