Patent ID: 9557013
Date: 2017-01-31
CPC Classifications: G03B,H04N

Claim:
1. An illumination optical system, comprising: a first light source configured to emit coherent light having a first peak wavelength that belongs to a wavelength region of visible light; a second light source configured to emit incoherent light having a second peak wavelength that belongs to a wavelength region of visible light; and a dichroic mirror configured to mainly reflect one of the coherent light and the incoherent light while mainly transmitting another one of the coherent light and the incoherent light, and synthesize optical paths of the coherent light and the incoherent light, wherein the dichroic mirror has characteristics in which a first separation wavelength having transmittance of 50% with respect to S-polarized light is smaller than a second separation wavelength having transmittance of 50% with respect to unpolarized light, wherein the first peak wavelength is larger than the first separation wavelength, and wherein the second peak wavelength is smaller than the second separation wavelength.