Ferroelectric liquid crystal display apparatus and method of making it
US5717418A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1994 |
| Grant date | Feb 10, 1998 |
| Priority date | — |
| Expiry date | Aug 30, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/2014
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A new and improved ferroelectric liquid crystal display system having a matrix structure of pixel elements each including a transistor active switching device and a ferroelectric cell. Each switching device is coupled to an individual storage capacitor which is charged during each row select time when the switching device is activated, and which is discharged during each frame time when the switching device is deactivated. A plurality of multi-level or analog column drivers supply selected drive currents to charge individually the storage capacitors of a row of pixel elements to desired initial voltage levels corresponding to desired gray scale levels for the pixel elements during a row select time to maintain the liquid crystal pixel images for lengths of time proportional to the initial charge levels of the capacitors, which discharge until their individual voltages reach a threshold voltage within predetermined discharge times during one frame time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.