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:
Nov. 08, 2011
Filed:
Oct. 16, 2007
Sang Gil Lee, Seoul, KR;
Tae Seok Jang, Seoul, KR;
Sang Hoon Lee, Yongin-Si, KR;
Abstract
An 'LED' driving circuit comprises an 'LED' driving voltage generator which generates an “LED” driving voltage, a pulse width modulation (“PWM”) control unit which outputs a “PWM” signal having a predetermined duty ratio, and a main switching unit which controls the driving voltage applied to the “LEDs” in accordance with the “PWM” signal. Further, the “PWM” control unit comprises a controller including an error amplifier which detects an error between a reference voltage and a driving voltage and amplifies the detected error, an oscillator which outputs a pulse signal having a predetermined oscillation frequency, and a comparator which compares the pulse signal output from the oscillator with an output voltage from the error amplifier to generate a “PWM” signal; and a high frequency damper connected to the main switching unit to prevent malfunction of the controller due to noise. A backlight unit and liquid crystal display incorporate the “LED” driving circuit.