US5134534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin-film magnetic head with enhanced crosstalk reduction
Assignee: Canon Inc
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Filing: 1990-03-06
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Granted: 1992-07-28
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Expires: 2010-03-06
Abstract
Abstract In a thin-film magnetic head including a magnetic circuit which is composed of upper and lower magnetic layers and a coil made of a conductive layer, a magnetic shield layer made of a conductive material is provided on the upper magnetic layer; and the intensity of the magnetic reluctance of the magnetic shielding action of the magnetic shield layer is arranged to be adjustable.
Inventors
- 👤 Toyoshige Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/10; G11B5/11; G11B5/112; G11B5/127; G11B5/29; G11B5/31; G11B5/3109; G11B5/313; G11B5/3143
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
81 words
A thin-film magnetic head comprising: a) a magnetic circuit part which is composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap; b) a coil which is made of electrically conductive material and is disposed between said upper and lower magnetic layers; and c) a magnetic shield layer which is disposed on said upper magnetic layer and is made of electrically conductive material, the amount of the magnetic reluctance of said magnetic shield layer being externally adjustable.
Claim 2
Dependent Claim
81 words
A thin-film magnetic head comprising: a) a magnetic circuit part which is composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap; b) a coil which is made of electrically conductive material and is disposed between said upper and lower magnetic layers; and c) a magnetic shield layer which is disposed on said upper magnetic layer and is made of electrically conductive material, the amount of the magnetic reluctance of said magnetic shield layer being externally adjustable.
Claim 3
Dependent Claim
61 words
A magnetic head according to claim 1, wherein said magnetic shield layer includes a plurality of first conductive lines which are arranged in rows in the direction of the track width of said magnetic gap and a plurality of second conductive lines which have smaller sectional areas than said first conductive lines and are arranged to intersect said first conductive lines.
Claim 4
Dependent Claim
40 words
A magnetic head according to claim 2, wherein said plurality of first conductive lines include at least three parallel lines, and wherein a voltage is arranged to be applied to two lines selected from said plurality of first conductive lines.
Claim 5
Dependent Claim
82 words
A magnetic head according to claim 1, wherein said magnetic shield layer includes a plurality of conductive layers, each of which is composed of a plurality of first conductive lines which are arranged in rows in the direction of the track width of said magnetic gap and a plurality of second conductive lines which are arranged to intersect said plurality of first lines, and wherein a voltage is arranged to be applied to a layer selected from said plurality of conductive layers.
Claim 6
Dependent Claim
69 words
A thin-film magnetic head comprising: a) a magnetic circuit part composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap; b) a coil disposed between said upper and lower magnetic layers and made of electrically conductive material; and c) a magnetic shield layer disposed on said upper magnetic layer, said magnetic shield layer including an electrically conductive part which is formed in a lattice-like shape.
Claim 7
Dependent Claim
69 words
A thin-film magnetic head comprising: a) a magnetic circuit part composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap; b) a coil disposed between said upper and lower magnetic layers and made of electrically conductive material; and c) a magnetic shield layer disposed on said upper magnetic layer, said magnetic shield layer including an electrically conductive part which is formed in a lattice-like shape.
Claim 8
Dependent Claim
49 words
A magnetic head according to claim 5, wherein said conductive part includes a plurality of first lines which are arranged in rows in the direction of the track width of said magnetic gape and a plurality of second lines which are arranged to intersect said plurality of first lines.
Claim 9
Dependent Claim
26 words
A magnetic head according to claim 6, wherein sectional areas of said plurality of second lines are smaller than those of said plurality of first lines.
Claim 10
Dependent Claim
19 words
A magnetic head according to claim 7, wherein said plurality of first lines include at least three parallel lines.
Claim 11
Dependent Claim
27 words
A magnetic head according to claim 8, wherein said plurality of first lines and said plurality of second lines are formed on one and the same plane.
Claim 12
Dependent Claim
21 words
A magnetic head according to claim 8, wherein said plurality of first lines are formed on said plurality of second lines.
Claim 13
Dependent Claim
58 words
A magnetic head according to claim 7, wherein said conductive part includes a plurality cf conductive layers, each of which is composed of a plurality of first lines which are arranged in rows in the direction of the track width of said magnetic gap and a plurality of second lines which are arranged to intersect said first lines.
Claim 14
Dependent Claim
117 words
A thin-film magnetic head comprising: a) a plurality of magnetic circuit parts, each of which is composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap, said lower magnetic layer being provided in common for all said plurality of magnetic circuit parts; b) coils each of which is made of electrically conductive material and is disposed between said upper and lower magnetic layers in each of said plurality of magnetic circuit parts; and c) a magnetic shield layer disposed on said upper magnetic layer of each of said plurality of magnetic circuit parts, said magnetic shield layer being made of electrically conductive material and having the amount of the magnetic reluctance externally adjustable.
Claim 15
Dependent Claim
117 words
A thin-film magnetic head comprising: a) a plurality of magnetic circuit parts, each of which is composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap, said lower magnetic layer being provided in common for all said plurality of magnetic circuit parts; b) coils each of which is made of electrically conductive material and is disposed between said upper and lower magnetic layers in each of said plurality of magnetic circuit parts; and c) a magnetic shield layer disposed on said upper magnetic layer of each of said plurality of magnetic circuit parts, said magnetic shield layer being made of electrically conductive material and having the amount of the magnetic reluctance externally adjustable.
Claim 16
Dependent Claim
61 words
A magnetic head according to claim 12, wherein said magnetic shield layer includes a plurality of first conductive lines which are arranged in rows in the direction of the track width of said magnetic gap and a plurality of second conductive lines which have smaller sectional areas than said first conductive lines and are arranged to intersect said first conductive lines.
Claim 17
Dependent Claim
30 words
A magnetic head according to claim 13, wherein said plurality of first conductive lines are formed to straddle over said upper magnetic layers of said plurality of magnetic circuit parts.
Claim 18
Dependent Claim
113 words
A thin-film magnetic head comprising: a) a plurality of magnetic circuit parts, each of which is composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap, said lower magnetic layer being provided in common for all said plurality of magnetic circuit parts; b) coils, each of which is made of a conductive material and is disposed between said upper and lower magnetic layers in each of said plurality of magnetic circuit parts; and c) a magnetic shield layer disposed on said upper magnetic layer of each of said plurality of magnetic circuit parts, said magnetic shield layer including an electrically conductive part which is formed in a lattice-like shape.
Claim 19
Dependent Claim
113 words
A thin-film magnetic head comprising: a) a plurality of magnetic circuit parts, each of which is composed of an upper magnetic layer, a lower magnetic layer and a magnetic gap, said lower magnetic layer being provided in common for all said plurality of magnetic circuit parts; b) coils, each of which is made of a conductive material and is disposed between said upper and lower magnetic layers in each of said plurality of magnetic circuit parts; and c) a magnetic shield layer disposed on said upper magnetic layer of each of said plurality of magnetic circuit parts, said magnetic shield layer including an electrically conductive part which is formed in a lattice-like shape.
Claim 20
Dependent Claim
61 words
A magnetic head according to claim 15, wherein said magnetic shield layer includes a plurality of first conductive lines which are arranged in rows in the direction of the track width of said magnetic gap and a plurality of second conductive lines which have sectional areas smaller than said first conductive lines and are arranged to intersect said first conductive lines.
Claim 21
Dependent Claim
30 words
A magnetic head according to claim 16, wherein said plurality of first conductive lines are formed to straddle over said upper magnetic layers of said plurality of magnetic circuit parts.
References Cited (Backward Citations)
US4901178A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-28 | 1996-01-27 | 1996-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-28 | 2000-01-27 | 2000-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-28 | 2004-01-27 | 2004-07-28 | $7700.00 | Window Closed / Lapsed |