Patent ID: 7286290

Claim:
An optical illumination apparatus comprising: a polarization conversion device for converting light from a light source into light uniformly polarized in a predetermined manner; and an optical integrator system for illuminating a display panel with the light polarized in the predetermined manner, the optical integrator system comprising a first lens array having a first lens cell, and a second lens array having a second lens cell; wherein the polarization conversion device is adapted to split the light from the light source into a first light beam and a second light beam such that the first and second light beams are polarized in different manners, and to convert one of the first and second light beams into light polarized in an identical manner as the other of the first and second light beams; wherein the first and second light beams, after being converted into light polarized in an identical manner, travel along paths at an angle relative to each other and are then integrated together at the position of the first lens array and wherein the first and second light beams pass through the first lens cell and are imaged on the second lens cell; and a color switching device disposed between the polarization conversion device and the optical integrator system, the color switching device adapted to time-divisionally switch colors of the light polarized in the predetermined manner from one color to another among a plurality of predetermined colors.