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:
Apr. 28, 2009
Filed:
Jun. 04, 2007
Mitsuo Matsushima, Kitasaku-gun, JP;
Mitsuo Matsushima, Kitasaku-gun, JP;
Minebea Co., Ltd., Nagano, JP;
Abstract
There is provided a discharge lamp lighting apparatus including common lines to which the low voltage side outputs of step-up transformers having a plurality of discharge lamps connected thereto are connected, wherein the low voltage side outputs connected to the common lines include two kinds of outputs in an equal number at which respective lam currents are phase-shifted by 180 degrees from each other. The discharge lamp lighting apparatus further includes: malfunction detecting circuits which is composed of sense resistors to sense the lamp currents synthesized on the common lines and comparators to compare with a sense voltage with a predetermined reference voltage, and which outputs a malfunction detecting signal when the sense voltage exceeds the reference voltage; and a protection circuit to stop driving of bridge circuits according to the malfunction detecting signal.