US 6,204,995 B1 · Magnetic disc apparatus

Abstract

The present invention provides a magnetic disc apparatus comprising a vertical two-layered magnetic recording (MR) medium and a mono-pole/MR composite head or ID/MR composite head, wherein the vertical two-layered magnetic recording medium includes a vertical magnetization film formed on an undercoat soft magnetic film having no magnetic domain wall structure. This eliminates the fatal defect of a conventional vertical two-layered medium that an undercoat soft magnetic film domain wall is easily shifted by an external magnetic field generated by motors for disc rotation and head positioning, causing demagnetization of the recording magnetization to lower the output. The magnetic disc apparatus according to the present invention enables to obtain a high output stability.

Claims17

Dependent claims

A magnetic disc apparatus comprising:

a vertical two-layered magnetic recording medium having an undercoat soft magnetic film and a vertical magnetization film;
and
a composite head for recording/reproducing to/from said vertical two-layered magnetic recording medium,
wherein said undercoat soft magnetic film is made from a material having no magnetic domain wall structure, and
wherein said undercoat soft magnetic film has a thickness in a range from 50 to 400 nm.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

09/250,421Filed 16 Feb 1999

Priority

JP 10-03776619 Feb 1998

Granted

20 Mar 2001

Term ends

Not estimatedThe source records don’t support an estimate.

Classification13 codes

G11B 5/667
The record carriers consisting of several layers: including a soft magnetic layer
G11B 5/012
Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor: recording on, or…
G11B 5/1278
Structure or manufacture of heads, e.g. inductive: specially adapted for magnetisations perpendicular to the surface of the record carrier
G11B 5/3967
Using magnetic thin film layers or their effects, the films being part of integrated structures: composite structural arrangements of transducers,…

Magnetic disc apparatus

Life of this patent

Magnetic disc apparatus

Life of this patent

Abstract

Claims17