| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light control plate unit and a surface light source device which are capable of sufficiently and evenly dispersing light from point-like light sources. <P>SOLUTION: A surface light source device comprises a plurality of point-like light sources having predetermined light distribution properties, and first to third light control plates 30<SB POS="POST">1</SB>to 30<SB POS="POST">3</SB>provided in a plate thickness direction. The light control plates comprise respective ridge portions 33<SB POS="POST">1</SB>to 33<SB POS="POST">3</SB>, and each of the light control plates comprises the plural ridge portions each extending in one direction on an upper surface of the light control plate. Extension directions of the ridge portions 33<SB POS="POST">2</SB>and 33<SB POS="POST">3</SB>which are parallel to each other are approximately orthogonal to an extension direction of the ridge portion 33<SB POS="POST">1</SB>. In each of the ridge portions 33<SB POS="POST">1</SB>to 33<SB POS="POST">3</SB>, when an axis line passing through both ends on a cross section surface orthogonal to the extension direction thereof is defined as a u-axis, a contour shape v(u) in a u-v coordinate system satisfies 0.95v<SB POS="POST">0</SB>(u)≤v(u)≤1.05v<SB POS="POST">0</SB>(u). v<SB POS="POST">0</SB>(u) satisfies a formula (1) shown below. (Where w<SB POS="POST">a</SB>represents a width of each of the ridge portions 33<SB POS="POST">1</SB>to 33<SB POS="POST">3</SB>. h<SB POS="POST">a</SB>and k<SB POS="POST">a</SB>represent constant numbers for the ridge portions 33<SB POS="POST">1</SB>to 33<SB POS="POST">3</SB>, respectively.) <P>COPYRIGHT: (C)2012,JPO&INPIT |
