US4410583A
Expired / Lapsed
US
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Ferromagnetic recording medium
Assignee: Olympus Corp
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Filing: 1981-03-17
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Granted: 1983-10-18
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Expires: 2001-03-17
Abstract
Abstract A magnetic recording medium having a base, a first magnetic layer formed on the base, and a second magnetic layer formed on the first magnetic layer. The magnetic recording medium further comprises a third magnetic layer which does not contain a binder formed on the second magnetic layer. A third magnetic layer containing a binder has a predetermined thickness to cover surface roughness of the second magnetic layer and functions as a protection layer for the second magnetic layer.
Inventors
- 👤 Naohiro Hanaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/716; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 94
Claim 1
Independent Claim
128 words
A ferromagnetic recording medium comprising: a base; a first magnetic layer which includes ferromagnetic material formed on said base; a second ferromagnetic layer which includes a fine grain metal which is ferromagnetic and which does not contain a binder formed on said first ferromagnetic layer, said second ferromagnetic layer being a thin layer which has a rough surface; and a third ferromagnetic layer having a smooth outer surface formed on said second ferromagnetic layer, said third ferromagnetic layer includes ferromagnetic material admixed with a binder which is formed of a synthetic resin and has a predetermined average thickness between 0.3 and 1 micron and sufficient to cover all of the rough surface of said second ferromagnetic layer and functions as a protective layer for said second magnetic layer.
Claim 2
Dependent Claim
128 words
A ferromagnetic recording medium comprising: a base; a first magnetic layer which includes ferromagnetic material formed on said base; a second ferromagnetic layer which includes a fine grain metal which is ferromagnetic and which does not contain a binder formed on said first ferromagnetic layer, said second ferromagnetic layer being a thin layer which has a rough surface; and a third ferromagnetic layer having a smooth outer surface formed on said second ferromagnetic layer, said third ferromagnetic layer includes ferromagnetic material admixed with a binder which is formed of a synthetic resin and has a predetermined average thickness between 0.3 and 1 micron and sufficient to cover all of the rough surface of said second ferromagnetic layer and functions as a protective layer for said second magnetic layer.
Claim 3
Dependent Claim
19 words
A recording medium according to claim 1, wherein said first magnetic layer includes magnetic material admixed with a binder.
Claim 4
Dependent Claim
26 words
A recording medium according to claim 1, wherein said second magnetic layer includes metal magnetic material and said third magnetic layer includes metal oxide magnetic material.
Claim 5
Dependent Claim
30 words
A recording medium according to claim 2, wherein said second magnetic layer consists essentially of metal magnetic material and said third magnetic layer consists essentially of metal oxide magnetic material.
Claim 6
Dependent Claim
19 words
A recording medium according to claim 3, wherein said first magnetic layer consists essentially of metal oxide magnetic material.
Claim 7
Dependent Claim
19 words
A recording medium according to claim 4, wherein said first magnetic layer consists essentially of metal oxide magnetic material.
Claim 8
Dependent Claim
24 words
A recording medium according to claim 5, wherein said first and third magnetic layers consist essentially of gamma hematite (γ--Fe 2 O 3 ).
Claim 9
Dependent Claim
24 words
A recording medium according to claim 6, wherein said first and third magnetic layers consist essentially of gamma hematite (γ--Fe 2 O 3 ).
Claim 10
Dependent Claim
22 words
A recording medium according to claim 1, wherein said second magnetic layer consists essentially or iron, cobalt or nickel and alloys thereof.
Claim 11
Dependent Claim
22 words
A recording medium according to claim 2, wherein said second magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 12
Dependent Claim
22 words
A recording medium according to claim 3, wherein said second magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 13
Dependent Claim
22 words
A recording medium according to claim 4, wherein said second magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 14
Dependent Claim
22 words
A recording medium according to claim 5, wherein said second magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 15
Dependent Claim
22 words
A recording medium according to claim 6, wherein said second magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 16
Dependent Claim
22 words
A recording medium according to claim 7, wherein said second magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 17
Dependent Claim
22 words
A recording medium according to claim 8, wherein said second magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 18
Dependent Claim
14 words
A recording medium according of claim 1, wherein said base is a nonmagnetic film.
Claim 19
Dependent Claim
14 words
A recording medium according of claim 2, wherein said base is a nonmagnetic film.
Claim 20
Dependent Claim
14 words
A recording medium according of claim 3, wherein said base is a nonmagnetic film.
Claim 21
Dependent Claim
14 words
A recording medium according of claim 4, wherein said base is a nonmagnetic film.
Claim 22
Dependent Claim
14 words
A recording medium according of claim 5, wherein said base is a nonmagnetic film.
Claim 23
Dependent Claim
14 words
A recording medium according of claim 6, wherein said base is a nonmagnetic film.
Claim 24
Dependent Claim
14 words
A recording medium according of claim 7, wherein said base is a nonmagnetic film.
Claim 25
Dependent Claim
14 words
A recording medium according of claim 8, wherein said base is a nonmagnetic film.
Claim 26
Dependent Claim
14 words
A recording medium according of claim 9, wherein said base is a nonmagnetic film.
Claim 27
Dependent Claim
53 words
A recording medium according of claim 17, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 28
Dependent Claim
53 words
A recording medium according of claim 18, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 29
Dependent Claim
53 words
A recording medium according of claim 19, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 30
Dependent Claim
53 words
A recording medium according of claim 20, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 31
Dependent Claim
53 words
A recording medium according of claim 21, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 32
Dependent Claim
53 words
A recording medium according of claim 22, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 33
Dependent Claim
53 words
A recording medium according of claim 23, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 34
Dependent Claim
53 words
A recording medium according of claim 24, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 35
Dependent Claim
53 words
A recording medium according of claim 25, wherein the thickness of said film is larger than the thickness of said first magnetic layer, and the thickness of said second or third magnetic layer is substantially equal to that of said first magnetic layer or smaller than the thickness of said first magnetic layer.
Claim 36
Dependent Claim
23 words
A recording medium according to claim 1, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 37
Dependent Claim
23 words
A recording medium according of claim 2, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 38
Dependent Claim
23 words
A recording medium according of claim 3, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 39
Dependent Claim
23 words
A recording medium according of claim 4, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 40
Dependent Claim
23 words
A recording medium according of claim 5, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 41
Dependent Claim
23 words
A recording medium according of claim 6, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 42
Dependent Claim
23 words
A recording medium according of claim 7, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 43
Dependent Claim
23 words
A recording medium according of claim 8, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 44
Dependent Claim
23 words
A recording medium according of claim 9, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 45
Dependent Claim
23 words
A recording medium according of claim 17, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 46
Dependent Claim
23 words
A recording medium according of claim 26, wherein the thickness of said third magnetic layer is about 0.3 μm to about 0.5 μm.
Claim 47
Dependent Claim
39 words
A ferromagnetic recording medium according to claim 1, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 48
Dependent Claim
38 words
A recording medium according of claim 2, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 49
Dependent Claim
38 words
A recording medium according of claim 3, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 50
Dependent Claim
38 words
A recording medium according of claim 4, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 51
Dependent Claim
38 words
A recording medium according of claim 5, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 52
Dependent Claim
38 words
A recording medium according of claim 6, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 53
Dependent Claim
38 words
A recording medium according of claim 7, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 54
Dependent Claim
38 words
A recording medium according of claim 8, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 55
Dependent Claim
38 words
A recording medium according of claim 9, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 56
Dependent Claim
38 words
A recording medium according of claim 17, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 57
Dependent Claim
38 words
A recording medium according of claim 26, wherein a forth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 58
Dependent Claim
38 words
A recording medium according of claim 35, wherein a fourth magnetic layer is formed on the surface of said base which is the reverse side of the surface on which said first to third magnetic layers are formed.
Claim 59
Dependent Claim
24 words
A recording medium according to claim 46, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 60
Dependent Claim
24 words
A recording medium according of claim 47, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 61
Dependent Claim
24 words
A recording medium according of claim 48, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 62
Dependent Claim
24 words
A recording medium according of claim 49, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 63
Dependent Claim
24 words
A recording medium according of claim 50, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 64
Dependent Claim
24 words
A recording medium according of claim 51, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 65
Dependent Claim
24 words
A recording medium according of claim 52, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 66
Dependent Claim
24 words
A recording medium according of claim 53, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 67
Dependent Claim
24 words
A recording medium according of claim 54, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 68
Dependent Claim
24 words
A recording medium according of claim 55, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 69
Dependent Claim
24 words
A recording medium according of claim 56, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 70
Dependent Claim
24 words
A recording medium according of claim 57, wherein said fourth magnetic layer has a larger coercive force than that of said first magnetic layer.
Claim 71
Dependent Claim
22 words
A recording medium according to claim 46, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 72
Dependent Claim
22 words
A recording medium according to claim 47, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 73
Dependent Claim
22 words
A recording medium according to claim 48, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 74
Dependent Claim
22 words
A recording medium according to claim 49, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 75
Dependent Claim
22 words
A recording medium according to claim 50, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 76
Dependent Claim
22 words
A recording medium according to claim 51, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 77
Dependent Claim
22 words
A recording medium according to claim 52, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 78
Dependent Claim
22 words
A recording medium according to claim 53, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 79
Dependent Claim
22 words
A recording medium according to claim 54, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 80
Dependent Claim
22 words
A recording medium according to claim 55, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 81
Dependent Claim
22 words
A recording medium according to claim 56, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 82
Dependent Claim
22 words
A recording medium according to claim 57, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 83
Dependent Claim
22 words
A recording medium according to claim 58, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 84
Dependent Claim
22 words
A recording medium according to claim 59, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 85
Dependent Claim
22 words
A recording medium according to claim 60, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 86
Dependent Claim
22 words
A recording medium according to claim 61, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 87
Dependent Claim
22 words
A recording medium according to claim 62, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 88
Dependent Claim
22 words
A recording medium according to claim 63, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 89
Dependent Claim
22 words
A recording medium according to claim 64, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 90
Dependent Claim
22 words
A recording medium according to claim 65, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 91
Dependent Claim
22 words
A recording medium according to claim 66, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 92
Dependent Claim
22 words
A recording medium according to claim 67, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 93
Dependent Claim
22 words
A recording medium according to claim 68, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
Claim 94
Dependent Claim
22 words
A recording medium according to claim 69, wherein said fourth magnetic layer consists essentially of iron, cobalt or nickel and alloys thereof.
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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) | 1986-10-17 | 1987-04-18 | 1987-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-17 | 1991-04-18 | 1991-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-17 | 1995-04-18 | 1995-10-18 | $7700.00 | Window Closed / Lapsed |