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Patent US4045786A successfully refreshed from Google Patents.
US4045786A
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Magnetic domain memory device having an improved drive coil arrangement
Assignee: Bull HN Information Systems Inc
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Filing: 1974-09-03
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Granted: 1977-08-30
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Expires: 1994-09-03
Abstract
Abstract An improved drive coil for a magnetic domain memory device has varying separation between adjacent conductors to improve the uniformity of the magnetic field.
Inventors
- 👤 Fred S. Lee
- 👤 William F. Neu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:58
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/085; H; H01; H01F; H01F5/00; H01F5/003
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
115 words
A magnetic domain memory device including substrates carrying domain materials, and independently energizable drive coils positioned to encompass said substrate for generating magnetic fields whose lines of force are parallel to the surface of said magnetic domain memory device, the improvement wherein: each of said drive coils includes a plurality of individual adjacent conductors, the spacing between the individual conductors gradually increasing as the centerline of the coils is approached from opposite edges of the coil for providing a plateau in the distribution of said magnetic fields, thus maximizing the useful area in said substrate; and said magnetic domain memory device further including means for energizing each of said coils for generating said magnetic fields.
Claim 2
Dependent Claim
115 words
A magnetic domain memory device including substrates carrying domain materials, and independently energizable drive coils positioned to encompass said substrate for generating magnetic fields whose lines of force are parallel to the surface of said magnetic domain memory device, the improvement wherein: each of said drive coils includes a plurality of individual adjacent conductors, the spacing between the individual conductors gradually increasing as the centerline of the coils is approached from opposite edges of the coil for providing a plateau in the distribution of said magnetic fields, thus maximizing the useful area in said substrate; and said magnetic domain memory device further including means for energizing each of said coils for generating said magnetic fields.
Claim 3
Dependent Claim
29 words
An improved magnetic domain memory device as recited in claim 1 wherein the individual conductors are more widely spaced at the center of the coil than at the edges.
References Cited (Backward Citations)
DE322499C
Cited
US3848209A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-29 | 1981-02-28 | 1981-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-29 | 1985-02-28 | 1985-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-29 | 1989-02-28 | 1989-08-30 | $7700.00 | Window Closed / Lapsed |