US4255772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Read/write magnetic head assembly with magnetoresistive sensor
Assignee: International Business Machines Corp
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Filing: 1979-06-29
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Granted: 1981-03-10
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Expires: 1999-06-29
Abstract
Abstract A thin film magnetic head assembly incorporates a nonconductive magnetic substrate which serves as a first pole piece and a thin film magnetic layer for the second pole piece. A magnetoresistive (MR) element is disposed between the pole pieces. During the write mode, the MR element serves as a partial write turn to enhance the write signal current applied to a conductor means. During the read mode, the conductor means serves as a magnetic shield, and the transducing gap is effectively narrowed.
Inventors
- 👤 Henry S. Perez
- 👤 Theodore A. Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:57
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3967; G11B5/31; G11B5/3109; G11B5/313
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
163 words
A thin film magnetic head assembly for recording and reading data comprising: a magnetic substrate for serving as a first pole piece, said substrate having an air bearing surface; a magnetically soft conductor means for providing magnetic shielding disposed on a second surface of said substrate , a portion of said conductor means being at said air bearing surface, said second surface being substantially orthogonal to said air bearing surface: a second pole piece located in juxtaposition to said substrate to form a magnetic circuit with said first pole piece; a magnetoresistive element disposed between said conductor means and said second pole piece; a first insulating layer disposed between said conductor means and said magnetoresistive element; a second insulating layer disposed between said magnetoresistive element and said second pole piece, so that a write transducing gap is formed between said substrate and said second pole piece, and a read transducing gap is effectively formed between said conductor means and said second pole piece.
Claim 2
Dependent Claim
163 words
A thin film magnetic head assembly for recording and reading data comprising: a magnetic substrate for serving as a first pole piece, said substrate having an air bearing surface; a magnetically soft conductor means for providing magnetic shielding disposed on a second surface of said substrate , a portion of said conductor means being at said air bearing surface, said second surface being substantially orthogonal to said air bearing surface: a second pole piece located in juxtaposition to said substrate to form a magnetic circuit with said first pole piece; a magnetoresistive element disposed between said conductor means and said second pole piece; a first insulating layer disposed between said conductor means and said magnetoresistive element; a second insulating layer disposed between said magnetoresistive element and said second pole piece, so that a write transducing gap is formed between said substrate and said second pole piece, and a read transducing gap is effectively formed between said conductor means and said second pole piece.
Claim 3
Dependent Claim
31 words
A thin film magnetic head assembly as in claim 1, wherein said first pole piece is made of nonconductive ferrite and said second pole piece is made of thin film Permalloy.
Claim 4
Dependent Claim
22 words
A thin film magnetic head assembly as in claim 1, wherein said conductor means comprises outer and inner turns of conductive material.
Claim 5
Dependent Claim
28 words
A thin film magnetic head assembly as in claim 3, wherein said outer turn is made of Permalloy and said inner turn is made of copper or gold.
Claim 6
Dependent Claim
25 words
A thin film magnetic head assembly as in claim 3, wherein said outer turn has a portion that is coincident with said air bearing surface.
Claim 7
Dependent Claim
27 words
A thin film magnetic head assembly as in claim 1, wherein said head assembly includes a transducing gap, and said magnetoresistive element is located within said gap.
Claim 8
Dependent Claim
36 words
A thin film magnetic head assembly as in claim 6, wherein said magnetoresistive element, said pole pieces and said conductor means have end portions that are disposed in a common plane at said air bearing surface.
Claim 9
Dependent Claim
24 words
A thin film magnetic head assembly as in claim 1, wherein said magnetoresistive element serves as a write turn during the data write mode.
Claim 10
Dependent Claim
22 words
A thin film magnetic head assembly as in claim 1, wherein said conductor means serves as a shield during the read mode.
Claim 11
Dependent Claim
20 words
A thin film magnetic head assembly as in claim 1, wherein said magnetoresistive element comprises layers of Permalloy and titanium.
Claim 12
Dependent Claim
20 words
A magnetic head assembly as in claim 1, wherein a wide recording gap and a narrow reproduce gap are coincident.
Claim 13
Dependent Claim
23 words
A magnetic head assembly as in claim 1, wherein said head defines a wide recording track width and a narrower reproduce track width.
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) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |