Patent US3607347A successfully refreshed from Google Patents.
US3607347A
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US
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Data reduction and storage
Assignee: Sprague Electric Co
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Filing: 1969-08-04
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Granted: 1971-09-21
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Expires: 1989-08-04
Abstract
Abstract Permanent high density storage of alphanumerical information is provided by fine-line cuts which are extended through a thin surface layer to an underlying substrate and are arranged to provide a representation of the alphanumerical characters in microscopic size. In the method, information in alphanumerical form is reduced to microscopic size and stored in a permanent medium by forming line cuts through a thin overlayer to a contrasting underlayer by photoreduction and photoetching techniques.
Inventors
- 👤 John L Sprague
- 👤 Robert S Pepper
- 👤 Eugene P Donovan
- 👤 Frederick W Howe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:43
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; G03F7/00; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/261
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
21 words
The device of claim 1 wherein said openings are fine-line openings arranged in conformance with the alphanumerical characters of said information.
Claim 2
Dependent Claim
34 words
The device of claim 1 wherein said substrate is a planar member of inorganic material having s smooth and substantially flat major surface and said thin film is an inorganic film of high permanence.
Claim 3
Dependent Claim
20 words
The device of claim 1 wherein said substrate is of transparent material, and said thin film is of opaque material.
Claim 4
Dependent Claim
40 words
The device of claim 1 wherein said substrate is of substantially opaque material, said overlayer is of substantially transparent material, said substrate having low optical reflectivity, and said coating being sufficiently thin as to provide optical contrast to said substrate.
Claim 5
Dependent Claim
17 words
The device of claim 5 wherein said substrate is silicon, and said film is of silicon dioxide.
Claim 6
Dependent Claim
16 words
The device of claim 5 wherein said thin film is approximately 1,000 to 5,000 Angstroms thick.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |