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:
Aug. 03, 1993
Filed:
Dec. 10, 1991
Applicant:
Inventors:
Jean J Heuvelmans, Eindhoven, NL;
Franciscus A Ligthart, Eindhoven, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ;
U.S. Cl.
CPC ...
313491 ; 313492 ;
Abstract
A low-pressure mercury vapour discharge lamp having a tungsten coil electrode which is supported at either end by a respective current supply wire and which has emitter-coated central turns and, on either side thereof, end turns which are free from emitter. Each of the current supply wire ends with adjoining end turns of the coil is surrounded by an electrically insulating sleeve, such as a glass tube, as a result of which the switching life of the lamp is considerably increased.