Abstract: An optical data storage and recording material in which a reflective major surface layer is coated with an optically clear dielectric material having grooves therein. The dielectric material is itself transparent and data may be recorded by grooves created in the dielectric material. The grooves may have one depth primarily for destructive interference of light and another depth for interference and light scattering, thereby permitting two levels of encoding for prerecorded information, as well as user data formed by laser generated pits in the reflective major surface layer.

Abstract: A method of making an underlayer for a laser recording and data storage medium with a light absorption characteristic suited to a recording laser. The underlayer is formed by creating a nuclei layer in a silver-halide photosensitive emulsion layer and then contacting the emulsion layer with a chromogenic reducing agent and a chromogenic dye coupler. The reflective layer may be formed prior to this step by subjecting the nuclei layer to a monobath having a silver-halide solvent and a silver reducing agent until a reflective surface layer of non-filamentary silver particles is formed, or after the step by chemical vapor deposition or sputtering of a reflective metal layer over the underlayer.

Abstract: A method for making a laser recording and data storage medium by first exposing a Lippman emulsion to light in order to form a depthwise nuclei gradient, then physically developing the emulsion until a reflective surface layer of spheroid silver particles, having the desired degree of reflectivity, is attained and then chemically developing the remaining nuclei to form a dark underlayer of filamentary silver particles.

Abstract: A data card having a pair of spaced apart information records. One record is a strip of high resolution reflective laser recording material, such as a metallic film. The other strip is a magnetic recording material. The strip of laser recording material has a capacity for recording at least 250,000 bits represented by pits having a dimension less than 50 microns.

Abstract: A laser recording medium consisting of shiny silver particles in a colloid matrix having at least one superposed layer of colloid matrix containing dispersed metal particles other than silver to lower the reflectivity of the medium.

Abstract: A method for making epoxy reinforced by gelatin by forming gelatin-epoxy sheets. Initially the gelatin is carried on a non-bonding support and receives the desired epoxy coating which bonds to the gelatin. Next the coating is cured and the support is peeled from the gelatin leaving a gelatin reinforced epoxy sheet stock material. The opposite side of the gelatin may be coated in the same manner.

Abstract: A protective removable coverplate for a reflective optical data storage and recording medium wherein a transparent coverplate is removably disposed over a transparent coating which is in intimate contact with the reflective medium. A slightly bumpy upper surface of the coating supports the coverplate with air gaps existing between the coating and the coverplate to a maximum depth of one micron under hand pressure on the coverplate.

Abstract: A recording medium for laser writing and a method of making same wherein a silver-halide emulsion coating disposed on a substrate is strongly exposed to actinic radiation and then developed, or otherwise processed for maximum blackness. The black opaque emulsion is converted to a reflective recording medium by heating at least to 270.degree. C. in an oxygen containing environment until the emulsion coating assumes a shiny reflective appearance and the gelatin partially pyrolyzes creating a carbon containing absorptive matrix. Prior to developing, patterns may be photographically imposed on the medium to provide control indicia for the recording system or data base information to a playback system or to provide a means of replicating master recordings.

Abstract: A broadband laser recording and data storage medium for direct read after writing, formed from a photosensitive silver-halide emulsion in four steps. First, a non-saturating actinic radiation exposure is used to create latent images. A normal photographic development is used to produce a medium of gray neutral density. The surface of the remaining silver halide is fogged in a water or alcohol based solution to create a very thin layer of silver precipitating nuclei on the surface. Finally, a single-step, negative silver diffusion transfer process is used to dissolve the unexposed and undeveloped silver halide, forming silver ion complexes.

Abstract: A method of replicating data from a master transmissive optical data storage medium whereby the resulting product displays areas of low reflectivity and high reflectivity. Actinic radiation is shone through transmissive areas onto a silver-halide emulsion photosensitive medium. The photosensitive medium is then chemically developed black. Next, the developed medium is fogged to create a latent image layer of silver precipitating nuclei. Finally, the fogged medium is placed in a monobath comprising a weak silver-halide reducing agent and a rapid-acting silver-halide solvent for partial chemical development and substantial physical development. The resulting product displays areas of low reflectivity, which correspond to the transmissive areas of the master, in a reflective field.

Abstract: A reflective laser recording and data storage medium, for direct reading after writing, formed from a photosensitive silver-halide emulsion including silver precipitating nuclei. A single step negative silver diffusion transfer process is used to develop silver nuclei of the latent image and dissolve unexposed silver halide elsewhere, forming silver ion complexes. These complexes are transported by diffusion transfer to the developing silver nuclei sites where silver is precipitated and adsorbed to form a high concentration of non-filamentary particles at a surface of a low melting temperature dielectric matrix which is highly reflective of light and electrically non-conducting.

Abstract: A broadband laser recording and data storage medium for direct read after writing, formed from a photosensitive silver-halide emulsion in four steps. First, a non-saturating actinic radiation exposure is used to create latent images. A normal photographic development is used to produce a medium of gray neutral density. The surface of the remaining silver halide is fogged in a water or alcohol based solution to create a very thin layer of silver precipitating nuclei on the surface. Finally, a single-step, negative silver diffusion transfer process is used to dissolve the unexposed and undeveloped silver halide, forming silver ion complexes.

Abstract: Epoxy is reinforced by gelatin to form gelatin-epoxy sheets. Initially the gelatin is carried on a non-bonding substrate for support and receives the desired epoxy coating which bonds to the gelatin. Next the coating is cured and the substrate is peeled from the gelatin leaving a gelatin reinforced epoxy sheet stock material. The opposite side of the gelatin may be coated in the same manner.

Abstract: A method for making a reflective data storage medium by creating a volume concentration gradient of silver precipitating nuclei on one surface of a silver halide emulsion coated photoplate. This volume concentration is then built up by a silver diffusion transfer negative development using primarily solution physical development until the surface becomes reflective. Lastly, a thermal annealing step is used to increase reflectivity, recording sensitivity and produce a more uniform contrast ratio.

Abstract: A reflective laser recording and data storage medium, for direct reading after writing, formed from a photosensitive silver-halide emulsion wherein a surface latent image exposure on the recording area forms a depthwise gradient of silver nuclei. A single step negative silver diffusion transfer process is used to develop silver nuclei of the latent image and dissolve unexposed silver halide elsewhere, forming silver ion complexes. These complexes are transported by diffusion transfer to the developing silver nuclei sites where silver is precipitated and adsorbed to form a high concentration of non-filamentary particles at a surface of a low melting temperature dielectric matrix which is highly reflective of light and electrically non-conducting.

Abstract: A reflective laser recording and data storage medium, for direct reading after writing, formed from a photosensitive silver-halide emulsion wherein a surface latent image exposure on the recording area forms a depthwise gradient of silver nuclei. A single step negative silver diffusion transfer process is used to develop silver nuclei of the latent image and dissolve unexposed silver halide elsewhere, forming silver ion complexes. These complexes are transported by diffusion transfer to the developing silver nuclei sites where silver is precipitated and adsorbed to form a high concentration of non-filamentary particles at a surface of a low melting temperature dielectric colloid matrix which is highly reflective of light and electrically non-conducting.

Abstract: An orange colored photomask visually transmissive to yellow-orange light formed by heating an exposed and developed silver-halide emulsion coated photomask. At approximately 200.degree. C., black silver in the photomask begins to show evidence of conversion to a transparent red material. At a temperature of 250.degree. C. to 320.degree. C., the black silver opaque images are rapidly converted to orange, visually transmissive images which are essentially opaque to the ultraviolet light used to expose photoresist covered silicon wafers, while clear areas remain clear.

Abstract: An error checking method and apparatus for recording digital data in an optical recording medium. Digital data are written onto the medium by a modulated laser whose beam is detected by a first photodetector means which measures laser output directed toward the recording medium. A second photodetector means measures light scattering from the medium, while a third photodetector detects and measures light transmitted through the recording layer of the medium serving to confirm recording of the data. Amounts of transmitted light or scattered light from the medium are correlated to the laser output and to expected values of light for detecting errors in recording immediately after the time of recording. Reversal processing of the recording medium eliminates a large fraction of potential errors.