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:
Mar. 20, 1990
Filed:
Dec. 20, 1984
Applicant:
Inventors:
Assignee:
U.S. Philips Corp., New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313631 ; 313574 ;
Abstract
The invention relates to a high-pressure sodium vapor discharge lamp having a ceramic discharge vessel. In addition to sodium and possibly mercury the discharge vessel also comprises a rare gas. In the discharge vessel an electrode of a refractory metal is accommodated. In the operating condition of the lamp the discharge emanates from the tip of the electrode. According to the invention the electrode is free from alkaline earth metals and the electrode tip in the operating condition of the lamp has a temperature between 2400 K and 2700 K. Disappearance of sodium caused by the electrode material is prevented in this manner.