Driving circuit for liquid crystal electro-optical device
US4560982A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1982 |
| Grant date | Dec 24, 1985 |
| Priority date | — |
| Expiry date | Jul 30, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/367
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A liquid crystal display device having non-linear characteristics provides uniform quality in a matrix display. In driving rows and columns of picture elements the duty ratio is substantially increased by shortening the time in which the picture element is selected and charged for lighting. Charging time is less than the half frame period divided by the number of columns to be driven in the half frame, and more rows of elements can be driven in the half frame period. The portion of time actually used for charging is designated as a fine scanning period. By modulating the voltage levels across the liquid crystal layer during fine scanning periods when the crystal element is not selected, effective voltage across the picture elements is maintained with little variation regardless of the number of picture elements driven on the same signal line. A gray scale display can be provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.