JPS58205916A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head having high recording and reproducing efficiency, by providing a ring-shaped magnetic pole and a yoke together in opposition to a magnetic recording medium and forming the entire head in closed circuit constitution via a medium to concentrate the magnetic flux vertically by a high-permeability thin piece. CONSTITUTION:The ring-shaped magentic pole 11 arranged with the high-permeability thin piece 14 along the moving direction of a magnetic recording medium 19 so as to clip a nonmagnetic gap of <=0.2mum thickness from the front and the rear direction is provided and a counter surface 15 of the magnetic pole 11 except the gap 13 and the thin piece 14 to a magnetic layer 20 of the medium 19 is formed with a hard nonmagnetic material such as ceramic. Further, a yoke 12 whose one end is connected to a part of the magnetic pole 11 and the other end protrudes behind the magnetic pole 11 and is in slide contact with the magnetic layer 20 of the medium 19 is provided, and an electromagnetic conversion coil 16 generating the magnetic flux is wound around the yoke 12 and electromagnetic conversion coils 17, 18 detecting the magnetic flux passing through the magent 11 are wound around the magnetic pole 11 to constitute a closed circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a magnetic head suitable for perpendicular magnetization recording and reproduction of magnetic recording media.

Conventionally, as a method for recording or reproducing information on a magnetic recording medium such as a magnetic tape or a magnetic disk, a method in which the magnetic layer of the medium is magnetized in a horizontal direction with respect to its surface has generally been widely used.

A magnetic head suitable for the above-mentioned recording/reproduction method is usually called a ring-type head, and while this head has excellent reproduction efficiency, it is difficult to achieve high-density recording because of the large demagnetizing field generated in the recording bits. It was something.

In recent years, instead of the in-plane recording and reproducing method using the ring-shaped head, that is, the horizontal magnetization recording and reproducing method, a perpendicular magnetization recording and reproducing method that allows high-density recording, that is, a method that performs magnetization recording and reproducing perpendicular to the surface of the magnetic layer of the medium has been proposed. In the 1J perpendicular magnetization recording and reproducing method, which has been confirmed to be extremely superior in principle, in order to perform ideal perpendicular magnetization recording, first, the magnetic field perpendicular to the recording surface must be A magnetic recording medium having anisotropy was required, and a magnetic head capable of generating a magnetic field component perpendicular to the recording surface in a steep distribution pattern was also essential.

Note that O2C! is a recording medium suitable for the above-mentioned perpendicular magnetization recording. It is known that r-sputtered films or vapor deposited thin films are suitable.

On the other hand, as shown in FIG. 1, the magnetic head has a main magnetic pole 2 on the magnetic layer side of the magnetic recording medium 1, and an auxiliary magnetic pole 3 around which an excitation coil 4 is wound on the diamagnetic layer side. or, as shown in FIG. 2, a main pole excitation type magnetic head comprising a main pole 5 around which an excitation coil 6 is wound around the magnetic layer side of the medium 1. The head, furthermore, as shown in FIG. 5, a yoke-type magnetic head comprising a main pole 7 of a magnetic thin film disposed at one end of a yoke 8 having an excitation coil 9 wound around the magnetic layer side of the medium 1; etc. are known.

However, each of the magnetic heads described above has the following drawbacks.

The auxiliary pole excitation type magnetic head shown in Fig. 1 is superior in that it generates a magnetic field with a steep distribution pattern in the vertical direction, but because it has an open magnetic path configuration, The recording and reproducing efficiency was low, and it was easily affected by external noise.

Furthermore, unless the magnetic poles 2.5 are precisely placed opposite each other on both sides of the medium 1, the desired effect cannot be achieved, and problems remain in practicality.

In the main pole excitation type magnetic head as shown in FIG. 2, each main part is arranged only on one surface of the medium 1, so it is easy to use and highly practical. Since the recording and playback efficiency is low because of the path configuration, the recording and reproduction efficiency is low, and it is easily affected by external noise.

In the yoke-type magnetic head as shown in Fig. 3, this magnetic head has a closed magnetic path configuration, so the drawbacks peculiar to the open magnetic path configuration of the head of the above-mentioned type are corrected. Due to the thickness of the main magnetic pole 7, many dips occur in the frequency characteristics during reproduction as shown in FIG. 4, making it difficult to use.

The dips may occur frequently in the auxiliary pole excitation type magnetic head and the main pole excitation type magnetic head due to the influence of the thickness of the main pole piece. Attempts have been made to use a head, but this requires accurate alignment of the perpendicular magnetization recording head and the reproducing head, resulting in many technical and cost problems.

-4-Immigration l-Saiwa 1st few head 1 many points + removal 1-
.

It is an object of the present invention to provide a magnetic head for perpendicular magnetization recording and reproducing that has high recording and reproducing efficiency and is highly practical.

An object of the present invention is to perform perpendicular magnetization recording by generating a magnetic field facing one surface of a magnetic recording medium in a direction perpendicular to the magnetic layer surface of the medium, and to record perpendicularly magnetized information. A magnetic head for perpendicular magnetization recording and reproducing that performs reading, comprising a ring-shaped magnetic pole consisting of high magnetic permeability thin pieces arranged across a non-magnetic gap from the front and rear directions, and a ring-shaped magnetic pole that protrudes rearward from the ring-shaped magnetic pole. This is achieved by constructing a magnetic head comprising a yoke, an electromagnetic conversion coil that generates magnetic flux in the yoke, and an electromagnetic conversion coil that detects the magnetic flux passing through the ring-shaped magnetic pole.

Hereinafter, the practical aspects of the head of the present invention will be described in detail based on the attached drawings.

In FIG. 5, the structure of the perpendicular magnetic recording/reproducing head 10 according to the present invention is roughly divided into a ring-shaped magnetic pole 11 and a yoke 12.

The ring-shaped magnetic pole 11 and the yoke 12 are usually made of ferrite, and have a form that allows each to contact one surface of the magnetic recording medium 19 (usually the surface of the magnetic layer 200).

The gap 13 in the ring-shaped magnetic pole 11 is α2μ
m or less, and is made of a non-magnetic material such as SiO.

High magnetic permeability thin pieces 14, for example, permalloy thin pieces, are provided so as to sandwich the gap 13 from the front and back directions along the moving direction of the medium 19, and their tips are protruded so as to be able to come into sliding contact with one surface of the medium 19. ing.

The magnetic layer facing surface 15 of the ring-shaped magnetic pole 11, excluding the gap 13 and the high magnetic permeability thin piece 14, is made of a non-magnetic hard material such as ceramics.

Further, the yoke 12 has one end connected to the ring-shaped magnetic pole 1.
1, and the other end protrudes rearward from the ring-shaped magnetic pole 11 along the moving direction of the medium 19 and is configured to be able to come into sliding contact with one surface of the medium 19. has been done.

A first coil 16 is wound around the yoke 12, and second and third coils 17 and 18 are wound around the ring-shaped magnetic pole 11, respectively.

The magnetic recording medium 19 suitable for perpendicular magnetization recording and reproduction is as follows:
A magnetic layer 20 having perpendicular magnetic anisotropy is formed into a high magnetic permeability thin film 2.
1. For example, it is generally formed by laminating a sputtered or vapor-deposited thin film of Permalloy by sputtering or vapor-deposition.

22 is a nonmagnetic support.

Next, the effect will be explained.

First, when recording, by passing a current through the first coil 16, a first magnetic flux loop 2 passing through the yoke 12, the ring-shaped magnetic pole 11, the high magnetic permeability thin piece 14, and the medium 19 is created.
6 (indicated by a solid line), a sharply distributed magnetic field is generated at the tip of the high magnetic permeability thin piece 14, and the magnetic layer 20
magnetize perpendicularly.

Next, when reproducing, the high magnetic permeability thin piece 14 and the ring-shaped magnetic pole 11 operate in a manner similar to that of a conventional ring-shaped head to generate a second magnetic flux loop 24 (indicated by a broken line) according to the magnetization state of the magnetic layer 2o. ) is formed and the second
and a voltage is induced in the sixth coil 17,18.

A large reproduction output can be obtained by connecting the second and third coils 17 and 18 so that the induced voltage is the sum.

Further, the first magnetic flux loop 2 is connected via the yoke 12.
A flow of magnetic flux occurs along 31C, which acts to increase the induced voltage in the second and third coils 1' 7.18, thereby increasing the reproduction efficiency of the head.

The resolution during operation as a reproducing head is determined by the interval of the gap 13 formed between each of the high magnetic permeability thin pieces 14, and by setting this gap 13 to 0.2 μm or less, extremely high resolution can be achieved. can be obtained,
It is also possible to solve the above-mentioned problem of dips occurring in the reproduced frequency characteristics.

No matter how small the gap 13 is, no problem occurs because the high magnetic permeability thin piece 14 is magnetized in the same direction.

Note that the first coil 16 can be omitted by switching the connection of the second and fifth coils 17 and 18 in each recording and playback mode instead of the first coil 16. be.

FIG. 6 shows a modification of the head of the present invention, in which a high conductivity metal layer 25, such as Au, Heg, Cu, etc. It has layers such as

By providing this metal layer 25, during recording, the magnetic flux leaking from the ring-shaped magnetic pole 11 to the magnetic layer facing surface 15 is prevented by the eddy current generated in the metal layer 25, and the magnetic flux is transferred to the magnetic layer facing surface 15. If it becomes possible to concentrate the magnetic field at the tip of the high magnetic permeability thin piece 14, it is possible to eliminate adverse effects such as weakening of once recorded magnetization information by leakage magnetic field.

As described above, in the head of the present invention, the ring-shaped magnetic pole 11 and the yoke 1 are arranged opposite to one surface of the medium 19.
2, and through the medium 19, the entire structure has a closed magnetic path configuration that is hardly affected by external noise, and the high magnetic permeability thin piece 14 makes it possible to vertically and centralize the magnetic flux. The ring-shaped magnetic pole 11 exhibits the same high resolution during reproduction as the conventional ring-shaped head, and also has the novel effects of being relatively easy to handle and highly practical.

[Brief explanation of drawings]

1 to 6 are schematic diagrams showing the main parts of a conventional head.
The figure is a graph showing the frequency characteristics during reproduction of a conventional head, and FIGS. 5 and 6 are schematic diagrams showing the main parts of the head based on the present invention. 11 is a ring-shaped magnetic pole, 12 is a yoke, 13 is a gear,
14 is a high magnetic permeability thin piece, 15 is a surface facing the magnetic layer, 20 is a magnetic layer, and 25 is a high conductivity metal layer. --2 Agent Patent attorney (8107) Kiyotaka Sasaki Fukuro (and 3 others) 2 Figure 1 Figure 2 Figure 3
Figure 5

Claims (1)

[Claims] 1) When perpendicular magnetization recording is performed by generating a magnetic field perpendicular to the magnetic layer surface of the medium facing one surface of the medium, perpendicularly magnetized information is A perpendicularly magnetized recording and reproducing magnetic head for reading, comprising a ring-shaped magnetic pole comprising high magnetic permeability thin pieces sandwiching a non-magnetic gap from the front and rear directions, and a yoke protruding rearward from the ring-shaped magnetic pole. . A magnetic head comprising: an electromagnetic conversion coil that generates magnetic flux in the yoke; and an electromagnetic conversion coil that detects magnetic flux passing through the ring-shaped magnetic pole. 2) The magnetic head according to claim 1, wherein the ring-shaped magnetic pole has a high conductivity metal layer layered above the surface facing the magnetic layer. 3) The magnetic head according to claim 1, wherein the tip of the high magnetic permeability thin piece is provided in a protruding manner so as to be able to come into contact with the surface of the magnetic recording medium. 4) The magnetic head according to claim 1, wherein the high magnetic permeability thin piece is magnetized in the same direction by the electromagnetic conversion coil. 5) The magnetic head according to claim 1, wherein the yoke has one end connected to the ring-shaped magnetic pole and the other end facing the surface of the magnetic recording medium.