Patent ID: 6891589

Claim:
A laminated optical film comprising: an optical film ( 1 ) whose three dimensional refractive index is controlled so that an Nz coefficient represented with Nz=(nx 1 −nz 1 )/(nx 1 −ny 1 ) satisfies a relationship of Nz≦0.9, when a direction where a refractive index in a film plane gives maximum is defined as X-axis, a direction perpendicular to X-axis as Y-axis, a thickness direction of the film as Z-axis, and refractive indexes in each axial direction are defined as nx 1 , ny 1 , and nz 1 , respectively, an optical film ( 2 ) that is formed with a material showing optically negative uniaxial property, and being tilting aligned, and an optical film ( 3 ) that satisfies nx 3 >ny 3 ≈nz 3 and demonstrates optically positive uniaxial property, when a direction where a refractive index in a film plane gives maximum is defined as X-axis, a direction perpendicular to X-axis as Y-axis, a thickness direction of the film as Z-axis, and refractive indexes in each axial direction are defined as nx 3 , ny 3 , and nz 3 , respectively.