Instant access one-layer color photography

Claim 1

An instant access multicolor reproduction process utilizing a photographic element carrying on a suitable transparent base in the following order a single red, green and blue screen layer in contiguous contact with a panchromatic silver halide emulsion layer, said process comprising (1) imagewise exposing to actinic light the panchromatically sensitized silver halide emulsion layer through the red, green, blue multi-colored screen layer, said screen layer being made up of three separate oil droplet dispersions, each containing a non-diffusible filter dye having one of the primary colors red, green or blue and containing in addition a color former which becomes diffusible at a pH of at least 12.5 and which is capable of reacting with the oxidation products of a paraphenylenediamine color developer to form a non-diffusible dye complementary in color to the primary color of the dye in the oil droplet, said color formers being free from water solubilizing groups but sufficiently oil soluble to be incorporated in an oily packet but containing a group which at a pH of at least 12.5 is capable of rendering the color former soluble in the developer solution, the imagewise exposure being sufficient to ensure maximum density in the silver halide emulsion upon color development in those areas of the emulsion receiving maximum exposure (2) color developing the emulsion in a paraphenylenediamine developer solution of a pH below 12.5 to produce maximum image density with complete conversion of the color formers to non-diffusible dye images in the areas of maximum density to pressing the negative photosensitive element into contact with a receiving sheet in the contiguous presence of an alkaline color developer solution of pH of at least 12.5, the higher alkalinity causing diffusion of the color formers from the oil droplets into the emulsion layer, thereby imagewise immobilizing the color formers in the exposed areas by coupling action with oxidized developer, and permitting the diffusion of the residual non-coupled color former and developer solution into an unsensitized image receiving layer which contains an encapsulated oxidizer thus permitting oxidation of developer and coupler to form a positive dye image in the layer.