Patent ID: 7161740
Filing Date: 2007-01-09
Classification: G02B

Abstract:
1. A projector, comprising: an illumination system that includes a light source device that emits a substantially parallel illumination light beam to a side of an illuminated region, a first lens array that has plural small lenses that divide the illumination light beam emitted from the light source device into a plurality of partial light beams, a second lens array that has plural small lenses corresponding to the plural small lenses of the first lens array, a polarization conversion element that converts into a polarized light an unpolarized light included in the illumination light beam emerging from the second lens array, and a superposition lens that superimposes the partial light beams emerging from the polarization conversion element on one another in the illuminated region; an electro-optic modulator that modulates the illumination light beam emerging from the illumination system in response to image information; and a projection optical system that projects the illumination light beam modulated by the electro-optic modulator, in order that the illumination light beam emerging from the illumination system is formed to have a cross section shape such as to illuminate all of an image formation region of the electro-optic modulator in one of vertical and horizontal directions of the image formation region and such as to illuminate part of the image formation region in the other direction, the small lenses of the first lens array have a planar shape compressed in the other direction; the projector further comprising between the illumination system and the electro-optic modulator, a scanner that scans the illumination light beam along the other direction, on the image formation region, in synchronism with a frame rate of the electro-optic modulator, the light source device further including a light emitting tube having a light emitting portion, an ellipsoidal reflector that reflects a light emitted from the light emitting portion, a parallelization lens that converts the light reflected off the ellipsoidal reflector into a substantially parallel light, and an auxiliary mirror that reflects the light emitted from the light emitting portion to the illuminated region side onto the light emitting portion, the auxiliary mirror having the shape in which part of its reflective concave surface is removed so that, in the cross section of the illumination light beam on a light incidence surface of the first lens array, a length thereof along the other direction becomes shorter than a length thereof along the one direction.