| 摘要 |
PURPOSE: To maintain uniformity of a desired illuminance despite changes in the energy distribution of a luminous flux due to the effect of the luminescent spot movement of a light source by providing, on a light path on the light source side of a fly eye lens, a light scattering plate to uniformize the energy distribution of the luminous flux through light diffusing action. CONSTITUTION: A luminous flux from a light source 1 and diverged from a light source image 22 is converted to a luminous flux having an energy distribution of some degree of uniformity via a light scattering plate 11 and enters a fly eye lens 6. Then, the luminous flux which has entered the fly eye lens 6 is condensed and a multiplicity of secondary light source images of the light source image 22 are formed on its issuing side. After the multiplicity of luminous fluxes formed on the issuing side of the fly eye lens 6 are assembled into a proper form by an aperture stop 7, reflected by a mirror 8, and condensed by a condenser lense 9, they illuminate evenly a surface 10 of an illuminated object in a multi-layer fasion. In this way, the uniformity of a desired illuminance is maintained despite changes in the energy distribution of the fluxes as a result of the luminescent spot movement of the light source. |
