EP0169928A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
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 comprising a high magnetic permeability material layer and a magnetic layer, the magnetic layer (a) being continuous magnetic layer made mainly from iron oxides, and (b) having not less than 0.5 of ratio between perpendicular-to-plane residual magnetization and in-plane residual magnetization: M V /M H .
Inventors
- 👤 Shozo Ishibasi
- 👤 Yuji Kasanuki
- 👤 Masahiko Naoe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 09:56
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/672; G11B5/676
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
50 words
A magnetic recording medium comprising a high magnetic permeability material layer and a magnetic layer, the magnetic layer (a) being continuous magnetic layer made mainly from iron oxides, and (b) having not less than 0.5 of ratio between perpendicular-to-plane residual magnetization and in-plane residual magnetization: M V /M H .
Claim 2
Dependent Claim
50 words
A magnetic recording medium comprising a high magnetic permeability material layer and a magnetic layer, the magnetic layer (a) being continuous magnetic layer made mainly from iron oxides, and (b) having not less than 0.5 of ratio between perpendicular-to-plane residual magnetization and in-plane residual magnetization: M V /M H .
Claim 3
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1 wherein iron oxides of said magnetic layer have substantially perpendicular anisotropy to the in-plane.
Claim 4
Dependent Claim
20 words
A magnetic recording medium as claimed in claim 1 wherein iron oxides of said magnetic layer is of spinel structure.
Claim 5
Dependent Claim
34 words
A magnetic recording medium as claimed in claim 1 wherein said high magnetic permeability material layer is more than 10 2 in magnetic permeability, µi, and not more than 10 Oe in coercive-force, Hc.
Claim 6
Dependent Claim
25 words
A magnetic recording medium as claimed in claim 4 wherein said high magnetic permeability material layer is magnetizable to the in-plane of said magnetic layer.
Claim 7
Dependent Claim
24 words
A magnetic recording medium as claimed in claim 1 wherein said high magnetic permeability material layer is of 0.05 to 5 µm in thickness.
Claim 8
Dependent Claim
30 words
7 . A magnetic recording medium as claimed in claim 1 wherein said high magnetic permeability material layer, a nonmagnetic layer and, as top layer, said magnetic layer are laminated.
Claim 9
Dependent Claim
22 words
A magnetic recording medium as claimed in claim 7 wherein said non-magnetic layer has a thickness of 100 Å to 5 µm.
Claim 10
Dependent Claim
19 words
A magnetic recording medium as claimed in claim 1 wherein said magnetic layer has regions of selectively-changed magnetic characteristics.
Claim 11
Dependent Claim
17 words
A magnetic recording medium as claimed in claim 1 wherein said magnetic layer is provided with grooves.
Claim 12
Dependent Claim
31 words
A magnetic recording medium as claimed in claim 1 wherein as the priming for said magnetic layer is provided a crystalline layer orientated correspondingly to the anisotropy of said magnetic layer.
Claim 13
Dependent Claim
22 words
1 12. A magnetic recording medium as claimed in claim 1 wherein said nagnetic layer is formed on an non-crystalline priming layer.
Claim 14
Dependent Claim
22 words
A magnetic recording medium as claimed in claim 1 wherein a priming layer of polycrystals with substantally no definite orientation is provided.
Claim 15
Dependent Claim
36 words
A magnetic recording medium as claimed in claim 1 wherein said substrate has on the surface a priming with a large number of scattered projections or pits and said magnetic layer is formed on said priming.
References Cited (Backward Citations)
EP0122030A1
Cited
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