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. 30, 1982
Filed:
Sep. 17, 1979
Peter A Tielemans, Eindhoven, NL;
Cornelis A Jacobs, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
High-pressure sodium vapor discharge lamps are used which contain an electron-emitting material consisting of alkaline earth metal bound to oxygen and tungsten bound to oxygen. It has been found that such lamps which have a high Hg/Na ratio, use neon/argon as a starter gas or have powers of less than 400 W fail prematurely when the alkaline earth metal and tungsten in the electron-emitting material are present in stoichiometric quantities (total alkaline earth metal oxide: WO.sub.3 =3). The free ends of electrodes of lamps according to the invention are wound with tungsten wire. Electron-emitting material consisting of strontium bound to oxygen and tungsten bound to oxygen is disposed in the cavities formed between the tungsten wire turns. The molar ratio of the strontium bound to oxygen to the tungsten bound to oxygen is between 3 and 50.