| 摘要 |
The present invention provides an illumination apparatus, which is capable of applying uniform light beams having a fixed angle distribution as illumination light to obtain illumination having a uniform light distribution. The illumination apparatus, including a light source and an optical member having an incidence surface on which light is made incident and an emission surface through which the light made incident on the incidence surface is emitted as illumination light, the optical member further having a_light direction conversion surface disposed so as to face the emission surface for, while regulating a traveling direction of light made incident on the incidence surface within the optical member, guiding the light to the emission surface, a plurality of prism-like portions each having a total reflection surface and a reincidence surface being continuously formed in the light direction conversion surface, in which, of light which travels within the optical member to reach the total reflection surface of one of the prism-like portions, only light of a predetermined angle component is totally reflected toward the emission surface on the total reflection surface, and light which is not totally reflected by the total reflection surface other than the light of the predetermined angle component is refracted in the one prism-like portion to be guided to an outside of the optical member once and is then guided to the optical member again through the reincidence surface of the prism-like portion next to the one prism-like portion. <IMAGE> |
