1. A projector, comprising:
an illumination optical system;
an image formation element that spatially modulates light from the illumination optical system; and
a projection lens that projects the spatially modulated light,
wherein the illumination optical system comprises:
a light source that emits light of a first wavelength;
a fluorophore unit including a reflection region reflecting the light of said first wavelength and a fluorophore region including
a fluorophore emitting fluorescent light of a wavelength that differs from said first wavelength by irradiation of the light
of said first wavelength;

an optical element reflecting the light of said first wavelength; and
a quarter-wave plate provided on a light path between said optical element and said fluorophore unit.