Patent ID: 7575326

Claim:
A projector comprising: a light source; an optical modulator that modulates a light beam irradiated from the light source in accordance with image information to form an optical image; a projection optical system that projects the formed optical image; and an integrator illuminating optical system that equalizes the light beam irradiated from the light source and uniformly illuminates an image formation area of the optical modulator, the integrator illuminating optical system including: a first lens array having a plurality of first lenses in a plane substantially orthogonal to an optical axis of the light beam irradiated from the light source and dividing the light beam into a plurality of partial light beams by the plurality of first lenses; a second lens array having a plurality of second lenses corresponding to the plurality of first lenses of the first lens array; and a polarization converter disposed on a light beam emitting-side of the first lens array and aligning a polarization direction of the light beam irradiated from the first lens array into a substantially uniform type, the polarization converter includes: at least one polarization separating layer; and at least one reflection layer and a phase layer disposed at a position corresponding to either the polarization separating layer or the reflection layer, the lengthwise direction of the polarization separating layer in a plane substantially orthogonal to the optical axis of the light beam irradiated from the light source being defined as a first direction, the polarization separating layer transmitting light having one polarization direction of an incident light beam and reflecting light having another polarization direction, the polarization separating layer and the reflection layer being alternately arranged in a second direction, the second direction being orthogonal to the optical axis of the light beam irradiated from the light source and the first direction, the reflection layer reflecting the polarized light reflected by the polarization separating layer into a common direction to that of the polarized light passed through the polarization separating layer, the phase layer converting the polarization direction of the incident polarized light into another polarization direction, a focal position in the first direction of the first lens being set in the vicinity of the second lens array in the optical axis direction of the light beam irradiated from the first lens, and a focal position in the second direction of the first lens being set in the vicinity of the polarization converter in the optical axis direction of the light beam irradiated from the first lens.