Patent US4687712A successfully refreshed from Google Patents.
US4687712A
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Vertical magnetic recording medium
Assignee: Panasonic Holdings Corp
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Filing: 1984-12-04
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Granted: 1987-08-18
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Expires: 2004-12-04
Abstract
Abstract A vertical magnetic recording medium comprises a non-magnetic substrate, a permalloy film consisting of plural permalloy layers separated by at least one non-magnetic layer placed therein, each of said plurality of permalloy layers being 2000 ANGSTROM or less thick, and a Co-Cr vertical magnetization film formed on the permalloy film directly or through another non-magnetic layer.
Inventors
- 👤 Ryuji Sugita
- 👤 Kazuyoshi Honda
- 👤 Hiroshi Nishida
- 👤 Kyoji Noda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:27
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/676; G11B5/678; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12632; Y10T428/12771; Y10T428/12806; Y10T428/12861; Y10T428/12931; Y10T428/12937
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
80 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therein, each of said plurality of permalloy layers being 2000 Å or less thick, and a vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 2
Dependent Claim
80 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therein, each of said plurality of permalloy layers being 2000 Å or less thick, and a vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 3
Dependent Claim
23 words
A vertical magnetization recording medium according to claim 1, wherein said first non-magnetic layer ranges from 10 Å to 500 Å in thickness.
Claim 4
Dependent Claim
18 words
A vertical magnetization recording medium according to claim 1, wherein said first non-magnetic layer is made of Ti.
Claim 5
Dependent Claim
23 words
A vertical magnetization recording medium according to claim 3, wherein said first magnetic layer ranges from 10 Å to 500 Å in thickness.
Claim 6
Dependent Claim
29 words
A vertical magnetization recording medium according to claim 1, wherein at least one pair of layers among said plurality of permalloy layers have a different thickness from each other.
Claim 7
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 5, wherein said first non-magnetic layer is made of Ti.
Claim 8
Dependent Claim
48 words
A vertical magnetic recording medium according to claim 5, wherein said at least one pair of layers are an upper layer most adjacent to the vertical magnetization film and a lower layer most adjacent to the non-magnetic substrate, and the upper layer is thinner than the lower layer.
Claim 9
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 7, wherein said first non-magnetic layer is made of Ti.
Claim 10
Dependent Claim
81 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therein, each of said plurality of permalloy layers being 2000 Å or less thick, and a Co-Cr vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 11
Dependent Claim
81 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therein, each of said plurality of permalloy layers being 2000 Å or less thick, and a Co-Cr vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 12
Dependent Claim
23 words
A vertical magnetization recording medium according to claim 9, wherein said first non-magnetic layer ranges from 10 Å to 500 Å in thickness.
Claim 13
Dependent Claim
18 words
A vertical magnetization recording medium according to claim 9, wherein said first non-magnetic layer is made of Ti.
Claim 14
Dependent Claim
23 words
A vertical magnetization recording medium according to claim 11, wherein said first non-magnetic layer ranges from 10 Å to 500 Å in thickness.
Claim 15
Dependent Claim
29 words
A vertical magnetization recording medium according to claim 9, wherein at least one pair of layers among said plurality of permalloy layers have a different thickness from each other.
Claim 16
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 13, wherein said first non-agnetic layer is made of Ti.
Claim 17
Dependent Claim
49 words
A vertical magnetic recording medium according to claim 13, wherein said at least one pair of layers are an upper layer most adjacent to the Co-Cr vertical magnetization film and a lower layer most adjacent to the non-magnetic substrate, and the upper layer is thinner than the lower layer.
Claim 18
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 15, wherein said first non-magnetic layer is made of Ti.
Claim 19
Dependent Claim
79 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therin, each of said plurality of permalloy layers being 1200 Å or less, and a vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 20
Dependent Claim
79 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therin, each of said plurality of permalloy layers being 1200 Å or less, and a vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 21
Dependent Claim
22 words
A vertical magnetization recording medium according to claim 17, wherein said first non-magnetic layer ranges 10 Å to 500 Å in thickness.
Claim 22
Dependent Claim
18 words
A vertical magnetization recording medium according to claim 17, wherein said first non-magnetic layer is made of Ti.
Claim 23
Dependent Claim
23 words
A vertical magnetization recording medium according to claim 19, wherein said first non-magnetic layer ranges from 10 Å to 500 Å in thickness.
Claim 24
Dependent Claim
29 words
A vertical magnetization recording medium according to claim 17, wherein at least one pair of layers among said plurality of permalloy layers have a different thickness from each other.
Claim 25
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 21, wherein said first nonnagnetic layer is made of Ti.
Claim 26
Dependent Claim
48 words
A vertical magnetic recording medium according to claim 21, wherein said at least one pair of layers are an upper layer most adjacent to the vertical magnetization film and a lower layer most adjacent to the non-magnetic substrate, and the upper layer is thinner than the lower layer.
Claim 27
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 23, wherein said first non-magnetic layer is made of Ti.
Claim 28
Dependent Claim
81 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therein, each of said plurality of permalloy layers being 1200 Å or less thick, and a Co-Cr vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 29
Dependent Claim
81 words
A vertical magnetization recording medium comprising a non-magnetic substrate, a permalloy film formed on the non-magnetic substrate said permalloy film consisting of a plurality of permalloy layers separated by at least one first non-magnetic layer placed therein, each of said plurality of permalloy layers being 1200 Å or less thick, and a Co-Cr vertical magnetization film formed on the permalloy film by one of: direct formation on the permalloy film, and formation on the permalloy film through a second non-magnetic layer.
Claim 30
Dependent Claim
13 words
A vertical magnetization recording medium according to claim 25, wherein said first non-magnetic
Claim 31
Dependent Claim
18 words
A vertical magnetization recording medium according to claim 25, wherein said first non-magnetic layer is made of Ti.
Claim 32
Dependent Claim
23 words
A vertical magnetization recording medium according to claim 27, wherein said first non-magnetic layer ranges from 10 Å to 500 Å in thickness.
Claim 33
Dependent Claim
29 words
A vertical magnetization recording medium according to claim 25, wherein at least one pair of layers among said plurality of permalloy layers have a different thickness from each other.
Claim 34
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 29, wherein said first non-magnetic layer is made of Ti.
Claim 35
Dependent Claim
49 words
A vertical magnetic recording medium according to claim 29, wherein said at least one pair of layers are an upper layer most adjacent to the Co-Cr vertical magnetization film and a lower layer most adjacent to the non-magnetic substrate, and the upper layer is thinner than the lower layer.
Claim 36
Dependent Claim
18 words
A vertical magnetic recording medium according to claim 31, wherein said first non-magnetic layer is made of Ti.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-17 | 1991-02-16 | 1991-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-17 | 1995-02-16 | 1995-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-17 | 1999-02-16 | 1999-08-18 | $7700.00 | Window Closed / Lapsed |