Optpo-mechanical filter for blending of images from a digital projector

Abstract

A filter mounting apparatus for use with an optical filter placed between a projector lens and screen. The filter mounting apparatus comprises a metallic disk connected to the projector lens, and an assembly magnetically connected to the metallic disk for mounting the optical filter a predetermined distance from the projector lens.

1 . An optical filter adapted for placement between a projector lens and screen, said filter comprising a plurality of layers of transparent polymer film incorporating a neutral density (ND) color dye and having respective edges profiled to conform to the shape of the edge of an image as it exits the projection lens, and wherein said edges are positioned relative to each other with an offset to create a stepped graduation of cumulative color dye density.  
   
   
       2 . The optical filter of  claim 1 , wherein said polymer film is pre fabricated from one of transparent polycarbonate and polyester.  
   
   
       3 . The optical filter of  claim 1 , wherein the density of the ND dye is selected for optimizing black image generation with different combinations of lenses, projector screen gains and geometries to minimize impact on mid tone and light scenes.  
   
   
       4 . The optical filter of  claim 1 , wherein the density of the ND dye on respective filter layers is relative to ND dye densities of other ones of said filter layers to vary said stepped graduation of cumulative color dye density.  
   
   
       5 . The optical filter of  claim 1 , wherein an edge of the film is profiled to conform to the shape of the edge of the light image leaving the projector.  
   
   
       6 . The optical filter of  claim 1 , wherein colour density of each said ND dye in said layers is selected to optimize light roll-off slope for filtering the light density of different images projected from different projectors having different power lamps and brightness.  
   
   
       7 . Use of a filter assembly having a pair of optical filters, each in accordance with  claim 1 , to create a single projected image from two overlapping projected images having an imperceptible blend region therebetween.  
   
   
       8 . The optical filter of  claim 1 , wherein said plurality of layers is variable in number to vary said stepped graduation of cumulative color dye density.