JPS58102323A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain the reproduction sensitivity of vertical magnetization recording which is higher than before by >=1 figure, by forming a magneto-resistance element on the plane of a main magnetic pole consisting of a film with high magnetic permeability. CONSTITUTION:A magnetic film 7 which has high specific resistance and high magnetic permeability and is sandwiched between a magnetoresistance element 8 and a magnetic pole 6 sends a magnetic field from a magnetic layer 3 to a magnetoresistance element 8 to prevent a short circuit between the element 8 and conductive magnetic pole 6. Magnetic flux from a magnetic recording medium 2 is received by the magnetic pole 6 and pierces the film 7 to reach the element 8. The electric resistance of the element 8 at this time varies with the magnetic field applied thereto from the medium 2. For this purpose, a specific current I is flowed through a barber pole type electrode 9 formed on the plane of the element. Then, variation V in the terminal voltage is detected and resistance variation across the magnetoresistance element is detected in the form of voltage variation to reproduce a signal, obtaining a large reproduction output.

Description

[Detailed description of the invention] The present invention relates to a magnetic head.

Perpendicular magnetization recording has recently been proposed as a method for improving the recording density of magnetic recording. This method magnetizes signals in a direction perpendicular to the surface of the magnetic recording medium, unlike the generally used method of magnetizing signals in the surface direction.
A high recording density can be obtained.

-]- The method of recording and reproducing vertical magnetization is roughly as follows. That is, as shown in FIG. 1, the end of the main magnetic pole 1 made of a high magnetic permeability magnetic film is brought into contact with the magnetic #3 of the magnetic recording medium 2, and the end of the main magnetic pole 1 made of a high magnetic permeability magnetic film is brought into contact with the magnetic material #3 of the magnetic recording medium 2, while a coil 4 made of a high permeability magnetic material is wound. By arranging the auxiliary magnetic pole 5 on the opposite side of the magnetic recording medium 20, causing the auxiliary magnetic pole 5 to generate a magnetic field, and concentrating this magnetic field on the tip of the main magnetic pole 1, that is, the part that is in contact with the magnetic recording medium 2. , the magnetic layer 3 is magnetized in the perpendicular direction.

However, reproduction in this device is performed by focusing the magnetic field from the magnetic recording medium on the main magnetic pole 1, and thereby generating a voltage in the coil 4 due to the change in the magnetic field generated at the auxiliary magnetic pole 5. The disadvantage of this is that reproduction is performed using the auxiliary magnetic pole 5 which is at least as far away from the magnetic layer as the thickness of the magnetic recording medium. Furthermore, since the main magnetic pole 1 is used in contact with the magnetic recording medium, the distance between the main magnetic pole and the auxiliary magnetic pole changes, and the optimum recording magnetic field set at the initial point J becomes impossible to obtain with use. .

2- The present invention eliminates such drawbacks and its purpose is to:
It is an object of the present invention to provide a magnetic head in which the reproduction sensitivity in perpendicular magnetization recording is increased by one order of magnitude or more compared to the past, and which is capable of stable reproduction regardless of the amount of wear of the main magnetic pole.

In the present invention, a high-resistance, high-permeability magnetic material is placed on the main pole plane, which is a high-permeability magnetic film, at a distance to the extent that it is not directly affected by thermal and magnetic effects from a magnetic recording medium. The above object is achieved by forming a magnetoresistive element.

The present invention will be explained in detail below with reference to the drawings.

FIG. 2 1aHb1 shows an embodiment of the present invention, with 1a1 being a sectional view and 1b1 being a front view.

8 is a magnetic resistance element, and this magnetic resistance element 8 and magnetic pole 6
A high resistivity and high permeability magnetic film 7 is sandwiched between the two.

This high specific resistance, high magnetic permeability magnetic film 7 is, for example, a ferrite film or the like, and has one role of transmitting the magnetic field from the magnetic layer 3 to the magnetoresistive element 8, and the conductive magnetic pole 5.
Another role is to prevent short circuits (consisting of a magnetically permeable heavy film containing Fg, -Ni as main components). If the film is a resistive ferrite or an amorphous film, the high resistivity and high magnetic permeability film 7 is not necessarily required. 9 is a barber pole type electrode.

An embodiment in which the present invention is combined with a perpendicular ik magnetization recording head is shown in FIG.

Recording of signals by this magnetic head is carried out in exactly the same way as in the prior art by passing a signal current through the coil 4 of the auxiliary magnetic pole 5. That is, when a signal current is passed through the coil 4, a magnetic field is generated, and the magnetic flux is concentrated at the toe of the magnetic pole, so that the magnetic field necessary to magnetize the magnetic recording medium 2 is magnetic).
fji 3, thereby recording the υ signal in the perpendicular direction (thickness direction) of the magnetic layer.

On the other hand, according to the magnetic head of the present invention, signals can be reproduced in the following manner. That is, the magnetic pole 6 absorbs the magnetic flux from the recorded magnetic recording medium 2, and the magnetic flux is introduced into the magnetoresistive element 8 through the high specific resistance and high magnetic permeability film 7. At this time, the electric resistance of the magnetoresistive element 8 increases from the magnetic recording medium 2 to there.

It changes depending on the magnetic field. Therefore, as shown in FIG. 1b1, a constant current l is caused to flow through the barber pole-shaped electrode 9 formed on the plane of the magnetoresistive element, and the voltage change V at both ends is detected. If the resistance change is detected as a voltage change, signal reproduction is possible and a large reproduction output can be obtained.

Another embodiment is shown in FIG.

This embodiment uses both sides of the magnetic recording medium (Il and Il) as in the previous embodiments.
This is a specific example of a head that has a recording and reproducing mechanism on one side of the magnetic recording medium, rather than having a head configuration in which the two sides face each other. That is, the bulk magnetic material H1 is formed into an L shape, and the portion corresponding to the so-called gap is filled with resin and SiO2.
In the present embodiment, which is a magnetic head of the type filled with an insulator 11 such as the above, and the magnetic head of the present invention is laminated thereto, an increase in reproduction sensitivity several times as much as in reproduction using a coil was observed.

Next, the most important feature of the present invention is as follows.

A difficulty in practical use of magnetoresistive elements is that a bias magnetic field current is required to improve the nonlinearity of the magnetoresistive element 8 with respect to the magnetic field, but by providing the barber pole type electrode 9, A bias magnetic field is no longer necessary. In addition, barber pole type electrodes tend to have large elements because they are created by fine etching, but if they are formed at a distance from the magnetic recording medium 3 as in the present invention, the recording density will be lower than the magnetic poles. It is affected only by the thickness and width of the tip, and is independent of the size of the magnetoresistive element 8. Next, the magnetoresistive element 8 has a resistance temperature coefficient of 10
When the temperature changes, the resistance changes by about 2%. The resistance change of the magnetoresistive element due to the magnetic field varies depending on the material, but is approximately 2 to 5%, and the thermal noise from the p1 output recording medium is the largest noise.

According to the present invention, thermal noise can be almost ignored because the magnetoresistive element is not in close contact with or in close proximity to the magnetic recording medium. Finally, since magnetoresistive elements have very high sensitivity, they are easily affected by recorded magnetizations other than adjacent recorded magnetizations. Therefore, shield films are generally required on both sides of the magnetoresistive element to block the magnetic field from other recording magnetizations, and the recording density is also limited by the spacing between the shield films.

According to the present invention, since the magnetoresistive element is separated from the magnetic recording medium, only the magnetic field absorbed by the main pole from the necessary recording magnetization flows through the magnetoresistive element, and noise from other recording magnetizations is sufficiently suppressed. I could ignore it.

As described above, according to the present invention, not only recording but also reproduction is possible, and moreover, it solves at once the difficulty in controlling bias magnetic fields, thermal noise, and magnetic shielding, which are practical problems when using magnetoresistive elements. However, the present invention proposes a magnetic head that exceeds the reproduction output of the conventional auxiliary magnetic pole by more than an order of magnitude.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a conventional perpendicular magnetic recording/reproducing head, FIG. 2 is a cross-sectional view of the magnetic head according to the present invention, and FIG. , is an embodiment of the magnetic head of the present invention, and is a diagram in which the magnetic head of the present invention is combined with a perpendicular head, a nail head, and a magnetic head of the present invention. It is a diagram showing a head configuration including a recording coil and a reproducing magnetic head of the present invention on one side. 1: Main magnetic pole 2: Magnetic H1 recording medium 3: Magnetic layer 4: Coil 5: Auxiliary magnetic pole 6: Magnetic pole 7 : High specific resistance, high permeability magnetic film 8: Magnetoresistive element 9; Electrode river: Bulk magnetic material 11: Insulator or higher Applicant: Sui Co., Ltd. #)j Seikosha 8-19C.

Claims (1)

[Claims] In a magnetic head having a magnetic pole made of a magnetic film provided facing a magnetic recording medium, a magnetoresistive element is provided on the magnetic pole via a high specific resistance, high permeability magnetic film, and the magnetoresistive element A magnetic head characterized in that it is disposed at a distance that is not affected by thermal effects from a recording medium and recording magnetization.