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. 26, 2013
Filed:
May. 12, 2009
Jun Kumagai, Suita, JP;
Naoki Komatsu, Kobe, JP;
Jun Kumagai, Suita, JP;
Naoki Komatsu, Kobe, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A device includes a direct current power circuit configured to convert an alternating current voltage from an alternating current power source into a direct current voltage, an output unit configured to convert a direct current from the direct current power circuit into a square wave alternating current whose polarity is inverted at a prescribed frequency and to supply the square wave alternating current to a high-pressure discharge lamp, a controller, and an anomaly detector configured to detect an instantaneous voltage drop of the alternating current power source. When the anomaly detector detects the instantaneous voltage drop, the controller switches from a normal lighting mode of controlling the output unit to supply the high-pressure discharge lamp with a square wave alternating current to a lighting maintained mode of controlling the output unit to supply the high-pressure discharge lamp with a square wave alternating current having a lower frequency than the square wave alternating current in the normal lighting mode. In this way, it is possible to maintain lighting of the high-pressure discharge lamp even upon occurrence of an instantaneous power failure, an instantaneous voltage drop, and the like.