| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface light source device in which luminance unevenness in a region in the vicinity of the light incident end surface of a light guide body is hardly visually recognized and a specific light emission in the inclined direction in the vicinity of the light incident end surface is little, accompanying the thinning of the light guide body. <P>SOLUTION: The surface light source device is equipped with a primary light source 1, a light guide body 3 that guides light emitted from this, and a light deflection element 4 arranged on the light outgoing surface 33. The light incident end surface 31 of the light guide body has the average inclination angle in thickness direction of the light guide body of 3° or more and 12° or less obtained based on a super-depth shape measuring microscope, a ratio of component of inclination angle of 20° or more in the inclination angle distribution of 40 % or less, the center-line average roughness Ra in the thickness direction of the light guide body of 0.2 μm or more and 0.4 μm or less, and the 10-point average of roughness height Rz in the thickness direction of the light guide body of 0.7 μm or more and 2.0 μm or less. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
