Process eliminating the use of a master positive film for making a duplicate negative of a color motion picture

Claim 1

The process of making a duplicate color motion picture negative from an original motion picture negative, comprising, an exposure cycle including the steps of generating an analog electrical signal corresponding to a single dye layer of a frame of the original color motion picture negative by projecting one or more scanning cycles of a continuous raster pattern formed upon a first monochromatic cathode ray tube, through a first optical filter restricting the light energy to a predetermined wave length band, focusing said raster pattern on a single frame of the original negative and thence to a photo sensor, supplying said analog signal to a second monochromatic cathode ray tube to simultaneously display a positive image thereon, precise synchronism of the raster patterns insured by providing both cathode ray tubes a common deflection source, and finally projecting the positive image through a second filter adapted to substantially restrict exposure to a single emulsion layer corresponding to the dye layer of the original negative being scanned, and onto a photosensitive surface of an unexposed color motion picture film; changing first and second optical filters and repeating the exposure cycle until the latent images of all duplicate negative emulsion layers are completed for said frame; advancing both negative and photosensitive films one frame and repeating the above process steps until the complete negative is copied; and finally chemically processing the photosensitive film to form a duplicate negative suitable for release printing, wherein the scanning cycles consist of a raster pattern formed by a continuously energized electron beam traversing a path, starting at one corner of the field of the cathode ray tube, proceeds along a path parallel to one edge of the field until it completes its passage to the opposite end of said path, then moves a distance approximately equal to the electron beam diameter at right angles, then proceeds along a path parallel to its previous movement, repeating this pattern until the complete field has been covered, whereupon the beam retraces the foregoing pattern in a reverse direction to return to its starting point.