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:
Jun. 17, 2003
Filed:
Dec. 05, 2001
Applicant:
Inventor:
Jerry M. Kramer, Yorktown Heights, NY (US);
Assignee:
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 3/702 ; H05B 3/904 ;
U.S. Cl.
CPC ...
H05B 3/702 ; H05B 3/904 ;
Abstract
Stable illumination of uniform color and reduced sensitivity to lamp orientation are achieved by driving a high-intensity discharge (HID) lamp with a carrier signal alternated between two VHF frequencies at a modulation rate approximately equal the second longitudinal frequency of the lamp, and feeding the signal through a filter having an inverse amplitude relationship to carrier frequency, to produce an input signal to the lamp that is amplitude modulated in an inverse relationship to the change in carrier frequency at a modulation rate approximately equal to the second longitudinal resonance of the lamp.