JPH04285712A - Magneto-resistance effect type head - Google Patents

Abstract

PURPOSE:To obtain the same reproduced output as the reproduced output obtd. with the conventional heads and to generate the magnetic fields sufficient for satd. recording of a recording medium. CONSTITUTION:A magnetic material 21 having the magnetic permeability sufficiently lower than the magnetic permeability of a magneto-resistance effect element 13 is provided in the gap part of the yokes provided with the magneto- resistance effect element 13 of the magneto-resistance effect type head which detects the signal magnetic fields from the magnetic recording medium by a gap formed of the yokes 11a, 11b, introduces the magnetic fields to the magneto-resistance effect element provided in the gap part of these yokes, executes a signal reproduction, introduces the magnetic fields generated by energizing a conductor coil 15 to the gap by the yokes and records the signals on the magnetic recording medium.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yoke-type magnetoresistive head used in magnetic disk drives and the like for recording and reproducing.

0002

2. Description of the Related Art FIGS. 2A and 2B show a plan view and a sectional view of an example of a conventional yoke type MR head. The upper yokes 11a, 11b and the lower yoke 12 are made of a permalloy film with a thickness of about 3 μm, and function as a magnetic flux introducing path for guiding the signal magnetic field from the magnetic recording medium to the MR element 13. The magnetoresistive (MR) element 13 has a film thickness of 1
It is formed of a permalloy film of a highly permeable magnetic material with a thickness of approximately 0.000 Å, and is insulated from the upper yokes 11a and 11b. Detection of signal magnetic flux from the recording medium during reproduction is performed by passing a sense current through lead wires 14 installed at both ends of the MR element 13 and extracting changes in voltage generated at both ends of the MR element 13. In addition, a desired bias magnetic field is generated by passing a weak current that does not erase recorded information on the recording medium through the conductor coil 15, and this is applied to the M
The voltage is applied to the R element 13 to move the operating point of the MR element 13 to a point with good linearity. Further, a gap 16 is provided above the upper yoke MR element 13 in order to efficiently pass the magnetic flux through the MR element. Also, to record,
A current is passed through the conductor coil 15, and a signal is recorded on the recording medium by the magnetic field generated in the gap between the upper yoke 11a and the lower yoke 12.

0003

However, when a conventional yoke-type MR head is used for recording, the air gap 16 provided between the upper yokes 11a and 11b creates a large magnetic resistance, making it difficult to hold the recording medium. There was a problem in that a head-generated magnetic field sufficient for saturation recording could not be obtained. Therefore, only media with relatively small coercive force can be recorded, or
Alternatively, a yoke type MR head is used only for reproduction.
It was necessary to create a separate thin film head for recording.

[0004] The present invention has been made in view of the above points.
It is an object of the present invention to provide a magnetoresistive head that can generate a magnetic field sufficient to saturate recording on a recording medium while obtaining a conventional reproduction output.

[0005]

[Means for Solving the Problems] A magnetoresistive head of the present invention detects a signal magnetic field from a magnetic recording medium using a gap formed by a yoke, and transmits the signal to a magnetoresistive element provided in a gap of the yoke. In a magnetoresistive head that reproduces guided signals and guides the magnetic field generated by energizing a conductor coil to a gap using a yoke to record on a magnetic recording medium, the magnetoresistive effect is applied to the gap in the yoke in which the magnetoresistive element is provided. A magnetic material having a sufficiently lower magnetic permeability than the element is provided.

[0006]

[Operation] In the present invention, since the magnetic material formed in the gap has sufficiently lower magnetic permeability than the magnetoresistive element, most of the reproduction magnetic flux flows from the yoke to the magnetoresistive element, and the reproduction output as before can be obtained. It will be done. Further, during recording, the magnetic flux generated by energizing the conductor coil passes through the magnetic material, so that saturation recording of the recording medium and a sufficient magnetic field can be obtained in the gap.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a plan view and an enlarged sectional view of an embodiment of the head of the present invention, respectively. In both figures, the same parts as in FIG. 3 are given the same reference numerals.

In FIGS. 1 and 2, a lower yoke 12 is formed on a substrate 17, and an upper yoke 11a is formed on the lower yoke 12 with a gap layer 18 of an insulating material interposed therebetween, and is in contact with the lower yoke 12. An upper yoke 11b is formed.

Upper yokes 11a, 11b and lower yoke 1
Insulating layer 19 is formed in the space surrounded by insulating layer 1 and
A conductor coil 15 is inserted through and wound inside the coil 9 . An MR element 13 made of a permalloy film is formed on the insulating layer 19 in a gap 16 formed by the upper yokes 11a and 11b.
1a and 11b are insulated from each other.

A magnetic layer 21 is formed within the gap 16 by, for example, a mask plating method or a lift-off method. The magnetic permeability of the magnetic layer 21 is about several hundreds, and the MR element 13
Materials with sufficiently low magnetic anisotropy field Hk compared to
is made of a material that is sufficiently larger than the MR element 13.

[0011] During reproduction, the reproduction magnetic flux due to the weak signal magnetic field generated from the recording medium hardly flows into the magnetic material with low magnetic permeability, but instead flows into the MR element 13 with high magnetic permeability, resulting in the conventional reproduction output. is obtained.

During recording, by passing a current through the conductor coil 15, a magnetic field exceeding the magnetic anisotropy field Hk of the magnetic body 21 is applied to the air gap 16 between the upper yokes 11a and 11b, and magnetic flux passes through the inside of the magnetic body 21. In the gap between the upper yoke 11a and the lower yoke 12, a head-generated magnetic field large enough to saturate the recording medium can be obtained.

[0013]

As described above, according to the magnetoresistive head of the present invention, it is possible to obtain a conventional reproduction output and generate a magnetic field sufficient to saturate recording on a recording medium.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the head of the present invention.

FIG. 2 is an enlarged cross-sectional view of the head in FIG. 1;

FIG. 3 is a plan view and a sectional view of an example of a conventional head.

[Explanation of symbols]

11a, 11b Upper yoke 12 Lower yoke 13 MR element 15 Conductor coil 16 Voids 21 Magnetic material

Claims (1)

[Claims] Claim 1: A signal magnetic field from a magnetic recording medium is transmitted through a gap formed by a yoke (11a, 11b, 12).
The signal is detected and guided to the magnetoresistive element provided in the gap (16) of the yoke for signal reproduction, and the conductor coil (
The magnetic field generated by energizing the yokes (11a, 15)
1b, 12) in which the magnetoresistive element (13) is guided into the gap to record on the magnetic recording medium, the magnetoresistive element (13) enters the gap (16) of the yoke in which the magnetoresistive element (13) is provided. A magnetoresistive head characterized by being provided with a magnetic material (21) having sufficiently low magnetic permeability.