| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a plane light source device free from bright lines and damage on a luminance uniformity, even if there is a boundary between structure groups in a light diffusion plate area on which a linear light source is vertically projected. <P>SOLUTION: In the plane light source device 1 provided with a light diffusion plate 30 having a light-incident face 30L and a light outgoing face 30U and a linear light source 10 fitted toward a side of the light-incident face 30L of the light diffusion plate 30, with the light outgoing face 30U equipped with two or more kinds of structure groups 31, 32 containing a plurality of function structure parts with a boundary 35 of the structure groups 31, 32 located at an area 36 of the light outgoing face 30U, where the linear light source 10 is vertically projected, a fine concavo-convex structure 38 with an arithmetic average roughness Ra of 0.1 μm or more and 1.0 μm or less is provided at an area 37 of the light-incident face 30L, where the linear light source 10 is vertically projected. <P>COPYRIGHT: (C)2011,JPO&INPIT |
