Patent ID: 8031308

Claim:
A uniaxial retardation film having an optical axis out of plane and where extraordinary ray refraction index<ordinary ray refraction index, wherein the retardation film satisfies the following equations (19) to (22): 0 nm≦ Rxy (550)≦10 nm (19) 108 nm≦ Ryz (550)≦379 nm (20) 1.04≦ Rxz (450)/ Rxz (550) (21) Rxz (650)/ Rxz (550)≦0.98 (22), in equations (19) to (22), Rxy(λ), Rxz(λ) represent the retardation Rxy, Rxz of the retardation film at wavelength λnm respectively, and are defined as Rxy=(nx−ny)×d, Rxz=(nx−nz)×d where nx, ny (nx≧ny) are the principal refraction indexes in the in plane direction, nz is the principal refraction index in the out of plane direction, and d is the thickness in the retardation film.