Patent ID: 6778242
Filing Date: 2004-08-17
Classification: C09K,G02B,G02F

Abstract:
An optical compensatory sheet comprising a cellulose acetate support comprising cellulose acetate, and an optically anisotropic layer containing a discotic liquid crystal molecule, wherein the cellulose acetate support has a Bth550 birefringence defined by the following formula in the range of 0.0007 to 0.004:Bth550={(nx+ny)/2}âˆ’nz in which each of nx and ny is a principal refractive index measured by light of 550 nm in plane of the support; and nz is a principal refractive index measured by light of 550 nm along a thickness direction of the support, wherein the cellulose acetate support has a thickness in the range of 40 to 120 &mgr;m, wherein the cellulose acetate support contains a compound having at least two aromatic rings, the compound being present in an amount of 0.3 to 20 weight parts based on 100 weight parts of the cellulose acetate, and wherein the compound having at least two aromatic rings has a plane of a &pgr; bond of at least seven carbon atoms and has a molecular weight in the range of 300 to 800.