JPH06150232A - Magnetic head - Google Patents

Abstract

(57) [Summary] [Structure] The front gap g
_{1. In} the magnetic head formed by joining with the back gap g ₂ , one or both of the magnetic cores 1 and 2 are provided with winding windows 3 and 4 at least a part of which has a curved shape. [Effect] It is possible to improve the recording efficiency of the magnetic head. In addition, it is possible to improve the manufacturing yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a rotary magnetic head device such as a video cassette recorder (VCR), a rotary head digital tape recorder (R-DAT), a digital data storage (DDS). The present invention relates to a magnetic head suitable for a magnetic recording / reproducing device.

[0002]

2. Description of the Related Art A rotary head device has been developed in order to achieve high density recording of a magnetic recording / reproducing device, and a video cassette recorder (hereinafter referred to as VCR) is used as a magnetic recording device using the rotary head device. , Rotary head digital tape recorder (hereinafter referred to as R-DAT), digital data storage (hereinafter referred to as D)
It is called DS. ) Etc. are widespread. Above VCR
Is a magnetic recording and reproducing device for recording and reproducing video information,
R-DAT is a magnetic recording / reproducing device for recording / reproducing information such as music information and DDS.

The above-mentioned rotary magnetic head device is one in which a magnetic head is mounted on the rotary drum so that a magnetic gap of the magnetic head is arranged on the side surface of the rotary drum, and the magnetic recording medium is rotated while running on the rotary drum. The drum itself also rotates to perform magnetic recording and reproduction.

As a magnetic head mounted on such a rotary magnetic head device, there is a magnetic head as shown in FIG. 8, for example. The magnetic head includes a pair of magnetic cores 71 and 72, which are separately formed on the left and right sides of a front gap g ₉ and a back gap g ₁₀ as boundaries, but are abutted and integrated with each other with a gap portion. 71 and 72 are made of a bonding material of single crystal ferrite, polycrystalline ferrite, single crystal ferrite and polycrystalline ferrite, and the gap film 7 is formed on the gap forming surface thereof.
8 and 79 are formed to form a front gap g ₉ and a back gap g ₁₀ . The magnetic cores 71 and 72 are provided with trapezoidal winding windows 73 and 74.
Coils 75 and 76 are wound around 3,74. Further, a fused glass 77, which is a non-magnetic material, is melt-filled near the front gap g ₉ to join the magnetic cores 71 and 72. The front gap g ₉ and the back gap g ₁₀ may be formed by melting and filling the fused glass 77.

[0005]

In recent years, the above-mentioned VCR,
There is a demand for higher density recording in R-DAT and DDS, and improvement is desired not only in magnetic recording media but also in rotary magnetic head devices. The recording / reproducing characteristics of this rotary magnetic head device largely depend on the recording / reproducing characteristics of the mounted magnetic head, and it is strongly desired to improve the recording / reproducing efficiency of the magnetic head.

Therefore, the present invention has been proposed in view of the conventional circumstances, and an object thereof is to provide a magnetic head having an improved recording / reproducing efficiency.

[0007]

As a matter of course, when magnetic recording is performed by a magnetic head, a current is applied to a coil in accordance with information, thereby generating a magnetic field in the magnetic core, It leaks from the gap to the magnetic recording medium, and information is recorded as the direction and strength of magnetization. on the other hand,
During reproduction, a magnetic field leaking from the magnetic recording medium in accordance with information enters the magnetic core through the gap portion and causes the coil to generate an electromotive force. At this time, in order to improve the recording / reproducing efficiency of the magnetic head as described above, the magnetic field generated in the magnetic core is efficiently transmitted in the magnetic core, that is,
It is necessary to efficiently pass the magnetic flux through the magnetic core.

However, as a result of intensive studies by the present inventors, in the magnetic head as described above, excessive focusing of magnetic flux or leakage of magnetic flux occurs at the edge portion of the trapezoidal winding window provided in the magnetic core. It has been found that these are hindering the improvement of the recording / reproducing efficiency of the magnetic head. Especially when used in a VCR, since the frequency band to be recorded is higher than that of recording music information, the influence of magnetic flux leakage is very large, and there is a strong need for improvement.

That is, according to the present invention, in a magnetic head in which a pair of magnetic cores are joined together with a gap portion, at least one magnetic core is provided with a winding window, and at least a part of the winding window is curved. It is characterized by having a shape. Further, the magnetic head of the present invention is suitable for use in a rotary magnetic head device.

[0010]

According to the present invention, in a magnetic head in which a pair of magnetic cores are joined with a gap portion, at least one of the magnetic cores is provided with a winding window, and at least a part of the winding window has a curved shape. Therefore, excessive focusing and leakage of magnetic flux at the edge of the winding window are unlikely to occur. Further, in a VCR, DDS or the like using a rotary magnetic head device, it is essential to efficiently pass a magnetic flux through a magnetic core in order to achieve high density recording, and it can be realized by using the magnetic head of the present invention. .

Further, in the magnetic head of the present invention, since the winding window has no edge portion, stress at the time of processing is not concentrated at one point, and deterioration of magnetic characteristics due to the processing stress is mitigated. It is possible to prevent the occurrence of cracks and chips from the edge of the winding window.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described below with reference to the drawings. In the magnetic head of this embodiment, as shown in FIG. 1, a pair of magnetic cores 1 and 2 made of an oxide magnetic material such as ferrite are butted together with a front gap g ₁ and a back gap g ₂ and are integrally bonded. It has been transformed into Although the front gap g ₁ and the back gap g ₂ are formed by the gap film in the present embodiment, the gap portion is formed by melting and filling the fused glass like an ordinary magnetic head. However, the magnetic head of the present invention is applicable. The gap length of the front gap g ₁ and the back gap g ₂ of the magnetic head of this embodiment is the sum of the film thicknesses of the gap films 8 and 9 formed on the gap forming surfaces of the magnetic cores 1 and 2. The magnetic cores 1 and 2 are composed of a single crystal ferrite, a polycrystalline ferrite, a single crystal ferrite and a polycrystalline ferrite bonding material. In addition, the magnetic core 1,
Winding windows 3 and 4 forming a water drop shape are provided in 2, and coils 5 and 6 are wound around the winding windows 3 and 4. Further, a fused glass 7, which is a non-magnetic material, is melt-filled near the front gap g ₁ to join the magnetic cores 1 and 2.

In the magnetic head as described above, since the winding window has no edge portion, excessive magnetic flux focusing or magnetic flux leakage does not occur, and the recording / reproducing efficiency of the magnetic head can be greatly improved. It is possible. Further, in the magnetic head of the present embodiment, since the winding window has a shape having no edge portion, stress at the time of processing is not concentrated at one point and the deterioration of the magnetic characteristics due to the processing stress can be mitigated. It is possible to improve the recording / reproducing efficiency. Furthermore, in the magnetic head of the present embodiment, cracks and chips from the edge of the winding window do not occur,
It is also possible to improve the manufacturing yield. However, if the winding window near the front gap is too large,
Since the saturation of the magnetic flux occurs near the front gap, it is desirable that the shape of the winding window be an inclined surface near the front gap as in the above-mentioned magnetic head so that the magnetic flux is properly focused.

When manufacturing the magnetic head as described above, the manufacturing is performed according to the following steps. First, in order to form one magnetic core 1, a block 11 made of ferrite or the like as shown in FIG. 2 is prepared, and a plurality of H-grooves 12 having a substantially semicircular cross section for regulating the track width of the magnetic core are formed therein. Then, the winding window 3 having a cross section formed for winding the coil next has a shape in which one end of a semicircle is an inclined surface
Is formed so as to be orthogonal to the H groove, a glass groove 13 having a quadrangular cross section for performing glass fusion bonding is formed so as to be orthogonal to the H groove, and the gap forming surface 11a of the block 11 is finished to be a mirror surface. At this time, the depth (depth) of the front gap g ₁ of the magnetic core 1 is regulated by the winding window 3, and the fused glass is arranged on the winding window 3 to form the magnetic core 1.
In order to join the two, the winding window 3 is formed at a position where the tip of the inclined surface of the winding window 3 has a depth of the front gap g ₁ of the magnetic core 1 of zero.

Then, as shown in FIG. 3, a gap film 8 is formed on the block 11 in which the winding window 3, the glass groove 13 and the H groove 12 are formed. The gap film 8 is, for example, SiO
_{It is made of} a non-magnetic material such as ₂ and is formed to a thickness of about half the gap length using a thin film forming technique such as magnetron sputtering.

Then, the winding window 3, the glass groove 13, and the H groove 12 to be one of the magnetic cores 1 are formed, and the gap film 8 is formed.
A block 11 formed with, a winding window 4, a glass groove 23, which will be the other magnetic core 2 manufactured in the same manner as the block 11.
The H groove 22 is formed and the block 21 having the gap film 9 formed thereon is joined. That is, as shown in FIG. 4, the blocks 11 and 12 are butted so that the positions of the winding windows 3 and 4, the glass grooves 13 and 23, and the H grooves 12 and 22 coincide with each other with the gap films 8 and 9 as the butted surfaces. The fusion-bonding glasses 7 and 14 are arranged in the winding windows 3 and 4 and the glass grooves 13 and 23, and the fusion-bonding glasses 7 and 14 are heated and pressurized to be melted, and the blocks 11 and 21 are fusion-bonded. The blocks 11 and 21 thus joined are cut into chips, the tape sliding surface of each magnetic core chip is subjected to cylindrical polishing, and a coil is wound around the winding window to obtain a magnetic head as shown in FIG.

In the above embodiment of the magnetic head, the example in which the pair of magnetic cores are symmetrical is described, but as another example, the one in which the pair of magnetic cores are asymmetric is described. For example, as shown in FIG.
1 is an example in which the magnetic core 32 and the magnetic core 32 are joined and integrated with each other with a front gap g ₃ and a back gap g ₄ . In the magnetic head, the winding window 33 is provided only in the magnetic core 31, and the coil 35 is wound around the winding window 33. Incidentally, front gap g _3, gap length of the back gap g ₄ is determined by the thickness of the gap film 39 formed on the gap forming surfaces of the magnetic cores 31 and 32, front gap g ₃ fused in the vicinity of glass 37 is melt-filled and joins the magnetic cores 31 and 32. Further, there is also an example in which the magnetic core 41 and the magnetic core 42 as shown in FIG. 6 are joined and integrated with each other with a front gap g ₅ and a back gap g ₆ . In the magnetic head, the winding window 43 is provided only on the magnetic core 41, the coil 45 is wound around the winding window 43, and the coil 46 is also wound around the magnetic core 42. Incidentally, the front gap g _5, the gap length of the back gap g ₆ is determined by the thickness of the gap film 48, 49 formed on the gap forming surfaces of the magnetic cores 41 and 42, front gap g ₅ fused in the vicinity of glass 47 is melt-filled and joins the magnetic cores 41 and 42. Also in these examples, since there is no edge portion in the winding window of the magnetic head, excessive magnetic flux focusing or magnetic flux leakage does not occur, and it is possible to greatly improve the recording / reproducing efficiency of the magnetic head. is there. Further, also in these examples, since the winding window does not have an edge portion, the stress during processing does not concentrate at one point, and the deterioration of the magnetic characteristics due to the processing stress can be alleviated. Therefore, the recording / reproducing efficiency can be improved. further,
It is also possible to improve the manufacturing yield without causing cracks and chips from the edge portion of the winding window.

The magnetic head of this embodiment is a composite type magnetic head composed of an oxide substrate such as ferrite and a metal magnetic material, that is, a so-called metal in gap.
p) It is also applicable to a head (hereinafter abbreviated as MIG head). For example, as shown in FIG. 7, a pair of magnetic cores 51 made of an oxide magnetic material such as ferrite,
52 has a front gap g ₇ and a back gap g ₈ butted and joined together. In addition,
The gap length of the front gap g ₇ and the back gap g ₈ is the sum of the film thicknesses of the gap films 58 and 59 formed on the gap forming surfaces of the magnetic cores 51 and 52. The magnetic cores 51, 52 are composed of substrates 60, 61 made of a bonding material of single crystal ferrite, polycrystalline ferrite, single crystal ferrite and polycrystalline ferrite, and metallic magnetic films 62, 63 formed thereon. In addition, the substrate 60,
Winding windows 53 and 54 forming a water drop shape are provided in 61, and the metal magnetic films 62 and 63 and the gap films 58 and 59 are formed along the shapes thereof. Coils 55 and 56 are wound around the winding windows 53 and 54. Further, a fused glass 57, which is a non-magnetic material, is melt-filled near the front gap g ₇ to join the magnetic cores 51 and 52. Also in this embodiment of the MIG head, since the winding window of the magnetic head has no edge portion, excessive magnetic flux focusing or magnetic flux leakage does not occur, and the recording / reproducing efficiency of the magnetic head is greatly improved. It is possible. Further, also in the above-mentioned embodiment, since the winding window has a shape having no edge portion, the stress at the time of processing is not concentrated at one point, and the deterioration of the magnetic characteristics due to the processing stress can be alleviated. Therefore, the recording / reproducing efficiency can be improved. Further, the production yield can be improved without cracking or chipping from the edge portion of the winding window.

In order to manufacture the magnetic head as described above, the H-groove, the winding window, and the glass groove are formed in the block for forming the magnetic core in the same manner as in the usual magnetic head manufacturing method, and the gap is formed. After the surface to be formed is mirror-finished, a metal magnetic film may be formed by a vacuum thin film forming technique typified by, for example, a sputtering method, a vacuum evaporation method or the like, and a gap film may be formed on the metal magnetic film to be manufactured. Examples of the material of the metal magnetic film include Fe-Al-Si system and Fe-Ga-Si.
-Based crystal materials, Fe-N-based, Fe-C-based microcrystalline materials and C
Examples thereof include o-Zr-based and Co-Nb-based amorphous materials. When the metal magnetic film is formed in this way, in the magnetic head of this embodiment, since the winding window has no edge portion, the metal is uniformly deposited. The recording / reproducing efficiency of the magnetic head is further improved.

[0020]

As is apparent from the above description, in the present invention, in a magnetic head in which a pair of magnetic cores are joined with a gap portion, at least one magnetic core is provided with a winding window. Since at least a part of the winding window has a curved shape, excessive focusing of the magnetic flux and leakage of the magnetic flux at the edge portion of the winding window hardly occur, and it is possible to greatly improve the recording / reproducing efficiency. . Further, in a VCR, DDS or the like using a rotary magnetic head device, it is essential to efficiently pass a magnetic flux through a magnetic core in order to achieve high density recording, and this can be realized by using the magnetic head of the present invention. Therefore, higher density recording can be achieved.

Further, in the magnetic head of the present invention, since the winding window has a shape having no edge portion, the stress at the time of processing is not concentrated at one point and the deterioration of the magnetic characteristics due to the processing stress is alleviated. It is possible to improve the recording / reproducing efficiency.

Further, in the magnetic head of the present invention,
It is also possible to improve the manufacturing yield without causing cracks and chips from the edge portion of the winding window.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing an example of a process of manufacturing a magnetic head to which the present invention is applied, in the order of processes, showing a process of forming an H groove, a winding window, and a glass groove in a block.

FIG. 3 is a perspective view showing a step of forming a gap film in a block in which an H groove, a winding window and a glass groove are formed.

FIG. 4 is a perspective view showing a step of joining two blocks having an H groove, a winding window, a glass groove, and a gap film formed therein.

FIG. 5 is a perspective view showing another example of a magnetic head to which the present invention is applied.

FIG. 6 is a perspective view showing still another example of a magnetic head to which the present invention is applied.

FIG. 7 is a perspective view showing still another example of a magnetic head to which the present invention is applied.

FIG. 8 is a perspective view showing an example of a conventional magnetic head.

[Explanation of symbols]

1, 2 ... Magnetic cores 3, 4 Winding windows g ₁ , g ₂ Gap section

Claims (2)

[Claims] 1. A magnetic head in which a pair of magnetic cores are joined with each other with a gap portion, wherein at least one of the magnetic cores has a winding window, and at least a part of the winding window has a curved shape. The magnetic head is characterized by 2. The magnetic head according to claim 1, wherein the magnetic head is used in a rotary magnetic head device.