Patent ID: 7261418
Filing Date: 2007-08-28
Classification: G02B,H04N

Abstract:
1. A projection engine device, comprising: a first polarizing beam splitter (PBS), the first PBS for substantial reflecting light incident along a first input direction in a first polarization state and substantially transmitting light incident in the first input direction in a second polarization state orthogonal to the first polarization state, the first PBS demonstrating an angularly dependent reflectivity for light in the second polarization state that is asymmetric about the first input direction and wherein the first PBS reflects less than 5% of light in the second polarization state when illuminated by light in the wavelength range from about 430 nm to about 700 nm and having an f-number of no more than f/2.5; a second PBS positioned to receive light reflected by the first PBS; a third PBS positioned to receive light transmitted through the first PBS; a first imaging element configured and arranged to a) receive, as first incident light, at least a first portion of the light received by the second PBS from the first PBS; b) polarization modulate at least a portion of the first incident light from the first polarization state to the second polarization state or from the second polarization state to the first polarization state; and c) reflect the polarization modulated light back to the second PBS as first image light; a second imaging element configured and arranged to a) receive, as second incident light, at least a first portion of the light received by the third PBS from the first PBS; b) polarization modulate at least a portion of the second incident light from the first polarization state to the second polarization state or from the second polarization state to the first polarization state; and c) reflect the polarization modulated light back to the third PBS as second image light; and a combiner positioned to receive the first and second image light from the second and third PBSs, respectively.