Liquid crystal light valve method and apparatus using right and left-handed twist cholesteric liquid crystal
US4688901A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1984 |
| Grant date | Aug 25, 1987 |
| Priority date | — |
| Expiry date | Jun 11, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A liquid crystal light valve is provided which either reflects or transmits all wavelengths of light. Micron size cholesteric liquid crystal micelles are formed by adding a chiral molecule dopant to a nematic liquid and dispersing into a polymeric solution. The chiral dopant twists the micelle into a helical planar order along a helical axis. The interior structure of the micelle is a series of concentric spheres, the distance between the envelopes of which is the pitch. The pitch of the helical planar order of the micelles is adjusted by varying the concentration of chiral molecules which have been added to the nematic liquid. The sense of the helical planar order of the micelles is controlled and the micelles are dispensed in an inert polymeric binder forming a film which may be applied to a surface for controlling the light applied thereto either passing or reflecting the light depending on the temperature of the film. The light valve is controlled in one way by controlling the right and left hand sense of the helical planar order of the micelles by adding equal amounts of chiral dopants which have right and left handed orders.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.