JPH08235519A - Magnetic head - Google Patents

Abstract

PURPOSE: To improve the output of head and to shorten the time for forming magnetic films by forming stepped parts on the magnetic film forming surfaces of magnetic cores. CONSTITUTION: The magnetic gap part forming the magnetic gap (g) of a pair of the magnetic cores 12, 13 consisting of oxide magnetic material (ferrite), etc., constituting the closed magnetic path of the magnetic head 11 is formed of magnetic films of, for example, 'SENDUST (R)', etc., having the higher saturation magnetic flux density than the saturation magnetic flux density of the ferrite. Coils 15 are wound around the magnetic cores 12, 13. The stepped parts 16 along the track width W direction of the magnetic cores 12, 13 are formed on the magnetic metallic film forming surfaces 12a, 13a of these cores. The magnetic metallic films 14 are formed on the stepped parts 16. While two steps are exemplified as the number of the stepped parts 16, >=2 steps are equally well. The head output is improved by providing the magnetic head with such stepped parts 16. In addition, the working accuracy is improved and the time for forming the magnetic films is shortened. The pseudo outputs are decreased by forming the magnetic films nonparallel with the magnetic gap.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head.
More particularly the magnetic gap portion of the magnetic core constituting a closed magnetic path is made of a magnetic film of high saturation magnetic flux density than the magnetic core, to a so-called MIG (M etal I n G ap ) type magnetic head.

[0002]

2. Description of the Related Art For example, in a magnetic recording / reproducing apparatus such as a VTR device, due to high signal density and high coercive force of a magnetic recording medium, a magnetic gap portion of a magnetic head is easily magnetically saturated and sufficient recording is performed. Cannot be done.

As a countermeasure against this, there has been proposed a so-called MIG type magnetic head in which a magnetic gap portion of a magnetic core forming a closed magnetic path is formed of a metal magnetic film having a saturation magnetic flux density higher than that of the magnetic core.

4 and 5 show an example of a MIG type magnetic head. The magnetic head 1 has a magnetic gap portion forming a magnetic gap g of a pair of magnetic cores 2 and 3 made of, for example, ferrite, which forms a closed magnetic path, and has a higher saturation magnetic flux density than ferrite, for example, a metal magnetic film such as sendust. 4 is formed and configured. Reference numeral 5 denotes a coil wound around the magnetic cores 2 and 3.

Here, if the metal magnetic film 4 is formed in parallel with the magnetic gap g, a pseudo gap is generated. Therefore, as shown in the figure, the metal magnetic film 4 is generally formed not in parallel with the magnetic gap g. , The method of suppressing the pseudo output is adopted. That is, in the case of the same drawing, the magnetic gap g is formed to be inclined at a predetermined angle with respect to the magnetic track formation direction, while the metal magnetic film forming surfaces 2a and 3a of the magnetic cores 2 and 3 are formed in the inclination direction of the magnetic gap g. In contrast, it is formed in the direction intersecting with Nono.

[0006]

By the way, as described above, in the conventional general MIG type magnetic head 1, in order to reduce the pseudo output due to the pseudo gap due to the metal magnetic film 4, the magnetic output is not parallel to the magnetic gap g. In order to form the metal magnetic film 4, the required film thickness d ₁ of the metal magnetic film 4 becomes thicker as compared with the configuration in which the metal magnetic film 4 is formed in parallel with the magnetic gap g.
For example, at least A μm is required. Therefore, as the film thickness of the metal magnetic film 4 becomes thicker, the output decreases due to the eddy current loss, the film forming time of the metal magnetic film 4 increases, and the manufacturing yield decreases due to film strain. It was

In view of the above points, the present invention provides a MIG type magnetic head which reduces eddy current loss and improves output.

[0008]

In a magnetic head according to the present invention, a magnetic film having a saturation flux density higher than that of the magnetic core is formed in a magnetic gap portion of a magnetic core forming a closed magnetic path, and the magnetic film is formed on the magnetic core. A step is formed on the surface.

[0009]

In the magnetic head according to the present invention, since the step portion is formed on the magnetic film forming surface of the magnetic core, the thickness of the magnetic film is reduced and the eddy current loss is reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a magnetic head according to the present invention, a magnetic film having a saturation magnetic flux density higher than that of the magnetic core is formed in a magnetic gap portion of a magnetic core forming a closed magnetic path, and a step portion is formed on a magnetic film forming surface of the magnetic core. And configure.

In the magnetic head according to the present invention, a magnetic film having a saturation magnetic flux density higher than that of the magnetic core is formed in the magnetic gap part of the magnetic core forming the closed magnetic path, and the magnetic film is formed non-parallel to the magnetic gap. A step is formed on the surface of the core on which the magnetic film is formed.

An embodiment of a magnetic head according to the present invention will be described below with reference to the drawings.

1 and 2 show an example of a MIG type magnetic head according to the present invention. In the magnetic head 11 of the present example, the magnetic gap portion forming the magnetic gap g of the pair of magnetic cores 12 and 13 that are made of, for example, an oxide magnetic body (ferrite) that forms a closed magnetic path has a saturation magnetic flux density higher than that of ferrite. It is formed by a magnetic film, for example, a metal magnetic film 14 such as sendust. Reference numeral 15 denotes a coil wound around the magnetic cores 12 and 13.

The magnetic gap g is formed so as to be inclined at a predetermined angle with respect to the magnetic track forming direction, that is, the sliding direction of the sliding surface of the magnetic recording medium (for example, magnetic tape).
The metal magnetic film forming surfaces 12a and 13a of the magnetic cores 12 and 13 are formed along a direction intersecting the tilt direction of the magnetic gap g so that the metal magnetic film 14 is not parallel to the magnetic gap g. It

In the present example, the metal magnetic film forming surfaces 12a and 13a of the magnetic cores 12 and 13 are particularly preferable.
Then, the step portion 16 is formed along the track width W direction. The metal magnetic film 14 is formed on the step portion 16. The number of steps of the step portion 16 is two in the illustrated example, but it may be two or more.

According to the MIG type magnetic head 11 having such a structure, the metal magnetic film forming surface 12a of the magnetic cores 12 and 13 is formed.
By forming the step portions 16 on the magnetic heads 13a and 13a, the amount of the metal magnetic film 14 formed is 1/2 when compared to the magnetic head of FIG. 4 when the step portions 16 have two steps as shown in the figure.
About. That is, the film thickness d ₂ of the metal magnetic film 14 is 1 /
It can be set to 2, for example, 1/2 A μm.

The film stress is generally proportional to the square of the film thickness.
Therefore, in the magnetic head 11 of the present example, warpage of the magnetic core, film peeling of the metal magnetic film 14 and the like are eliminated, and the processing accuracy can be greatly improved.

Since the metal magnetic film 14 has a small thickness, the eddy current loss can be reduced, the head output can be improved, and the noise can be reduced. Further, it is possible to shorten the film formation time of the metal magnetic film 14, suppress film distortion, and improve the manufacturing yield.

FIG. 3 shows a graph comparing the recording / reproducing outputs. This graph relatively shows the output (see line I) of the magnetic head 11 of this embodiment with reference to the output of the conventional magnetic head 1 shown in FIGS. 4 and 5 (see line II). From this graph, there is almost no difference at 1 MHz, but 5
It can be seen that the output is improved by 0.5 dB at 10 MHz and 1 dB at 10 MHz.

[0020]

According to the magnetic head of the present invention, by providing a stepped portion on the magnetic film forming surface of the magnetic core, the head output is improved and the processing accuracy is improved, and the magnetic film forming time is improved. Can be shortened. Further, when the magnetic film is formed non-parallel to the magnetic gap, the pseudo output can be particularly reduced.

[Brief description of drawings]

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

FIG. 2 is a plan view seen from the sliding surface side of the magnetic head according to the present invention.

FIG. 3 is a graph comparing the recording / reproducing output of the magnetic head of the present invention with that of the conventional example.

FIG. 4 is a perspective view of a conventional magnetic head.

FIG. 5 is a plan view seen from the sliding surface side of a conventional magnetic head.

[Explanation of symbols]

 11 MIG type magnetic head 12, 13 Magnetic core (ferrite) 12a, 13a Metal magnetic film forming surface 14 Metal magnetic film 15 Coil 8 Magnetic gap 16 Step core

Claims (2)

[Claims] 1. A magnetic film having a saturation magnetic flux density higher than that of the magnetic core is formed in a magnetic gap portion of a magnetic core forming a closed magnetic path, and a step portion is formed on a magnetic film forming surface of the magnetic core. Characteristic magnetic head. 2. A magnetic film having a saturation magnetic flux density higher than that of the magnetic core is formed in a magnetic gap portion of a magnetic core forming a closed magnetic circuit, the magnetic film being formed non-parallel to the magnetic gap, A magnetic head having a step formed on a surface on which a magnetic film is formed.