JPH05120619A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To reduce a ferrite noise by having a short ring being wound a conductive body around a circumference of a core in parallel to a head running direction between a sliding surface against a medium and a winding wire. CONSTITUTION:A magnetic head 1 is constituted with a ferrite 2 and a magnetic metal 3 and the winding wire 4 is wound around both cores 11. Between the sliding surface 5 and the winding wire 4, A 1 is attached as the conductive body 6 so as to wind each core 11 in parallel to the head running direction. A short ring winding around each core 11 with the conductive body 6 and the magnetic metal core 3 is formed. The magnetic flux 7 of the ferrite noise generated by sliding against the medium is orthogonally crossed with the short ring and on the other hand a signal flux 8 taken in from the medium 10 via a gap 9 flows mainly in the metal core 3, and a magnetic flux flowing in the remaining ferrite is intersected with an angle theta to the short ring. Since the effective permeability of a magnetic path of the magnetic flux 7 becomes lower than that of the short wring, the noise magnetic flux does not reach to the winding wire 4, thus the ferrite noise is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly, it has a high S / S ratio for recording and reproducing information by sliding contact with a magnetic recording medium.
N magnetic head.

[0002]

2. Description of the Related Art Noise must be suppressed in order to provide a high S / N magnetic head. As a conventional technique, as described in JP-A-58-111120, a magnetic head used in a magnetic recording / reproducing apparatus such as a video tape recorder, particularly a double azimuth head, has a countermeasure against external radio wave interference which causes noise to improve S / N. In order to reduce the crosstalk, an unbalanced winding is formed so that the first magnetic head is wound with the second magnetic head.

[0003]

A composite type magnetic head composed of a ferrite material and a magnetic metal material, when the ferrite exposed on the sliding surface and the medium slide when the signal is reproduced,
Ferrite noise is generated, leading to S / N deterioration. The causes are the reverse magnetostriction effect due to the sliding of the ferrite material, the change in the magnetization distribution inside the head due to friction heat, etc. In both cases, noise is the ferrite part near the sliding surface, especially the edge part where the sliding conditions are severe. Has arisen from.

In the prior art, regarding the improvement of S / N and the suppression of noise, only the measures against external radio wave interference and the reduction of crosstalk are taken into consideration, and the ferrite noise is not taken into consideration. There is a problem that the S / N is deteriorated due to the generation of noise accompanying movement.
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a composite magnetic head in which ferrite noise generated during signal reproduction is reduced.

[0005]

In order to achieve the above object, a conductor is wound around the core so as to form a short ring between the sliding surface and the winding portion in parallel with the head traveling direction. ..

[0006]

[Function] Ferrite noise mainly occurs at the edge portion of the ferrite core, not near the gap. The wound conductor forms a short ring of the magnetic path of the ferrite noise magnetic flux generated near the sliding surface, particularly at the edge portion, and shorts the induced current due to the noise magnetic flux. As a result, the magnetic flux of ferrite noise is not transmitted to the winding portion, and ferrite noise is reduced. On the other hand, the reproduction signal output does not decrease because a conductor is placed between the sliding surface and the winding so as not to interlink the reproduction signal magnetic flux with the short ring or a closed magnetic circuit is formed in the short ring. ,
A magnetic head with high S / N can be provided.

[0007]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows a magnetic head according to a first embodiment of the present invention. FIG. 2 schematically shows the state of magnetic flux near the sliding surface in FIG. In FIG. 1, a magnetic head 1 is composed of a ferrite 2 and a magnetic metal 3, and a winding 4 is wound around both cores 11. Between the sliding surface 5 and the winding 4, each core 1 is parallel to the head traveling direction (arrow in the figure).
An aluminum is attached as a conductor 6 so as to surround 1. The conductor 6 is connected to the magnetic metal 3 exposed on the side surface of the head, and the conductor 6 and the magnetic metal core 3 form a short ring surrounding each core 11.

As shown in FIG. 2, the magnetic flux 7 of ferrite noise generated by sliding on the medium is orthogonal to the short ring formed by the conductor 6 and the magnetic metal core 3. on the other hand,
The signal magnetic flux 8 taken from the medium 10 through the gap 9 flows mainly in the metal core 3, and the magnetic flux flowing in the remaining ferrite also forms an angle with respect to the short ring formed by the conductor 6 and the magnetic metal core 3. Interlink with θ. Since the effective magnetic permeability of the magnetic path of the ferrite noise magnetic flux 7 is reduced by the short ring, the noise magnetic flux does not reach the winding 4, and as a result, the ferrite noise can be reduced. Most of the reproduction signal magnetic flux 8 does not interlink with the short ring, or even if it interlinks, it interlinks at an angle θ, so that the decrease in the magnetic permeability of the magnetic path is relatively small, and the reproduction output of the short ring is small. It rarely reduces the signal. Therefore, a high S / N magnetic head with reduced noise can be provided.

Since the conductor 6 is attached to the core 11 as a thin film, forming the short ring with the conductor 6 and the magnetic metal core 3 can reduce the electric resistance of the short ring because the length thereof can be shortened. It is more effective in reducing the magnetic permeability of the magnetic path of the ferrite noise magnetic flux 7.

The short ring is also effective in suppressing the magnetic flux leaking from the head edge portion, and in the present embodiment, also has the effect of reducing the self-inductance of the head.

Examples of the conductor 6 include various metal conductors such as copper and chromium or conductive pastes, and the effect is the same in any case.

The method of attaching the conductor 6 includes vapor deposition, sputtering, coating, etc., but the effect is the same in any case.

By such a method, it is possible to provide a high S / N composite type magnetic head with reduced ferrite noise.

FIG. 3 shows a magnetic head according to the second embodiment of the present invention. In FIG. 3, the magnetic head 1 is composed of a ferrite 2 and a magnetic metal 3, and the winding 4 has both cores 11.
It is wound around. An aluminum is attached as a conductor 6 between the sliding surface 5 and the winding wire 4 so as to surround the head element in parallel with the head traveling direction. The conductor 6 forms a short ring surrounding both cores 11.

The ferrite noise magnetic flux 7 generated by sliding on the medium is orthogonal to the short ring formed by the conductor 6. Since the effective magnetic permeability of the magnetic path of the ferrite noise magnetic flux 7 is reduced by the short ring, the noise magnetic flux does not reach the winding 4, resulting in reduction of the ferrite noise. Since the magnetic path of the reproduction signal magnetic flux 8 is a closed magnetic circuit in the short ring, the reproduction signal output is not affected by the short ring at all. If the conductor 6 and the magnetic metal 3 are connected in the same manner as in the first embodiment, the resistance value of the short ring can be lowered, which is more effective.

Examples of the conductor 6 include various metal conductors such as copper and chromium or conductive pastes, and the effect is the same in any case.

As a method of attaching the conductor 6, there are vapor deposition, sputtering, coating, etc., but the effect is the same in any case.

From the above, there is no reduction in the reproduction signal output,
A high S / N composite type magnetic head with reduced ferrite noise can be provided.

Further, as an application of the present embodiment, if the winding portion and the rear core are covered with an insulating resin so as not to enter the winding window, the winding side end portion of the conductor 6 is extended to surround the entire head element. You can also do it. As a result, ferrite noise suppression and a higher shielding effect can be obtained, and a high S / N composite type magnetic head can be provided.

[0021]

Since the present invention is constructed as described above, it has the following effects.

By attaching a conductor 6 between the sliding surface 5 and the winding wire 4 of the composite type magnetic head composed of the ferrite 2 and the magnetic metal 3 so as to surround the core in parallel with the head traveling direction, the ferrite sliding portion The generated ferrite noise can be reduced. Also, the self-inductance can be reduced. Therefore, it is possible to provide a high S / N composite type magnetic head in which ferrite noise generated during signal reproduction is reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a composite magnetic head showing a first embodiment of the present invention.

FIG. 2 is a schematic diagram of the flow of magnetic flux near the sliding surface of the composite magnetic head according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a composite magnetic head showing a second embodiment of the present invention.

[Explanation of symbols]

1 ... Magnetic head, 2 ... Ferrite, 3 ... Magnetic metal, 4
... Winding, 5 ... Sliding surface, 6 ... Conductor, 7 ... Ferrite noise magnetic flux, 8 ... Signal magnetic flux, 9 ... Gap, 10 ... Medium, 11
…core.

Claims (2)

[Claims] 1. A composite magnetic head comprising a ferrite (2) and a magnetic metal (3), between a sliding surface (5) for a medium and a winding (4), parallel to the head running direction. A composite magnetic head having a short ring formed by winding a conductor (6) around a core (11). 2. The composite magnetic head according to claim 1, wherein the conductor (6) has a short ring by being connected to the magnetic metal (3) exposed on the side surface of the head.