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. 06, 2008
Filed:
Dec. 22, 2004
Kazutoshi Suganuma, Toyonaka, JP;
Takashi Kanbara, Ikeda, JP;
Toshifumi Tanaka, Katano, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
In a discharge lamp lighting apparatus, a power supplied to a discharge lamp La through a DC-DC converterand an inverteris controlled depending on detection results of a lamp voltage detection unitand a lamp current detection unit, and in an electrode heating period an alternation time of an output to the discharge lamp when starting actuation of the discharge lamp is set longer than an alternation time in a steady lighting period, and the alternation time in the electrode heating period is increased depending on lowering of a supply power or current to the discharge lamp. Thus, even when a lamp current is suddenly changed, the discharge lamp is prevented from going off at the time of polarity inversion without lowering a life.