| 摘要 |
PROBLEM TO BE SOLVED: To provide a retardation film excellent in travelling property, processability, and product reliability.SOLUTION: The retardation film comprises a stretched polymer film and satisfies the following formulae (1) to (3): (1) 0.70<Re[450]/Re[550]<0.97; (2) 1.5×10<Δn<6×10; and (3) 1.13<NZ<1.50. In the formulae, Re[450] and Re[550] represent in-plane retardation values of the retardation film measured at 23°C using light at a wavelength of 450 nm and light at a wavelength of 550 nm, respectively; Δn represents an in-plane birefringence equal to nx-ny, where nx and ny represent refractive indexes in a slow axis direction and a fast axis direction of the retardation film, respectively; and NZ represents a ratio of a thickness-direction birefringence equal to nx-nz, where nz represents a refractive index in a thickness direction of the retardation film, to the in-plane birefringence equal to nx-ny.SELECTED DRAWING: None |
