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. 22, 2014
Filed:
Dec. 15, 2011
Katunobu Hamamoto, Neyagawa, JP;
Masafumi Yamamoto, Kyoto, JP;
Keisuke Ueda, Hirakata, JP;
Hisaya Takikita, Habikino, JP;
Katunobu Hamamoto, Neyagawa, JP;
Masafumi Yamamoto, Kyoto, JP;
Keisuke Ueda, Hirakata, JP;
Hisaya Takikita, Habikino, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An LED lighting device includes a power converter for outputting a variable output voltage, two LED lamps being connected in series between output terminals of the power converter; a current detector for detecting an output current from the power converter; a first detector for detecting the output voltage of the power converter and generating a first detection voltage corresponding to the output voltage; a second detector for detecting an applied voltage to one of the two LED lamps and generating a second detection voltage corresponding to the applied voltage; and a controller for controlling the power converter to adjust the output voltage to thereby make the output current coincide with a target value. The controller controls the power converter to decrease the output voltage if at least one of the second detection voltage and the deference between the first and the second detection voltage does not fall within a range.