Normally white twisted nematic LCD with positive uniaxial and nebative biaxial retarders having n.sub.x >n.sub.y >n.sub.z
US5859681A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1998 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | May 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2413/14
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A normally white twisted nematic liquid crystal display is provided for outputting improved viewing characteristics which are defined by high contrast ratios and reduced inversion. The display includes both positive and negative retardation films, the negative films being biaxial and defined by n.sub.x >n.sub.y >n.sub.z in certain embodiments where the "z" direction is substantially perpendicular to the film plane and the "x" and "y" directions are substantially parallel to the film plane. By providing the positive and biaxial negative retarders with specific retardation values and/or ratios, improved viewing characteristics are provided. According to other embodiments, a positive and a negative (uniaxial or biaxial) retarder may be provided on only one side of the liquid crystal layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.