Patent ID: 7507470

Claim:
A diffusion sheet, comprising a transparent base sheet, a light-diffusing layer laminated on one surface of the base sheet, and an antiblocking layer laminated on the other surface of the base sheet; wherein the base sheet satisfies Equation 1 below: SR =|( N max −N z )/( N td −N md )|>20 N z ≦1.494 Equation 1 wherein SR is a three dimensional refraction constant of the base sheet, N max is a value greater than either a refractive index of the sheet in a machinery direction or a refractive index of the sheet in a transverse direction, N z is a refractive index of the sheet in a thickness direction, N td is a refractive index of the sheet in a transverse direction, and N md is a refractive index of the sheet in a machinery direction.