Light pipe based projection engine
View Patent ↗A light pipe based projection engine includes a X-prism transmitting substantially light of a useful polarization in an output direction and reflecting substantially light of a non-useful polarization in a first orthogonal direction substantially orthogonal to the output direction. An initial reflector may reflect the non-said low, said medium, and said high bands of wavelengths in a second orthogonal direction substantially orthogonal to the output direction and the first orthogonal direction, and a final reflector may reflect the non-said low, said medium, and said high bands of wavelengths in the output direction. The non-said low, said medium, and said high bands of wavelengths may be rotated substantially to light of the useful polarization by the initial and final reflectors.
1. A light pipe-based projection engine comprising:
a polarizing beam splitter receiving substantially un-polarized light at an input surface, the polarizing beam splitter transmitting first light energy of a useful polarization in an output direction and reflecting second light energy of a non-useful polarization in an recovery direction;
a wave plate disposed in said recovery direction to receive and modify the polarization of a substantial portion of the second light energy to said useful polarization;
a recovery reflector disposed reflectably to said recovery direction, said recovery reflector reflecting said second light energy in said output direction;
a modulator disposed in said output direction to modulate substantially said first light energy and said second light energy;
an initial light pipe disposed in said output direction to receive said first light energy from said polarization beam splitter and said second light energy from said recovery reflector and transmit said first and second light energies to said modulator;
a lens disposed proximate to said output direction to focus substantially said first and second light energies received from said modulator;
an output light pipe having an input surface disposed proximate to said output direction and an output surface, said output light pipe receiving said first and second light energies at said input surface from said lens and transmitting substantially said first and second light energies at said output surface; and
a projection lens disposed in said output direction to collect and focus said first and second light energies from said output light pipe.
2. The light pipe-based projection engine of claim 1 , comprising further:
an input light pipe having an input surface and an output surface, said output surface disposed proximate to said input face of said polarization beam splitter, said input light pipe receiving substantially un- polarized light at said input surface and transmitting said un-polarized light at said output surface to said polarizing beam splitter.
3. The light pipe-based projection engine of claim 1 , comprising further:
a color wheel disposed proximate to said output direction to provide sequential color substantially to said first and second light energies.
4. The light pipe-based projection engine of claim 1 , comprising further:
scrolling color disposed proximate to said output direction to provide color display substantially to said first and second light energies.