Patent US4641213A successfully refreshed from Google Patents.
US4641213A
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Magnetic head
Assignee: Alps Alpine Co Ltd
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Filing: 1984-07-16
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Granted: 1987-02-03
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Expires: 2004-07-16
Abstract
Abstract A cobalt-base ternary alloy containing small amounts of hafnium and tantalum formed by sputtering, vapor deposition, etc., is used as the principal magnetic pole of a magnetic head for perpendicular magnetic recording, the core thin layers of a thin layer magnetic recording head, or the magnetic shield thin layers of a thin layer magnetic reproducing head. The ternary amorphous alloy has a high permeability and a high saturation magnetic flux density and hence the thickness of the foregoing layers composed of the alloy can be reduced as thin as possible.
Inventors
- 👤 Yutaka Shimada
- 👤 Takashi Hatanai
- 👤 Koichi Mukasa
- 👤 Keishi Nakashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:46
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/1278; G11B5/31; G11B5/3109
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
82 words
A magnetic head for perpendicular magnetic recording for magnetizing in the thickness direction of a magnetic layer of a magnetic recording medium by disposing the principal magnetic pole of the magnetic head facing a surface of the magnetic layer, wherein said principal magnetic pole is composed of a cobalt-based ternary amorphous alloy containing small amounts of hafnium and tantalum, wherein the content of hafnium is from 1 atom% to 5 atom% and the content of tantalum is from 4 to 10 atom%.
Claim 2
Dependent Claim
82 words
A magnetic head for perpendicular magnetic recording for magnetizing in the thickness direction of a magnetic layer of a magnetic recording medium by disposing the principal magnetic pole of the magnetic head facing a surface of the magnetic layer, wherein said principal magnetic pole is composed of a cobalt-based ternary amorphous alloy containing small amounts of hafnium and tantalum, wherein the content of hafnium is from 1 atom% to 5 atom% and the content of tantalum is from 4 to 10 atom%.
Claim 3
Dependent Claim
77 words
A thin layer magnetic head comprising a base plate composed of a non-magnetic material having formed thereon in layers a first core thin layer, a non-magnetic thin layer, and a second core thin layer, wherein the core layers are composed of a cobalt-based ternary amorphous alloy containing small amounts of hafnium and tantalum, wherein the content of hafnium is from 1 atom% to 5 atom% and the content of tantalum is from 4 atom% to 10 atom%.
Claim 4
Dependent Claim
77 words
A thin layer magnetic head comprising a base plate composed of a non-magnetic material having formed thereon in layers a first core thin layer, a non-magnetic thin layer, and a second core thin layer, wherein the core layers are composed of a cobalt-based ternary amorphous alloy containing small amounts of hafnium and tantalum, wherein the content of hafnium is from 1 atom% to 5 atom% and the content of tantalum is from 4 atom% to 10 atom%.
Claim 5
Dependent Claim
70 words
A thin layer magnetic reproducing head comprising a magnetic resistance effect element having magnetic shield thin layers formed on both sides of the element, respectively, wherein the magnetic shield thin layers are composed of a cobalt-based ternary amorphous alloy containing small amounts of hafnium and tantalum, wherein the content of hafnium is from 1 atom% to 5 atom% and the content of tantalum is from 4 atom% to 10 atom%.
Claim 6
Dependent Claim
70 words
A thin layer magnetic reproducing head comprising a magnetic resistance effect element having magnetic shield thin layers formed on both sides of the element, respectively, wherein the magnetic shield thin layers are composed of a cobalt-based ternary amorphous alloy containing small amounts of hafnium and tantalum, wherein the content of hafnium is from 1 atom% to 5 atom% and the content of tantalum is from 4 atom% to 10 atom%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-02 | 1990-08-04 | 1991-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-02 | 1994-08-04 | 1995-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-02 | 1998-08-04 | 1999-02-03 | $7700.00 | Window Closed / Lapsed |