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US4907115A
Expired / Lapsed
US
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Super conducting thin-film magnetic head including a magnetoresistive element
Assignee: US Philips Corp
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Filing: 1988-07-12
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Granted: 1990-03-06
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Expires: 2008-07-12
Abstract
Abstract Thin-film magnetic head including a magnetoresistive element (1) and a face (9) for magnetically coupling the element with a magnetic recording medium. A magnetic yoke constituted by three layers (3, 5, 7) of a magnetically permeable material has a gap (13) which is bridged by the magnetoresistive element. A layer (15) of a superconducting material for improving the efficiency of the magnetic head is provided between the layers (3) and (5) and the element (1) on the one hand and the layer (7) on the other hand. For protection from external disturbing magnetic fields and reduction of stray flux a layer (43A, 43B, respectively) of a superconducting material is provided on the layers (3) and (5) and under the layer (7).
Inventors
- 👤 Jacobus J. M. Ruigrok
- 👤 Victor Zieren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:54
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3916; G11B5/3919; G11B5/3922; G11B5/3925; G11B2005/0002; G11B2005/0032; G11B2005/0034; G11B2005/0037; G11B5/10; G11B5/11; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/872
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
A thin-film magnetic head including a magnetoresistive element and a face for magnetically coupling the magnetoresistive element with a magnetic recording medium, comprising a first layer and an aligned second layer, both consisting of a magnetically permeable material, a gap provided which is bridged by the magnetoresistive element, being present between said layers, the first layer having an end remote from the magnetoresistive element and adjoining the said face, and a third layer of a magnetically permeable material located on a side of the magnetoresistive element remote from the first and second layers extending from the said face and being magnetically connected to the second layer of a magnetically permeable material, characterized in that a layer of a superconducting material is provided between the magnetoresistive element and the third layer of a magnetically permeable material.
Claim 2
Dependent Claim
135 words
A thin-film magnetic head including a magnetoresistive element and a face for magnetically coupling the magnetoresistive element with a magnetic recording medium, comprising a first layer and an aligned second layer, both consisting of a magnetically permeable material, a gap provided which is bridged by the magnetoresistive element, being present between said layers, the first layer having an end remote from the magnetoresistive element and adjoining the said face, and a third layer of a magnetically permeable material located on a side of the magnetoresistive element remote from the first and second layers extending from the said face and being magnetically connected to the second layer of a magnetically permeable material, characterized in that a layer of a superconducting material is provided between the magnetoresistive element and the third layer of a magnetically permeable material.
Claim 3
Dependent Claim
32 words
A magnetic head as claimed in claim 1, characterized in that the layer of a superconducting material extends from the face for magnetically coupling the magnetoresistive element with a magnetic recording medium.
Claim 4
Dependent Claim
39 words
A magnetic head as claimed in claim 1, characterized in that a further layer of a superconducting material is provided on a side of the first and second layers of a magnetically permeable material remote from the magnetoresistive element.
Claim 5
Dependent Claim
43 words
A magnetic head as claimed in claim 1, characterized in that a layer of a superconducting material is provided on the side of the first, the second as well as the third layer of a magnetically permeable material remote from the magnetoresistive element.
References Cited (Backward Citations)
DE1522971A1
Cited
EP0021392A1
Cited
JPS56145514A
Cited
JPS56156914A
Cited
EP0063397A1
Cited
EP0122660A1
Cited
US4679107A
Cited
GB2146481A
Cited
JPS60154315A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |