LIGHT COMBINER

摘要

Light combiners and light splitters, and methods of using light combiners and light splitters are described. In particular, the description relates to light combiners and splitters that combine and split, respectively, light of different wavelength spectrums using polarizing beam splitters. The polarizing beam splitters include a reflective polarizer to efficiently split incident light into transmitted and reflected beams having different polarization directions. Reflectors and quarter-wave retarders are positioned facing selected prism faces of the polarizing beam splitters, to affect the polarization state of light passing through the prism faces. The reflectors can be dichroic filters adapted to reflect light that is outside a selected wavelength range, so that light of different wavelength spectrums can be affected at different prism faces. The surfaces of each polarizing beam splitter can be polished so that the light utilization efficiency is increased due to total internal reflection within the polarizing beam splitter. The light combiners can combine up to five unpolarized different color lights to produce an unpolarized polychromatic light output, which may be white light useful for a projection display. The light splitters can split unpolarized polychromatic light to produce up to five unpolarized different color light outputs.