Patent ID: 7215839
Filing Date: 2007-05-08
Classification: G02B,G02F

Abstract:
1. An optical film in which a retardation film is laminated on at least one side of a polarizing plate provided with a transparent protective film on at least one side of a polarizer, wherein the retardation film comprises a stretched film of a polymer film containing a norbornene-based resin, wherein the stretched film satisfies the following equation (1) and the equation (2); where the refractive indices in the slow axis direction, the fast axis direction and the thickness direction of the film are nx, ny and nz, respectively, d(nm) is thickness of the film, and the slow axis direction is a direction that the refractive index in film plane is maximum, and wherein the slow axis of the retardation film is parallel or perpendicular to the absorption axis of the polarizer, and wherein the transparent protective film is arranged between the polarizer and the retardation film, and the transparent protective film satisfies the following equation (3) and equation (4); where the refractive indices in the slow axis direction, the fast axis direction and the thickness direction of the film are nx, ny and nz, respectively, d(nm) is thickness of the film, and the slow axis direction is a direction in which the refractive index in film plane is maximum.