Patent ID: 9541691
Date: 2017-01-10
CPC Classifications: G02B

Claim:
1. An optical film having a first phase difference layer and a second phase difference layer, wherein the second phase difference layer has an optical property represented by formula (3) and the optical film has optical properties represented by formulae (1), (2) and (30): wherein, Re(450) represents the in-plane phase difference value at a wavelength of 450 nm, Re(550) represents the in-plane phase difference value at a wavelength of 550 nm, Re(650) represents the in-plane phase difference value at a wavelength of 650 nm, and Rth(550) represents the phase difference value in thickness direction at a wavelength of 550 nm, nx represents a principal refractive index in a direction parallel to the film plane in an index ellipsoid formed by the second phase difference layer, ny represents the refractive index in a direction parallel to the film plane and orthogonally-crossing the direction of nx in an index ellipsoid formed by the second phase difference layer, and nz represents the refractive index in a direction vertical to the film plane in an index ellipsoid formed by the second phase difference layer.