US Patent 7929087 Optical film, polarizing plate, and liquid crystal display device

The present invention provides an optical film which includes at least a first optically anisotropic layer, and a second optically anisotropic layer, wherein the first optically anisotropic layer satisfies the following Expression (1), the second optically anisotropic layer satisfied the following Expression (2), and a slow axis of the first optically anisotropic layer is orthogonal to a slow axis of the second optically anisotropic layer,0≦Re(450)/Re(550)≦0.5   Expression (1)0.95≦Re(450)/Re(550)≦1.05   Expression (2)where Re(λ) represents an in-plane retardation value (unit: nm) of the corresponding optically anisotropic layer measured at a wavelength of λ nm.