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:
May. 05, 1998
Filed:
Sep. 10, 1996
Applicant:
Inventor:
Peter Michael Tyler, Woodmancote, GB;
Assignee:
Smiths Industries Public Limited Corporation, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F / ;
U.S. Cl.
CPC ...
315291 ; 315330 ; 315 60 ; 315D / ; 315D / ; 313607 ; 313594 ;
Abstract
A fluorescent discharge lamp has two glow mode electrodes wound around it in a helical fashion. One circuit drives the main electrodes at opposite ends of the lamp at high levels of brightness. Another circuit drives the glow mode electrodes at low levels of brightness, at about 10MHz. At intermediate levels of brightness, both the main electrodes and the glow mode electrodes are driven, the two sets of electrodes being driven for alternate on and off periods with the glow mode electrodes being on when the main electrodes are off and the glow mode electrodes being off when the main electrodes are on.