Liquid crystal devices and systems using such devices
US4848877A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 1987 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Sep 29, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/48
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A liquid crystal device which uses parallel transparent plates having a nematic crystal material which is free of chiral or twisting additives positioned therebetween. The device applies an AC carrier modulated signal to establish an electric field across the material, the modulation level thereof controlling the state of the directors thereof over a range from a selected partially driven state to a fully driving state. The device can be used in a system to measure and to control the retardance of the device and in systems for controlling the intensity of light being transmitted through the device. The devices can further be used in a system to provide a birefringent filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.