LIGHT DIFFUSION LENS SHEET, DIRECT BACKLIGHT USING THE SAME, AND LIQUID CRYSTAL TELEVISION WITH BACKLIGHT INCORPORATED THEREIN

PROBLEM TO BE SOLVED: To provide a light diffusion lens sheet which uses light with high efficiency, allows easy observation of a screen from the front side, makes a light source installation part hardly visible, can reduce occurrence of interference fringes to emit homogeneous light from the whole of the emission face, can reduce the number of components of a backlight, prevents reduction in front luminance even if it is stuck to a diffusion plate, and consequently, can lower production cost without deteriorating optical performance and improve productivity, and to provide a direct backlight and a liquid crystal television using the above light diffusion lens sheet. SOLUTION: The light diffusion lens sheet has a lens surface and a back surface, in which a projection rib line structure is formed, and is formed of a transparent material containing a dispersing agent. On the lens surface, a plurality of prism parts each having a substantially triangle pole shape are arranged at a fixed period so that the major axes of the triangle poles are approximately parallel to each other. On the back surface, the projection rib line structure is arranged at a swing angle of 10-90 degrees to the major axes of the prism parts. The direct backlight and the liquid crystal television use the light diffusion lens sheet. COPYRIGHT: (C)2009,JPO&INPIT