JP2003045005A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve output characteristics and the freedom of head designing. SOLUTION: This magnetic head 1 is constructed in such a manner that a pair of magnetic core halves 2, 3 are butted together to form a magnetic path, and a nonmagnetic film 6 is formed in a butted surface to form a magnetic gap G. In this case, a coil is wound on at least one of the pair of magnetic core halves 2, 3, grooves 10a, 10b are formed on a surface other than the butted surface of the coil wound part to reduce the volume of the magnetic core part in which the magnetic path is formed, and dimensions A of the grooves 10a, 10b in a depth direction are set to 20 to 50% of the dimensions B of the magnetic core halves 2, 3 in the same direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for recording and / or reproducing a signal on a magnetic recording medium.

[0002]

2. Description of the Related Art In recent years, in the field of magnetic recording, it has been required to record and reproduce more signals at high speed in order to improve the image quality of video signals, increase the recording capacity and increase the transfer rate. ing.

In response to this demand, in magnetic recording / reproducing apparatuses such as video tape recorders (VTRs) and digital data recorders, the wavelength of signals to be recorded / reproduced on / from a magnetic recording medium is being shortened. On the other hand, as a magnetic recording medium that meets this requirement, metal tape coated with a ferromagnetic metal powder on a base film or a vapor deposition tape formed by directly depositing a ferromagnetic metal powder on a base film has a high coercive force and high frequency. Those capable of stably recording / holding the magnetic signals of (3) have come to be used.

As a magnetic head mounted in a magnetic recording / reproducing apparatus compatible with such a high coercive force magnetic recording medium, for example, a magnetic head 100 as shown in FIG. 17 has been proposed.

In this magnetic head 100, a pair of guard members 101 mainly composed of a non-magnetic material is used to form a metal magnetic film 10.
A pair of magnetic core halves 103a, 1 in which 2 is sandwiched
03b, a magnetic path is formed by abutting the metal magnetic films 102 with each other, and a magnetic gap g is formed by abutting the abutting surfaces of the metal magnetic films 102 via the non-magnetic film 104. It will be done.

A pair of magnetic core halves 103a, 10
3b has winding grooves 106a and 106b, which are located substantially in the center of the surfaces facing each other and regulate the depth of the magnetic gap g and configure the winding window portion 105 after the butting. And this winding window portion 105
A coil (not shown) is wound around the peripheral surfaces of the pair of magnetic core halves 103a and 103b.

Also, a pair of magnetic core halves 103a, 10
3b includes a medium sliding surface 100a that slides on the magnetic recording medium.
Further, contact width regulating grooves 107 for adjusting the contact width with the magnetic recording medium are formed along both ends in the longitudinal direction.

In this magnetic head 100, the metal magnetic film 1
02 constitutes a magnetic core, and the metal magnetic film 102
Since the thickness of the metal magnetic layer becomes the track width, the metal magnetic film 102
By controlling the film thickness of, it is possible to easily form a narrow track. In addition, such a magnetic head 100
Has the advantage that no pseudo gap is structurally generated.

[0009]

By the way, in the above-described magnetic head 100, there is a demand to improve the output characteristics without changing a predetermined standard such as an outer dimension or an inductance.

However, in order to improve the output characteristics of the magnetic head 100, for example, a pair of magnetic core halves 1 is used.
Although it is conceivable to increase the number of turns of the coils wound on the coils 03a and 103b, simply increasing the number of turns of the coil causes an increase in inductance and deviates from the standard.

In the magnetic head 100, since the length of the wire (coil) that can be wound by the automatic winding machine is determined in the winding step of winding the coil, the existing automatic winding machine is used. There is naturally a limit to increasing the number of coil turns. In this case, it is necessary to manually wind the winding process or purchase a new automatic winding machine, which causes a decrease in productivity and an increase in cost.

Further, the magnetic head 100 is used in a magnetic recording / reproducing apparatus such as a video tape recorder (VTR).
When mounted on a rotary drum and rotated, as shown in FIG. 18, the coil 108 wound around the pair of magnetic core halves 103a, 103b causes the medium sliding surface 100a to move by centrifugal force.
However, in the worst case, there is a problem that the magnetic recording medium comes into contact with the magnetic recording medium and disconnects. Since the magnetic recording / reproducing apparatus tends to have a higher transfer rate, such a problem will increase in the future as the rotating drum rotates at a higher speed.

As described above, in the conventional magnetic head, the number of turns of the coil is limited, and the standard limits the degree of freedom for the head design.

Therefore, the present invention has been proposed in view of such conventional circumstances, and an object of the present invention is to provide a magnetic head which has improved output characteristics and improved flexibility in head design. To do.

[0015]

In a magnetic head according to the present invention which achieves this object, a magnetic path is formed by a pair of magnetic core halves butting together, and a non-magnetic film is formed on the abutting surface. As a result, a magnetic gap is formed, a coil is wound around at least one of the pair of magnetic core halves, and a magnetic path is formed on a surface other than the abutting surface of the portion around which the coil is wound. Grooves are formed to reduce the volume of the magnetic core portion to be formed, and the dimension in the depth direction of the groove is 20 to 50% of the dimension in the same direction of the magnetic core half around which the coil is wound. It is characterized by the ratio.

As described above, in the magnetic head according to the present invention, the groove for reducing the volume of the magnetic core portion forming the magnetic path is formed on the surface other than the abutting surface of the portion around which the coil is wound. Therefore, it is possible to increase the number of turns of the coil wound around the magnetic core half while suppressing the increase of the inductance.

Further, in this magnetic head, the size of the groove in the depth direction is set to be 20 to 50% of the size of the magnetic core half body around which the coil is wound in the same direction, whereby the magnetic It is possible to prevent the coil wound around the core half body from being displaced, and to suppress the decrease in magnetic efficiency due to the decrease in the volume of the magnetic core portion.

[0018]

DETAILED DESCRIPTION OF THE INVENTION A magnetic head to which the present invention is applied will be described below in detail with reference to the drawings.

A magnetic head to which the present invention is applied is, for example, a laminated type magnetic head (hereinafter referred to as a laminated head) 1 as shown in FIG.

The laminating head 1 comprises a pair of magnetic core halves 2 and 3, and a pair of magnetic core halves 2 and 3.
Have a structure in which they are butted and integrated.
The medium sliding surface 1a that slides on the magnetic recording medium has a substantially arc shape having a predetermined curvature in the longitudinal direction.

The pair of magnetic core halves 2 and 3 has a structure in which a metal magnetic film 5 serving as a magnetic core is sandwiched by a pair of guard members 4 containing a non-magnetic material as a main component. A non-magnetic film 6 is formed on the abutting surfaces of the pair of magnetic core halves 2 and 3.

In the laminating head 1, a magnetic path is formed by abutting the metal magnetic films 5 of the pair of magnetic core halves 2 and 3, and the abutting surface of the metal magnetic film 5 forms the non-magnetic film 6. The magnetic gap G is formed by being abutted against each other.

In addition, the pair of magnetic core halves 2 and 3 is located at the intermediate portion of the main surfaces facing each other, and has a magnetic gap G.
And the winding grooves 8a and 8b that form the winding window portion 7 after the butting are formed. In other words, the pair of magnetic core halves 2 and 3 abut the abutting surfaces protruding from the winding grooves 8a and 8b, respectively, so that the metal magnetic film 5 constitutes a substantially annular magnetic core.

In this laminating head 1, since the film thickness of the metal magnetic film 5 becomes the track width, by controlling the film thickness of the metal magnetic film 5, it is possible to easily realize a narrow track. Further, this laminating head 1 has an advantage that a pseudo gap does not structurally occur.

A low melting point glass 9 is filled on the medium sliding surface 1a side of the winding window 7 for the purpose of improving the bonding strength of the pair of magnetic core halves 2 and 3.

In the pair of magnetic core halves 2 and 3, the guide grooves 10a, which are located on the main surface opposite to the main surfaces facing each other and face the above-described winding grooves 8a, 8b, are provided. 10b
Are formed respectively.

In the laminating head 1, the winding window portion 7
Through the winding grooves 8a, 8 of the pair of magnetic core halves 2, 3.
b and the magnetic core portion between the guide grooves 10a and 10b,
Each coil (not shown) is wound. Thereby, the coil can be wound around the pair of magnetic core halves 2 and 3 without being displaced from the winding grooves 8a and 8b and the guide grooves 10a and 10b.

Further, the pair of magnetic core halves 2 and 3 are provided with contact width regulating grooves 11 for adjusting the contact width with the magnetic recording medium along both longitudinal ends of the medium sliding surface 1a. Each is formed.

The pair of guard members 4 are made of a ceramic material containing Ca, Ti and Ni as main components, although the material is not particularly limited. This allows
Head efficiency and wear resistance can be improved.

As shown in FIG. 2, the metal magnetic film 5 constitutes a magnetic core, and has a structure in which a plurality of metal magnetic films 5 are laminated with an insulating film 12 interposed therebetween. In this laminating head 1, since the laminated metal magnetic films 5 are magnetostatically coupled to each other at their ends, eddy current loss can be reduced,
In particular, the head efficiency can be improved in the high frequency region.

Examples of the material of the metal magnetic film 5 include Fe-Al-Si alloy, Fe-Ni-Al-Si alloy, Fe-Ga-Si alloy, Fe-Al-Ge alloy, and alloys thereof. Co, Ti, C of about 8 atomic% or less
r, Nb, Mo, Ta, Ru, Au, Pd, N, C, O
Examples of the amorphous material include at least one selected from the group consisting of:

Further, as a material of the metal magnetic film 5,
With Co as the main material, Zr, Ta, Ti, Hf, Mo,
An amorphous material formed by adding at least one selected from Nb, Au, Pd, Ru and the like can be mentioned. Alternatively, with Co and Fe as the main materials, Ni,
Zr, Ta, Ti, Hf, Mo, Nb, Si, Al,
Examples thereof include a microcrystalline material formed by adding at least one selected from B, Ga, Ge, Cu, Sn, Ru, B, and the like, and at least one selected from N, C, and O. .

On the other hand, the material of the insulating film 12 is not particularly limited as long as it is an electrically insulating material, but for example, oxides such as SiO ₂ , Al ₂ O ₃ and Si ₃ N ₄ and nitriding. I can list things.

The non-magnetic film 6 constitutes the magnetic gap G and has a function as a bonding film for bonding the pair of magnetic core halves 2 and 3. Specifically, this non-magnetic film 6
Is made of a non-magnetic material such as fused glass (SiO ₂ ) when the fusion method is used as the joining method, and is made of Au, Ag, Pd or the like when the low temperature metal diffusion joining method is used. Made of precious metal material.

The laminating head 1 constructed as described above is mounted on a rotary drum such as a video tape recorder (VTR) or a digital data recorder for recording and / or reproducing a signal at a high recording density, and a metal tape or A signal is recorded and / or reproduced on a high coercive force magnetic recording medium such as a vapor deposition tape.

By the way, in the laminating head 1,
Guide grooves 10a and 10b facing the winding grooves 8a and 8b, respectively, are formed on the main surfaces of the pair of magnetic core halves 2 and 3 opposite to the main surfaces (butting surfaces) facing each other.

In this case, the portion of the pair of magnetic core halves 2 and 3 around which the coils are wound, that is, the portion of the magnetic core between the winding grooves 8a and 8b and the guide grooves 10a and 10b is wound. The number of turns can be increased. For example, even if the length of the wire (coil) that can be wound by the automatic winding machine is determined, it is possible to increase the number of windings of the coil wound using the existing automatic winding machine.

Specifically, the length of one winding of the wire (coil) wound around the pair of magnetic core halves 2 and 3 is about 1.
It can be shortened from 32 mm to about 0.57 mm. As a result, it is possible to increase the number of turns of the coil, which has been 32 turns, from 36 turns to 36 turns, and as a result, the output level of the head can be increased by about 3 dB as compared with the conventional case.

The guide grooves 10a and 10b are
The metal magnetic film 5 forming the magnetic cores of the pair of magnetic core halves 2 and 3 is formed so as to be partially cut away. As a result, in the laminating head 1, the volume of the metal magnetic film 5, that is, the magnetic core portion can be reduced.

Therefore, in the laminating head 1, the number of coils wound around the pair of magnetic core halves 2 and 3 is increased while suppressing the increase in inductance by reducing the volume of the magnetic core portion. Is possible.

As a result, in the laminating head 1, the output characteristics can be further improved by increasing the number of windings of the coil without changing the predetermined standard such as the inductance and the outer dimension.

The laminating head 1 is shown in FIG.
As shown in FIG. 5, the dimension A in the depth direction of the guide grooves 10a and 10b (hereinafter referred to as the guide groove depth A) is the dimension in the same direction of the pair of magnetic core halves 2 and 3 around which the coil is wound. B
It has a structure in which a ratio of 20 to 50% (hereinafter, referred to as ratio A / B) with respect to (hereinafter referred to as core width B).

As a result, in the laminating head 1, the coil wound around the pair of magnetic core halves 2 and 3 is prevented from being displaced, and the decrease in magnetic efficiency due to the decrease in the volume of the magnetic core portion is suppressed. It is possible to

FIG. 3 shows the measurement results of the rate of occurrence of coil displacement when the ratio A / B was changed in the above-described laminating head 1.

From the measurement results shown in FIG. 3, when the ratio A / B increases, that is, when the guide groove depth A increases with respect to the core width B which is a constant standard dimension, the occurrence rate of coil deviation gradually decreases. I understand that I will do it. It can be seen that when the ratio A / B is 20% or more, the occurrence rate of the coil deviation is 0%.

From this, in the laminating head 1,
When the ratio A / B is 20% or more, in a magnetic recording / reproducing apparatus such as a video tape recorder (VTR), when it is mounted on a rotating drum and rotated, it is wound around a pair of magnetic core halves 2 and 3. The generated coil is moved by the centrifugal force to the medium sliding surface 1
It is possible to reliably prevent the shift to the a side.

Next, in the laminating head 1 described above, FIG. 4 shows the measurement results of the difference in the head output from the conventional head when the ratio A / B was changed.

From the measurement results shown in FIG. 4, when the ratio A / B increases, that is, when the guide groove depth A increases with respect to the core width B which is a constant standard dimension, the number of turns of the coil increases. It can be seen that the head output gradually increases. However, when this ratio A / B exceeds 50%, the head output decreases conversely. This is because when the ratio A / B exceeds 50%, the volume of the magnetic core portion becomes too small, and conversely the magnetic efficiency decreases.

From this, in the laminating head 1,
By setting the ratio A / B to 20 to 60%, it is possible to suppress a decrease in magnetic efficiency due to a decrease in the volume of the magnetic core portion, and it is possible to improve the head output more than ever before.

Further, in the above-mentioned laminating head 1, considering that the mechanical strength of the pair of magnetic core halves 2 and 3 is lowered due to the increase of the guide groove depth A of the guide grooves 10a and 10b, The ratio A / B is preferably 50% or less.

From the above, this laminating head 1
Then, it is preferable to set the ratio A / B to 20 to 50%, which prevents the coils wound around the pair of magnetic core halves 2 and 3 from being displaced and reduces the volume of the magnetic core portion. By doing so, it is possible to suppress a decrease in magnetic efficiency.

As described above, in the laminating head 1, the output characteristics can be further improved without changing the predetermined standard such as the inductance and the outer dimension, and the flexibility of the head design is further improved. It is possible.

Therefore, in the laminating head 1, it is possible to perform stable and reliable recording / reproducing even if the wavelength of the signal to be recorded / reproduced on / from the magnetic recording medium is shortened, and it is possible to increase the recording density. It is possible to cope with higher transfer rates.

Next, a method of manufacturing the above-mentioned laminating head 1 will be described.

When producing this laminating head 1,
First, as shown in FIG. 5, for example, AlTiC (Al ₂ O
A substrate 30 formed of a non-magnetic hard material such as _3- TiC) or various ceramics is prepared, and both main surfaces of the substrate 30 are mirror-ground. This substrate 30 finally becomes the guard material 4 of the laminating head 1.

Next, as shown in FIG. 6, a metal magnetic film 31 and an insulating film (not shown) are sequentially laminated and formed on one main surface of the substrate 30. The metal magnetic film 31 and the insulating film finally become the metal magnetic film 5 and the insulating film 12 of the laminating head 1, and are formed by using various thin film forming techniques such as a sputtering method and a vacuum deposition method. It

Next, as shown in FIG. 7, a plurality of substrates 30 are arranged side by side and joined together to form a magnetic core substrate 32.
To make. At this time, each substrate 30 has a metal magnetic film 31.
Are joined and integrated so that the main surface on the side where is formed faces one side. That is, the magnetic core substrate 32 is the plurality of substrates 30.
Has a structure in which they are joined and integrated via the metal magnetic film 31.

Next, as shown in FIG. 8, the magnetic core substrate 32 is cut to form a pair of magnetic core half blocks 33 and 34. At this time, the magnetic core substrate 32 is inclined by a predetermined angle θ with respect to the direction substantially orthogonal to the main surface of each substrate 30, that is, the CC ′ line and the DD ′ line shown in FIG. 7. , And EE ′ line. In this case, the magnetic gap G of the produced laminating head 1 is inclined by a predetermined azimuth angle θ with respect to the medium sliding direction. Further, the magnetic core substrate 32 may be cut along a direction substantially orthogonal to the main surface of each substrate 30.

Next, as shown in FIG. 9, both ends of one magnetic core half block (here, magnetic core half block 33) of the pair of magnetic core half blocks 33 and 34 are shown in FIG. It cuts along the FF 'line and GG' line shown in 9. As a result, one magnetic core half block 3
3 is shorter than the other magnetic core half block 34, as shown in FIG.

Next, as shown in FIG. 11, the pair of magnetic core half blocks 33 and 34 are ground to form a winding along the longitudinal direction at the intermediate portion of the main surfaces 33a and 34a facing each other. The turning grooves 35a and 35b are formed, respectively. The winding grooves 35a and 35b finally become the winding grooves 8a and 8b of the laminating head 1.

Then, the pair of magnetic core half blocks 3
Mirror-polishing is performed on the main surfaces 33a and 34a of the surfaces 3 and 34 that face each other.
A non-magnetic film (not shown) is formed on each of 4a. This non-magnetic film will eventually become the non-magnetic film 6 of the laminating head 1, and is formed by using various thin film forming techniques such as a sputtering method and a vacuum evaporation method.

Next, as shown in FIG. 12, a magnetic core block 36 is manufactured by integrally joining a pair of magnetic core half blocks 33 and 34 with their metallic magnetic films 31 butted against each other. To do. At this time, the pair of magnetic core half blocks 33 and 34 are fused by a fusion method using a non-magnetic material such as fused glass (SiO ₂ ), or low temperature metal diffusion using a noble metal material such as Au, Ag, or Pd. They are joined and integrated by a joining method or the like.

Next, as shown in FIG. 13, the glass rod 37 is inserted between the winding grooves 35a and 35b, with the surface serving as the medium sliding surface 1a of the magnetic core block 36 serving as the lower surface.

Next, as shown in FIG. 14, the low melting point glass 8 is filled by heating and melting the glass rod 37 and then cooling and solidifying.

Then, the main surface of the magnetic core block 36 on the side filled with the low melting point glass 8 is subjected to cylindrical polishing to form a medium sliding surface 1a having a predetermined curvature. At this time, the polishing process can be performed while measuring the end of the magnetic core half block 34 facing from the end of the magnetic core half block 33 indicated by the arrow H in the figure. Thereby, the length from the medium sliding surface 1a to the winding window portion 7,
That is, the dimension Dp in the depth direction can be accurately defined to a predetermined value.

Further, the magnetic core block 36 is ground, and the main surfaces on the opposite side to the main surfaces 33a, 34a facing each other are guided by the guide grooves 38a, 38a, 35b facing the winding grooves 35a, 35b. 38b are formed respectively. The guide grooves 38a, 38b finally become the guide grooves 10a, 10b of the laminating head 1.

At this time, the dimension A of the guide grooves 38a and 38b in the depth direction is set to be the pair of magnetic core half blocks 33 and 3.
It is preferable to set the ratio to 20 to 50% with respect to the dimension B of 4 in the same direction.

Next, as shown in FIG. 15, the magnetic core block 36 is ground to form contact width regulating grooves 39 having a predetermined width on both sides of each metal magnetic film 31. The contact width restriction groove 39 finally becomes the contact width restriction groove 11 of the laminating head 1.

Next, as shown in FIG. 16, the magnetic core block 36 is hit on the bottom surface of the contact width regulating groove 39 by the line II ′, the line JJ ′, and the line KK ′ shown in the figure. , LL 'line,
And cut along the line MM '.

As described above, a plurality of the above-described laminating heads 1 can be collectively manufactured.

In the laminating head 1 described above,
The pair of magnetic core halves 2 and 3 is of a so-called double window type in which winding grooves 8a and 8b are respectively formed on the main surfaces opposite to the main surfaces (butting surfaces) facing each other. However, it is not necessarily limited to such a configuration.

For example, one of the pair of magnetic core halves 2 and 3 is provided with the winding window portion 7 described above on one of the magnetic core halves.
It may be a so-called single-window type in which the winding groove constituting the above is formed.

The magnetic head to which the present invention is applied is not limited to the laminating head 1 described above, and a coil is wound around a magnetic core formed of a magnetic material to form a magnetic path, and the magnetic core is formed. It is widely applicable to a bulk type magnetic head in which a magnetic gap having a magnetically small interval is formed.

In the case of such a magnetic head, it is also possible to form a guide groove for reducing the volume of the magnetic core portion on the surface other than the abutting surface of the portion around which the coil is wound.

[0075]

As described in detail above, according to the magnetic head of the present invention, it is possible to increase the number of turns of the coil wound around the magnetic core half while suppressing the increase of the inductance. Therefore, it is possible to further improve the output characteristics without changing the predetermined standard such as the inductance and the external dimensions, and it is possible to further improve the degree of freedom in the head design.

Therefore, with this magnetic head, it is possible to perform stable and reliable recording / reproducing even when the wavelength of the signal to be recorded / reproduced on / from the magnetic recording medium is further shortened, and it is possible to realize high recording density / high recording density. It is possible to cope with the transfer rate.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a laminating head to which the present invention is applied.

FIG. 2 is a main part plan view showing an encircled portion X in FIG. 1 in an enlarged manner.

FIG. 3 is a characteristic diagram showing a relationship between A / B and a coil deviation occurrence rate.

FIG. 4 is a characteristic diagram showing a relationship between A / B and head output.

FIG. 5 is a diagram for explaining a manufacturing process of the laminating head, and is a perspective view showing a substrate.

FIG. 6 is a view for explaining the manufacturing process of the laminating head, and is a perspective view showing a state in which a metal magnetic film is formed on a substrate.

FIG. 7 is a diagram for explaining a manufacturing process of the laminating head, and is a perspective view showing a state in which a plurality of substrates are joined to manufacture a magnetic core substrate.

FIG. 8 is a diagram for explaining a manufacturing process of the laminating head, and is a perspective view showing a state in which a magnetic core half block is manufactured by cutting the magnetic core substrate.

FIG. 9 is a diagram for explaining the manufacturing process of the laminating head, and is a perspective view showing a cutting position with respect to one of the pair of magnetic core half blocks.

FIG. 10 is a diagram for explaining the manufacturing process of the laminating head, and is a perspective view showing a state in which one of the pair of magnetic core half blocks is cut.

FIG. 11 is a diagram for explaining the manufacturing process of the laminating head, and is a perspective view showing a state in which winding grooves are formed in a pair of magnetic core half blocks.

FIG. 12 is a view for explaining the manufacturing process of the laminating head, and is a perspective view showing a state in which a pair of magnetic core half blocks are joined and integrated to form a magnetic core block.

FIG. 13 is a view for explaining the manufacturing process of the laminating head, and is a perspective view showing a state where the glass rod is inserted into the winding groove of the magnetic core block.

FIG. 14 is a diagram for explaining the manufacturing process of the laminating head, and is a perspective view showing a state in which a medium sliding surface is formed on the magnetic core block.

FIG. 15 is a view for explaining the manufacturing process of the laminating head, and is a perspective view showing a state in which a contact width regulating groove is formed on the magnetic core block.

FIG. 16 is a diagram for explaining the manufacturing process of the laminating head, and is a perspective view showing a cutting position with respect to the magnetic core block.

FIG. 17 is a perspective view showing the configuration of a conventional magnetic head.

FIG. 18 is a perspective view showing a state in which coil displacement has occurred in the conventional magnetic head.

[Explanation of symbols]

1 laminating head, 2, 3 magnetic core half body, 4 guard material, 5 metal magnetic film, 6 non-magnetic film, 7 winding window part, 8a, 8b winding groove, 9 low melting point glass, 10a,
10b guide groove, 11 width limiting groove, 30 substrate, 31 metal magnetic film, 32 magnetic core substrate, 33, 3
4 magnetic core half block, 35a, 35b winding groove, 3
6 magnetic core block, 37 glass rods, 38a, 38
b Guide groove, 39 width limit groove

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11B 5/147 G11B 5/147 5/17 5/17 RW 5/23 5/23 K (72) Invention Heiyoshi Sato 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Osamu Onodera 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo F-Term (Reference) 5D093 AA01 AC01 AD05 BD01 HC03 HC09 JA01 JC12 5D111 AA01 AA13 AA23 BB24 BB38 BB41 CC22 FF04 FF39 GG18 HH03 KK05

Claims (4)

[Claims] 1. A magnetic head in which a magnetic path is formed by abutting a pair of magnetic core halves, and a magnetic gap is formed by forming a non-magnetic film on the abutting surface. A coil is wound around at least one of the magnetic core halves, and a groove for reducing the volume of the magnetic core portion forming the magnetic path is formed on a surface other than the abutting surface of a portion around which the coil is wound. And the size of the groove in the depth direction is 20 to 50% of the size of the magnetic core half around which the coil is wound in the same direction. head. 2. The magnetic head according to claim 1, wherein the groove is formed on a surface of the portion around which the coil is wound, the surface being opposite to the abutting surface. 3. The pair of magnetic core halves is characterized in that a metal magnetic film serving as the magnetic core is sandwiched by a pair of guard materials containing a non-magnetic material as a main component. Magnetic head. 4. The magnetic head according to claim 3, wherein the metal magnetic film is laminated via an insulating film.