Patent US4130846A successfully refreshed from Google Patents.
US4130846A
Expired / Lapsed
US
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Magnetic transducer
Assignee: Unisys Corp
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Filing: 1977-04-27
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Granted: 1978-12-19
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Expires: 1997-04-27
Abstract
Abstract A magnetic read/record head having a layer of uniaxially anisotropic magnetic material as the pole faces, which increases the ratio of magnetic reluctance between the pole faces to the magnetic reluctance along the fringing flux path through the recording medium. Two embodiments of the invention are disclosed, one embodiment providing a layer of anisotropic magnetic material in a continuous layer around a complete loop from one pole face to the other pole face, and the other embodiment providing a layer of anisotropic magnetic material confined to each of the pole regions.
Inventors
- 👤 Donald T. Best
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/23
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
117 words
A magnetic read/record transducer structure having a pair of poles with apposed pole faces spaced from one another by a separation layer which defines a single gap between said pole faces, each of said pole faces comprising a layer of uniaxially anistropic magnetic material characterized by low magnetic permeability in a first direction between the pole faces through the separation layer and characterized by substantially higher magnetic permeability in a direction orthogonal to said first direction, whereby the ratio of magnetic head gap reluctance between the pole faces to the gap reluctance along the fringing flux path through the recording medium is increased to thereby provide sharper more narrowly defined recorded pulses and higher amplitude readback pulses.
Claim 2
Dependent Claim
117 words
A magnetic read/record transducer structure having a pair of poles with apposed pole faces spaced from one another by a separation layer which defines a single gap between said pole faces, each of said pole faces comprising a layer of uniaxially anistropic magnetic material characterized by low magnetic permeability in a first direction between the pole faces through the separation layer and characterized by substantially higher magnetic permeability in a direction orthogonal to said first direction, whereby the ratio of magnetic head gap reluctance between the pole faces to the gap reluctance along the fringing flux path through the recording medium is increased to thereby provide sharper more narrowly defined recorded pulses and higher amplitude readback pulses.
Claim 3
Dependent Claim
33 words
A magnetic transducer structure as defined in claim 1 wherein both of said pair of pole faces each comprise a layer of uniaxially anisotropic magnetic material characterized as set forth in claim 1.
Claim 4
Dependent Claim
31 words
A magnetic transducer structure as defined in claim 1 wherein said structure comprises a complete magnetic loop and said anisotropic magnetic material is confined substantially to the region of said poles.
Claim 5
Dependent Claim
39 words
A magnetic transducer structure as defined in claim 1 wherein said structure comprises a complete magnetic loop and said anisotropic magnetic material extends in a continuous layer around said loop from one pole face to the other pole face.
Claim 6
Dependent Claim
19 words
A magnetic transducer structure as defined in claim 1 wherein said uniaxially anisotropic magnetic material is a nickel-iron material.
Claim 7
Dependent Claim
19 words
A magnetic transducer structure as defined in claim 1 wherein said separation layer is made of isotropic non-magnetic material.
Claim 8
Dependent Claim
17 words
A magnetic transducer structure as defined in claim 1 wherein said separation layer is an epoxy resin.
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) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |