JPH06168416A - Magnetic head - Google Patents

Abstract

PURPOSE:To decrease wear of a head and to improve recording and reproducing efficiency by forming a groove to remove dust on the sliding plane of a magnetic core where a magnetic recording medium enters. CONSTITUTION:A dust-removing groove 8 is formed to remove dust cutrapped by a magnetic recording medium 9. This groove has a square cross section and is formed on the sliding plane of a magnetic core 1 where the magnetic recording medium 9 enters in a manner that the groove is almost perpendicular to the traveling direction of the medium. Thereby, dust cutrapped with the magnetic recording medium 9 is trapped by the groove 8 before the dust reaches to the front gap FG. Thereby, such a problem that dust 10 wears the sliding surface 7 while traveling with the medium 9 is avoided and wear of the head is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head mounted on, for example, a tape recorder or a video tape recorder.

[0002]

2. Description of the Related Art Generally, in a thin film magnetic head, since a magnetic film and a conductor coil forming a magnetic circuit portion are formed by a vacuum thin film forming technique, it is easy to make a fine dimension such as a narrow track or a narrow gap. It has the feature of being capable of high-resolution recording, and is attracting attention as a magnetic head compatible with high-density recording.

As such a thin film magnetic head, as shown in FIGS. 13 and 14, for example, a conductor coil and sendust are formed on a magnetic core 101 made of an oxide magnetic material such as ferrite by a vacuum thin film forming technique. A plurality of magnetic cores 102 are laminated at predetermined intervals, and for the purpose of improving wear resistance, a guard material 104 having a high hardness is laminated via a glass 103. In order to secure the contact with the magnetic recording medium, the sliding surface 105 of the magnetic recording medium, which is in sliding contact with the magnetic recording medium, is polished to have an arc shape.

In the thin-film magnetic head having the above structure, the magnetic cores 102 made of sendust, which are laminated on the magnetic cores 101 made of ferrite, and the magnetic cores 101 made of ferrite respectively form closed magnetic circuits. It is supposed to function as.
That is, this thin film magnetic head is a so-called multi-channel type magnetic head in which head chips made up of a plurality of thin film heads are arranged.

[0005]

When a tape recorder, a video tape recorder or the like equipped with the above-mentioned thin film magnetic head is used in an environment with much dust such as dust or sand, it is shown in FIG. As described above, the dust 106 is caught in the magnetic tape 107, and the magnetic recording medium sliding surface 10
There are many cases of passing 5 while rubbing. For this reason,
The dust 106 abrades the sliding surface 105 of the magnetic recording medium, resulting in a decrease in head output and head life.

In order to avoid such an inconvenience, a material having high hardness is used for the magnetic cores 101 and 102 forming the magnetic path,
Alternatively, it is possible to reduce the wear of the head by reducing the contact pressure between the magnetic tape 107 and the head.

However, the wear of the head does not depend only on the hardness of the material, and there are many cases where the wear is not reduced even if a high hardness material is used, and conversely, the wear is caused by uneven wear due to the difference in the hardness of the material. A step may be generated on the moving surface 105. Further, the contact pressure between the magnetic tape 107 and the head depends on the effective surface between the magnetic tape 107 and the head,
Or, there is a limit in reducing the pressure in terms of reliable signal reception and reception.

Therefore, the present invention has been proposed in view of such conventional technical circumstances, and is excellent in wear resistance,
It is an object of the present invention to provide a magnetic head having excellent head life and high head efficiency and reliability.

[0009]

In order to achieve the above-mentioned object, the present invention provides a magnetic head having a closed magnetic path composed of a pair of magnetic cores, and the magnetic core of the magnetic core on the side where the magnetic recording medium enters. A groove or a corner for removing dust is provided on the sliding surface of the recording medium.

The magnetic head according to the present invention is characterized in that the groove or the corner for removing dust is formed in a direction substantially orthogonal to the entering direction of the magnetic recording medium.

Further, according to the present invention, in a magnetic head having a closed magnetic path formed by a pair of magnetic cores, a dust removing member is arranged further on the entrance side of the magnetic core on the side where the magnetic recording medium enters. And

In the magnetic head according to the present invention, the dust removing member is a dummy core.

A magnetic head according to a third aspect of the present invention is characterized in that the dummy core is provided with a groove, a corner or an inclined surface for removing dust.

[0014]

In the magnetic head of the present invention, since a groove or a corner for removing dust is provided on the sliding surface of the magnetic recording medium on the side where the magnetic recording medium enters, it is possible to prevent dust, sand, etc. , Even if enormous dust is caught in the magnetic recording medium,
Before reaching the magnetic gap portion, it is trapped in the dust removing groove or is surely removed by the corner portion. As a result, the wear of the sliding surface of the magnetic recording medium of the magnetic head is reduced, and the head life and head output are improved.

Further, in the magnetic head of the present invention, since the dust removing member is arranged further on the entry side of the magnetic core on the side where the magnetic recording medium enters, dust is deposited on the sliding surface of the magnetic recording medium of the magnetic head. Before reaching, the dust is reliably removed by the dust removing member. Therefore, in this magnetic head as well, reduction of wear on the sliding surface of the magnetic recording medium of the magnetic head is suppressed, and head life and head output are improved.

Further, in the magnetic head of the present invention,
Since the dust removing member is a dummy core, and the dummy core is provided with a dust removing groove or a corner portion or an inclined surface, dust caught in the magnetic recording medium is trapped in the dust removing groove or is removed. It is reliably removed by the corners or bevels.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings. Example 1 As shown in FIGS. 1 and 2, the magnetic head of this example is
For example, on a main surface of the magnetic core 1 made of ferrite, a conductor coil (not shown in the figure) that constitutes a magnetic circuit section with the magnetic core 1 and a magnetic core 2 made of sendust are arranged at predetermined intervals by a vacuum thin film forming technique. A plurality of guard members 3 made of crystallized glass are laminated so as to cover the magnetic circuit portion with glass 4 interposed therebetween.

That is, in the magnetic head of this embodiment, each of the magnetic core 1 made of ferrite and the magnetic core 2 made of sendust and the conductor coil formed at a predetermined interval functions as a magnetic head. It is a so-called multi-channel type magnetic head.

Each magnetic head is, for example, as shown in FIG.
As shown in FIG. 3, a conductor coil 6 is spirally formed on the magnetic core 1 made of ferrite with an insulating layer 5 interposed therebetween, and extends from the central portion of the conductor coil 6 to the magnetic recording medium sliding surface 7 side. Thus, the magnetic core 2 made of sendust is formed in the depth direction of the magnetic gap. The magnetic core 2 made of sendust is opposed to the magnetic core 1 made of ferrite on the front side through a gap film (not shown) to form a front gap FG, and is directly connected to the magnetic core 1 on the back side. The back gap BG is formed by the contact. As a result, the pair of magnetic cores 1 and 2 and the conductor coil 6 constitute a magnetic circuit section.

Each of the above magnetic heads is manufactured by a vacuum thin film forming technique which is usually used for manufacturing a thin film magnetic head. Further, as the material of the magnetic core 2 functioning as the upper layer core, in addition to sendust, any conventionally known ferromagnetic metal material generally used as a core material of a thin film magnetic head can be used. On the other hand, for the conductor coil 6, any metal material such as Cu, Au, Ag, which is also used in this kind of field, can be used. Further, in order to form the conductor coil 6, a photo etching method, an ion etching method or the like is adopted.

In this magnetic head, in order to secure the contact with the magnetic recording medium and reduce the spacing loss, the magnetic recording medium sliding surface 7 which is in sliding contact with the magnetic recording medium is polished into an arcuate cross section. ing. Further, in this magnetic head, the guard member 4 is joined via the glass 3, but the guard member 4 serves to protect the magnetic circuit portion and secure the contact with the magnetic recording medium. There is.

In particular, the magnetic head of this embodiment is provided with a dust removing groove 8 for removing dust such as dust and sand entrained by the magnetic recording medium. As shown in FIG. 4, the dust-removing groove 8 is inserted into the magnetic recording medium sliding surface 7 of the magnetic core 1 on the side where the magnetic recording medium 9 enters, in the direction in which the magnetic recording medium 9 enters (arrow in the figure). It is formed as a groove having a rectangular cross section in a direction substantially orthogonal to the (direction indicated by A).

The dust-removing groove 8 is located at a position not in contact with the front gap FG which operates as a recording / reproducing gap, has no influence on recording / reproducing, and ensures sufficient contact with the magnetic recording medium 9 and has a high mechanical strength. The width and depth of the groove are determined within a range in which the reduction does not occur. Further, the dust removing groove 8 is formed in a direction substantially orthogonal to the approaching direction of the magnetic recording medium 9, but it does not necessarily have to be 90 degrees, and has an angle of 90 degrees plus α. It does not matter if it is slightly inclined.

Thus, the groove 8 for removing dust is formed on the magnetic recording medium sliding surface 7 of the magnetic core 1 on the side where the magnetic recording medium 9 enters.
By providing the above, the dust 10 caught in the magnetic recording medium 9 is trapped in the dust removing groove 8 before reaching the front gap FG. Therefore, unlike the conventional case, the dust 10 does not come into sliding contact with the magnetic recording medium sliding surface 7 while rubbing the magnetic recording medium 9,
The wear of the head can be significantly reduced. As a result, the life of the head can be significantly extended and the recording / reproducing efficiency can be improved.

Although the groove 8 for removing dust is formed in the magnetic core 1 in the above-mentioned embodiment, as shown in FIGS. 5 and 6, for example, the magnetic core 1 on the entrance side of the magnetic recording medium 9 is magnetized. A notch 1 is formed in a part of the recording medium sliding surface 7 in a direction parallel to the magnetic gap and substantially orthogonal to the approach direction of the magnetic recording medium 9.
2 is provided, and dust 1 is provided by the corner portion 13 that is the edge portion.
You may make it remove 0. In this way, the dust 10 caught in the magnetic recording medium 9 can be reliably removed at the corners 13 as in the case of the dust removing groove 8 described above.

Embodiment 2 In the magnetic head of this embodiment, a dummy core 14 is arranged as a dust removing member for removing the dust 10 on the magnetic core 1 on the entrance side of the magnetic recording medium 9. This magnetic head has the same structure as the magnetic head of the first embodiment except that the dust removing groove 8 formed in the magnetic head of the first embodiment is removed. Therefore, in this embodiment, only the portion different from the head of the first embodiment will be described.

In such a magnetic head, as shown in FIGS. 7 and 8, the dummy core 1 as a dust removing member is further provided on the entry side of the magnetic core 1 on the side where the magnetic recording medium 9 enters.
4 are arranged. The dummy core 14 is formed as a rectangular parallelepiped having a length substantially the same as that of the magnetic head and a height slightly lower than the head height of the magnetic head. Then, the tip portion 15 of the dummy core 14
Are formed in an arc shape so that the contact angle θ with respect to the magnetic recording medium 9 is 90 degrees or less. When the contact angle θ exceeds 90 degrees, the dust 10 is caught in the sliding surface 7 of the magnetic recording medium and the magnetic recording medium 9 is damaged.

The dummy core 14 is made of, for example, a high hardness material such as crystallized glass or ceramics, a non-magnetic material such as an elastic material such as sponge or felt that does not damage the tape, or a non-magnetic material that does not participate in recording / reproduction, or ferrite. And the like magnetic material.

By arranging the dummy core 14 further on the entry side of the magnetic core 1 in the entry direction of the magnetic recording medium 9 as described above, the dust 10 caught in the magnetic recording medium 9 slides on the magnetic recording medium of the magnetic head. It is surely removed by the dummy core 14 before reaching the surface 7. Therefore, as with the magnetic head of the first embodiment, the wear of the head can be significantly reduced, the life of the head can be significantly extended, and the recording / reproducing efficiency can be improved.

In addition to this, as shown in FIG.
It is also possible to cut out a part of the tip portion 15 of No. 4 and remove the dust 10 by the corner portion 16 which is the edge portion of the cutout. Further, as shown in FIG. 10, a groove 17 having a rectangular cross section for removing dust may be formed in the tip portion 15 of the dummy core 14. Furthermore, as shown in FIG.
The notch groove 18 may be formed in the tip portion 15 of No. 4, and the dust 10 may be removed at the corner portion 19 which is the edge portion. Further, as shown in FIG. 12, the inclined surface 20 is formed on the dummy core 14, and the dust 10 is removed by the corner portion 21 which is the intersection of the inclined surface 20 and the arcuate portion of the tip portion 15. Good. Incidentally, these FIG. 9 to FIG.
Then, in both cases, the contact angle θ is set to 90 degrees or less.

Although the embodiments to which the present invention is applied have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, although the present invention is applied to the thin film magnetic head in this example, a bulk type magnetic head for a video tape recorder, a magnetic head for an audio,
The magnetic head can be applied to all magnetic heads as long as it is a magnetic head that performs recording / reproduction by slidingly contacting a magnetic recording medium, such as a magnetic head for a floppy disk, and the same effects are obtained.

[0032]

As is clear from the above description, in the magnetic head of the present invention, the groove or corner for removing dust is formed on the sliding surface of the magnetic recording medium on the side where the magnetic recording medium enters. Since it is provided, even if dust such as dust or sand dust is caught in the magnetic recording medium, it can be trapped in the dust removal groove before reaching the magnetic gap portion,
Alternatively, it can be reliably removed by the corners. Therefore, the amount of wear of the head can be significantly reduced, the life of the head can be extended, and the recording / reproducing efficiency can be improved.

Further, in the magnetic head of the present invention, since the magnetic core on the side where the magnetic recording medium enters is provided with the dummy core which is a dust removing member further on the entering side, dust is deposited on the sliding surface of the magnetic recording medium of the magnetic head. The dust can be reliably removed by the dummy core before the arrival of the. Therefore, the amount of wear of the head can be reduced, the life of the head can be extended, and the recording / reproducing output can be improved.

Further, in the magnetic head of the present invention,
Since the dummy core is provided with a groove for removing dust, a corner or an inclined surface, the dust caught in the magnetic recording medium can be trapped in this groove, and is reliably removed by the corner or the inclined surface. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic head according to a first embodiment.

FIG. 2 is an enlarged plan view of an essential part showing the sliding surface of the magnetic recording medium of the magnetic head of Example 1 in an enlarged manner.

FIG. 3 is an enlarged cross-sectional view of a main part of the magnetic head of the first embodiment.

FIG. 4 is an enlarged side view of essential parts showing an enlarged sliding surface portion of the magnetic recording medium of the magnetic head of the first embodiment.

FIG. 5 is a perspective view showing another example of the magnetic head of the first embodiment.

6 is an enlarged side view of an essential part showing an enlarged sliding surface portion of a magnetic recording medium of the magnetic head of FIG.

FIG. 7 is a perspective view of a magnetic head according to a second embodiment.

FIG. 8 is an enlarged side view of essential parts showing a sliding surface portion of a magnetic recording medium of a magnetic head of Example 2 in an enlarged manner.

FIG. 9 is an enlarged side view of essential parts showing another example of the magnetic head of Example 2 and showing an enlarged sliding surface portion of the magnetic recording medium.

FIG. 10 is an enlarged side view of an essential part showing still another example of the magnetic head of Example 2, showing an enlarged sliding surface portion of the magnetic recording medium.

FIG. 11 is an enlarged side view of an essential part showing another example of the magnetic head of Example 2 and showing an enlarged sliding surface portion of the magnetic recording medium.

FIG. 12 is a main part enlarged side view showing still another example of the magnetic head of Example 2 and showing an enlarged sliding surface portion of the magnetic recording medium.

FIG. 13 is a perspective view of a conventional magnetic head.

FIG. 14 is an enlarged plan view of an essential part showing an enlarged sliding surface of a magnetic recording medium of a conventional magnetic head.

FIG. 15 is an enlarged side view of an essential part showing a sliding portion of a magnetic recording medium of a conventional magnetic head in an enlarged manner.

[Explanation of symbols]

 1, 2 ... Magnetic core 3 ... Glass 4 ... Guard material 6 ... Conductor coil 7 ... Magnetic recording medium sliding surface 8 ... Dust removal groove 9 ... Magnetic recording Medium 10 ... Dust 12 ... Notch groove 14 ... Dummy core

Claims (5)

[Claims] 1. A magnetic head comprising a pair of magnetic cores forming a closed magnetic circuit, wherein grooves or corners for removing dust are provided on a magnetic recording medium sliding surface of a magnetic core on the side where a magnetic recording medium enters. A magnetic head characterized in that 2. The magnetic head according to claim 1, wherein the dust-removing groove or corner is formed in a direction substantially orthogonal to the approaching direction of the magnetic recording medium. 3. A magnetic head having a closed magnetic path formed by a pair of magnetic cores, wherein a dust removing member is arranged further on the entrance side of the magnetic core on the side where the magnetic recording medium enters. head. 4. The magnetic head according to claim 3, wherein the dust removing member is a dummy core. 5. The magnetic head according to claim 4, wherein the dummy core is provided with a groove, a corner or an inclined surface for removing dust.