Addressing device and method for rapid video response in a bistable liquid crystal display
US5699074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1995 |
| Grant date | Dec 16, 1997 |
| Priority date | — |
| Expiry date | Mar 24, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2310/06
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A front-lit, non-gray scale liquid crystal display device (10) including a polymer stabilized cholesteric liquid crystalline material has two optical states stable in the absence of an electric field. In a reflecting optical state incident illumination is directly reflected by the liquid crystal, producing a light pixel. In a scattering optical state incident illumination is absorbed by a black surface on the rear of the display, producing a dark pixel. A method employing a plurality of display control signals having the same polarity and differing phase relationships permits the fast video response of the display, notwithstanding that the average time to switch from a scattering optical state to a reflecting optical state is about 30 milliseconds, requiring about fifteen seconds to update a typical 480-row liquid crystal display using conventional array sequencing techniques. Several routines are presented for determining when to update such a display for a variety of applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.