| 摘要 |
PROBLEM TO BE SOLVED: To provide a back light which is capable of attaining stable and higher luminance regardless of viewing directions. SOLUTION: This back light is constituted by arranging a resin sheet which is formed with a prism array 12 on one surface of a resin sheet, is formed smooth 14 at the other surface and of which the vertexes (a) of the sectional shapes of the respective prisms of the prism array 12 are 50 to 60 deg. and the angle (Θ1 ) formed by the normal from the vertexes (a) and the prism surface is 10 to 30 in such a manner that the prism face thereof faces a scattering light transmission plate. The scattering light transmission plate formed by dispersing a transparent dispersion material into a transparent resin material is used. |
