Three-prism projection display

A three-prism projection display adapted to process an input light beam and to provide an output light beam to a projection lens, the input light beam including a first color component, a second color component and a third color component, each of which has a first polarization state, said three-prism projection display comprising:

• a polarization state converting device adapted to receive the input light beam and to convert the polarization state of the first color component from the first polarization state to a second polarization state different from the first polarization state;
• a polarization beam splitter prism having a first side to be disposed adjacent to the projection lens, a second side disposed adjacent to said polarization state converting device, a third side opposite to said first side, and a fourth side opposite to said second side, said polarization beam splitter prism receiving the input light beam from said polarization state converting device at said second side thereof, and separating the input light beam into the first color component, which passes through said third side thereof, and the second and third color components, which pass through said fourth side thereof;
• a first dichroic beam splitter prism disposed adjacent to said third side of said polarization beam splitter prism, said first dichroic beam splitter prism permitting the first color component from said polarization beam splitter prism to pass therethrough;
• a first light modulator disposed adjacent to said first dichroic beam splitter prism so as to receive the first color component therefrom, said first light modulator modulating the first color component and changing the polarization state of the first color component back to the first polarization state when activated, said first light modulator reflecting the first color component back to said first dichroic beam splitter prism;
• a second dichroic beam splitter prism having a first surface disposed adjacent to said fourth side of said prolarization beam splitter prism, a second surface opposite to said first surface, and a third surface between said first and second surfaces, said second dichroic beam splitter prism permitting the second color component from said polarization beam splitter prism to pass through said second surface thereof, and reflecting the third color component from said polarization beam splitter prism in a transverse direction so as to pass through said third surface thereof;
• a second light modulator disposed adjacent to said second surface of said second dichroic beam splitter prism so as to receive the second color component therefrom, said second light modulator modulating the second color component and changing the polarization state of the second color component to the second polarization state when activated, said second light modulator reflecting the second color component back to said second dichroic beam splitter prism;
• and
• a third light modulator disposed adjacent to said third surface of said second dichroic beam splitter prism so as to receive the third color component therefrom, said third light modulator modulating the third color component and changing the polarization state of the third color component to the second polarization state when activated, said third light modulator reflecting the third color component back to said second dichroic beam splitter prism.