Back lighting source module for liquid crystal display
US6531835B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2000 |
| Grant date | Mar 11, 2003 |
| Priority date | — |
| Expiry date | May 6, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.