Patent ID: 10709320

Abstract:
An illumination optical system according to the present invention is provided with: an illumination-light guiding portion configured to guide illumination light emitted from a light source portion; and an illumination-light deflecting portion configured to emit the illumination light guided thereto by the illumination-light guiding portion after deflecting the illumination light by means of reflection, wherein, in one cross-section along a direction in which the illumination light travels, the illumination-light guiding portion has a pair of total reflection surfaces in which the distance therebetween gradually increases in a forward traveling direction of the illumination light, and the illumination-light deflecting portion is provided with an emission surface from which the illumination light guided by the illumination-light guiding portion is emitted, and a reflection surface that has a convex shape facing the emission surface and that reflects the illumination light guided by the illumination-light guiding portion toward the emission surface.