| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable effectively a light beam proceeding backward to direct forward out of the light beams emitted from a light source. <P>SOLUTION: An illumination optical system has a light source 2, and an optical member 3 made of a transparent body placed on the opposite side to the light irradiation side (on the back side) of the light source. The optical member has a refraction surface 3a into which the light from the light source goes, and a reflection surface 3b which reflects the light from the refraction surface toward the light irradiation side. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
