Patent ID: 6384972
Filing Date: 2002-05-07
Classification: G02B,H04N

Abstract:
A projection display for processing a light beam that is to be provided to a projection lens, the light beam including first, second and third color components, said projection display comprising:a dichroic beam splitter adapted to separate the first color component from the second and third color components; a first polarization beam splitter prism disposed adjacent to said dichroic beam splitter so as to receive the first color component therefrom; a second polarization beam splitter prism disposed adjacent to said dichroic beam splitter so as to receive the second and third color components therefrom; a third polarization beam splitter prism disposed adjacent to said first and second polarization beam splitter prisms; a first reflective light valve disposed adjacent to said first polarization beam splitter prism so as to receive the first color component therefrom, said first reflective light valve processing the first color component from said first polarization beam splitter prism by changing polarization state of the first color component when in an active state, and reflecting the first color component back to said first polarization beam splitter prism, said first polarization beam splitter prism providing the first color component processed by said first reflective light valve to said third polarization beam splitter prism; a first light polarization selector disposed between said dichroic beam splitter and said second polarization beam splitter prism for changing polarization state of one of the second and third color components so as to enable said second polarization beam splitter prism to separate the second color component from the third color component; a second reflective light valve disposed adjacent to said second polarization beam splitter prism so as to receive the second color component therefrom, said second reflective light valve processing the second color component from said second polarization beam splitter prism by changing polarization state of the second color component when in an active state, and reflecting the second color component back to said second polarization beam splitter prism, said second polarization beam splitter prism providing the second color component processed by said second reflective light valve to said third polarization beam splitter prism; a third reflective light valve disposed adjacent to said second polarization beam splitter prism so as to receive the third color component therefrom, said third reflective light valve processing the third color component from said second polarization beam splitter prism by changing polarization state of the third color component when in an active state, and reflecting the third color component back to said second polarization beam splitter prism, said second polarization beam splitter prism providing the third color component processed by said third reflective light valve to said third polarization beam splitter prism; a second light polarization selector disposed between said second and third polarization beam splitter prisms for changing polarization state of one of the second and third color components that passes from said second polarization beam splitter prism to said third polarization beam splitter prism; said third polarization beam splitter prism being further disposed so as to direct the first, second and third color components received from said first and second polarization beam splitter prisms to the projection lens; and a third light polarization selector to be disposed between said third polarization beam splitter prism and the projection lens, said third light polarization selector ensuring that the first, second and third color components from said third polarization beam splitter prism have the same polarization state prior to reaching the projection lens.