Light valve projection system employing coaxial beams of colored light

Claim 2

In a system for projecting images in color by passing light through optical diffraction gratings formed in a substantially planar, deformable medium, said gratings being generally directed along first and second substantially orthogonal directions, means for improving quality of images produced by said system, comprising: dichroic means situated at a finite angle other than the normal with respect to the plane of said medium, said dichroic means being transparent to light of a first color and reflective to light of a second color; means situated to direct stripes of light of said first color along an optic axis onto said gratings through a predetermined area on said dichroic means, said stripes of light of said first color being longitudinally directed along said first direction; means situated to direct stripes of light of said second color onto said predetermined area on said dichroic means so as to enable said light of said second color to be reflected onto said gratings from said dichroic means along said optic axis, said stripes of light of said second color being longitudinally directed along said second direction; and an output light mask situated in the path of light emanating from said gratings, said output light mask comprising alternate opaque and transparent regions directed longitudinally along said first direction, with respect to light of said first color, superimposed upon alternate opaque and transparent regions directed longitudinally along said second direction, with respect to light of said second color.

Claim 3

In a system for projecting images in color by passing light through optical diffraction gratings in a substantially planar medium, said gratings being generally directed along first and second substantially orthogonal directions so as to define an image to be projected, means for improving quality of images produced by said system, comprising: dichroic means having two substantially parallel surfaces situated at a finite angle other than the normal with respect to the plane of said medium, said dichroic means being transparent to light of a first color and reflective to light of a second color; means situated to direct light of said first color along an optic axis onto said medium by passing light of said first color, incident on one of said surfaces of said dichroic means, through a predetermined area on the opposite surface of saId dichroic means; means situated to direct light of said second color onto said predetermined area on the opposite surface of said dichroic means at an angle other than the normal with respect thereto so as to reflect light of said second color from said dichroic means along said optic axis onto said medium; a first plurality of alternate bars and slots being respectively opaque and transparent to light of said first color and being situated along said optic axis in the path of light of said first color falling upon said dichroic means, said first plurality of bars and slots having longitudinal axes directed along said first direction; a second plurality of alternate bars and slots being respectively opaque and transparent to light of said second color and being situated in the path of light of said second color falling upon said dichroic means, said second plurality of bars and slots having longitudinal axes directed along said second direction; and an output light mask situated in the path of light emanating from said medium, said output light mask comprising alternate opaque and transparent regions directed longitudinally along said first direction, with respect to light of said first color, superimposed upon alternate opaque and transparent regions directed longitudinally along said second direction, with respect to light of said second color.

Claim 4

In a system for projecting images in color by passing light through optical diffraction gratings in a substantially planar medium, said gratings being generally directed along first and second substantially orthogonal directions so as to define an image to be projected, means for improving quality of images produced by said system, comprising: dichroic means having two substantially parallel surfaces situated at a finite angle other than the normal with respect to the plane of said medium, said dichroic means being transparent to light of a first color and reflective to light of a second color; means situated to direct light of said first color along an optic axis onto said medium by passing light of said first color, incident on one of said surfaces of said dichroic means, through a predetermined area on the opposite surface of saId dichroic means; means situated to direct light of said second color onto said predetermined area on the opposite surface of said dichroic means at an angle other than the normal with respect thereto so as to reflect light of said second color from said dichroic means along said optic axis onto said medium; a first plurality of alternate bars and slots being respectively opaque and transparent to light of said first color and being situated along said optic axis in the path of light of said first color falling upon said dichroic means, said first plurality of bars and slots having longitudinal axes directed along said first direction; a second plurality of alternate bars and slots being respectively opaque and transparent to light of said second color and being situated in the path of light of said second color falling upon said dichroic means, said second plurality of bars and slots having longitudinal axes directed along said second direction; and an output light mask situated in the path of light emanating from said medium, said output light mask comprising alternate opaque and transparent regions directed longitudinally along said first direction, with respect to light of said first color, superimposed upon alternate opaque and transparent regions directed longitudinally along said second direction, with respect to light of said second color.

Claim 5

The system of claim 2 wherein said means situated to direct light of said first color onto said medium comprises a source of light of said first color, and said means situated to direct light of said second color onto said predetermined area on the opposite surface of said dichroic means comprises a source of light of said second color.

Claim 6

The system of claim 2 wherein said means situated to direct light of said first color onto said medium comprises a source of white light directed onto said opposite surface of said dichroic means, and first reflective means situated to face said one surface of said dichroic means, said first reflective means receiving light of said first color from said source of which light through said dichroic means and directing said light of said first color onto said one surface of said dichroic means so as to pass through said predetermined area on the opposite surface of said dichroic means, and wherein said means situated to direct light of said second color onto said predetermined area on the opposite surface of said dichroic means comprises second reflective means situated to face said opposite surface of said dichroic means, said second reflective means receiving light of said second color from said white light as reflected by said dichroic means and directing said light of said second color onto said opposite surface of said dichroic means so as to be reflected at said predetermined area on the opposite surface of said dichroic means.