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:
Nov. 12, 2002
Filed:
Mar. 09, 2001
Jason P. Harris, Schaumburg, IL (US);
Salvatore Perno, Winfield, IL (US);
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A dual filament x-ray tube assembly ( ) includes an evacuated envelope ( ) having an anode ( ) disposed at a first end of the evacuated envelope ( ) and a cathode assembly ( ) disposed at a second end of the evacuated envelope ( ). The cathode assembly includes a variable-length filament assembly ( ) which emits electron beams for impingement on the anode ( ) at focal spots having varying lengths. The cathode assembly ( ) further includes a cathode cup ( ) which is subdivided into a plurality of electrically insulated deflection electrodes ( ). A filament select circuit ( ) selectively and individually heats a portion of the variable-length filament assembly ( ). Electron beams emitted from the filament assembly ( ) are electrostatically focused and controlled by applying potentials to different ones of the deflection electrodes ( ). The x-ray tube assembly ( ) provides longer focal spots for thick-slice scanning applications and shorter focal spots for thin-slice scanning applications along with the benefit of electrostatic focusing and control.