Dynamic magnetic information storage or retrieval – Record transport with head stationary during transducing – Disk record
Patent
1997-10-27
1998-09-29
Thomas, Tom
Dynamic magnetic information storage or retrieval
Record transport with head stationary during transducing
Disk record
360134, 360135, 20419215, G11B 5012, G11B 1700, G11B 578, G11B 582
Patent
active
058153438
ABSTRACT:
A magnetic recording medium includes a non-magnetic substrate, and a magnetic layer provided on the non-magnetic substrate. The value of the product Br.sub.1 .delta. of the residual flux density Br.sub.1 of the magnetic layer determined in a recording direction and the thickness .delta. of the magnetic layer is not less than 5 G.mu.m and not more than 180 G.mu.m; the value of the ratio of Br.sub.1 to the residual flux density Br.sub.2 determined in a direction parallel to the substrate plane and perpendicular to the recording direction, Br.sub.1 /Br.sub.2, is not less than 1.3 and not more than 3; the surface of the non-magnetic substrate has texture grooves therein extending predominantly in the recording direction; and the average roughness factor Ra of the surface of the magnetic layer determined in a direction perpendicular to the substrate plane and perpendicular to the recording direction is not less than 0.3 nm and not more than 1.9 nm. Alternatively, the value of the product Br.delta. of the residual flux density Br of the magnetic layer determined in the recording direction and the thickness .delta. of the magnetic layer is not less than 5 G.mu.m and not more than 80 G.mu.m; and the value of the anisotropic magnetic field H.sub.k of the magnetic recording medium is not less than 7 kOe and not more than 20 kOe.
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Fumioka Jun
Hosoe Yuzuru
Igarashi Masukazu
Ishikawa Akira
Kato Yoshiki
Giordana Adriana
Hitachi , Ltd.
Thomas Tom
LandOfFree
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