Method for photographic replication of information on an optical data storage medium

• US 4,304,848 A
• Filed: 06/04/1980
• Issued: 12/08/1981
• Est. Priority Date: 07/06/1979
• Status: Expired due to Term

• Current Assignee: LaserCard Corp. (Assa Abloy AB)
• Original Assignee: Drexler Technology Corporation (Assa Abloy AB)
• Inventors: Drexler, Jerome, Bouldin, Eric W.
• Primary Examiner(s): Bowers, Jr., Charles L.
• Application Number:
  US06/153,791
• Time in Patent Office: 552 Days
• Field of Search: 430/416, 430/417, 430/414, 430/153, 430/1, 430/396, 430/16, 430/246, 430/231, 430/229, 430/945, 430/8, 430/5, 430/21, 430/401, 430/495, 346/1.1, 346/76 L, 346/135.1, 358/128.5, 358/128.7, 358/130, 358/6, 369/84, 369/100, 369/112, 369/121, 369/125, 369/153, 369/284, 369/285, 369/288
• US Class Current: 430/401
• CPC Class Codes: G03C 5/40 Chemically transforming developed images G03C5/50 takes precedence
• CPC Class Codes: G03C 8/06 Silver salt diffusion transfer
• CPC Class Codes: G11B 7/0045 Recording G11B7/006, G11B7/0065 take precedence
• CPC Class Codes: G11B 7/013 for discrete information, i.e. where each information unit is stored in a distinct discrete location , e.g. digital information formats within a data block or sector
• CPC Class Codes: G11B 7/24 Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the arrangement of information on the carrier G11B7/007
• CPC Class Codes: G11B 7/251 comprising inorganic materials dispersed in an organic matrix
• CPC Class Codes: G11B 7/261 Preparing a master, e.g. exposing photoresist, electroforming
• CPC Class Codes: G11B 7/28 Re-recording, i.e. transcribing information from one optical record carrier on to one or more similar or dissimilar record carriers
• CPC Class Codes: G11C 13/048 using other optical storage elements
• CPC Class Codes: Y10S 430/146 Laser beam

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.

Claims

1. A negative photographic process for replicating data from a master optical data storage medium, comprising,

orienting a major surface of a fine-grained silver-halide emulsion photosensitive medium in a reference plane,

aligning an opaque master optical data storage medium having lighttransmissive areas in a plane parallel to the major surface of the photosensitive medium, in a non-contacting projection relationship therewith,

projecting actinic radiation through said light-transmissive areas of the master, thereby forming silver latent image areas in the photosensitive medium corresponding to said light-transmissive areas,

chemically developing said silver latent image areas of the photosensitive medium, thereby forming dark, filamentary, low reflective silver areas corresponding to said light-transmissive areas of the master,

forming an areawise layer of silver precipitating nuclei by chemical fogging or by exposure to actinic radiation at the major surface of the silver-halide emulsion in the unexposed and undeveloped region of the photosensitive emulsion,

depositing nonfilamentary silver on said nuclei by silver diffusion transfer from said unexposed and undeveloped region, said silver particles being adsorbed on the nuclei, thereby forming an areawise high reflective field in areas corresponding to opaque areas of said master.

2. The method of claim 1 further defined by contacting said dark filamentary silver areas with a silver bleach prior to forming an areawise layer of silver precipitating nuclei.

3. The method of claim 1, wherein said nuclei layer is formed by an areawise exposure of a major surface of the photosensitive medium to actinic radiation, whereby a depthwise decreasing concentration of silver precipitating nuclei is formed.

4. The method of claim 1, wherein said nuclei layer is formed by chemically fogging the major surface of the photosensitive medium.

5. The method of claim 1 further defined by physically separating said opaque master from said silver-halide emulsion photosensitive medium a distance of greater than one inch.

6. The method of claim 1 further defined by physically separating said opaque master from said silver-halide emulsion photosensitive medium a distance of 0.01 inch or less.

7. The method of claim 1 further defined by placing said opaque master in contact with said silver-halide photosensitive emulsion through a liquid layer.

8. The method of claim 1 further defined by placing said opaque master in contact with said silver-halide emulsion.

9. A negative photographic process for replicating data from a master optical data storage medium, comprising,

orienting a major surface of a fine-grained silver-halide emulsion photosensitive medium in a reference plane,

aligning an opaque master optical data storage medium having light-transmissive areas in a plane parallel to the major surface of the photosensitive medium, in a non-contacting projection relationship therewith,

projecting actinic radiation through said light-transmissive areas of the master, thereby forming silver latent areas in the photosensitive medium corresponding to said light-transmissive areas,

chemically developing said silver latent image areas of the photosensitive medium, thereby forming dark filamentary, low reflective silver areas corresponding to said light-transmissive areas of the master,

forming an areawise layer of silver precipitating nuclei at the major surface of the silver-halide emulsion in the unexposed and undeveloped region of the photosensitive emulsion,

contacting said nuclei layer in the photosensitive medium with a reagent comprising a weak silver-halide developing agent for partial chemical development of said layer of silver precipitating nuclei and a rapid-acting silver-halide complexing solvent for reacting with unexposed and undeveloped silver-halide to form soluble silver ion complexes which are transported by diffusion transfer to said chemically developed nuclei where silver of said silver ion complexes is precipitated and adsorbed on said chemically developed nuclei in the presence of said developing agent acting as a reducing agent, thereby forming a high reflective, electrically nonconducting layer of aggregated and individual silver particles, the activity of solvent being sufficiently low to permit partial chemical development of said surface latent image by the weak developing agent before all of the undeveloped and unexposed silver-halide is dissolved where high reflective area is located in areas corresponding to opaque areas of said master.

10. The method of claim 9 further defined by contacting said dark filamentary silver areas with a silver bleach prior to forming an areawise layer of silver precipitating nuclei.

11. The method of claim 9, wherein said nuclei layer is formed by an areawise exposure of a major surface of the photosensitive medium to actinic radiation, whereby a depthwise decreasing concentration of silver precipitating nuclei is formed.

12. The method of claim 9, wherein said nuclei layer is formed by chemically fogging the major surface of the photosensitive medium.

13. The method of claim 9 further defined by physically separating said opaque master from said silver-halide photosensitive medium a distance of greater than one inch.

14. The method of claim 9 further defined by physically separating said opaque master from said silver-halide emulsion photosensitive medium a distance of 0.01 inch or less.

15. The method of claim 9 further defined by placing said opaque master in contact with said silver-halide photosensitive emulsion through a liquid layer.

16. The method of claim 9 further defined by placing said opaque master in contact with said silver-halide emulsion.