US4649448A
Expired / Lapsed
US
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Thin film magnetic head having a sliding surface
Assignee: Hitachi Ltd
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Filing: 1984-06-04
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Granted: 1987-03-10
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Expires: 2004-06-04
Abstract
Abstract In a thin film magnetic head having a thin film on a substrate to form a magnetic circuit associated with a recording medium, a sliding surface of the substrate opposing the recording medium is made of a material; namely, ZrO2, having a coefficient of thermal conductivity which is sufficient to carbonize a binder of the recording medium when the magnetic head slides on the recording medium, so that a carbonized material can afford to provide good slidability of the recording medium against the magnetic head and life of the thin film magnetic head and recording medium can be prolonged.
Inventors
- 👤 Hiroyasu Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:49
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/40; G11B23/00; G11B23/50; G11B5/127; G11B5/31; G11B5/3103; G11B5/3106
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
77 words
In a thin film magnetic head having a thin film on a substrate to form a magnetic circuit associated with a recording medium, the improvement wherein at least a sliding surface of said substrate opposing said recording medium is made of a material having a coefficient to thermal conductivity which is sufficient to carbonize a binder of said recording medium when said magnetic head slides on said recording medium; said material consisting essentially of ZrO 2 .
Claim 2
Dependent Claim
77 words
In a thin film magnetic head having a thin film on a substrate to form a magnetic circuit associated with a recording medium, the improvement wherein at least a sliding surface of said substrate opposing said recording medium is made of a material having a coefficient to thermal conductivity which is sufficient to carbonize a binder of said recording medium when said magnetic head slides on said recording medium; said material consisting essentially of ZrO 2 .
Claim 3
Dependent Claim
17 words
A thin film magnetic head according to claim 1 wherein said material consists of ZrO 2 .
Claim 4
Dependent Claim
23 words
A thin film magnetic head according to claim 1 wherein the coefficient of thermal conductivity of said material is less than 0.03 cal/cm·sec·°C.
References Cited (Backward Citations)
US4409633A
Cited
JPS5589915A
Cited
US4317147A
Cited
JPS56137516A
Cited
US4441132A
Cited
US4430440A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-09 | 1990-09-08 | 1991-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-09 | 1994-09-08 | 1995-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-09 | 1998-09-08 | 1999-03-10 | $7700.00 | Window Closed / Lapsed |