Method and apparatus for driving ferroelectric liquid crystal optical modulation device for providing a gradiational display
US4938574A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1987 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | Aug 17, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/0209
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical modulation device, such as a ferroelectric liquid crystal device, comprises a matrix of pixels arranged in a plurality of rows and a plurality of columns, pixels on each row being electrically connected to a scanning electrode and pixels on each column being electrically connected to a signal electrode. The optical modulation device is driven by a method comprising, in a scanning selection period applying a scanning selection signal to a selected scanning electrode, the scanning selection signal comprising plural voltage levels including a maximum value .vertline.Vs.max.vertline. in terms of an absolute value with respect to the voltage level of a non-selected scanning electrode, and applying in phase with the scanning selection signal a voltage signal comprising plural voltage levels to a signal electrode so as to apply to a pixel on the selected scanning electrode plural pulse voltages including a maximum value voltage .vertline.Vmax.vertline. and a minimum pulse voltage .vertline.Vmin.vertline. respectively in terms of an absolute value, satisfying the relationship of: EQU .vertline.Vmax.vertline.-.vertline.Vmin.vertline..ltoreq..vertline.Vs.max.v ertline..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.