Patent ID: 7019130
Filing Date: 2006-03-28
Classification: G02B,G02F

Abstract:
1. A cellulose acetate film comprising cellulose acetate having an acetic acid content of 59.0 to 61.5%, wherein the film has a Re retardation value defined by the following formula (I) in the range of 0 to 20 nm, a Rth retardation value defined by the following formula (II) in the range of 30 to 70 nm, and a thickness in the range of 10 to 70 μm: in which nx is a refractive index along the slow axis in the film plane; ny is a refractive index along the fast axis in the film plane; nz is a refractive index along the depth of the film; and d is the thickness of the film in terms of nm, and wherein the film is a biaxially stretched film.