| 摘要 |
PROBLEM TO BE SOLVED: To provide a light diffusion plate capable of further improving the luminance in the front direction when being used for a direct type back light device, and to provide a direct type back light device provided with the light diffusing plate. SOLUTION: In the light diffusing plate 21, at least either face in a light incidence surface 21A and a light emission surface 21B lies in a specular state in which the center line average roughness (Ra(maxl)) measured in a direction at which the obtained value reaches the maximum is 0.0001 to 0.1μm. COPYRIGHT: (C)2007,JPO&INPIT |
