Reverse mode microdroplet liquid crystal light shutter displays
US5056898A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 1989 |
| Grant date | Oct 15, 1991 |
| Priority date | — |
| Expiry date | Jul 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13347
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A reverse mode liquid crystal light shutter and display device is field-off transparent and field-on non-transparent (i.e., scattering and/or absorbing). The reverse phase mode is obtained by modification of the surface energy of the polymer which encases liquid crystal droplets via reaction of a surfactant, incorporated inside of the LC droplets during droplet formation, within the inside polymer layer. The reverse phase transparent "off" state is achieved by refractive index matching of the average refractive index (.about.n.sub.o) of the LC droplets at electric field off state with the refractive index of the containing polymer materials and by obtaining appropriate droplet size and shape and polymer surface energy to cause the major axis of the liquid crystal molecule to be oriented perpendicular to the substrate surface. The inner surface layer aligns the liquid crystal molecules in an homeotropic manner in a resultant composite multi-layer microcapsulate with a homogeneous material for the capsule skin. A compressive force, such as obtained by rapid drying or application of external pressure, is used to provide the correct droplet shape and resulting homeotropic alignment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.