Patent ID: 7288296

Claim:
A multilayer compensator comprising one or more polymeric first layers and one or more polymeric second layers, where at least one of the one or more polymeric first layers and at least one of the one or more polymeric second layers, are contiguous, wherein: said first layers comprise a polymer having an out-of-plane birefringence (Δn th ) not more negative than −0.01 and not more positive than +0.01; said second layers comprise an amorphous polymer having an out-of-plane birefringence more negative than −0.01 or more positive than +0.01; wherein the term “amorphous” means that the polymer does not show molecular order as measured by X-ray diffraction; the overall in-plane retardation (R in ) of said multilayer compensator is greater than 20 nm, and the out-of plane retardation (R th ) of said multilayer compensator is either: (a) more negative than −20 nm , in which case at least one second layer includes a polymer containing in the backbone a non-visible chromophore group and has a glass transition temperature (T g ) above 180° C. without containing a non-visible chromophore off the backbone, or (b) more positive than +20 nm, in which case at least one second layer includes a polymer which contains off the backbone a non-visible chromophore group and has a glass transition temperature above 160° C.; and wherein the in-plane retardation of said one or more first layers is 30% or less of the overall in-plane retardation of said multilayer compensator.