Patent ID: 8259239

Claim:
An image display system comprising: an image source configured to generate image light; projection optics configured to project and focus said image light; a polarizing beam splitter optically coupled to the projection optics and configured to propagate, into a first optical path separate from the projection optics, first polarized light having a first polarization and to propagate, into a second optical path separate from the projection optics, second polarized light having a second polarization; a quarter wave converter disposed in said first optical path and configured to rotate said first polarization by a quarter phase as said first polarized light first passes through said quarter wave converter; a retro-reflective screen separate from the projection optics, disposed in said first optical path and configured to reflect rotated first polarized light from said quarter wave converter back on a same direction to said quarter wave converter as from said quarter wave converter through said quarter wave converter for further quarter phase rotation, whereby image light of the rotated first polarized light is converted to converted image light of the second polarization, said converted image light of the second polarization propagated in said first optical path back to the polarizing beam splitter for propagation by said polarizing beam splitter; and an output port disposed in said first optical path and configured to receive the converted image light of the second polarization propagated by the beam splitter.