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:
Dec. 13, 1983
Filed:
Aug. 28, 1980
Cornelis A Jacobs, Eindhoven, NL;
Peter A Tielemans, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A high-pressure sodium vapor discharge lamp contains an electron-emitting material consisting of alkaline earth metals bound to oxygen and tungsten bound to oxygen. It has been found that such lamps of less than 400 W which have either a high Hg/Na ratio or use neon/argon as a starter gas fail prematurely when the alkaline earth metals and tungsten in the electron-emitting material are present in stoichiometric quantities. The free ends of electrodes of lamps according to the invention are wound with tungsten wire. Electron-emitting material comprising carium, strontium and calcium bound to oxygen and tungsten bound to oxygen is disposed in the cavities formed between the tungsten wire turns. The molar ration of the total barium, strontium and calcium bound to oxygen to the tungsten bound to oxygen is between 8 and 50.