Projector having polarization conversion element

A projector, comprising:

• an illumination system that includes a light source device that emits a first luminous flux toward a region to be illuminated;
• a first lens array having a plurality of small lenses that separate the first luminous flux emitted from the light source device into a plurality of first lens array light fluxes;
• a second lens array having a plurality of small lenses corresponding to the plurality of small lenses of the first lens array;
• a polarization conversion element that converts non-polarized light contained in second lens array light fluxes emitted from the second lens array into polarized light;
• and a superposing lens that superimposes individual polarization conversion element light fluxes emitted from the polarization conversion element on a region to be illuminated;
• an electro-optical modulator that modulates a second luminous flux emitted from the illumination system in accordance with image information;
• a projection optical system that projects a third luminous flux modulated by the electro-optical modulator;
• each of the plurality of small lenses in the first lens array having, so as to make the second luminous flux emitted from the illumination system a luminous flux having a sectional shape that illuminates an entirety of an image formation region in one direction of vertical and horizontal directions in the image formation region of the electro-optical modulator and partially illuminates the image formation region thereof in an other direction, a planar shape compressed in the other direction;
• a scanning system that is further disposed between the illumination system and the electro-optical modulator and that scans the second luminous flux along the other direction on the image formation region in synchronization with a frame rate of the electro-optical modulator;
• the light source device emits the first luminous flux diverging with travel toward a region to be illuminated;
• the plurality of small lenses in the first lens array being arranged along the one direction and the other direction;
• the polarization conversion element including a polarized light separating element that splits the second lens array light fluxes into a luminous flux involving a first polarized light component and a luminous flux involving a second polarized light component;
• and a phase plate that converts one of the luminous flux involving the first polarized light component and the luminous flux involving the second polarized light component into an other;
• the polarized light separating element including a plurality of polarized light separating prisms each of which has a polarized light separating surface that allows the luminous flux involving the first polarized light component of two polarized light components transmitting through as it is and reflects the luminous flux involving the second polarized light component in a direction perpendicular to an illumination optical axis;
• and a reflection surface that reflects the second polarized light component in a direction in parallel with the illuminationoptical axis;
• the plurality of polarized light separating prisms being arranged along the one direction;
• and
• polarized light separating surfaces in the plurality of polarized light separating prisms at both ends in one direction of the polarized light separating element being constituted so as to reflect the luminous flux involving the second polarized light component in a direction approaching the illumination optical axis;
• wherein
• in the first lens array, a column in which the plurality of small lenses is arranged along the one direction being arranged in four columns along the other direction;
• the plurality of polarized light separating prisms being arranged in four columns corresponding to columns of the plurality of small lenses in the first lens array;
• and
• in the respective small lenses in the first lens array, in comparison with amounts of eccentricity in the other direction of small lenses in first and fourth columns, amounts of eccentricity in the other direction of small lenses in second and third columns being larger.