Color display system

Claim 1

A recording and projection system comprising: a laser providing a substantially single frequency beam of coherent energy having a wavelength outside the range of wavelengths of visible light; means for focusing said laser beam; controllable polarization means interposed in the path of said laser beam for selectively controlling the polarization of said laser beam within a range between a first plane of polarization and a second plane of polarization so as to control the distribution of laser energy in said first and second planes of polarization; a dichroic polarizer cube interposed in the path of said laser beam downstream from said polarization means, said cube having the property that it is substantially totally reflective to components of said laser beam that are polarized in said first plane and substantially totally transmissive to components of said laser beam that are polarized in said second plane, said cube having the further property that short wavelength visible light is reflected by said cube and long wavelength visible light is transmitted by said cube; first and second locally erasable recording mediums positioned at the focal points of the reflected and transmitted laser beams, respectively; deflecting means upstream from said polarizer cube for scanning said reflected and transmitted laser beams across said first and second recording mediums, respectively; modulating means upstream from said deflecting means for modulating the intensity of said laser beam; means for selectively erasing said first and second recording mediums; means for providing a beam of white projection light; a dichroic element interposed in said projection beam having dichroic properties substantially identical to the further property of said polarizer cube, said element producing from said beam of white light a beam of long wavelength visible light that is transmitted through said element and a beam of short wavelength visible light that is reflected by said element; means for back lighting said first recording medium with said long wavelength visible light beam to form a long wavelength image; means for back lighting said second recording medium with said short wavelength visible light beam to form a short wavelength image; a first colored filter interposed in said long wavelength visible light beam; a second colored filter interposed in said short wavelength visible light beam; means for combining said long and short wavelength visible light beams to form a combined wavelength image; and means for projecting said combined wavelength image.