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:
May. 08, 1990
Filed:
Jul. 15, 1988
Applicant:
Inventors:
Burkhard Lischke, Munich, DE;
Dieter Winkler, Munich, DE;
Assignee:
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313336 ; 3133 / ; 313292 ;
Abstract
Beam generating system for electron beam measuring instruments. In prior art beam generators, the life expectancy of directly heated boride cathodes is limited by their thermally disadvantageous mount. The present invention provides a cathode not clamped at the lower end of the crystal shank as was previously standard, but clamped immediately below the cathode tip. The inventive mount of the boride cathode results in the crystal being only insignificantly hotter in the region of the clamping plane than at the electron-emitting tip.