| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain luminance unevenness of two round belt shapes around white color light at the center of an irradiation face without degrading brightness. <P>SOLUTION: An open end part 27 of a recessed part as a boundary part of a second incident face 21 and a total reflection face 22 is processed into a shape other than a flat face. For instance, an R chamfering process (a process of rounding corners so as a cross section to be a given radius) is applied to a connection part of the open end part 27 and the second incident face 21. Moreover, a first incident face 20 is processed into a shape other than a flat face. For instance, a process of forming a groove part 31 with an arc-shaped cross section is applied to the first incident face 20. <P>COPYRIGHT: (C)2011,JPO&INPIT |
