Abstract: A LCOS projection system includes an illumination device, a LCOS microdisplay element, a polarization beam splitter, an optical projection lens, and a beam recycling module. A first portion of the lighting beams provided by the illumination device are transmissible through the polarization beam splitter and directed to the LCOS microdisplay element. A second portion of the lighting beams provided by the illumination device and from the polarization beam splitter are introduced into the beam recycling module. By the beam recycling module, a polarization state of the second portion of the lighting beams is converted. Consequently, the second portion of the lighting beams in the converted polarization state can also be projected onto the LCOS microdisplay element. The beam recycling module includes a total internal reflection prism, which is arranged in a transmission path of the first portion and the second portion of the lighting beams.

Abstract: A projection system includes an illumination device, a LCOS microdisplay element, an optical projection lens, a total internal reflection prism, and a polarizer. The polarizer is a reflective polarizer or an absorptive polarizer. The total internal reflection prism is arranged between the illumination device, the LCOS microdisplay element and the optical projection lens. A plurality of lighting paths are created between the illumination device and the LCOS microdisplay element. A plurality of imaging paths are created between the LCOS microdisplay element and the optical projection lens. The polarizer is only located in the lighting paths.