Projection type display apparatus

1. A projection type display apparatus comprising:

an illumination light source device;

an image display element;

an illumination optical system having a plurality of optical elements for illuminating the image display element with light from the illumination light source device; and

a projection lens for enlarging an optical image formed by the image display element and for projecting the enlarged image;

wherein the illumination optical system has first array lens and second array lens each of which has a plurality of lens elements having a plurality of rectangular shape openings and arranged in a matrix form,

wherein the illumination light source device has one or more light sources having a polarization degree not smaller than 50%, one or more polarizers for transmitting one type polarized light and for reflecting other type polarized light, and one or more polarization conversion elements;

wherein at least one set of the light sources is arranged so that polarization directions of light fluxes having high polarization degrees are optionally perpendicular to each other, the light fluxes are combined by the polarizer, polarization directions of the combined light fluxes are changed and aligned by the polarization conversion element; and

wherein two sets of the illumination light source devices are provided, the polarization directions of the light fluxes changed and aligned by the polarization conversion element are perpendicular to each other, the light fluxes are combined by the polarizer provided in a subsequent stage of the two sets of illumination light source devices, the light fluxes are condensed to a single region by a light-flux condensing means, and then directed toward another illumination optical system located in a subsequent stage.

2. A projection type display apparatus comprising:

an illumination light source device;

an image display element;

an illumination optical system having a plurality of optical elements for illuminating the image display element with light from the illumination light source device: and

a projection lens for enlarging an optical image formed by the image display element and for projecting the enlarged image,

wherein means for condensing light fluxes from the illumination light source device is provided, the light fluxes are condensed by the light-flux condensing means to an opening on an incident side of a light tunnel having four reflection surfaces, the light fluxes exiting from an opening on the incident side of the light tunnel are projected by an lens element onto an optical modulating means for modulating an intensity of its incident light in response to an image signal;

wherein the illumination light source device has one or more light sources having a polarization degree larger than 50%, one or more polarizers for transmitting one type polarized light and for reflecting other type polarized light, and one or more polarization conversion elements;

wherein at least one set of the light sources is provided so that directions of light fluxes having high polarization degrees are optionally perpendicular to each other, the light fluxes are combined by the polarizer, polarization directions of the combined light fluxes are changed and aligned by the polarization conversion element; and

wherein two sets of the illumination light source devices are provided, polarization directions of the aligned light fluxes are changed to be perpendicular to each other by the polarization conversion element, the light fluxes are combined by the polarizer provided in a subsequent stage of the two sets of the illumination light source devices and condensed by light-flux condensing means to a single region, and then directed toward another illumination optical system located in a subsequent stage.

3. A projection type display apparatus according to claim 1 , wherein the light source is a laser.

4. A projection type display apparatus according to claim 2 , wherein the light source is a laser.