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:
Aug. 23, 2011
Filed:
Mar. 06, 2009
Ching-wei Hsueh, Sinshih Township, Tainan County, TW;
Kuan-jen Tseng, Sinshih Township, Tainan County, TW;
Ching-Wei Hsueh, Sinshih Township, Tainan County, TW;
Kuan-Jen Tseng, Sinshih Township, Tainan County, TW;
Himax Analogic, Inc., Tainan County, TW;
Abstract
A LED circuit is provided. The LED circuit comprises: an inductor, a group of LEDs, a power MOS and a switching circuit. The switching circuit comprises: an error amplifier generating an error output, a PWM, a RC circuit and a control means. The PWM generates a switching signal according to the error output to control the power MOS to charge or discharge the group of LEDs; the RC circuit comprises at least one first capacitor each comprising a switch, at least one second capacitors; and a resistive means connected in series between the first and the second capacitors and the error output. The control means generates a control signal according to the dimming signal to turn on the switches to activate the first capacitors during the active period of the dimming signal and turn off the switches to deactivate the first capacitors during the inactive period of the dimming signal.