Projection type image display apparatus for improving illumination of a light source

A projection type image display apparatus comprising:

• a lamp;
• a reflector that reflects a light flux emitted from the lamp;
• a collimation lens that collimates the light reflected by the reflector;
• a light modulation device that modulates the collimated light to output the modulated light;
• and a projection lens that projects the modulated light,
• wherein the reflector is configured to prevent the lamp from being irradiated with the reflected light of the light flux emitted from the lamp,
• wherein the reflector is formed in an aspherical shape such that a focal length is made long with respect to a region that reflects a beam of light passing near the lamp and the focal length is made relatively short with respect to a region that reflects the other beams of light,
• wherein the collimation lens is formed of one biconcave lens having concave surfaces on both an incident side and an exit side of the biconcave lens, and
• wherein the beam of light of the long focal length passes through the concave surface on the exit side of the biconcave lens without passing through the concave surface on the incidence side of the biconcave lens, a portion of the beam of light of the short focal length in the vicinity of an optical axis passes through the concave surfaces on both the incident side and the exit side of the biconcave lens, and a portion of the beam of light of the short focal length around the optical axis passes through the concave surface on the exit side of the biconcave lens without passing through the concave surface on the incidence side of the biconcave lens.