DIRECTIONAL LIGHT GUIDE PLATE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a directional light guide plate and its manufacturing method by which a surface light source for a large screen having uniform and high luminance is realized. SOLUTION: In the directional light guide plate (A) wherein light made incident from the end surface (a11) is exited from either surface of the upper surface or the rear side surface, also innumerable fine spherical surface shaped grains (a10) are provided in the light exit surface (a13) and prisms are continuously provided in the direction orthogonal to the light incident surface in the opposite surface, diffusion grains patterns on which fine angular grains (a20) are superposed are provided in areas (shown in Fig.) where luminance is relatively reduced in the light exit surface (a13).