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:
Oct. 26, 2004
Filed:
Feb. 21, 2002
Thomas F. Soules, Richmond Heights, OH (US);
Igor V. Lisitsyn, Chagrin Falls, OH (US);
Zsolt Buday, Godoll, HU;
General Electric Company, Schenectady, NY (US);
Abstract
A fluorescent lamp ( ) with improved life is formed by winding a coil ( ) using first, second, and third mandrels ( ), the third mandrel having a diameter of at least 1.0 mm. The coil is wound around the second mandrel to provide at least 80 turns per inch (TPI). The third mandrel is larger than in conventional coils, allowing about 50% more emitter material ( ) than can be loaded on a conventional coil. This has been found to lead to substantially increased lamp life, about 50% longer for a diameter of 1.25 mm than for a coil with diameter of about 0.86 mm. Increasing the TPI of the second coil over that of a coil having a TPI of 60-70 also increases the lamp life by providing better retention of the emitter material. By combining both the increased third diameter with increased second coil TPI, lifetimes of about twice that of a corresponding conventional coil may be achieved.