Patent ID: 8231226
Filing Date: 2012-07-31
Classification: G03B

Abstract:
1. An illumination optical system, comprising: a light source which includes a plurality of light emitting sections arrayed in a specific direction; an integrator which includes a plurality of lens cells arrayed in the specific direction, wherein the integrator has a first lens array and a second lens array, the first lens array including a first plurality of lens cells, the second lens array including a second plurality of lens cells, each lens cell included in the first lens array and each lens cell included in the second lens array being provided so as to be counterpart to each other; and an overlapping optical system configured to overlap, on a plane to be illuminated, a plurality of light beams emitted from the light source and passed through the integrator, wherein the illumination optical system illuminates the plane to be illuminated with a light beam emitted from each of the plurality of light emitting sections and passing through the integrator and the overlapping optical system, wherein a plurality of light beams from the plurality of light emitting sections enter an incident surface of the integrator with a shift from each other in the specific direction, as divergent light beams in the specific direction, and wherein two light beams from two light emitting sections adjacent to each other among the plurality of light emitting sections are overlapped with each other in a region larger than one of the lens cells on the incident surface of the integrator.