Portable computer system and controlling method thereof
US6963329B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 21, 2002 |
| Grant date | Nov 8, 2005 |
| Priority date | — |
| Expiry date | Jan 28, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2360/16
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A portable computer system comprises a main body and an LCD apparatus having an LCD panel and a back light for illuminating the LCD panel. The system further comprises: a DC/AC inverter for supplying AC power to the back light; a contrast sensing part for sensing contrast of a video signal displayed on the LCD panel; a DC converter for converting a PWM signal outputted from the contrast sensing part into a DC signal; a voltage controller causing the DC signal from the DC converter to be appropriate for an operating voltage of the DC/AC inverter so as to supply the operating voltage to the DC/AC inverter; and a controller for sensing the operating voltage of the DC/AC inverter, and for controlling the voltage controller on the basis of the operating voltage. With this configuration, the brightness of a back light can be automatically controlled according to a contrast sensed by a contrast sensing part regardless of the input impedance of the inverter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.