US Patent 7375896 Digital light-processing projection apparatus and beam splitter module thereof

A digital light-processing projection apparatus includes a light source, a beam splitter module and an optical combiner module. The beam splitter module is used in conjunction with an optical combiner module that includes combiners and a plurality of prisms. The beam splitter module comprises a beam splitter element for splitting the beam into a plurality of color lights that pass through the respective prisms separately. The polarization direction of each color light when separated in the beam splitter module is equal to the polarization direction of each respective color light when colour combination in the combiner module.