| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light transmission plate or a surface light source device in which the brightness characteristic of a light-emitting surface is improved. <P>SOLUTION: A light beam emitted from a point light source 16 is made incident from an incident plane 14c formed at an angle section CN1 formed by sides 14a, 14b and is then emitted from an upper surface 14f. A prism Pr extended in a circular arc shape is formed on the upper surface 14f to connect the side 14a and the side 14b with the angle section CN1 as a center point. <P>COPYRIGHT: (C)2003,JPO |
