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:
Oct. 22, 2013
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 step-up chopper which includes a first switching element and increases an output voltage applied from a DC power supply, a step-down chopper which includes a second switching element and decreases the output voltage from the step-up chopper to apply the decreased output voltage to a light source unit having light emitting diodes, a controller which controls operations of the first and the second switching element, a current limiter which includes a current limiting element and a switch; and a voltage detection unit. The controller stops an operation of the first switching element when the voltage detection unit detects the voltage applied to the light source unit exceeding a predetermined voltage value, and the switch allows a current to flow through the path passing through the current limiting element when the operation of the first switching element is stopped.