Patent ID: 7755730
Filing Date: 2010-07-13
Classification: G02B,G02F

Abstract:
1. An optical compensation film having thickness d 1 (nm), and mean refractive indices nx, ny and nz respectively in the directions of x-axis, y-axis and z-axis orthogonal to each other, nx and ny being in-plane main mean refractive indices in parallel with the surface of said optical compensation film, where ny<nx, with nz being a depth main mean refractive index, and having Re/Rth(450 nm), a ratio of Re to Rth measured at 450 nm, 0.6 to 0.8 times as large as Re/Rth(550 nm) at 550 nm, and having Re/Rth(650 nm) at 650 nm 1.05 to 1.9 times as large as Re/Rth(550 nm) at 550 nm, Re being in-plane retardation defined as Re={(nx−ny)xd 1 }, and Rth being depth retardation defined as Rth=[{(nx+ny)/2−nz}xd 1 ], and wherein Re(550 nm) is from 20 to 110 nm.