| abstract |
A phase difference element that can suppress a change in retardation by tilt in a Z-axis direction has an in-plane retardation R0 and a retardation Rth in a thickness direction that satisfy 0.7×R0≦Rth≦1.3×R0 (R0: |Nx−Ny|×d, Rth: |((Nx+Ny)/2)−Nz|×d, Nx: refractive index in width direction, Ny: refractive index in longitudinal direction, Nz: refractive index in thickness direction, and d: element thickness). |