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. 19, 1991
Filed:
Aug. 23, 1989
Applicant:
Inventor:
Andre C Bouchard, Peabody, MA (US);
Assignee:
GTE Products Corporation, Danvers, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ;
U.S. Cl.
CPC ...
313619 ; 313601 ; 313631 ; 313491 ; 315 75 ;
Abstract
A preheat-type fluorescent lamp, such as a negative glow discharge lamp, includes a cathode contained within an evelope and supported by a pair of lead-in wires. A thermal switch is located within the evelope shunting the cathode and electrically coupled to the supporting lead-in wires. Closure of the thermal switch during lamp operation produces a double hot spot on the shunted cathode. As a result, the cathode temperature is lowered sufficiently causing an improvement in the lumen maintenance and life of the lamp.