Electrooptical liquid crystal system containing dual frequency liquid crystal mixture
US5621552A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1994 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | Feb 28, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/1334
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention relates to an electrooptical liquid crystal system PA1 which contains a dual frequency liquid crystal mixture and a further optically transparent polymeric medium between two electrode layers which optionally may be attached to substrates, PA1 in which the ordinary refractive index of the liquid crystal mixture essentially agrees with the refractive index of the polymeric medium n.sub.m and/or in which the quotient of the mass of the liquid crystal mixture and of the mass of the polymeric medium is 1.5 or more, PA1 which has a reduced transmission in the on-state compared to the off-state, and PA1 which is obtained by polymerization of a composition containing the dual frequency liquid crystal mixture and a precursor of the polymeric medium, characterized in that an electrical field is applied during the curing process which exhibits a frequency below the cross-over frequency of the dual frequency liquid crystal mixture so that the molecules of the dual frequency liquid crystal mixture are aligned essentially into the direction of the electrical field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.