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US4556925A
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Magnetoresistive head
Assignee: Hitachi Ltd
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Filing: 1982-07-28
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Granted: 1985-12-03
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Expires: 2002-07-28
Abstract
Abstract A magnetoresistive head comprising a magnetoresistive element, to which a magnetic bias field is applied, is disposed opposite to a magnetic recording medium moving relative thereto, and the resistance value of the magnetoresistive element varying as a result of the relative movement of the magnetoresistive element and the magnetic recording medium is detected to reproduce information recorded on the magnetic recording medium. The magnetoresistive element of the magnetic head has an elongate shape extending along the easy axis of magnetization and has protrusions at its longitudinal ends. The protrusions have, for example, a semicircular or triangular contour. These protrusions are effective for suppressing formation of undesirable domain walls in the magnetoresistive element, so that the magnetic head can operate without substantial variation of its output voltage level and with reduced Barkhousen noise.
Inventors
- 👤 Masahide Suenaga
- 👤 Kousaku Chida
- 👤 Masaki Ohura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:28
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/398; G11B5/399; H; H10; H10N; H10N50/00; H10N50/10
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
130 words
A magnetoresistive head for reproducing information recorded on a magnetic recording medium by movement to the recording medium comprising: an elongate magnetoresistive element of a magnetically anisotropic material disposed opposite to said recording medium and having protrusions provided by extending the both ends thereof along a longitudinal axis coinciding with the easy axis of magnetization of said magnetically anisotropic material so that said magnetoresistive element has a non-rectangular configuration; magnetic bias field applying means for applying a magnetic bias field to said magnetoresistive element in a predetermined direction; conductive terminals connected to opposite ends of said magnetoresistive element in said longitudinal axis, for electrically connecting said magnetoresistive element to an external circuit; and a substrate mounting said magnetoresistive element, said conductive terminals and said magnetic bias field applying means thereon.
Claim 2
Dependent Claim
130 words
A magnetoresistive head for reproducing information recorded on a magnetic recording medium by movement to the recording medium comprising: an elongate magnetoresistive element of a magnetically anisotropic material disposed opposite to said recording medium and having protrusions provided by extending the both ends thereof along a longitudinal axis coinciding with the easy axis of magnetization of said magnetically anisotropic material so that said magnetoresistive element has a non-rectangular configuration; magnetic bias field applying means for applying a magnetic bias field to said magnetoresistive element in a predetermined direction; conductive terminals connected to opposite ends of said magnetoresistive element in said longitudinal axis, for electrically connecting said magnetoresistive element to an external circuit; and a substrate mounting said magnetoresistive element, said conductive terminals and said magnetic bias field applying means thereon.
Claim 3
Dependent Claim
51 words
A magnetoresistive head according to claim 1, wherein said magnetic bias field applying means includes a plurality of parallel short bars arranged to make a predetermined angle with the easy axis of magnetization of said magnetoresistive element so as to generate the magnetic bias field when a current is supplied thereto.
Claim 4
Dependent Claim
23 words
A magnetoresistive head according to claim 1, wherein said magnetic bias field applying means includes a permanent magnet for biasing said magnetoresistive element.
Claim 5
Dependent Claim
28 words
A magnetoresistive head according to claim 1, wherein said magnetic bias field applying means applies a magnetic bias field to said magnetoresistive element of less than 3 Oe.
Claim 6
Dependent Claim
107 words
A magnetoresistive head comprising an elongate magnetoresistive element of a magnetically anisotropic material which at its both ends has conductive terminals for connection to a current source and means for forcing the current to flow through said magnetoresistive element at a predetermined angle with an easy axis of magnetization of said element thereby applying a magnetic bias field to said magnetoresistive element, wherein said magnetoresistive element has a longitudinal axis which coincides with the easy axis of magnetization thereof, and the longitudinal ends of said magnetoresistive element are extended along the easy axis of magnetization to provide protrusions so that said magnetoresistive element has a non-rectangular configuration.
Claim 7
Dependent Claim
107 words
A magnetoresistive head comprising an elongate magnetoresistive element of a magnetically anisotropic material which at its both ends has conductive terminals for connection to a current source and means for forcing the current to flow through said magnetoresistive element at a predetermined angle with an easy axis of magnetization of said element thereby applying a magnetic bias field to said magnetoresistive element, wherein said magnetoresistive element has a longitudinal axis which coincides with the easy axis of magnetization thereof, and the longitudinal ends of said magnetoresistive element are extended along the easy axis of magnetization to provide protrusions so that said magnetoresistive element has a non-rectangular configuration.
Claim 8
Dependent Claim
20 words
A magnetoresistive head according to claim 1 or 5, wherein said protrusions of said magnetoresistive element have an arcuate contour.
Claim 9
Dependent Claim
41 words
A magnetoresistive head according to claim 1 or 5, wherein each of said protrusions of said magnetoresistive element has a triangular contour having an angle outwardly protruding along the easy axis of magnetization as one of the vertices of the triangle.
Claim 10
Dependent Claim
20 words
A magnetoresistive head according to claim 1 or 5, wherein said protrusions of said magnetoresistive element have a quadrant contour.
Claim 11
Dependent Claim
34 words
A magnetoresistive head according to claim 5, wherein said means for forcing the current to flow through said magnetoresistive element applies a magnetic bias field to said magnetoresistive element of less than 3 Oe.
Claim 12
Dependent Claim
152 words
A magnetoresistive head for reproducing information recorded on a magnetic recording medium by movement relative to the recording medium comprising: an elongate magnetoresistive element of a magnetically anisotropic material disposed opposite to said recording medium, said magnetoresistive element including means in the form of a main body portion and means in the form of two end portions respectively disposed along the longitudinal axis of the main body portion, said means in the form of the end portions being configured for suppressing the formation of undesirable domain walls in said magnetoresistive element; magnetic bias field applying means for applying a magnetic bias field to said magnetoresistive element in a predetermined direction; a conductive terminals connected to opposite ends of said magnetoresistive element in said longitudinal axis, for electrically connecting said magnetoresistive element through an external circuit; and a substrate mounting said magnetoresistive element, said conductive terminals and said magnetic bias applying means thereon.
Claim 13
Dependent Claim
152 words
A magnetoresistive head for reproducing information recorded on a magnetic recording medium by movement relative to the recording medium comprising: an elongate magnetoresistive element of a magnetically anisotropic material disposed opposite to said recording medium, said magnetoresistive element including means in the form of a main body portion and means in the form of two end portions respectively disposed along the longitudinal axis of the main body portion, said means in the form of the end portions being configured for suppressing the formation of undesirable domain walls in said magnetoresistive element; magnetic bias field applying means for applying a magnetic bias field to said magnetoresistive element in a predetermined direction; a conductive terminals connected to opposite ends of said magnetoresistive element in said longitudinal axis, for electrically connecting said magnetoresistive element through an external circuit; and a substrate mounting said magnetoresistive element, said conductive terminals and said magnetic bias applying means thereon.
Claim 14
Dependent Claim
24 words
A magnetoresistive head according to claim 10 wherein said magnetic bias field applying means applies a magnetic bias field of less than 3 Oe.
Claim 15
Dependent Claim
51 words
A magnetoresistive head according to claim 11, wherein said magnetic bias field applying means includes a plurality of parallel short bars arranged to make a predetermined angle with the easy axis of magnetization of said magnetoresistive element so as to generate the magnetic bais field when a current is supplied thereto.
Claim 16
Dependent Claim
23 words
A magnetoresistive head according to claim 11, wherein said magnetic bias field applying means includes a permanent magnet for biasing said magnetoresistive element.
Claim 17
Dependent Claim
20 words
A magnetoresistive head according to claim 10, wherein said two end portions of said magnetoresistive element have a non-rectangular configuration.
Claim 18
Dependent Claim
17 words
A magnetoresistive head according to claim 14, wherein said main body portion has a substantially rectangular configuration.
Claim 19
Dependent Claim
55 words
A magnetoresistive head according to claim 14 wherein the longitudinal axis of said magnetoresistive element coincides with the easy axis of magnetization of said magnetically anisotropic material, said end portions adjoining said main body portion having an outer contour with protrusions extending in opposite directions outwardly from the main body portion along the longitudinal axis.
Claim 20
Dependent Claim
14 words
A magnetoresistive head according to claim 16, wherein said protrusions have an arcuate contour.
Claim 21
Dependent Claim
40 words
A magnetoresistive head according to claim 16, wherein said two end portions have a triangular configuration with said protrusions being formed as an angle outwardly protruding along the easy axis of magnetization as one of the vertices of the triangle.
Claim 22
Dependent Claim
14 words
A magnetoresistive head according to claim 16, wherein said protrusions have a quadrant contour.
Claim 23
Dependent Claim
28 words
A magnetoresistive head according to claim 16, wherein said magnetic bias field applying means applies a magnetic bias field to said magnetoresistive element of less than 3 Oe.
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) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |