Patent ID: 6330114
Filing Date: 2001-12-11
Classification: G02B

Abstract:
A color mixing apparatus for reflective displays which receives R, G, and B light and forms an image on a screen, the color mixing apparatus comprising:an R reflective display device for receiving and reflecting R color light that is incident upon said R reflective display device;a G reflective display device for receiving and reflecting G color light that is incident upon said G reflective display device;a B reflective display device for receiving and reflecting B color light that is incident upon said B reflective display device;at least three total internal reflection (TIR) prisms each being associated with one of said R, G, and B reflective display devices, said TIR prisms each having in input surface, an intermediate surface, and an output surface, said input surface being at an angle less than 90 degrees from said output surface, said TIR prisms each receiving inputted color light via said input surface, outputting said color light via said intermediate surfaces to said associated reflective device and receiving back reflected color light from said associated reflective device through said intermediate surface, and outputting color light through said output surface, an angle between said input surface and said intermediate surface being a prism angle, an angle between said inputted light and a normal to said input surface being an incident angle;a color cube for receiving said R, G and B color lights from said respective output surfaces of said R, G, and B TIR prisms and mixing said R, G, and B color lights; anda projection lens for receiving said mixed light from said color cube and transmitting the mixed light to form an image on a screen, the magnitudes of said prism angles and said incident angles are determined in accordance with the design of said projection lens.