Projector

A projector comprising:

• a light source;
• a Fresnel lens group that parallelizes a beam output from the light source;
• a light-incident-side polarizer that transmits the beam that exits out of the Fresnel lens group;
• a light modulator that modulates the beam passing through the light-incident-side polarizer to form a projection image;
• a light-exiting-side polarizer that transmits the beam modulated by the light modulator;
• and
• a projection lens that projects the beam passing through the light-exiting-side polarizer,
• wherein the Fresnel lens group includes a first Fresnel lens having positive power and disposed at a position closest to the light source in the Fresnel lens group, and a second Fresnel lens having positive power and disposed at a position shifted from the first Fresnel lens toward the light modulator,
• a light incident surface of the first Fresnel lens has a Fresnel surface,
• a light exiting surface of the first Fresnel lens does not have a Fresnel surface, and
• an adjustment mechanism that changes an axial distance between the first Fresnel lens and the second Fresnel lens, wherein
• the adjustment mechanism comprises:
• a first frame holding the first Fresnel lens,
• a second frame holding the second Fresnel lens,
• an adjustment screw inserted between the first frame and the second frame, and
• at least one spring disposed around the adjustment screw,
• the adjustment mechanism changes an axial distance between the first Fresnel lens and the second Fresnel lens by adjusting the adjustment screw.