US3842407A
Expired / Lapsed
US
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Inductive sensor for magnetic bubble domain detection
Assignee: International Business Machines Corp
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Filing: 1972-06-30
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Granted: 1974-10-15
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Expires: 1992-06-30
Abstract
Abstract A sensor for detection of magnetic bubble domains in which the domains are oscillated in size to cause a change in a detector coupled to the domains. In one embodiment, the oscillator is a conductor loop driven by an electrical source to oscillate a domain therein, and the detector is a circuit connected to the conductor loop and responsive to the change in self-inductance of the loop, due to a difference in the amount of magnetic flux coupling the loop as the domain oscillates. Another embodiment uses the change in capacitance between conducting plates as an indication of the presence of a domain. Still another embodiment uses the change in amount of light passing through an oscillating domain as an indication of the presence of a domain.
Inventors
- 👤 B Argyle
- 👤 T Distefano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:58
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0866; G01; G01R; G01R33/00; G01R33/02; G11B; G11B5/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
48 words
An apparatus for detecting magnetic bubble domains in a magnetic medium, comprising: resonant means coupled to said domains which has first and second values depending upon the amount of magnetic flux coupled thereto, and detection means coupled to said resonant means for detecting said first and second values.
Claim 2
Independent Claim
48 words
An apparatus for detecting magnetic bubble domains in a magnetic medium, comprising: resonant means coupled to said domains which has first and second values depending upon the amount of magnetic flux coupled thereto, and detection means coupled to said resonant means for detecting said first and second values.
Claim 3
Dependent Claim
33 words
The apparatus of claim 1, where said resonant means includes an inductance whose value is changed by said oscillating domain when the magnetic field of the domain is coupled to said detection means.
Claim 4
Independent Claim
47 words
An apparatus using magnetic bubble domains in a magnetic medium, comprising: oscillation means for alternately decreasing and increasing the size of a magnetic bubble domain, detection means for sensing said domain, said detection means being coupled to said domain whose size is changed by said oscillation means.
Claim 5
Independent Claim
47 words
An apparatus using magnetic bubble domains in a magnetic medium, comprising: oscillation means for alternately decreasing and increasing the size of a magnetic bubble domain, detection means for sensing said domain, said detection means being coupled to said domain whose size is changed by said oscillation means.
Claim 6
Dependent Claim
36 words
The apparatus of claim 3, where said oscillation means includes a conductor and a current source for producing an oscillating current in said conductor, the magnetic field established by said oscillating current coupling to said domain.
Claim 7
Independent Claim
94 words
An apparatus for detecting mAgnetic bubble domains in a magnetic medium, comprising: oscillation means coupled to a domain for producing oscillating magnetic fields which couple to said domain causing it to alternately decrease and increase in size, detection means responsive to said domain, said detection means including means coupled to said domain which has a first value in the absence of a domain coupled to said oscillation means and a second value when a domain is coupled to said oscillation means and oscillates in size, indicating means for indicating said first and second values.
Claim 8
Independent Claim
94 words
An apparatus for detecting mAgnetic bubble domains in a magnetic medium, comprising: oscillation means coupled to a domain for producing oscillating magnetic fields which couple to said domain causing it to alternately decrease and increase in size, detection means responsive to said domain, said detection means including means coupled to said domain which has a first value in the absence of a domain coupled to said oscillation means and a second value when a domain is coupled to said oscillation means and oscillates in size, indicating means for indicating said first and second values.
Claim 9
Dependent Claim
20 words
The apparatus of claim 5, where said oscillation means is a conductor connected to a source of oscillating electrical current.
Claim 10
Dependent Claim
34 words
The apparatus of claim 5, where said detection means includes means for producing polarized light which is incident on said magnetic medium and means for receiving said light after it strikes said magnetic medium.
Claim 11
Dependent Claim
30 words
The apparatus of claim 5, said detection means including a resonant circuit whose resonant properties are responsive to said first and second values of said means coupled to said domain.
Claim 12
Dependent Claim
23 words
The apparatus of claim 8, where said first and second values are values of inductance of an inductive element in said detection means.
Claim 13
Dependent Claim
20 words
The apparatus of claim 8, where said first and second values are values of a capacitance in said detection means.
Claim 14
Independent Claim
61 words
An apparatus for detecting magnetic bubble domains in a magnetic medium, comprising: resonant means having a frequency which is dependent on the presence and absence of an oscillating magnetic domain coupled to said resonant means, and oscillation means for oscillating the size of a magnetic domain coupled thereto, said oscillation means alternately decreasing and increasing the size of said coupled domain.
Claim 15
Independent Claim
61 words
An apparatus for detecting magnetic bubble domains in a magnetic medium, comprising: resonant means having a frequency which is dependent on the presence and absence of an oscillating magnetic domain coupled to said resonant means, and oscillation means for oscillating the size of a magnetic domain coupled thereto, said oscillation means alternately decreasing and increasing the size of said coupled domain.
Claim 16
Independent Claim
61 words
An apparatus for detecting magnetic bubble domains in a magnetic medium, comprising: resonant means having a voltage amplitude at a terminal thereof which is dependent on the presence and absence of an oscillating magnetic domain coupled to said resonant means, oscillation means for oscillating the size of magnetic domains coupled thereto, causing said domains to alternately decrease and increase in size.
Claim 17
Independent Claim
61 words
An apparatus for detecting magnetic bubble domains in a magnetic medium, comprising: resonant means having a voltage amplitude at a terminal thereof which is dependent on the presence and absence of an oscillating magnetic domain coupled to said resonant means, oscillation means for oscillating the size of magnetic domains coupled thereto, causing said domains to alternately decrease and increase in size.
Claim 18
Independent Claim
67 words
An apparatus using magnetic bubble domains which can move in a magnetic medium, comprising: oscillation means for oscillating the size or shape of a magnetic bubble at a frequency which is greater than the propagation time of said domains when they are moved in said magnetic medium, detection means responsive to said domain oscillation for detecting the presence of a domain being oscillated by said oscillation means.
Claim 19
Independent Claim
67 words
An apparatus using magnetic bubble domains which can move in a magnetic medium, comprising: oscillation means for oscillating the size or shape of a magnetic bubble at a frequency which is greater than the propagation time of said domains when they are moved in said magnetic medium, detection means responsive to said domain oscillation for detecting the presence of a domain being oscillated by said oscillation means.
Claim 20
Independent Claim
60 words
An apparatus using magnetic bubble domains in a magnetic medium, comprising: oscillation means for oscillating the size or shape of a magnetic bubble domain at a frequency approximately the resonant frequency of said bubble domain in said magnetic medium, and detection means responsive to said domain oscillation for detecting the presence of a domain being oscillated by said oscillation means.
Claim 21
Independent Claim
60 words
An apparatus using magnetic bubble domains in a magnetic medium, comprising: oscillation means for oscillating the size or shape of a magnetic bubble domain at a frequency approximately the resonant frequency of said bubble domain in said magnetic medium, and detection means responsive to said domain oscillation for detecting the presence of a domain being oscillated by said oscillation means.
Claim 22
Independent Claim
54 words
An apparatus using magnetic bubble domains in a magnetic medium, comprising: oscillation means for oscillating the size or shape of a magnetic bubble domain at a frequency of about 1-100 megacycles per second, and detection means responsive to said domain oscillations for detecting the presence of a domain being oscillated by said oscillation means.
Claim 23
Independent Claim
54 words
An apparatus using magnetic bubble domains in a magnetic medium, comprising: oscillation means for oscillating the size or shape of a magnetic bubble domain at a frequency of about 1-100 megacycles per second, and detection means responsive to said domain oscillations for detecting the presence of a domain being oscillated by said oscillation means.
References Cited (Backward Citations)
US3523286A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |