Patent ID: 8134659

Claim:
An elliptical polarizer comprising at least a first polarizer, a first optically anisotropic layer, a second optically anisotropic layer, and a third optically anisotropic layer, laminated in this order, wherein the first optically anisotropic layer satisfies the following requirements [1] to [3]: 50≦Re1≦500 [1] 30≦Rth1≦750 [2] 0.6 ≦Rth 1 /Re 1≦1.5 [3] wherein Re1 and Rth1 denote the retardation values in the plane and thickness direction of the first optically anisotropic layer, respectively and are defined as Re1=(nx1−ny1)×d1 [nm] and Rth1={(nx1+ny1)/2−nz1}×d1 [nm], respectively wherein d1 indicates the thickness of the first optically anisotropic layer, nx1 and ny1 indicate the main refractive indices in the plane of the first optically anisotropic layer with respect to a light of a wavelength of 550 nm, nz1 indicates the main refractive index in the thickness direction of the first optically anisotropic layer with respect to a light of a wavelength of 550 nm, and nx1>ny1≧nz1; the second optically anisotropic layer satisfies the following requirements [4] and [5]: 0≦Re2≦20 [4] −500 ≦Rth 2≦−30 [5] wherein Re2 and Rth2 denote the retardation values in the plane and thickness direction of the second optically anisotropic layer, respectively and are defined as Re2=(nx2−ny2)×d2 [nm] and Rth2={(nx2+ny2)/2−nz2}×d2 [nm], respectively wherein d2 indicates the thickness of the second optically anisotropic layer, nx2 and ny2 indicate the main refractive indices in the plane of the second optically anisotropic layer with respect to a light of a wavelength of 550 nm, nz2 indicates the main refractive index in the thickness direction of the second optically anisotropic layer with respect to a light of a wavelength of 550 nm, and nz2>nx2≧ny2; and the third optically anisotropic layer satisfies the following requirements [6] to [8]: 100≦Re3≦180 [6] 50≦Rth3≦600 [7] 0.5 ≦Rth 3 /Re 3≦3.5 [8] wherein Re3 and Rth3 denote the retardation values in the plane and thickness direction of the third optically anisotropic layer, respectively and are defined as Re3=(nx3−ny3)×d3 [nm] and Rth3={(nx3+ny3)/2−nz3}×d3 [nm], respectively wherein d3 indicates the thickness of the third optically anisotropic layer, nx3 and ny3 indicate the main refractive indices in the plane of the third optically anisotropic layer with respect to a light of a wavelength of 550 nm, nz3 indicates the main refractive index in the thickness direction of the third optically anisotropic layer with respect to a light of a wavelength of 550 nm, and nx3>ny3≧nz3.