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:
Jul. 23, 2013
Filed:
Oct. 30, 2009
Naohito Sato, Tokyo, JP;
Naohito Sato, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
A discharge lamp lighting apparatus has a configuration including a control unit which discriminates, for each polarity of an AC rectangular wave output, the output voltage detected with an output voltage detector for detecting the voltage applied to a discharge lamp, and carries out constant power control for each polarity separately. By thus detecting the output voltage for each polarity separately and by outputting a target current for each identical polarity, it can carry out constant power control positively even if the output voltage varies for each polarity, thereby being able to prevent current feedback to a different polarity, and to prevent power oscillation and partial reduction of electrodes due to an increase of the output voltage difference for each polarity.