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:
Sep. 13, 2016
Filed:
Jul. 17, 2014
Panasonic Corporation, Osaka, JP;
Hirofumi Konishi, Osaka, JP;
Masanao Okawa, Nara, JP;
Yohei Hayashi, Osaka, JP;
Itaru Onishi, Osaka, JP;
Abstract
A light-emitting element lighting device includes: a step-down chopper circuit which outputs a current that flows to a light-emitting element; a current command circuit which selects between a rated mode for passing a rated current for turning ON the light-emitting element and a detection mode for passing an abnormality detection current, which is smaller than the rated current, for detecting an abnormality in the light-emitting element; a voltage detection circuit which detects a voltage across both ends of the light-emitting element; and a control circuit which causes the step-down chopper circuit to stop outputting the current to the light-emitting element, when the voltage across both ends detected by the voltage detection circuit in the detection mode is lower than or equal to an abnormality detection threshold voltage which is set lower than the rated voltage at the time when the light-emitting element is turned ON.