Drexler Technology Corporation

Eric W Bouldin

Jerome Drexler

Richard M Haddock

Christopher J Dyball

Brad W Dreisbach

A system and method of creating transmissive images in a developed photographic film is disclosed. A light-sensitive silver halide emulsion is developed to form an opaque surface layer of fine silver grains with a clear underlayer supported on a transparent substrate. Transmissive images are created in the opaque surface layer by selectively applying an oxidizing solution which oxidizes the silver grains to silver ions which are poor absorbers of light. The underlayer absorbs excess oxidizing solution with little or no swelling. The oxidizing solution may be dispersed by a modified ink-jet printer. The imaged film has high contrast and can be directly used without further processing in color printing plate making systems and other applications requiring a transmissive film or mask.

Instant high contrast imaging system

A transmissively read light beam sensitive recording medium is disclosed having a thin layer of irregularly shaped spheroidal silver grains which are capable of being modified by a light beam into smoothly rounded spherical silver grains. Portions of the thin layer which contain the irregularly shaped grains are highly absorptive of light, while portions of the layer which have been modified are transmissive. Also disclosed are methods for creating said medium.

Transmissively read optical recording medium

A method for extending the life of information recorded on an optical storage medium, such as direct-read-after-write laser recording material. Information and an index are recorded on the medium. When the optical contrast ratio of the recording begins to deteriorate, when a specified error rate in reading data bits occurs, or after a predetermined time elapses, the information is re-recorded at another location on the medium and a new index entry is added.

Method for extending life of optically recorded information

A system for recording data onto optical tape by means of a laser. The optical tape may be disposed on reels and transported along a tape path between supply and takeup hubs. A laser or laser array is used to write data on the tape in a plurality of parallel tracks as it is driven along the tape path. The tape features a flexible web backing, a reflective metallic layer deposited over the backing and an optical storage layer on top of the metallic layer with a planar crust of irregular, nonfilamentary and oblong black silver particles within the top one-half micron of the storage layer and substantially clear gelatin below the crust. The tape may have prepatterned indica, such as servo track guides or timing marks. Laser recording modifies the black silver particles of the crust to expose the reflective underlayer through the clear gelatin. The laser at low power together with a light detector may be used to read the data, an optical reflective contrast ratio of at least 1.2 to one being sufficient to distinguish the data spots from the surrounding field.

Data recording system for optical memory tape

A data card comprising a self-supporting, wallet size plastic card base upon which is disposed a film substrate layer, a highly reflective layer and an optical storage layer which is a selected photosensitive layer which has been exposed at an actinic wavelength and developed to be substantially opaque over a portion of its extent, except for an imagewise exposure pattern of clear and partially clear data marks revealing to varying extends reflectivity in the underlying reflective layer. Data spots may have one of four different reflectivities thereby representing a quadrinary digit 0, 1, 2 or 3 replacing two binary digits. The reflective layer is matched to the selected optical storage layer so that the reflective layer is highly reflective at a read beam wavelength in the red or near infrared and less reflective at actinic wavelengths either in the blue/green range or in the ultraviolet. A double-sided data card with a transparent card base and two film substrate layers, two reflective layers and two optical storage layers is also disclosed. A method for forming the data cards comprises vacuum or vapor deposition of the reflective layer over the substrate layer, disposing the photosensitive layer over the reflective layer, making an imagewise exposure of the emulsion at actinic wavelengths through a multilevel opacity mask, developing the photosensitive layer opaque and disposing the resulting strip onto the card base. The photosensitive layers may be silver-halide, diazo or vesicular film emulsions.

Read-only optical data card

A data card for optical information featuring a gelatin layer having a thin black crust at the top of the layer. The crust is formed by developed black irregular oblong silver particles within the top 0.5 micron of the gelatin colloid matrix. The remainder of the colloid matrix is substantially clear gelatin and a reflective metallic layer is disposed below the gelatin. The strip is laminated into a wallet-size card and may be pre-patterned during formation of the crust with control indicia or pre-recorded data. User data may be recorded by modifying the black silver particles in the crust with a laser to expose the reflective underlayer. A laser or other light source is used to read data on the medium with optical contrast between the black surface metallic layer underlying the gelatin layer which can be observed in the recorded spots.

Optical memory card with versatile storage medium

A medium in tape form for laser recorded optical information featuring a gelatin layer having a thin black crust at the top of the layer. The crust is formed by developed black filamentary silver particles within the top 0.5 micron of a gelatin colloid matrix. The remainder of the colloid matrix is substantially clear gelatin and a reflective metallic layer is disposed below the gelatin. The tape may be disposed on reels and may be pre-patterned during formation of the crust with indicia, such as servo track guides or timing marks. User data may be recorded by modification or by displacing the black silver particles in the crust with a laser to expose the reflective underlayer. A laser or other light source is used to read data on the medium with optical contrast between the black surface and the reflective metallic layer underlying the gelatin layer which can be observed in the recorded spots.

High contrast optical memory tape

An optical memory disk for laser recorded optical information featuring a gelatin layer having a thin black crust at the top of the layer. The crust is formed by developed black irregular oblong silver particles within the top 0.5 micron of a gelatin colloid matrix. The remainder of the colloid matrix is substantially clear gelatin and a reflective metallic layer is disposed below the gelatin. The disk may be pre-patterned during formation of the crust with control indicia, such as servo track guides or timing marks. User data may be recorded by modification of the black silver particles in the crust with a laser to expose the reflective underlayer. A laser or other light source is used to read data on the medium with optical contrast between the black surface and the reflective metallic layer underlying the gelatin layer which can be observed in the recorded spots.

High contrast optical memory disk

A medium in tape form for laser recorded optical information featuring a gelatin layer having a thin black crust at the top of the layer. The crust is formed by developed black irregular silver particles within the top 0.5 micron of a gelatin colloid matrix. The remainder of the colloid matrix is substantially clear gelatin and a reflective metallic layer is disposed below the gelatin. The tape may be disposed on reels and may be pre-patterned during formation of the crust with indicia, such as servo track guides or timing marks. User data may be recorded by modification of the black silver particles in the crust with a laser to expose the reflective underlayer. A laser or other light source is used to read data on the medium with optical contrast between the black surface and the reflective metallic layer underlying the gelatin layer which can be observed in the recorded spots.

An optical data storage medium, such as a data card with a strip of optical data storage material, having peelable transparent protective layers adhered above the storage material. When a protective layer becomes too scratched to read or write through, it may be removed by peeling. More than one layer may be adhered successively above one another, and removed one by one as they become scratched. The peelable protective layers are preferably adhesive tapes made of Aclar, Mylar, polyester, or other hard-to-tear polymers with pressure sensitive adhesive. One or more of the layers, and an underlayer between substrate or card base and the storage material may be a water barrier material such as a polytrichlorofluoroethylene.

Data card with peelable protective layers

An optical data storage medium, such as a data card with a strip of optical data storage material, having a thickness approximately that of a credit card and one or more moisture barrier layers. One of the moisture barrier layers is an underlayer between substrate or card base and the storage material, while a second moisture barrier layer is one or more of the transparent laminating sheet and protective layers adhered above the storage material. The barrier layers may be any of the transparent materials, having a maximum moisture vapor transmission rate of 0.1 grams water vapor/100 inch square/mil/24 hours at 38 C and 90% relative humidity, such as polytrichlorofluoroethylene and polyvinylidene chloride. The underlayer may also be a nontransparent aluminum layer.

Ultrathin optical recording medium with moisture barrier

An improved reflective silver laser recording and data storage medium for direct read after writing, having a protective gold plating on the silver particles of the reflective surface. The gold plating increases the recording sensitivity resulting in higher contrast ratios for the recorded data. Increased contrast ratios between recorded and non-recorded reflective areas are obtained by the gold plating allowing lower laser energy for readout of recorded data. The reflective silver surface is plated with gold by an electroless ion displacement procedure.

Reflective optical data storage and laser recording medium

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.

Highly absorptive dye-containing underlayer for laser recording and data

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.

Method of making a highly absorptive dye-containing underlayer for laser

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.

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Atherton, CA, United States of America

Eric W Bouldin