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:
Sep. 12, 1989
Filed:
Aug. 05, 1988
Applicant:
Inventor:
Hideaki Uematu, Tokyo, JP;
Assignee:
Rigaku Denki Kabushiki Kaisha, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
378134 ; 378136 ;
Abstract
An X-ray is generated when thermoelectrons emitted from a cathode impinge upon an anode, and the X-ray thus generated is taken out from a window. The cathode has a surface formed with two grooves intersecting at a right angle with each other and two coil filaments are fitted thereinto. By selectively heating one of the two coil filaments, a region on the anode upon which the thermoelectrons impinge is changed, whereby one of point- and line-focusing X-rays is selectively taken out from the window provided at a portion slightly below the face of the anode and at a wall of a casing of an X-ray tube.