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US4422159A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical information storage and retrieval

Assignee: AT&T Inc
•
Filing: 1981-09-03
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Granted: 1983-12-20
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Expires: 2001-09-03
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Abstract

Abstract A process employing bodies that are fabricated to have a specific configuration are useful for the storage of information such as digital data. In one embodiment a material, such as germanium, is etched to produce a structure having a multiplicity of columnar or conical features. By providing a sufficient number of these features per unit area, it is possible to store at a relatively high density a variety of information. This information storage is accomplished by melting the columns or cones in a localized area. If these structures are of the appropriate size and spacing, they appear optically absorbing before melting and a reflective region appears in the treated area. In this manner archival storage of densely packed information is possible.

Inventors

  • 👤 Harold G. Craighead
  • 👤 Richard E. Howard

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 23:19
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/244; G11B7/245; G11B7/243; G11B2007/24302; G11B2007/24306; G11B2007/24312; G11B7/252; G11B7/253; G11B7/2531

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 152 words
A process for storing information in a storage medium comprising the steps of treating said storage medium with a source of energy so that optical changes which define said information are produced in said storage medium characterized in that said storage medium comprises a material having a region that has a configuration including void volumes that delimit storage structures wherein the total area of all said storage structures in said region is between 10 and 90 percent of the area of a plane at the medium surface coextensive with said region wherein the characteristic distance of said configuration is equal to or smaller than the wavelength of the electromagnetic radiation ultimately used to read said information, and wherein an optical change is induced with said source of energy by altering the optical properties of said storage structures that are impacted by said energy in a region where information is to be stored.
Claim 2
Dependent Claim 152 words
A process for storing information in a storage medium comprising the steps of treating said storage medium with a source of energy so that optical changes which define said information are produced in said storage medium characterized in that said storage medium comprises a material having a region that has a configuration including void volumes that delimit storage structures wherein the total area of all said storage structures in said region is between 10 and 90 percent of the area of a plane at the medium surface coextensive with said region wherein the characteristic distance of said configuration is equal to or smaller than the wavelength of the electromagnetic radiation ultimately used to read said information, and wherein an optical change is induced with said source of energy by altering the optical properties of said storage structures that are impacted by said energy in a region where information is to be stored.
Claim 3
Dependent Claim 37 words
The process of claim 1 wherein said void volume has a mean depth greater than 10 percent of the absorption length of said storage medium for the electromagnetic radiation ultimately to be used to read said information.
Claim 4
Dependent Claim 16 words
The process of claim 1 wherein said storage medium is coated with an abrasive resistant material.
Claim 5
Dependent Claim 16 words
The process of either claim 1 or 2 wherein said source of energy is a laser.
Claim 6
Dependent Claim 24 words
The process of either claim 1 or 2 wherein said material comprises a substance chosen from the group consisting of germanium, silicon and polystyrene.
Claim 7
Dependent Claim 16 words
The process of either claim 1 or 2 wherein said optical change is induced by melting.
Claim 8
Dependent Claim 70 words
The process of either claim 1 or 2 wherein on average at least 10 equivalent areas of storage structure measured at half the average depth of said void volume occupy an area delineated by the cross-section of said source of energy at the surface of said medium and wherein said equivalent area is equal to the area of a circle having a diameter length the same as said characteristic distance.
Claim 9
Dependent Claim 23 words
The process of claim 7 wherein at least 50 equivalent areas of surface structure occupy said area delineated by said source of energy.
Claim 10
Dependent Claim 13 words
The process of claim 7 wherein said source of energy is a laser.
Claim 11
Dependent Claim 21 words
The process of claim 7 wherein said material comprises a substance chosen from the group consisting of germanium, silicon, and polystyrene.
Claim 12
Dependent Claim 13 words
The process of claim 10 wherein said optical change is induced by melting.
Claim 13
Dependent Claim 13 words
The process of claim 7 wherein said optical change is induced by melting.
Claim 14
Dependent Claim 13 words
The process of claim 12 wherein said abrasive resistant material is poly(methyl methacrylate).
Claim 15
Dependent Claim 123 words
An article for storing information comprising a storage medium comprising a material having a region with a first optical characteristic that has a configuration including void volumes that delimit storage structures and written regions that correspond to a region of storage structures altered to have a second optical characteristic wherein the characteristic distance of said configuration is equal to or smaller than the wavelength of the electromagnetic radiation ultimately used to read said information, wherein said regions correspond to said information, and wherein the sum of the areas of said storage structures in said region of first optical characteristic is between 10 and 90 percent of the area of a plane at the medium surface coextensive with said region of first optical characteristic.
Claim 16
Dependent Claim 123 words
An article for storing information comprising a storage medium comprising a material having a region with a first optical characteristic that has a configuration including void volumes that delimit storage structures and written regions that correspond to a region of storage structures altered to have a second optical characteristic wherein the characteristic distance of said configuration is equal to or smaller than the wavelength of the electromagnetic radiation ultimately used to read said information, wherein said regions correspond to said information, and wherein the sum of the areas of said storage structures in said region of first optical characteristic is between 10 and 90 percent of the area of a plane at the medium surface coextensive with said region of first optical characteristic.
Claim 17
Dependent Claim 38 words
The storage medium of claim 14 wherein eaid void volume has a mean depth greater than 10 percent of the absorption length of said storage medium from the electromagnetic radiation ultimately to be used to read said information.
Claim 18
Dependent Claim 71 words
The article of either claim 14 or 15 wherein on average at least 10 equivalent areas of storage structure measured at half the average depth of said void volume, occupy an area delineated by the cross-section of said source of energy at the surface of said medium and wherein said equivalent area is equal to the area of a circle having a diameter of the same length as said characteristic distance.
Claim 19
Dependent Claim 23 words
The article of claim 16 wherein at least 50 equivalent areas of surface structure occupy said area delineated by said source of energy.
Claim 20
Dependent Claim 14 words
The storage medium of claim 16 wherein said source of energy is a laser.
Claim 21
Dependent Claim 22 words
The storage medium of claim 16 wherein said material comprises a substance chosen from the group consisting of germanium, silicon and polystyrene.
Claim 22
Dependent Claim 14 words
The storage medium of claim 16 wherein said optical change is induced by melting.
Claim 23
Dependent Claim 17 words
The storage medium of either claim 14 or 15 wherein said source of energy is a laser.
Claim 24
Dependent Claim 25 words
A storage medium of either claim 14 or 15 wherein said material comprises a substance chosen from the group consisting of germanium, silicon and polystyrene.
Claim 25
Dependent Claim 17 words
The storage medium of either claim 14 or 15 wherein said optical change is induced by melting.

References Cited (Backward Citations)

US3406405A Cited
US4245229A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-12-19 1987-06-20 1987-12-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-12-19 1991-06-20 1991-12-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-12-19 1995-06-20 1995-12-20 $7700.00 Window Closed / Lapsed

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