Patent ID: 7172290

Claim:
A light pipe-based projection engine comprising: a low distributing reflector reflecting substantially light of a low band of wavelengths in a low initial direction and transmitting substantially light of a medium and a high bands of wavelengths in an output direction; a low initial reflector disposed reflectably to said low initial direction, said low initial reflector reflecting said light of said low band of wavelengths in a low intermediate direction substantially parallel to said output direction; a low initial light pipe disposed between said low distributing reflector and said low initial reflector; a low final reflector disposed reflectably to said low intermediate direction, said low final reflector reflecting said light of said low band of wavelengths in a low final direction substantially diametrically opposed to said low initial direction; a low final light pipe disposed between said low initial reflector and said low final reflector; a low modulator disposed to modulate substantially said light of said low band of wavelengths; a high distributing reflector reflecting substantially said light of said high band of wavelengths in a high initial direction and transmitting substantially said light of said low and said medium bands of wavelengths in substantially said output direction; a high initial reflector disposed reflectably to said high initial direction, said high initial reflector reflecting said light of said high band of wavelengths in a high intermediate direction substantially parallel to said output direction; a high initial light pipe disposed between said high distributing reflector and said high initial reflector; a high final reflector disposed reflectably to said high intermediate direction, said high final reflector reflecting said light of said high band of wavelengths in a high final direction substantially diametrically opposed to said high initial direction; a high final light pipe disposed between said high initial reflector and said high final reflector; a high modulator disposed to modulate substantially said light of said high band of wavelengths; and a medium modulator disposed in said output direction to modulate substantially said light of said medium band of wavelengths.