| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical element capable of emitting light in a linear fashion extending in a longitudinal direction like a filament of an incandescent lamp when observed from a side direction, and taking a slim shape extending in an optical axis direction not a lateral direction; and an illumination device thereof. <P>SOLUTION: The optical element 2 includes: an incident surface 3 on which light is incident; a first region 4 which is projected in a conical shape and refracts light into a downward direction to emit it; a second region 5 which is arranged more outside than the incident surface 3, and reflects light into an upward direction in almost parallel to the optical axis; a third region 6 formed by repeatedly and step-wisely connecting, in a plane 12 almost parallel to the optical axis, a plurality of total reflection surfaces 11 which totally reflect light which is upwardly reflected by the second region 5; and a fourth region 7 and fifth region 8 which have surfaces almost parallel to the optical axis. <P>COPYRIGHT: (C)2013,JPO&INPIT |
