US 6,333,840 B1Granted

Magnetic recording apparatus

AssigneeKabushiki Kaisha Toshiba

InventorsHiroaki Yoda, Tadahiko Kobayashi, Kohichi Tateyama, Hiromi Sakata

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Abstract

There is provided a magnetic recording apparatus capable of carrying out signal reproduction with high accuracy by using a narrow gap head structure corresponding to high recording density. An asymmetric gap structure MR head includes a magnetoresistance element 26 having a magnetoresistance film 24 and a pair of electrodes 25 disposed at the upper side; a reproducing magnetic gap film 23 disposed only at the lower side of the magnetoresistance element 26; a magnetic shielding film 22 disposed so as to make a laminate with the magnetoresistance element 26 through the reproducing magnetic gap film 23; and an insulating film 27 disposed at the upper side of the magnetoresistance element 26. When a signal is read by use of such a reproducing head, the signal of the present bit is read by subtracting a value obtained by multiplying signals of a plurality of previous bits by predetermined coefficients from the present reproduction signal. As another reproduction signal processing system, a partial response system is adopted.

Claims10

Dependent claims

A magnetic recording apparatus, comprising:

a magnetic recording medium having a plurality of recording bits;
a magnetoresistance head configured to detect a signal magnetic field from the magnetic recording medium, the magnetoresistance head including a magnetic field detecting film, and upper and lower magnetic shielding films provided above and below the magnetic field detecting film through upper and lower magnetic gap films, a distance from a film thickness center of the magnetic field detecting film to the upper magnetic shielding film being different from a distance from the film thickness center to the lower magnetic shielding film;
a signal processing circuit configured to process a signal from the magnetoresistance head, the signal processing circuit obtaining a reproduction signal of a present bit by subtracting a correction value obtained by multiplying a signal value of a previous bit identified prior to the present bit by a predetermined coefficient from a signal value of the present bit;
and
wherein the distance from film thickness center of the magnetic field detecting film to one of the upper and lower magnetic shielding films is not less than twice the distance from film thickness center of the magnetic field detecting film to another of the upper and lower magnetic shielding films, and the distance from film thickness center of the magnetic field detecting film to the another of the upper and lower magnetic shielding films is less than the distance from magnetic recording medium facing surface of the magnetic field detecting film to the surface of recording layer of the magnetic recording medium.

2 more elements

A magnetic recording apparatus, comprising:

a magnetic recording medium with a plurality of recording bits;
a magnetoresistance head configure to detect a signal magnetic field from the magnetic recording medium, the magnetoresistance head including a magnetic field detecting film, and upper and lower magnetic shielding films provided above and below the magnetic field detecting film through upper and lower magnetic gap films, a distance from a film thickness center of the magnetic field detecting film to the upper magnetic shielding film being different from a distance from the film thickness center to the lower magnetic shielding film;
and
a signal processing circuit configured to process a signal from the magnetoresistance head, the signal processing circuit using a partial response system;
wherein the distance from film thickness center of the magnetic field detecting film to one of the upper and lower magnetic shielding films is not less than twice the distance from film thickness center of the magnetic field detecting film to another of the upper and lower magnetic shielding films, and the distance from film thickness center of the magnetic field detecting film to the another of the upper and lower magnetic shielding films is less than the distance from magnetic recording medium facing surface of the magnetic field detecting film to the surface of recording layer of the magnetic recording medium.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/270,681Filed 16 Mar 1999
Priority: JP 10-06520916 Mar 1998
Granted: 25 Dec 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G11B 5/09
Recording, reproducing, or erasing methods; Read, write or erase circuits therefor: digital recording
B82Y 10/00
Nanotechnology for information processing, storage or transmission
G11B 5/3903
Using magneto-resistive devices or effects: using magnetic thin film layers or their effects, the films being part of integrated structures
G11B 20/10
Signal processing not specific to the method of recording or reproducing; Circuits therefor: digital recording or reproducing