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:
Dec. 09, 2014
Filed:
Oct. 29, 2013
Richtek Technology Corp., Hsinchu County, TW;
Chih-Feng Huang, Hsinchu County, TW;
Kuo-Chin Chiu, Hsinchu County, TW;
Richtek Technology Corp., Zhubei, Hsinchu County, TW;
Abstract
An LED driving device includes: a rectifying circuit for outputting a DC voltage to a string of M LED units; (M−1) first switching circuits each coupled between a corresponding one of first to (M−1)LED units and ground; and a second switching circuit coupled between an MLED unit and ground. When the DC voltage is sufficient to turn on first to kLED units, where 1≦k≦M, the kLED unit is coupled to ground through first and second conductive paths provided by a resistor unit, and a corresponding first switching circuit or the second switching circuit, and each of the first to (k−1)LED units is coupled to ground through a third conductive path provided by a corresponding first switching circuit and the resistor unit.