Patent US4599668A successfully refreshed from Google Patents.
US4599668A
Expired / Lapsed
US
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Inductively-coupled, thin-film M-R head
Assignee: Eastman Kodak Co
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Filing: 1983-06-15
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Granted: 1986-07-08
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Expires: 2003-06-15
Abstract
Abstract The invention teaches that if a "shorted" electrically conductive turn--deposited on a magnetic substrate--is employed to sense recorded signal flux, then the underlying substrate will efficiently support flux induced about the shorted turn . . . and such induced flux will correspond proportionately to the recorded signal flux. In accordance with the invention, an MR element is so situated that it senses induced flux about the shorted turn at a location thereof that is remote from the medium whose signal flux is to be reproduced.
Inventors
- 👤 Neil J. Griffith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/17; G11B5/33; G11B5/39; G11B5/3903; G11B5/3967
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
177 words
A magnetic head for reproducing signals recorded in a track on a magnetic recording medium, said head comprising (a) a magnetic substrate, (b) a core structure magnetically short circuited to said magnetic substrate at a first point thereof, and physically separated from said substrate at a second point thereof, thereby to form a transducer gap for said head at said second point, (c) an electrically shorted turn of electrically conductive material partially disposed between said core structure and said magnetic substrate, said turn being supported by said head and so arranged with respect to said core structure and said substrate that changing magnetic flux which traverses said core structure and said substrate induces current in said electrically shorted turn, and (d) magnetoresistive means disposed remoted from said transducer gap but in such proximity to said shorted turn that flux induced about said shorted turn couples with said magnetoresistive means, thereby to produce a detectable change in the magnetization of said magnetoresistive means that is substantially immune to thermomechanically caused noise occurring in proximity to said transducer gap.
Claim 2
Dependent Claim
177 words
A magnetic head for reproducing signals recorded in a track on a magnetic recording medium, said head comprising (a) a magnetic substrate, (b) a core structure magnetically short circuited to said magnetic substrate at a first point thereof, and physically separated from said substrate at a second point thereof, thereby to form a transducer gap for said head at said second point, (c) an electrically shorted turn of electrically conductive material partially disposed between said core structure and said magnetic substrate, said turn being supported by said head and so arranged with respect to said core structure and said substrate that changing magnetic flux which traverses said core structure and said substrate induces current in said electrically shorted turn, and (d) magnetoresistive means disposed remoted from said transducer gap but in such proximity to said shorted turn that flux induced about said shorted turn couples with said magnetoresistive means, thereby to produce a detectable change in the magnetization of said magnetoresistive means that is substantially immune to thermomechanically caused noise occurring in proximity to said transducer gap.
Claim 3
Dependent Claim
29 words
The magnetic head of claim 1 wherein said electrically shorted turn of electrically conductive material is comprised of a thin film of electrically conductive material deposited on said substrate.
Claim 4
Dependent Claim
14 words
The magnetic head of claim 1 wherein said substrate is comprised of ferrite material.
Claim 5
Dependent Claim
29 words
The magnetic head of claim 3 wherein said electrically shorted turn of electrically conductive material is comprised of a thin film of electrically conductive material deposited on said substrate.
Claim 6
Dependent Claim
26 words
The magnetic head of claim 4 wherein said magnetoresistive means is disposed to carry current in the general direction of the widthwise dimension of said track.
Claim 7
Dependent Claim
30 words
The magnetic head of claim 4 wherein said magnetoresistive means is disposed to carry current in a direction that is generally perpendicular to the plane of said magnetic recording medium.
Claim 8
Dependent Claim
100 words
A magnetoresistive reproduce head for reproducing signals recorded in a track of a magnetic recording medium, said head comprising (a) first and second magnetic means disposed to form a transducer gap, (b) a shorted electrical turn so disposed with respect to said first and second magnetic means that changing flux in said means induces electrical current in said turn, and (c) magnetoresistive means disposed remote from said transducer gap but in such proximity to said shorted electrical turn that flux induced about said turn in response to current flow therein links said magnetoresistive means to affect the electrical resistance thereof.
Claim 9
Dependent Claim
100 words
A magnetoresistive reproduce head for reproducing signals recorded in a track of a magnetic recording medium, said head comprising (a) first and second magnetic means disposed to form a transducer gap, (b) a shorted electrical turn so disposed with respect to said first and second magnetic means that changing flux in said means induces electrical current in said turn, and (c) magnetoresistive means disposed remote from said transducer gap but in such proximity to said shorted electrical turn that flux induced about said turn in response to current flow therein links said magnetoresistive means to affect the electrical resistance thereof.
Claim 10
Dependent Claim
79 words
The reproduce head of claim 7 wherein (a) said first magnetic means is a magnetic substrate, (b) said second magnetic means is a magnetic thin film formed on said substrate, and (c) said shorted electrical turn is a thin film of electrically conductive material that is also deposited on said substrate, whereby said substrate, by virtue of its proximity to the shorted electrical turn formed thereon, provides efficient transfer of flux from about said turn to said magnetoresistive means.
Claim 11
Dependent Claim
15 words
The reproduce head of claim 8 wherein said magnetic substrate is comprised of ferrite material.
Claim 12
Dependent Claim
53 words
The reproduce head of claim 9 including means for conveying electrical current to and from said magnetoresistive means, said magnetoresistive means being so disposed with respect to said shorted electrical turn that, in operation, said magnetoresistive means carries current in a direction that is generally parallel to the crosswise dimension of said track.
Claim 13
Dependent Claim
54 words
The reproduce head of claim 9 including means for conveying electrical current to and from said magnetoresistive means, said magnetoresistive means being so disposed with respect to said shorted electrical turn that, in operation, said magnetoresistive means conveys current in a direction that is generally perpendicular to the plane of said magnetic recording medium.
References Cited (Backward Citations)
US3987485A
Cited
US3860965A
Cited
US3864751A
Cited
US4051542A
Cited
US4300177A
Cited
US4012781A
Cited
US4315291A
Cited
US4255772A
Cited
US4375657A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-07 | 1990-01-06 | 1990-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-07 | 1994-01-06 | 1994-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-07 | 1998-01-06 | 1998-07-08 | $7700.00 | Window Closed / Lapsed |