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. 12, 2008
Filed:
Dec. 20, 2006
Da-jing Hsu, Taipei County, TW;
Hui-qiang Yang, Taipei County, TW;
Da-Jing Hsu, Taipei County, TW;
Hui-Qiang Yang, Taipei County, TW;
Niko Semiconductor Co., Ltd., Taipei, TW;
Abstract
A feedback and protection circuit is provided for detecting voltage and current of a cold cathode fluorescent lamp (CCFL) of a liquid crystal display (LCD) panel backlight apparatus and integrating all voltage and current input signals to output single current and voltage feedback signals to a PWM controller, so as to stabilize and control the voltage and current of the CCFL and determine whether any detected input signal is abnormal. If any CCFL is short circuited (CCFL is touched by people) or open circuited (CCFL is not lit), an abnormal status protection signal will be produced and sent to the PWM controller to stop all outputs of the backlight apparatus to prevent damages to circuit components or injuries to people. The circuit is designed in an integrated circuit to achieve the effects of reducing the area occupied by the circuit component layout and lowering the overall cost.