Multi-layered compensation film using specified Tg material as a birefringent layer
US7479309B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 2005 |
| Grant date | Jan 20, 2009 |
| Priority date | — |
| Expiry date | Sep 15, 2026 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2323/031
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A multilayer compensator includes one or more polymeric first layers and one or more polymeric second layers. The first layers comprise a polymer having an out-of-plane birefringence between −0.005 and +0.005. The second layers comprise an amorphous polymer having an out-of-plane birefringence that is either less than −0.005 or greater than +0.005. The overall in-plane retardation of the multilayer compensator is greater than 20 nm, and the out-of-plane retardation is more negative than −20 nm or more positive than +20 nm. The amorphous polymer of the second layer(s) has a glass transition temperature (Tg) such that 110° C.≦Tg≦180° C. when the Rth of the multilayer compensator is more negative than −20 nm, and 100° C.≦Tg≦160° C. when the Rth of the multilayer compensator is more positive than +20 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.