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:
Jan. 20, 2009
Filed:
May. 16, 2006
Applicants:
Kotaro Matsui, Shizuoka, JP;
Tomoyuki Ichikawa, Shizuoka, JP;
Soichi Yagi, Shizuoka, JP;
Inventors:
Assignee:
Koito Manufacturing Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05F 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A discharge lamp lighting circuitincludes a direct current-alternating current converting circuit, a starting circuit, controlling meansfor controlling power, switching elementsH,L driven by the controlling meansand a series LC resonance circuit (). A frequency modulating circuit is provided for restraining acoustic resonance by modulating a frequency of driving the switching element. When a basic frequency related to the drive frequency is equal to or higher than 1 MHz, a modulation width is set to be equal to or higher than 20 kHz.