Driving a liquid crystal display
US6717561B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2001 |
| Grant date | Apr 6, 2004 |
| Priority date | — |
| Expiry date | Jan 31, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/041
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention includes methods and apparatus for driving a cholesteric display system using a dynamic drive scheme. The dynamic drive scheme is used to drive the electrodes of the cholesteric display in order to provide desired pixel states. Pixel states are controlled by the voltage applied across the pixel. The present invention uses pulse width modulation (PWM) during the dynamic drive scheme in order to control the voltage applied across the pixels. PWM modulation may be used during any phase (e.g., preparation phase, selection phase, evolution phase, and/or final phase) of the dynamic drive waveform depending on the needs of the cholesteric display system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.