| 摘要 |
PROBLEM TO BE SOLVED: To provide an illumination device capable of effectively reducing a speckle.SOLUTION: An illumination device (2b) includes: a light source device (7); a uniformizing optical system (10) configured to uniformize the illuminance distribution of light from the light source device on a region to be illuminated; and a diffraction optical element (81) disposed on an optical path between the light source device and the uniformizing optical system, and configured to rotate around a predetermined rotary shaft (81a). The diffraction optical element includes: a first region where first luminance distribution is formed; and a second region disposed at a position different from the first region around the rotary shaft, where second illuminance distribution different from the first illuminance distribution is formed. |
