JPH0863710A - Magnetic head assembly - Google Patents

Abstract

PURPOSE: To approximately equalize wear characteristics of more than one magnetic head disposed close to one head supporting body. CONSTITUTION: Two magnetic heads 1 and 2 are disposed close to the head supporting body 5, constituting double azimuth heads. The magnetic head 2 is a precedent A head in slide contact with a magnetic tape, while the magnetic head 1 is a following B head. Inclined orientations of crystal axes [100] 3a, 3b, 3c and 3d to a gap butting surface in a magnetic path forming surface [110] 4 in both of these magnetic heads 1 and 2 are made to be identical. By this method, wear speeds. of the A head 2 and the B head 1 are approximately equalized, and wear of a difference in level and changing a sliding surface in shape, etc., of these heads are reduced, and hence FM lacking, etc., due to partial wear are suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a home VTR or the like, and more particularly, to recording, reproduction and erasing of a video signal and an audio signal in which two or more magnetic heads are arranged close to each other. The present invention relates to a magnetic head assembly capable of maximally utilizing the characteristics of the magnetic head according to the purpose.

[0002]

2. Description of the Related Art A conventional example in which a plurality of magnetic heads are arranged on one head support is disclosed in Japanese Patent Laid-Open No. 3-46105, but the [100] crystal axis of single crystal ferrite is particularly specified. I haven't. On the other hand, examples of conventional magnetic heads that define the [100] crystal axis of single crystal ferrite include those described in Japanese Patent Application Laid-Open No. 4-10206 and Japanese Patent Application Laid-Open No. 2-177007. It describes the improvement of output. However, it does not mention the effect of the combination of crystal axis orientations in a composite head using two or more magnetic heads such as a double azimuth head.

Here, a manufacturing process of a conventional magnetic head will be described with reference to FIG.

In FIG. 6A, the ferrite core 6
A track width regulating groove is formed on the substrate, a metal magnetic film 8 is formed thereon by a sputtering method, and then glass 7 is filled. At this time, the [100] crystal axis 9 of the single crystal ferrite
The angle θ (= 25 °) formed by the gap abutting surface in the magnetic path forming surface 10 of {110} is as illustrated. Further, the winding groove 11 is formed in one of the core halves, the gap abutting surface is ground to form the track width, and then the gap material is formed to form the core halves 12 and 13. Figure 6
In (b), the core halves 12 and 13 are butted against each other to form a joined core block 14. This core block 1
The core half 12 on which the winding groove 4 is not formed is ground, and the sliding contact surface with the magnetic tape is cylindrically ground to obtain the core block 15 shown in FIG. 6C.

FIG. 7 is a perspective view showing a double azimuth head formed from the core block 15 obtained by the above manufacturing process.

In FIG. 6, the A head 17 which precedes the sliding contact with the magnetic tape and the B head 16 which follows the magnetic tape are manufactured by the same method as shown in FIG. That is, the core block 15 shown in FIG. 6C is sliced perpendicularly to the sliding surface to obtain a plurality of magnetic heads, and two of the obtained magnetic heads are paired,
One of the heads is the A head 17 and the other is the B head 16, which are mounted in proximity to the head support as shown in FIG. In this case, in order to bring the gaps of the magnetic heads 16 and 17 close to each other, the A head 17 and the B head 16 are arranged with their side surfaces reversed. Therefore, as shown in FIG. 7, the two heads 16 and 17 have different inclination directions of the [100] crystal axis with respect to the gap abutting surface. However, as shown in FIG. 5, it has been confirmed that there is no difference in reproduction output characteristics between the names c and d. From this,
Conventionally, the A head 17 and the B head 16 are manufactured by the same method as described above.

[0007]

However, if the directions of inclination of the [100] crystal axes are different between magnetic heads arranged close to each other, the wear characteristics of the respective heads are different. It has recently been found that there is step wear on the. In the case of the double azimuth head shown in FIG. 7, the sliding contact with the magnetic tape precedes A
There is a problem that the B head 16 following the head 17 is worn earlier and the change of the sliding surface shape becomes larger.

An object of the present invention is to eliminate such a problem and equalize the wear characteristics of a plurality of closely arranged heads,
It is an object of the present invention to provide a magnetic head assembly in which step wear does not occur.

[0009]

In order to achieve the above object, the present invention comprises one head support and two or more magnetic heads arranged close to each other, each of which has a gap. In the two core halves facing each other, the [100] crystal axis direction, which is the easy axis direction of the single crystal ferrite core as the matrix, is close to the sliding contact surface with the magnetic tape and the gap abutting surface. In the magnetic head assembly in which the magnetic path forming surface is inclined in the same direction by 10 ° to 50 ° with respect to the gap abutting surface, the [100] crystal axis of the ferrite core in each of these magnetic heads has a magnetic path forming surface. Inside it should be tilted in the same direction as the gap abutment surface.

Further, according to the present invention, a metal magnetic film is arranged in the vicinity of one or more gaps of these magnetic heads.

Further, according to the present invention, a pair of magnetic heads are arranged on the head support, and a double azimuth
A head is formed and a metal magnetic film is arranged near the gap between them.

[0012]

The wear characteristics of a plurality of magnetic heads arranged close to each other are substantially equalized, step wear is eliminated, and FM drop due to uneven wear can be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a magnetic head assembly according to the present invention, in which 1 and 2 are magnetic heads and 3a to 3d.
Is a [100] crystal axis of single crystal ferrite, 4 is a main magnetic path forming surface {110}, and 5 is a head support.

In the figure, two magnetic heads 1 and 2 are arranged close to a head support 5, and these magnetic heads 1 and 2 form a double azimuth head. If the A head that precedes the sliding contact with a magnetic tape (not shown) is the magnetic head 2 and the subsequent B head is the magnetic head 1,
In both of the A head 2 and the B head 1, the [100] crystal axes 3a, 3b, 3c, 3d are inclined in the same direction in the {110} magnetic path forming surface 4 with respect to the gap abutting surface.

In order to obtain such a double azimuth head, the A head 2 is manufactured by the method described in FIG. 6, but the B head 1 needs to be manufactured by the manufacturing method shown in FIG. That is, as shown in FIG. 2A, the core half body 1
The processing of Nos. 8 and 19 was carried out with respect to the side formed by the magnetic tape sliding surface and the magnetic path forming surface 4 in the core halves 12 and 1 in FIG.
It is performed so as to be line-symmetric with 3. As a result, FIG.
As shown in FIG. 6B, the core block 20 having the [100] crystal axis tilt direction opposite to that shown in FIG. 6C can be obtained, and the double azimuth head shown in FIG. 1 can be obtained. .

FIG. 3 shows the relationship between the magnetic tape sliding time and the wear amount of the B heads 1 and 16 following the double azimuth head shown in FIG. 1 and the conventional double azimuth head shown in FIG. Are shown by comparison.

In the figure, comparing the amount of wear at a sliding time of 2000 h, the amount of wear of the B head 1 is 4.5 μm.
m, which is less than half the amount of wear of the B head 16 of 11 μm.

In this example, the [100] crystal axis is the magnetic tape.
It is possible to extend the wear life by making them face each other in sliding contact with the slide. However, what is most important here is that the change in the wear amount of the preceding A head 2 (and the A head 17) almost coincides with the change in the wear amount of the B head 1 shown as a solid line along with ◯ in FIG. That is. In other words, the A head 2 and the B head 1 are worn out by the same amount, and the problem of step wear that has occurred in the A head 17 and the B head 16 in the conventional double azimuth head can be solved.

This is because, for example, when the magnetic powder is clogged in the gap due to sliding contact with the magnetic tape, the [100] crystal axis should be oriented so as to be easily worn. Also, it is effective to align the inclination directions of the [100] crystal axes of the leading A head and the trailing B head as in this embodiment.

FIG. 4 is a diagram showing changes in the curvature radius Ry in the direction orthogonal to the sliding direction within the sliding surface with respect to the sliding time.

In the conventional double azimuth head shown in FIG. 7, not only the step wear of the B head 16 but also the change of the sliding surface shape is large. As shown in FIG. 4, the radius of curvature Ry of the B head 16 is initially 2.5.
It was about 8 mm, but it was about 8 mm when the sliding time was 2000 h.
Has changed to. As a result, the condition of sliding contact with the magnetic tape deteriorates, causing FM drop. On the other hand, in the B head 1 in this embodiment, the change amount of the curvature radius Ry is suppressed within 3 mm in the same sliding time, and the change amount is almost the same as that of the A head 2.

The amount of change in the radius of curvature Ry of the A head 17 in FIG. 7 is 0.8 mm larger than that of the A head 2 in this embodiment.

That is, as in this embodiment, it is also effective to minimize the change in the radius of curvature Ry by aligning the directions of the [100] crystal axis inclinations.

[0024]

As described above, according to the present invention,
It is possible to make the wear characteristics of the plurality of magnetic heads arranged close to the head support substantially equal to each other, thereby preventing step wear and FM drop.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a magnetic head assembly according to the present invention.

FIG. 2 is a diagram showing a part of the manufacturing process of the embodiment shown in FIG.

FIG. 3 is a diagram showing a comparison of changes in wear amount with respect to sliding time between the embodiment shown in FIG. 1 and a conventional magnetic head assembly.

FIG. 4 is a view showing a comparison of changes in a radius of curvature Ry with respect to a sliding time between the embodiment shown in FIG. 1 and a conventional magnetic head assembly.

FIG. 5 is a diagram showing a relationship between a [100] crystal axis of a single crystal ferrite and a reproduction output.

FIG. 6 is a diagram showing a manufacturing process of a conventional double azimuth head.

FIG. 7 is a perspective view showing an example of a conventional magnetic head assembly.

[Explanation of reference symbols] 1, 2 Magnetic heads 3a, 3b, 3c, 3d [10
0] Crystal axis 4 Main magnetic path forming surface {110} 5 Head support

Claims (3)

[Claims] 1. Two or more magnetic heads are arranged close to one head support, and each of the magnetic heads comprises:
In the two core halves facing each other across the gap, the [100] crystal axis direction, which is the direction of the easy axis of the single crystal ferrite core as the matrix, is close to the sliding contact surface with the magnetic tape and the gap abutting surface. In the magnetic head assembly in which the magnetic path forming surface is inclined in the same direction by 10 ° to 50 ° with respect to the gap abutting surface, [1] of the ferrite core in each magnetic head is provided.
[00] A magnetic head assembly in which the crystal axis is tilted in the same direction as the gap abutting surface in the magnetic path forming surface. 2. The magnetic head assembly according to claim 1, wherein at least one of the two or more magnetic heads is a magnetic head having a metal magnetic film disposed in the vicinity of the gap. 3. The double azimuth roller according to claim 1, wherein a pair of magnetic heads having different azimuth angles are arranged close to the head support.
A magnetic head assembly comprising a head and a metal magnetic film disposed near a gap between these magnetic heads.