Patent US4695908A successfully refreshed from Google Patents.
US4695908A
Expired / Lapsed
US
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Thin film type magnetic transducer head
Assignee: Sony Corp
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Filing: 1984-08-23
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Granted: 1987-09-22
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Expires: 2004-08-23
Abstract
Abstract A thin film type magnetic transducer head comprises a magnetic substrate, and a thin film magnetic core formed on the substrate through an effective magnetic gap at one end of the substrate to be faced to a magnetic recording medium, the magnetic substrate and the thin film magnetic core forming a magnetic circuit to reproduce signals on the magnetic medium, wherein a length between a center of the magnetic gap and an edge of the magnetic core and wave length satisfy definite relations, thereby the S/N ratio and the output are improved in the digital magnetic recording.
Inventors
- 👤 Shigeyoshi Imakoshi
- 👤 Yutaka Soda
- 👤 Hideo Suyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:04
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/02; G11B5/09; G11B5/31; G11B5/3109; G11B5/3116
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
132 words
A thin film type magnetic transducer head comprising a magnetic substrate, and a thin film magnetic core forced on said substrate through an effective magnetic gap at one end of said substrate arranged to face a travelling magnetic recording medium, said magnetic substrate and said thin film magnetic core forming a magnetic circuit to reproduce signals on said travelling magnetic medium, wherein a length b and a wave length λm=v/f m satisfy the following relations b<0.64λm, or 0.83λm<b<1.61λm wherein b is the thickness of said thin film magnetic core facing said travelling magnetic recording medium plus one-half the gap length of said effective magnetic gap, v is the relative velocity of said travelling magnetic recording medium to said magnetic transducer head, and f m is maximum frequency or half of transmission rate.
Claim 2
Dependent Claim
132 words
A thin film type magnetic transducer head comprising a magnetic substrate, and a thin film magnetic core forced on said substrate through an effective magnetic gap at one end of said substrate arranged to face a travelling magnetic recording medium, said magnetic substrate and said thin film magnetic core forming a magnetic circuit to reproduce signals on said travelling magnetic medium, wherein a length b and a wave length λm=v/f m satisfy the following relations b<0.64λm, or 0.83λm<b<1.61λm wherein b is the thickness of said thin film magnetic core facing said travelling magnetic recording medium plus one-half the gap length of said effective magnetic gap, v is the relative velocity of said travelling magnetic recording medium to said magnetic transducer head, and f m is maximum frequency or half of transmission rate.
Claim 3
Dependent Claim
130 words
A thin film type magnetic transducer head comprising a magnetic substrate, and a thin film magnetic core formed on said substrate through an effective magnetic gap at one end of said substrate arranged to face a travelling magnetic recording medium, said magnetic substrate and said thin film magnetic core forming a magnetic circuit to reproduce signals on said travelling magnetic medium, wherein a length b and a wave length λm=v/f m satisfy the following relations 0.83λm<b<1.33λm wherein b is the thickness of said thin film magnetic core facing said travelling magnetic recording medium plus one-half the gap length of said effective magnetic gap, v is the relative velocity of said travelling magnetic recording medium to said magnetic transducer head, and f m is maximum frequency or half the transmission rate.
Claim 4
Dependent Claim
130 words
A thin film type magnetic transducer head comprising a magnetic substrate, and a thin film magnetic core formed on said substrate through an effective magnetic gap at one end of said substrate arranged to face a travelling magnetic recording medium, said magnetic substrate and said thin film magnetic core forming a magnetic circuit to reproduce signals on said travelling magnetic medium, wherein a length b and a wave length λm=v/f m satisfy the following relations 0.83λm<b<1.33λm wherein b is the thickness of said thin film magnetic core facing said travelling magnetic recording medium plus one-half the gap length of said effective magnetic gap, v is the relative velocity of said travelling magnetic recording medium to said magnetic transducer head, and f m is maximum frequency or half the transmission rate.
Claim 5
Dependent Claim
129 words
A thin film type magnetic transducer head comprising a magnetic substrate, and a thin film magnetic core formed on said substrate through an effective magnetic gap at one end of said substrate arranged to face a travelling magnetic recording medium, said magnetic substrate and said thin film magnetic core forming a magnetic circuit to reproduce signals on said travelling magnetic medium, wherein a length b and a wave length λm=v/f m satisfy the following relations b<0.64λm, or 1.06λm<b<1.61λm wherein b is thickness of said thin film magnetic core facing said travelling magnetic recording medium plus one-half the gap length of said effective magnetic gap, v is relative velocity of said travelling magnetic recording medium to said magnetic transducer head, f m is maximum frequency or half the transmission rate.
Claim 6
Dependent Claim
129 words
A thin film type magnetic transducer head comprising a magnetic substrate, and a thin film magnetic core formed on said substrate through an effective magnetic gap at one end of said substrate arranged to face a travelling magnetic recording medium, said magnetic substrate and said thin film magnetic core forming a magnetic circuit to reproduce signals on said travelling magnetic medium, wherein a length b and a wave length λm=v/f m satisfy the following relations b<0.64λm, or 1.06λm<b<1.61λm wherein b is thickness of said thin film magnetic core facing said travelling magnetic recording medium plus one-half the gap length of said effective magnetic gap, v is relative velocity of said travelling magnetic recording medium to said magnetic transducer head, f m is maximum frequency or half the transmission rate.
References Cited (Backward Citations)
US4490760A
Cited
US4423451A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |