Optical system for producing a modulated color image

Abstract

An optical system divides a light source into its component color bands red, green and blue by making the light travel different physical paths, at least two of these paths use stack retardation films and a polarization beamsplitter. By creating distinct paths, each code can be independently processed and combined to form a single path using a polarization splitter and retarder stack. The system preferably includes an input retarder that aligns a first spectrum of a light from a light source, along a first polarization state, and aligns a second spectrum of the light from the light source, along a second polarization state different than the first polarization state, and a beam splitting unit, optically coupled to the input retarder, and including a first beamsplitter that transmits the first spectrum, as a transmitted spectrum, and that reflects the second spectrum, as a reflected spectrum. The system also includes a first spatial light modulator optically coupled to the beam splitting unit, that alters and reflects the transmitted spectrum, as a modulated transmitted spectrum, towards the beam splitting unit, and a second spatial light modulator optically coupled to the beam splitting unit, that alters and reflects the reflected spectrum, as a modulated reflected spectrum, towards the beam splitting unit. The beam splitting unit combines the modulated transmitted spectrum and the modulated reflected spectrum into a combined spectrum.