US3916396A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bubble domain circuit
Assignee: NEC Corp
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Filing: 1974-06-25
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Granted: 1975-10-28
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Expires: 1994-06-25
Abstract
Abstract A magnetic bubble domain memory of the major loop and minor loop type is constructed of thin film elements placed on an orthoferrite or the like material for retaining bubble domains. The pattern of the overlay elements is such that gate elements normally used between major and minor loops may be eliminated and storage elements may be part of the major loop and one of the minor loops. In-plane magnetic fields of a sequential and pulsed nature are applied to the material. The sequence and magnitude of the pulses determines whether the major loop, the minor loop, write-in, or erase propagation paths are effectively operable. Thus, a first pulse sequence will cause domains to circulate in the minor loops but remain stationary in the major loops. A second pulse sequence will cause domains to propagate in the major loop but remain stationary in the minor loop.
Inventors
- 👤 Haruki Kohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:06
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0875; G11C19/0883
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
266 words
A bubble domain circuit comprising, a sheet of magnetic material capable of retaining bubble domains, means for applying a biasing magnetic field normal to said sheet, means for generating in-plane magnetic fields parallel with the surface of said sheet and in varying directions, a major loop means disposed on said sheet for circulating bubble domains, said major loop means comprising a first plurality of bubble domain storage elements arranged and Disposed to cause bubble domain circulation in said major loop when the magnitude and direction of said in-plane magnetic fields are of a first predetermined sequence, at least one minor loop means disposed on said sheet for circulating bubble domains, said at least one minor loop means comprising a second plurality of bubble domain storage elements arranged and disposed to cause bubble domain circulation in said minor loop when the magnitude and direction of said in-plane magnetic fields are of a second predetermined sequence, said first and second plurality of bubble domain storage elements having at least one such element in common, which common element is in said major loop and said at least one minor loop, said arrangement of said storage elements being such that said first predetermined sequence will not cause bubble domain circulation in said minor loop and said second predetermined sequence will not cause bubble domain circulation in said major loop, and wherein bubble domain transfer between said major and said at least one minor loop is accomplished by changing from one to the other of said first and second sequences when a bubble domain is at a said common storage element.
Claim 2
Dependent Claim
266 words
A bubble domain circuit comprising, a sheet of magnetic material capable of retaining bubble domains, means for applying a biasing magnetic field normal to said sheet, means for generating in-plane magnetic fields parallel with the surface of said sheet and in varying directions, a major loop means disposed on said sheet for circulating bubble domains, said major loop means comprising a first plurality of bubble domain storage elements arranged and Disposed to cause bubble domain circulation in said major loop when the magnitude and direction of said in-plane magnetic fields are of a first predetermined sequence, at least one minor loop means disposed on said sheet for circulating bubble domains, said at least one minor loop means comprising a second plurality of bubble domain storage elements arranged and disposed to cause bubble domain circulation in said minor loop when the magnitude and direction of said in-plane magnetic fields are of a second predetermined sequence, said first and second plurality of bubble domain storage elements having at least one such element in common, which common element is in said major loop and said at least one minor loop, said arrangement of said storage elements being such that said first predetermined sequence will not cause bubble domain circulation in said minor loop and said second predetermined sequence will not cause bubble domain circulation in said major loop, and wherein bubble domain transfer between said major and said at least one minor loop is accomplished by changing from one to the other of said first and second sequences when a bubble domain is at a said common storage element.
Claim 3
Dependent Claim
22 words
A circuit as claimed in claim 1 wherein each said storage element comprises a ferromagnetic thin film overlay having substantially point-symmetric shape.
Claim 4
Dependent Claim
27 words
A circuit as claimed in claim 2 wherein each said ferromagnetic thin film overlay comprises parts on either one or both of the surfaces of the sheet.
Claim 5
Dependent Claim
16 words
A circuit as claimed in claim 2 wherein each ferromagnetic thin film overlay has an X-shape.
Claim 6
Dependent Claim
34 words
A circuit as claimed in claim 1 wherein said sequence of said in-plane magnetic fields are a sequential application of main and small magnetic fields, each succeeding field overlapping in time the preceding field.
Claim 7
Dependent Claim
83 words
A circuit as claimed in claim 1 further comprising a plurality of minor loop means disposed on said sheet for circulating bubble domains, each of said minor loops comprising a separate plurality of bubble domain storage elements arranged and disposed to cause bubble domain circulation therein when the magnitude and direction of said in-plane magnetic fields are of said second predetermined sequence, each of said separate plurality of domain storage elements having at least one storage element in common with said major loop.
Claim 8
Dependent Claim
88 words
A bubble domain circuit as claimed in claim 6 further comprising an eraser means for erasing bubble domains, and an eraser propagation path means disposed on said sheet for propagating domains from a given storage element in said major loop to said eraser means, said eraser propagation path means comprising a third plurality of bubble domain storage elements, including said given storage element, arranged and disposed to cause bubble domain propagation therein when the magnitude and direction of said in-plane magnetic fields are of a third predetermined sequence.
Claim 9
Dependent Claim
90 words
A bubble domain circuit as claimed in claim 7 further comprising a bubble domain generator means for generating bubble domains, and a generator propagation path means disposed on said sheet for propagating domains from said generator means to a selected storage element of said major loop, said generator propagation path means comprising a fourth plurality of bubble domain storage elements, including said selected storage element, arranged and disposed to cause bubble domain propagation therein when the magnitude and direction of said in-plane magnetic fields are of a fourth predetermined sequence.
Claim 10
Dependent Claim
34 words
A circuit as claimed in claim 8 wherein said sequence of said in-plane magnetic fields are a sequential application of main and small magnetic fields, each succeeding field overlapping in time the preceding field.
Claim 11
Dependent Claim
22 words
A circuit as claimed in claim 8 wherein each said storage element comprises a ferromagnetic thin film overlay having substantially point-symmetric shape.
Claim 12
Dependent Claim
27 words
A circuit as claimed in claim 10 wherein each said ferromagnetic thin film ovErlay comprises parts on either one or both of the surfaces of the sheet.
Claim 13
Dependent Claim
16 words
A circuit as claimed in claim 10 wherein each ferromagnetic thin film overlay has an X-shape.
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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |