Illumination optical system and image projector including the same

摘要

An illumination optical system capable of reducing nonuniformity in an intensity distribution on a surface to be illuminated (400) is provided. The illumination optical system of the present invention is an illumination optical system for illuminating the surface to be illuminated with a beam from a light source (100). The illumination optical system includes a first beam splitting unit (201) and a second beam splitting unit (202) for splitting the beam from the light source into a plurality of beams. The second beam splitting unit (202) has a plurality of minute optical elements which are one-dimensionally arranged in a predetermined arrange direction (Y). Two of the plurality of minute optical elements have refractive powers different from each other in a direction perpendicular (X) to the predetermined arrange direction.