US4280194A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Parametric bubble detector
Assignee: International Business Machines Corp
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Filing: 1979-11-26
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Granted: 1981-07-21
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Expires: 1999-11-26
Abstract
Abstract A parametric bubble detector contains a coupled film sensor stripe and an excitation conductor which, electrically insulated from each other, cross at right angles. A sensor stripe consists of a pair of superpositioned Permalloy stripes which are separated by a thin nonmagnetic layer. A high frequency excitation current in the conductor produces an inductive output signal in the sensor stripe. The waveform of this periodic signal is responsive to bubble domains proximate to the sensor/conductor crossover area.
Inventors
- 👤 Otto Voegeli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:57
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0866
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
59 words
A parametric bubble detector comprising a coupled film sensor strip, and excitation means interacting over a limited area with said stripe wherein the passage of a periodically varying current in said excitation means produces a similarly periodic inductive output signal from said stripe having a waveform responsive to the present of a bubble domain proximal to said limited area.
Claim 2
Dependent Claim
59 words
A parametric bubble detector comprising a coupled film sensor strip, and excitation means interacting over a limited area with said stripe wherein the passage of a periodically varying current in said excitation means produces a similarly periodic inductive output signal from said stripe having a waveform responsive to the present of a bubble domain proximal to said limited area.
Claim 3
Dependent Claim
39 words
A detector as described in claim 1 wherein said coupled film sensor stripe comprises a pair of substantially identical soft magnetic layers separated by a nonmagnetic layer whose thickness is substantially smaller than the thickness of either magnetic layer.
Claim 4
Dependent Claim
18 words
A detector as described in claim 1 including means for supplying a direct current to said sensor stripe.
Claim 5
Dependent Claim
24 words
A detector as described in claim 1 including a read means responsive to the amplitude of the second harmonic of the periodic output waveform.
Claim 6
Dependent Claim
31 words
A detector as described in claim 1 wherein said excitation means is a current conductor stripe which crosses the sensor stripe at right angles to form a limited area of interaction.
Claim 7
Dependent Claim
18 words
A detector as described in claim 5 including means for supplying an alternating current to said conductor stripe.
Claim 8
Dependent Claim
18 words
A detector as described in claim 5 including means for supplying a direct current to said conductor stripe.
Claim 9
Dependent Claim
20 words
A detector as described in claim 5 wherein said stripe forms at least two areas of interaction with said conductor.
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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) | 1984-07-20 | 1985-01-19 | 1985-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-20 | 1989-01-19 | 1989-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-20 | 1993-01-19 | 1993-07-21 | $7700.00 | Window Closed / Lapsed |