Patent ID: 7604362

Claim:
A backlight apparatus having at least an optical unit, the optical unit comprising: a first light source for emitting a first primary color light; a second light source for emitting a second primary color light; a third light source for emitting a third primary color light; a first mirror surface body for reflecting the first primary color light and/or transmitting other primary color light; a second mirror surface body for reflecting the second primary color light and/or transmitting other primary color light; a third mirror surface body for reflecting the third primary color light and/or transmitting other primary color light; wherein the first, mirror surface body transmits a first polarized wave and reflects a second polarized wave; wherein the second mirror surface body transmits the second polarized wave reflected by the first mirror surface body; and a polarization converting device for converting the second polarized wave reflected by the second mirror surface body into the first polarized wave; wherein a polarized wave to be emitted is emitted aligned with the first polarized wave; and a color mixing means that mixes each of the color light transmitted through the first, second and third mirror surface bodies and emits white light.