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:
Jun. 12, 2012
Filed:
Jan. 28, 2009
Shui-mu Lin, Longjing Township, Taichung County, TW;
Tsung-wei Huang, Jubei, TW;
Jien-sheng Chen, Toufen Township, Miaoli County, TW;
Kwan-jen Chu, Hsinchu, TW;
Shui-Mu Lin, Longjing Township, Taichung County, TW;
Tsung-Wei Huang, Jubei, TW;
Jien-Sheng Chen, Toufen Township, Miaoli County, TW;
Kwan-Jen Chu, Hsinchu, TW;
Richtek Technology Corp., Hsinchu, TW;
Abstract
A current regulator includes a first current source to provide a reference current varying with a dimming step, and a second current source to generate a drive current for a white LED according to the reference current. The reference current and the dimming step have a relationship identical to or approximating a relationship between luminance and lightness perceived by human eyes. Thus, the white LED is controlled to have a linear variation of the luminance perceived by human eyes when the dimming step is changed.