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US3846770A
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Serial access memory using magnetic domains in thin film strips
Assignee: United States Department of the Navy
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Filing: 1973-07-11
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Granted: 1974-11-05
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Expires: 1993-07-11
Abstract
Abstract A polycrystalline thin film strip to store information in a serial manner in the form of reversal domains. The reversal domains are propagated along the thin film strip, which may be Permalloy, and then sensed to detect the stored digital information.
Inventors
- 👤 L Schwee
- 👤 H Irons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:11
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0808; G11C19/0841
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
70 words
A magnetic storage system comprising: a polycrystalline thin film strip approximately 25 Mu m wide; means for placing reversal domains on said strip; an easy axis field applied along the width of strip whereby several reversal domains collapse enabling the remaining reversal domains to be stable; means producing a field for propagating said reversal domains along the hard axis; and conductor means for sensing said reversal domains on said strip.
Claim 2
Dependent Claim
70 words
A magnetic storage system comprising: a polycrystalline thin film strip approximately 25 Mu m wide; means for placing reversal domains on said strip; an easy axis field applied along the width of strip whereby several reversal domains collapse enabling the remaining reversal domains to be stable; means producing a field for propagating said reversal domains along the hard axis; and conductor means for sensing said reversal domains on said strip.
Claim 3
Dependent Claim
19 words
A magnetic storage system is recited in claim 1 wherein: said propagating means comprises conductors placed above said strip.
Claim 4
Dependent Claim
21 words
A magnetic storage system as recited in claim 1 wherein said propagating means comprises thick film strips placed above said strip.
Claim 5
Dependent Claim
23 words
A magnetic storage system as recited in claim 1 wherein a reversal domain represents a digital one and its absence a digital zero.
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) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |