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.

Date of Patent:
Aug. 09, 2016

Filed:

Dec. 17, 2014
Applicant:

Panasonic Intellectual Property Management Co., Ltd., Osaka, JP;

Inventors:

Keisuke Seki, Osaka, JP;

Takeshi Kamoi, Kyoto, JP;

Daisuke Yamahara, Osaka, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 37/02 (2006.01); H05B 33/08 (2006.01);
U.S. Cl.
CPC ...
H05B 33/0818 (2013.01);
Abstract

A lighting device includes a constant-current circuit, a smoothing capacitor, a bypass circuit, a detection unit, and a bypass control unit. The constant-current circuit supplies a constant current to a plurality of solid-state light-emitting elements connected in series. The smoothing capacitor is connected between output terminals of the constant-current circuit. The bypass circuit is connected in parallel to one or more of the plurality of solid-state light-emitting elements. The detection unit detects whether the one or more solid-state light-emitting elements are open-circuited. When the detection unit detects that at least one of the one or more solid-state light-emitting elements is open-circuited, the bypass control unit discharges the smoothing capacitor during a discharge period to then bypass the one or more solid-state light-emitting elements through the bypass circuit.


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