Patent ID: 6909480

Claim:
An anisotropic scattering sheet adapted to scatter an incident light in a light-advancing direction and having a light-scattering characteristic F(θ) satisfying the following expression representing a relation between a light-scattering angle θ and a scattered light intensity F over a range of θ=4 to 30°: Fy (θ)/ Fx (θ)>2 wherein Fx(θ) represents the light-scattering characteristic in a direction of an X-axis and Fy(θ) represents a light-scattering characteristic in a Y-axial direction which is perpendicular to the X-axial direction; wherein the light-scattering characteristic Fy(θ) is decreased gradually with increasing the light-scattering angle θ and wherein the light-scattering characteristic satisfies the following expression representing the relation between the light-scattering angle θ and the scattered light intensity F over a range of θ=0 to 30°: 10<Fy(0°)/Fy(30°)<150; and wherein the sheet is composed of a continuous phase comprising a crystalline resin and a dispersed phase particle comprising a noncrystalline resin. which phases are different in refraction index by not less than 0.001 from each other, wherein the mean aspect ratio of the dispersed phase particles is larger than 1 and the major axes of the dispersed phase particles are oriented in the X-axial direction of the film.