Patent ID: 7445341
Filing Date: 2008-11-04
Classification: H04N

Abstract:
1. A microdisplay projection system comprising: a blue LED illuminator; a red LED illuminator; a green LED illuminator; optics for directing light from the blue LED illuminator to a blue LCD image-forming panel, for directing light from the red LED illuminator to a red LCD image-forming panel, and for directing light from the green LED illuminator to first and second green LCD image-forming panels; wherein the blue LCD panel, the red LCD panel, and the first and second green LCD panels are transmissive LCD panels; and wherein the optics comprise: a first polarizing mechanism arranged to provide blue light of a reflecting polarization from the blue LED illuminator through the blue transmissive LCD image-forming panel to yield imaged blue light of a transmitting polarization; a first polarization beam splitter arranged to: a second polarization mechanism arranged to provide red light of the reflecting polarization from the red LED illuminator through the red transmissive LCD image-forming panel to yield imaged red light of the transmitting polarization; a first dichroic prism configured and arranged to transmit the imaged red light of the transmitting polarization and to reflect the imaged green light of the transmitting polarization; a first polarization rotator configured and arranged to rotate the polarization of the imaged red light of the transmitting polarization to the reflecting polarization and to rotate the polarization of the imaged green light of the transmitting polarization to the reflecting polarization; a second dichroic prism configured and arranged to transmit the imaged blue light of the transmitting polarization and to reflect the imaged green light of the reflecting polarization; a second polarization rotator configured and arranged to rotate the polarization of the imaged green light of the reflecting polarization to the transmitting polarization; and a second polarization beam splitter configured and arranged to: reflect the red light of the reflecting polarization from the first polarization rotator toward the projection optics.