Liquid crystal cell with twist angle from 180 to 270 degrees and twisted optical compensating element
US7019804B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2002 |
| Grant date | Mar 28, 2006 |
| Priority date | — |
| Expiry date | Jan 17, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2202/40
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A liquid crystal display device has a liquid crystal cell, a liquid crystalline substance layer, a pair of polarizers, and an optical compensation element. The twist angle of the liquid crystal cell is set to 180 to 270 degrees. The optical compensation element has a twisted structure twisted in the opposite direction to that of the liquid crystal cell. The difference in the absolute values of the twist angles between the liquid crystal cell and the optical compensation element is from 40 to 100 degrees. The difference in retardation at a wavelength λ=550 nm between the liquid crystal cell and the optical compensation element is from 100 to 250 nm. When the absolute values of the differences in retardation at wavelengths λ of 400 nm and 550 nm between the liquid crystal cell and the optical compensation element are represented by ΔR(400) and ΔR(550), respectively, and the ratio D therebetween is represented by D=ΔR(400)/ΔR(550), D is within the range of 0.5 to 1.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.