Patent ID: 8500285

Claim:
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.