Patent ID: 7535531

Claim:
A birefringent optical film comprising: at least one birefringent A-layer; and at least one birefringent B-layer, wherein the birefringent optical film is capable of being used for viewing-angle compensating films for VA mode liquid crystal displays, the birefringent A-layer has a property satisfying ny a >nz a >nx a and the birefringent B-layer has a property satisfying nx b >ny b >nz b , the birefringent B-layer is formed of a polymer exhibiting positive birefringence, and an in-plane retardation of the birefringent optical film has reciprocal wavelength dispersion characteristics, where nx a , ny a and nz a respectively represent refractive indices in an X-axis direction, a Y-axis direction, and a Z-axis direction in the birefringent A-layer, with the X-axis direction being an axial direction that is the same as a below-mentioned X-axis direction of the birefringent B-layer, the Y-axis direction being an axial direction that is the same as a below-mentioned Y-axis direction of the birefringent B-layer, and the Z-axis direction being a thickness direction perpendicular to the X axis and the Y axis, and nx b , ny b and nz b respectively represent refractive indices in the X-axis direction, the Y-axis direction, and a Z-axis direction in the birefringent B-layer, with the X-axis direction being an axial direction exhibiting a maximum refractive index within a plane of the birefringent B-layer, the Y-axis direction being an axial direction perpendicular to the X axis within the plane, and the Z-axis direction being a thickness direction perpendicular to the X axis and the Y axis.