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:
Nov. 28, 2006
Filed:
Sep. 26, 2003
Jun Kumagai, Kadoma, JP;
Akihiro Kishimoto, Osaka, JP;
Hirofumi Konishi, Hirakata, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
A full bridge circuit including four switching elements (Qto Q) is alternated with a high switching frequency and a series-connected resonance circuit () including an inductor (L) and a capacitor (C) is made to resonate at a switching frequency of the full bridge circuit multiplied by an integer (for example, frequency multiplied by three), thereby generating a high voltage pulse for start up. After a high-pressure discharge lamp (DL) is started up, the full bridge circuit is alternated with a low switching frequency so as to operate as a step-down chopper for inverting the output polarity, thereby stably supplying rectangular wave voltage of low frequency to the high-pressure discharge lamp (DL) via a filter circuit including an inductor (L) and a capacitor (C).