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:
Jan. 14, 1992
Filed:
Jan. 22, 1990
Applicant:
Inventors:
Johannes Schneider, Munich, DE;
Bernd Lewandowski, Munich, DE;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313630 ; 313631 ; 313633 ; 313571 ;
Abstract
To prevent the formation of melt-back slugs or granules on electrodes of h pressure, high power discharge lamps, when the lamps are operated under alternating current conditions of between about 20 to 60 A, for example, the electrodes are terminated in regions of decreasing diameter and, in accordance with the invention, comprise tungsten doped with lanthanum oxide (La.sub.2 O.sub.3) between about 0.5 to 2%, by weight, preferably about 1%. The doping intensity may increase towards the inside region of the electrode.