Reflection type electrooptical device and a projection type display apparatus using the same
US5105289A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1990 |
| Grant date | Apr 14, 1992 |
| Priority date | — |
| Expiry date | Aug 1, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a reflection type liquid crystal electrooptical device having a twisted nematic liquid crystal sandwiched between two substrates faced to each other, a linearly polarized incident light enters into the liquid crystal layer and after the reflection in the state of a circularly polarized light, enters into the liquid crystal layer again. As to an outgoing light, twisted angle, .DELTA.nd and polarized incident angle are fixed so as to rotate the polarized surface at 90.degree. with respect to that of the incident light (the condition of twist angle of 63.degree., 0.33.lambda..ltoreq..DELTA.nd.ltoreq.0.47.lambda., and twist angle of 193.degree., 0.95.lambda..ltoreq..DELTA.nd.ltoreq.1.15.lambda. (.mu.m) is preferable, wherein the direction of polarizing shaft coincides with the direction of liquid cyrstal molecules.) Whereby, it is possible to use the largest value of .DELTA.nd so that the thick liquid crystal layer can be used and a wide margin for manufacturing can be also secured. Due to the outgoing light as linearly polarized light, light loss can be prevented in comparison with the case of where the outgoing light is an elliptically polarized light. Further, the improved liquid…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.