Patent ID: 9696475
Date: 2017-07-04
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), the second phase difference layer has a thickness of 0.2 μm to 2.0 μm, and further, the optical film has optical properties represented by formula (1) and formula (2): wherein, Re(450) represents an in-plane phase difference value at a wavelength of 450 nm, Re(550) represents an in-plane phase difference value at a wavelength of 550 nm, and Re(650) represents an in-plane phase difference value at a wavelength of 650 nm, nx represents a principal refractive index in a direction parallel to the film plane in an index ellipsoid formed by a second phase difference layer, ny represents a refractive index in a direction parallel to the film plane and orthogonally-crossing the direction of the principal refractive index in an index ellipsoid formed by a second phase difference layer, nz represents a refractive index in a direction vertical to the film plane in an index ellipsoid formed by a second phase difference layer.