EP0169929A1
Expired / Lapsed
EP
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Magnetic recording medium
Assignee: Konica Minolta Inc
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Filing: 1984-08-02
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Granted: —
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Expires: 2004-08-02
Abstract
Abstract A magnetic recording medium having a plurality of laminated magnetic recording layers on a substrate wherein at least one of these magnetic recording layers satisfy the following two requisites: (a) Iron oxide based continuous magnetic layer; and (b) Ratio of the perpendicular residual magnetization M v to the in-plane residual magnetization M H or M v /M H not smaller than 0.5. And a magnetic recording medium having a magnetic recording layer or layers on each of two or more surfaces of a substrate and magnetic recording layer on at least one of these surfaces satisfies the following requisites: (a) Iron oxide based continuous magnetic film; and (b) Ratio of the perpendicular residual magnetization M v to the in-plane residual magnetization M H or M v /M H not smaller than 0.5.
Inventors
- 👤 Shozo Ishibasi
- 👤 Yuji Kasanuki
- 👤 Masahiko Naoe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 20:29
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/658; G11B5/66; G11B5/672
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
72 words
A magnetic recording medium having a plurality of laminated magnetic recording layers on a substrate wherein one or more of said magnetic recording layers satisfy the following two requisites: (a) Iron oxide based continuous magnetic layer; and (b) Ratio of the perpendicular residual magnetization M V , namely residual magnetization perpendicular to the plane of layer to the in-plane residual magnetization M H or M v /M H not smaller than 0.5.
Claim 2
Dependent Claim
72 words
A magnetic recording medium having a plurality of laminated magnetic recording layers on a substrate wherein one or more of said magnetic recording layers satisfy the following two requisites: (a) Iron oxide based continuous magnetic layer; and (b) Ratio of the perpendicular residual magnetization M V , namely residual magnetization perpendicular to the plane of layer to the in-plane residual magnetization M H or M v /M H not smaller than 0.5.
Claim 3
Dependent Claim
21 words
A magnetic recording medium as claimed in Claim 1 wherein the particular crystalline axis of said iron oxide is almost perpendicular.
Claim 4
Dependent Claim
17 words
A magnetic recording medium as claimed in Claim 1 wherein said iron oxide is of spinel type.
Claim 5
Dependent Claim
66 words
A magnetic recording medium as claimed in Claim 1 wherein said laminated magnetic recording layers comprise said iron oxide based continuous magnetic layer and a layer which is one or the other of the following two layers: (a) Coating or continuous thin film type magnetic layer with its magnetizable axis in-plane; and (b) Coating or continuous thin film type magnetic layer with its magnetizable axis perpendicular.
Claim 6
Dependent Claim
24 words
A magnetic recording medium as claimed in Claim 1 wherein areas where magnetic characteristics are selectively changed are formed in said magnetic recording layers.
Claim 7
Dependent Claim
22 words
A magnetic recording medium as claimed in Claim 1 wherein grooves are formed in a stripped pattern in said magnetic recording layers.
Claim 8
Dependent Claim
69 words
A magnetic recording medium having a magnetic recording layer or layers on each of two or more surfaces of a substrate and magnetic recording layer on at least one of said surfaces satisfies the following requisites: (a) Iron oxide based continuous magnetic layer; and (b) Ratio of the perpendicular residual magnetization M V to the in-plane residual magnetization M H or M V /M H not smaller than 0.5.
Claim 9
Dependent Claim
69 words
A magnetic recording medium having a magnetic recording layer or layers on each of two or more surfaces of a substrate and magnetic recording layer on at least one of said surfaces satisfies the following requisites: (a) Iron oxide based continuous magnetic layer; and (b) Ratio of the perpendicular residual magnetization M V to the in-plane residual magnetization M H or M V /M H not smaller than 0.5.
Claim 10
Dependent Claim
21 words
A magnetic recording medium as claimed in Claim 7 wherein the particular crystal axis of said iron oxide is almost perpendicular.
Claim 11
Dependent Claim
17 words
A magnetic recording medium as claimed in Claim 7 wherein said iron oxide is of spinel type.
Claim 12
Dependent Claim
18 words
A magnetic recording medium as claimed in Claim 7 wherein said substrate is shaped either tape-like or sheet-like.
Claim 13
Dependent Claim
36 words
A magnetic recording medium as claimed in Claim 7 wherein said substrate shaped drum-like and a magnetic recording layer or layers are formed on each of the outer circumferential surface and outer side end faces thereof.
Claim 14
Dependent Claim
32 words
A magnetic recording medium as claimed in Claim 7 wherein said substrate is hollowed and a magnetic recording layer or layers are formed on each of the outer and inner surfaces thereof.
Claim 15
Dependent Claim
26 words
A magnetic recording medium as claimed in Claim 7 wherein areas where magnetic characteristics are selectively changed are formed in said magnetic recording layer or layers.
Claim 16
Dependent Claim
24 words
A magnetic recording medium as claimed in Claim 7 wherein grooves are formed in a striped pattern in said magnetic recording layer or layers.
References Cited (Backward Citations)
EP0122030A1
Cited
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