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:
Mar. 11, 2003
Filed:
Dec. 18, 2000
Jason Chen, Hsinchu, TW;
Peter Liu, Hsinchu, TW;
Ambit Microsystems Corporation, Hsinchu, TW;
Abstract
A back lighting source module for a liquid crystal display comprises a pulse width modulation (PWM) controller for providing a pulse width signal to control output current of a lighting element. A half bridge converter includes two power transistors connected in series. An output is formed in a middle between the two power transistors. The output is controllable by the signal from the PWM controller to perform alternating opening and closing. A resonance circuit generates a sine-wave voltage to empower the lighting element. A feedback circuit includes a resistor. When a load varies, a voltage signal generated between two ends of the resistor of the feedback circuit timely changes a conductive time of the power transistors of the half bridge converter to complete regulation of current passing through the lighting element.