Process for making a reflective data storage medium

Claim 1

A method of making a reflective electrically non-conducting data storage medium comprising, forming an areawise, latent image exposure in a photosensitive silver-halide emulsion layer disposed on a substrate, thereby defining an area for data storage, said exposure creating an areawise layer of silver precipitating nuclei having a volume concentration gradient through the depth of the emulsion, said emulsion having unexposed photosensitive silver-halide remaining therein in concentrations inversely related to said nuclei concentration, contacting said unexposed photosensitive silver-halide emulsion layer with an aqueous monobath comprising a weak silver-halide developing agent for developing said latent image and a rapid-acting silver-halide solvent for reacting with unexposed and undeveloped silver halide to form soluble silver ion complexes which are transported by chemical diffusion transfer to said silver-precipitating nuclei of said latent image where silver of said silver ion complexes is precipitated and adsorbed on said nuclei in the presence of said developer acting as a reducing agent, thereby forming a reflective electrically non-conducting silver negative of said latent image in said area for data storage, and heating said reflective electrically non-conducting data storage medium at least to 250° C. until the reflectivity of the surface increases by at least 5% of the initial reflectivity percentage.

Claim 2

A method of making a reflective electrically non-conducting data storage medium comprising, forming an areawise, latent image exposure in a photosensitive silver-halide emulsion layer disposed on a substrate, thereby defining an area for data storage, said exposure creating an areawise layer of silver precipitating nuclei having a volume concentration gradient through the depth of the emulsion, said emulsion having unexposed photosensitive silver-halide remaining therein in concentrations inversely related to said nuclei concentration, contacting said unexposed photosensitive silver-halide emulsion layer with an aqueous monobath comprising a weak silver-halide developing agent for developing said latent image and a rapid-acting silver-halide solvent for reacting with unexposed and undeveloped silver halide to form soluble silver ion complexes which are transported by chemical diffusion transfer to said silver-precipitating nuclei of said latent image where silver of said silver ion complexes is precipitated and adsorbed on said nuclei in the presence of said developer acting as a reducing agent, thereby forming a reflective electrically non-conducting silver negative of said latent image in said area for data storage, and heating said reflective electrically non-conducting data storage medium at least to 250° C. until the reflectivity of the surface increases by at least 5% of the initial reflectivity percentage.

Claim 10

A method of making a reflective electrically non-conducting data storage medium of the type wherein information is recorded by laser writing at a specified wavelength comprising, forming an areawise, latent image exposure in a photo-sensitive silver-halide emulsion layer disposed on a substrate, thereby defining an area for data storage, said exposure creating an areawise layer of silver precipitating nuclei having a volume concentration gradient through the depth of the emulsion, said emulsion having unexposed photosensitive silver-halide remaining therein in concentrations inversely related to said nuclei concentration, contacting said unexposed photosensitive silver-halide emulsion layer with an aqueous monobath comprising a weak silver-halide developing agent for developing said latent image and a rapid-acting silver-halide solvent for reacting with unexposed and undeveloped silver halide to form soluble silver ion complexes which are transported by chemical diffusion transfer to said silver-precipitating nuclei of said latent image where silver of said silver ion complexes is precipitated and adsorbed on said nuclei in the presence of said developer acting as a reducing agent, thereby forming a reflective electrically non-conducting silver negative of said latent image in said area for data storage, and heating said reflective electrically non-conducting data storage medium at least to 250° C. until the absorptivity of the emulsion layer rises to at least 20% at the wavelength of a laser to be used for recording.

Claim 11

A method of making a reflective electrically non-conducting data storage medium of the type wherein information is recorded by laser writing at a specified wavelength comprising, forming an areawise, latent image exposure in a photo-sensitive silver-halide emulsion layer disposed on a substrate, thereby defining an area for data storage, said exposure creating an areawise layer of silver precipitating nuclei having a volume concentration gradient through the depth of the emulsion, said emulsion having unexposed photosensitive silver-halide remaining therein in concentrations inversely related to said nuclei concentration, contacting said unexposed photosensitive silver-halide emulsion layer with an aqueous monobath comprising a weak silver-halide developing agent for developing said latent image and a rapid-acting silver-halide solvent for reacting with unexposed and undeveloped silver halide to form soluble silver ion complexes which are transported by chemical diffusion transfer to said silver-precipitating nuclei of said latent image where silver of said silver ion complexes is precipitated and adsorbed on said nuclei in the presence of said developer acting as a reducing agent, thereby forming a reflective electrically non-conducting silver negative of said latent image in said area for data storage, and heating said reflective electrically non-conducting data storage medium at least to 250° C. until the absorptivity of the emulsion layer rises to at least 20% at the wavelength of a laser to be used for recording.