PLANAR LIGHT SOURCE AND NON-LIGHT-EMITTING DISPLAY DEVICE

摘要

PURPOSE: To enhance the luminance of planar light projected from a light- emitting surface by providing a diffuse irregular reflection part so as to make a diffuse irregular reflection area per unit area larger as it goes away from a linear light source on the back surface of a light transmission plate. CONSTITUTION: The surface 12A of the light transmission plate 12 constituted of transparent acrylic resin is a planar surface, and a prism array is formed on the back surface 12B. A dot-like white coating layer 23 is formed as the diffusion irregular reflection surface on the prism array by a silk printing. This layer 23 is formed so that the diffuse irregular reflection area becomes large as the layer 23 goes away from the end face of the cold cathode tube 10 of the light transmission plate 12 in a longitudinal direction or the end face 12E in a short direction. By this constitution, light amount leaked from the back surface 12B of the light transmission board 12 to a reflector 25 side is decreased, and the luminance of the planar light projected from a diffusion board 27 can be enhanced.