US3790935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bubble in low coercivity channel
Assignee: Nortel Networks Technology Corp
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Filing: 1971-03-26
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Granted: 1974-02-05
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Expires: 1991-03-26
Abstract
Abstract The surface of a magnetic oxide layer, or platelet, has one or more cavities formed therein. The cavities extend in a predetermined pattern and the bottom of each cavity has a coercivity lower than the coercivity at the surface of the layer. Thus magnetic domains follow the pattern of a cavity. A cavity may be formed with a base surface and at least one intermediate surface which has a coercivity intermediate the bottom or base surface, and the outer surface. The bottom of a cavity can be given a stepped formation to provide positive domain locations along a cavity.
Inventors
- 👤 P Luff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:30
CPC Classifications
H; H01; H01F; H01F10/00; G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0808
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
68 words
A magnetic single wall domain device comprising: a layer of mangetic oxide material having an outer surface; and a channel formation in said layer extending from said outer surface and having a base surface; said base surface having a magnetic coercivity less than 0.5 oe, said outer surface having a magnetic coercivity of approximately 1.0 oe, magnetic domains developed and propagated at said base surface of said channel.
Claim 2
Dependent Claim
68 words
A magnetic single wall domain device comprising: a layer of mangetic oxide material having an outer surface; and a channel formation in said layer extending from said outer surface and having a base surface; said base surface having a magnetic coercivity less than 0.5 oe, said outer surface having a magnetic coercivity of approximately 1.0 oe, magnetic domains developed and propagated at said base surface of said channel.
Claim 3
Dependent Claim
53 words
A device as claimed in claim 1, the channel of stepped formation whereby the base surface is divided into separate sections by spaced apart intermediate surfaces at a level between the base surface and the outer surface, the intermediate surfaces having a coercivity value intermediate the values for the base and outer surfaces.
Claim 4
Dependent Claim
21 words
A device as claimed in claim 1, the width of the channel reduced at predetermined spaced apart positions along the channel.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |