Birefringent film with n.sub.x >n.sub.z >n.sub.y, process for producing the same, retardation film, elliptically polarizing plate, and liquid crystal display
US5245456A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1991 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | Oct 23, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2413/13
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A birefringent film in which molecules oriented in a direction parallel to the film plane and molecules oriented in the direction of the thickness of the film are present in a mixed state. Also, a process for producing the birefringent film, which comprises laminating a resin film on one or both sides thereof with a shrinkable film, thereby preparing a laminate, and then heat stretching the laminate, thereby performing stretching treatment of the resin film while imparting to the resin film the ability to shrink in the direction crossing the stretching direction. A retardation film is formed by using at least one birefringent film and has refractive indexes, n.sub.x and n.sub.y, in two directions parallel to the plate plane and crossing each other at right angles and a refractive index, n.sub.z, in the direction of the thickness of the plate, said refractive indexes n.sub.x, n.sub.y, and n.sub.z satisfying the following equation: EQU 0<(n.sub.x -n.sub.z)/(n.sub.x -n.sub.y)<1 provided that n.sub.x >n.sub.y. Also, an elliptically polarizing plate comprises a laminate of the retardation film with a polarizing plate. Additionally, a liquid crystal display comprises a liquid crystal cel…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.