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US5014149A
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Thin film magnetic head
Assignee: Alps Alpine Co Ltd
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Filing: 1989-08-25
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Granted: 1991-05-07
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Expires: 2009-08-25
Abstract
Abstract A thin film magnetic head used for a magnetic disk device. The thin film magnetic head comprises two magnetic layers, a magnetic insulating layer sandwiched between the magnetic layers, an intermediate magnetic layer which is thinner than the magnetic layers, and an intermediate magnetic insulating layer formed in the vicinity of a gap surface between the intermediate magnetic layer and one of the magnetic layers. A track width in the gap surface of the intermediate magnetic layer is narrower than a track width in the gap surface of the two magnetic layers.
Inventors
- 👤 Atsushi Ibaraki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:32
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109; G11B5/313; G11B5/187; G11B5/245; G11B5/2452
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
106 words
A thin magnetic head comprising: two magnetic layers each formed of a magnetic material; a magnetic insulating layer formed of a non-magnetic material, said magnetic insulating layer being sandwiched between said two magnetic layers; an intermediate magnetic layer formed to be thinner than said magnetic layers and within said magnetic insulating layer along one of said two magnetic layers; and an intermediate magnetic insulating layer formed in the vicinity of at least a gap surface between said intermediate magnetic layer and one of said magnetic layers, wherein said intermediate magnetic layer has a lower saturated magnetic flux density than does either of said two magnetic layers.
Claim 2
Dependent Claim
106 words
A thin magnetic head comprising: two magnetic layers each formed of a magnetic material; a magnetic insulating layer formed of a non-magnetic material, said magnetic insulating layer being sandwiched between said two magnetic layers; an intermediate magnetic layer formed to be thinner than said magnetic layers and within said magnetic insulating layer along one of said two magnetic layers; and an intermediate magnetic insulating layer formed in the vicinity of at least a gap surface between said intermediate magnetic layer and one of said magnetic layers, wherein said intermediate magnetic layer has a lower saturated magnetic flux density than does either of said two magnetic layers.
Claim 3
Dependent Claim
40 words
A thin film magnetic head according to claim 1, wherein a track width in the gap surface of said intermediate magnetic layer is formed to be narrower than a track width in the gap surface of said two magnetic layers.
Claim 4
Dependent Claim
54 words
The device of claim 1, wherein said intermediate magnetic insulating layer extends between all of said intermediate magnetic layer and said magnetic layer, and wherein said intermediate magnetic layer has substantially the same thickness in said vicinity of said gap surface as a thickness in a second vicinity spaced apart from said gap surface.
References Cited (Backward Citations)
US4644432A
Cited
US4897749A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-06 | 1994-11-05 | 1995-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-06 | 1998-11-05 | 1999-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-06 | 2002-11-05 | 2003-05-07 | $7700.00 | Window Closed / Lapsed |