Light valves with positive dielectric anisotropy liquid crystal and highly tilted off-perpendicular surface alignment, and associated operating method
US4917472A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1988 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Mar 14, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/135
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A liquid crystal cell useful in light valves is disclosed in which positive anisotropy liquid crystals are installed at an initial off-perpendicular alignment within the approximate range of 6.degree.-45.degree.. A light valve employing the cell is initially biased to a voltage approximately corresponding to a transmissivity peak; the selection of the exact bias voltage involves a trade-off between contrast and response speed. The cell surfaces are characterized by generally flat macrostructures and tilted surface microstructures, with an overcoat on the surfaces of a long chain alcohol with alkoxy groups derived therefrom bonded to the tilted surface microstructure. The alcohol molecules have the formula ROH, where R is a carbon chain having at least six carbon atoms therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.