Illumination apparatus and projection display apparatus using the same

An illumination device comprising a light source, a first integrator into which light from the light source enters, and a second integrator into which light exiting from the first integrator enters,

• wherein the light source comprises:
• a first light source emitting light of a first color,
• a second light source emitting light of a second color, and
• a third light source emitting light of a third color;
• and
• the first integrator comprises:
• a first integrator for the first light source into which light from the first light source enters,
• a first integrator for the second light source into which light from the second light source enters, and
• a first integrator for the third light source into which light from the third light source enters,
• the device further comprising:
• a first optical thin film that synthesizes light of the first color and light in which light of the second color and light of the third color are color-synthesized, and
• a second optical thin film that synthesizes light of the second color and light of the third color,
• wherein light synthesized by the first optical thin film enters the second integrator.