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:
Feb. 11, 2003
Filed:
Nov. 21, 2001
Applicant:
Inventor:
Da Feng Weng, Winchester, MA (US);
Assignee:
Matsushita Electric Works, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 3/702 ;
U.S. Cl.
CPC ...
H05B 3/702 ;
Abstract
A circuit to start an HID lamp in a high-frequency start mode and, after starting, to operate the lamp in a low-frequency operating mode is controlled, during the high-frequency start mode, to drive the lamps with a voltage that includes a high-frequency component to ignite the lamp and a unipolar or bipolar offset component to keep the lamp ignited during a transition from the high-frequency start mode to the low-frequency operating mode.