An optical projecting system, comprising:
- a light source for generating light;
- a beam polarization converter optically coupled to said light source for receiving and polarizing said light to obtain polarized light having a predetermined polarization distribution;
- a light splitting and synthesizing device optically coupled to said beam polarization converter for receiving and splitting said polarized light to a first color beam, a second color beam and a third color beam, and for synthesizing a first color projecting beam, a second color projecting beam and a third color projecting beam into projecting light, wherein said light splitting and synthesizing device comprises
- a light incoming port for receiving said polarized light,
- a first transporting port for outputting said first color beam and for receiving said first color projecting beam, a second transporting port for outputting said second color beam and for receiving said second color projecting beam, and a third transporting port for outputting said third color beam and for receiving said third color projecting beam, and
- a light outgoing port for outputting said projecting light;
- a first reflective liquid crystal panel, optically aligned with said first transporting port, for changing a status of said first color beam and outputting said first color projecting beam to said first transporting port;
- a second reflective liquid crystal panel, optically aligned with said second transporting port, for changing a status of said second color beam and outputting said second color projecting beam to said second transporting port;
- a third reflective liquid crystal panel, optically aligned with said third transporting port, for changing a status of said third color beam and outputting said third color projecting beam to said third transporting port;
- and
- a projecting lens, optically aligned with said light outgoing port, for receiving and transmitting said projecting light;
- wherein said light splitting and synthesizing device further comprises:
- a first component for transmitting lights, having said light incoming port and said first transporting port;
- a second component for transmitting lights, having said light outgoing port and said second transporting port, a polarization beam splitting coating layer being formed between said first component and said second component, wherein said polarization beam splitting coating layer allows said second color beam passing through and reflects the other color beams;
- and
- a third component for transmitting lights, having said third transporting port, a dichroic splitting coating layer being formed between said third component and said first component, wherein said dichroic splitting coating layer allows said third color beam passing and reflects the other color beams.