JPH07326018A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To improve head efficiency and to stably and easily produce a head. CONSTITUTION:An approximately I-shaped first core 3 between a magnetic gap 1 for recording and reproducing and a magnetic gap 2 for erasing is provided with an auxiliary core 9 and its apex angle C is specified to >=40 to <=70 deg.. The front end 12 of this auxiliary core is formed in proximity to an apex part 6 in a range of >=0.15 to <=0.6mm from this apex part so that the front end face 10 of the auxiliary core parallels with the part 11 near the apex of an approximately L-shaped second core 4.

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 floppy disk device or the like and a method of manufacturing the same.

[0002]

2. Description of the Related Art In order to increase the capacity of a floppy disk device, it is necessary to improve the performance of a magnetic head. A magnetic head for a floppy disk device requires an erasing magnetic gap in addition to a recording / reproducing magnetic gap for electromagnetically converting a signal, and the distance between the two types of magnetic gaps is limited to be short. The first core made of ferrite provided between the two types of magnetic gaps is
Generally, it has an I-shape, but the core thickness is limited to be thin due to the limitation of the distance between the two types of magnetic gaps.

For example, the distance between magnetic gaps needs to be about 0.57 mm for a 1-megabyte magnetic head and 0.35 mm for a 2-megabyte magnetic head. Had to be reduced to about 0.19 mm. For this reason, the magnetic resistance in the magnetic path is high in the I-shaped first core portion, and when it is attempted to improve the head efficiency in order to improve the performance of the magnetic head, the I-shaped first core is required. It was necessary to reduce the magnetic resistance of the part.

In a magnetic head for a floppy disk, a method of providing an auxiliary core in the I-shaped core portion in order to reduce the magnetic resistance of the I-shaped core is disclosed in Japanese Patent Laid-Open No. 59-21301.
It is proposed in Japanese Patent No. 4 and Japanese Utility Model Laid-Open No. 62-18813. These are the same in that at least the magnetic resistance at the rear is reduced and the head efficiency is improved by attaching the auxiliary core to the I-shaped core.
The latter is focused on shortening the magnetic gap between the I-shaped core and the auxiliary core. Based on these inventions, when the auxiliary core is provided on the I-shaped core, it can be expected that the head efficiency can be improved by increasing the thickness of the auxiliary core. However, in these technologies, the shape in the vicinity of the apex portion was the same as that without the auxiliary core.

[0005]

In a magnetic head for a floppy disk, the distance between two types of magnetic gaps for recording / reproducing and erasing is 0.19 m such as for 4 megabytes.
When the length is shortened to about m, the magnetic resistance in the I-shaped first core portion becomes higher than that of a magnetic head having a relatively long gap distance.

Therefore, the magnetic head for 4 megabytes is
The head output for the same signal is reduced by about 15% as compared with a widely used magnetic head for 2 megabytes and the like. This output difference includes factors caused by differences in specifications such as the gap length, but if this output drop can be compensated for by improving the head efficiency of the 4-megabyte magnetic head, it will be backward compatible with the floppy disk drive. This is convenient for signal processing considering the characteristics. Therefore, as described above, it is conceivable that the head efficiency can be improved by providing the auxiliary core on the I-shaped first core and thickening the auxiliary core. It became impossible to completely compensate for the decrease in

As a result of various studies, it has been found that the head efficiency can be improved more by increasing the thickness of the auxiliary core by bringing the tip end portion of the auxiliary core closer to the apex portion. However, in the case where a thick auxiliary core is used and the auxiliary core is further brought closer to the apex portion, it is inconvenient if the shape in the vicinity of the apex portion remains unchanged. In FIG. 15, the substantially I-shaped first core 3 is shown.
A side view of a conventional magnetic head provided with an auxiliary core 9 is shown. In this case, when trying to bring the auxiliary core 9 closer to the apex portion 6, the auxiliary core tip surface 10 becomes the I-shaped first core 3. It contacts the apex vicinity portion 11 of the substantially L-shaped second core 4 that is joined via the magnetic gap, causing leakage of magnetic flux from the auxiliary core 9 side to the second core 4, and conversely head efficiency. The phenomenon that lowers appears. In addition, it is not easy to make the auxiliary core 9 close to the apex portion 6 in this way and to stably form a shape capable of stably reducing the leakage magnetic flux from the auxiliary core tip surface 10 to the second core 4 with good yield. Absent. Therefore, the distance between the auxiliary core tip portion 12 and the apex portion 6 could not be shortened unless the shape around the apex portion 6 was devised under the condition that the processing was easy.

In order to solve the above conventional problems, the present invention provides a magnetic head having improved head efficiency by bringing an auxiliary core provided in an I-shaped first core close to an apex portion. With the goal. It is another object of the present invention to provide a method of manufacturing a magnetic head that can easily and stably bring an auxiliary core provided on an I-shaped first core close to the apex portion in order to improve head efficiency. And

[0009]

To achieve the above object, at least with respect to the recording / reproducing magnetic core, a substantially I-shaped first core is arranged between the recording / reproducing magnetic gap and the erasing magnetic gap. A closed magnetic circuit is formed by the first core, the substantially L-shaped second core, and the back core, and the second core is formed so that the angle formed by the first core and the second core in the apex portion is 40 degrees or more and 70 degrees or less. An apex portion of the core is provided, and an auxiliary core having a front end surface parallel to the apex portion of the second core is provided on the winding window side of the first core. The distance between the auxiliary core tip portion and the apex portion is 0.15 mm. As described above, the first magnetic head having a size of 0.6 mm or less is used.

Alternatively, at least with respect to the recording / reproducing magnetic core, a substantially I-shaped first core is arranged between the recording / reproducing magnetic gap and the erasing magnetic gap, and the first core and the substantially L-shaped second core and The back core forms a closed magnetic circuit, and the apex vicinity of the second core is provided so that the angle formed by the first core and the second core in the apex part is 40 degrees or more and 70 degrees or less, and is continuous with the apex vicinity. The second core is provided with a staircase portion, and the first core is provided with an auxiliary core having a tip end surface parallel to the staircase portion of the second core on the winding window side. A second magnetic head having a distance of 0.15 mm or more and 0.6 mm or less is used.

In order to easily manufacture the above-mentioned magnetic head in a large amount, parallel blades whose both side surfaces are parallel are used, and in a direction inclined at an angle of 40 degrees or more and 70 degrees or less with respect to a strip-shaped ferrite side surface, A first step of forming a grooved core half to form a portion near the apex and a first core made of a substantially I-shaped ferrite and a polished core half are joined to form a magnetic gap. A second step of forming a head block by joining a pair of recording / reproducing and erasing core blocks to each other, and forming a groove for a winding window from the rear surface side of the head block, A method of manufacturing a magnetic head comprising a third step of attaching an auxiliary core to a first core to obtain a substantially L-shaped second core, and a fourth step of cutting a head block to obtain a head chip. By the first magnetic The head can be produced.

[0012] In addition, it is 40
The groove for the apex part is formed in a direction inclined at an angle of 70 degrees or more and 70 degrees or less, and a part of the groove for the apex part is stepped in a direction substantially perpendicular to the ferrite side surface, using parallel blades whose both side surfaces are parallel. A first step of processing a groove for a core to form a core half body, and a core block in which a magnetic core is formed by joining a first core made of a substantially I-shaped ferrite and a polished core half body And a second step of joining a pair of recording / reproducing and erasing core blocks to form a head block, and a groove for a winding window is formed from the rear surface side of the head block. By using a magnetic head manufacturing method including a third step of attaching an auxiliary core and obtaining a substantially L-shaped second core and a fourth step of cutting a head block to obtain a head chip, Magnetic head can be manufactured.

[0013]

The magnetic head of the present invention relates to a magnetic head having magnetic gaps for recording / reproducing and erasing, and these two kinds of magnetic gaps are close to each other. An auxiliary core is provided on the winding window side of the I-shaped first core provided between the two types of magnetic gaps to reduce the magnetic resistance of the first core portion. However, in the present invention, not only the auxiliary core is provided, but also the core shape in the winding window near the apex is devised.

First, the apex angle is set to 40 degrees or more and 70 degrees or less, and the distance from the apex portion to the magnetic core gap side auxiliary core tip surface in the winding window is 0.15 mm or more and 0.6 m.
The head efficiency is improved by making them close to each other within a range of m or less. The reason why the apex angle and the distance from the apex portion to the tip of the auxiliary core are defined in such a range is to obtain an increase in the head output of 15% or more. If this output increase is achieved, it is for 4 megabytes. This is because even a magnetic head or the like can obtain a head output equivalent to that of a 2-megabyte magnetic head or the like, which is convenient in signal processing. Further, it is characterized in that the apex vicinity portion of the second core and the tip end surface of the auxiliary core are made parallel to each other so that they can come close to each other without coming into contact with each other.

Such a head structure can be stably and easily manufactured by the following manufacturing method.
That is, when the second core shown in the second step is manufactured, a groove is formed in the vicinity of the apex using parallel blades whose both side surfaces are parallel to each other so that the auxiliary core and the apex of the second core finally formed are formed. The distance in the vicinity can be stably kept constant. By performing such processing in advance, after the groove processing for the winding window shown in the fourth step is performed, the distance between the apex portion and the tip of the auxiliary core in the head chip can be reduced, Moreover, the two never come into contact with each other.

The apex angle is 40 degrees or more and 70 degrees or less, and the distance from the apex portion to the magnetic gap side auxiliary core tip surface in the winding window is 0.15 mm or more and 0.6 m.
The head efficiency is improved by making them close to each other within a range of m or less. Further, a step portion that is substantially perpendicular to the first core is provided near the apex of the second core, and the step portion and the tip end surface of the auxiliary core are parallel to each other so that they can come close to each other without contacting each other. There is. Such a head structure can be stably and easily manufactured by the manufacturing method described below. That is, the second step shown in the second step
At the time of manufacturing the core, temporarily perform groove processing for the apex part in a direction inclined from the ferrite side surface, and finally perform groove processing for the step part using parallel blades with parallel side surfaces, thereby finally The distance between the formed auxiliary core and the vicinity of the apex of the second core can be stably kept constant. By performing such processing in advance, after the groove processing for the winding window shown in the fourth step is performed, the distance between the apex portion and the tip of the auxiliary core in the head chip can be reduced, Moreover, the two never come into contact with each other.

Therefore, in the magnetic head and the method of manufacturing the magnetic head of the present invention, the auxiliary core tip portion is apex portion by the structure and the manufacturing method such that the apex vicinity portion of the second core and the auxiliary core tip portion are parallel to each other. It is possible to stably bring it closer to.

[0018]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of a magnetic head according to the first embodiment of the present invention. The magnetic head of FIG. 1 is a magnetic head for a 4 megabyte floppy disk having a magnetic gap 1 for recording and reproducing and a magnetic gap 2 for erasing,
A substantially I-shaped first core 3 is disposed between both magnetic gaps, and a substantially L-shaped second core 4 and back core 5 form a closed magnetic circuit. Further, these magnetic gaps are joined by a bonding glass 14, and the recording / reproducing magnetic core and the erasing magnetic core are integrated via an adhesive layer 13.

Here, the distance between the recording / reproducing magnetic gap 1 and the erasing magnetic gap 2 is defined as a small value of 0.19 mm, and therefore the first in the recording / reproducing magnetic core.
The thickness of the core 3 is as thin as about 0.1 mm. In the case of such a magnetic head, the first I-shaped first
The apex portion 6 is formed by the core 3 and the substantially L-shaped second core 4.
Is formed, and the coil 7 is arranged so as to surround the substantially L-shaped second core 4, and the hole in the closed magnetic circuit serves as the winding window 8. However, a characteristic of the magnetic head of FIG. 1 of the present embodiment is that the first core 3 is provided with the auxiliary core 9,
The auxiliary core tip portion 12 and the apex portion 6 are close to each other, and the auxiliary core tip surface 10 and the apex vicinity portion 11 of the second core 4 are parallel to each other without contact. With such a structure around the apex portion 6, even if the auxiliary core 9 is thick, the auxiliary core tip portion 12 and the apex portion 6 can be brought close to each other, and further, from the auxiliary core 9 to the second core 4. Since the leakage of magnetic flux can be stably reduced, the head efficiency can be improved.

When the auxiliary core thickness A is 0.25 mm, the distance B between the auxiliary core tip portion 12 and the apex portion 6 is 0.4 mm, and the apex angle C is 45 degrees in the magnetic head shown in FIG. 17 for conventional magnetic heads without
As much as a% increase in head output was obtained. The relationship between the dimensions of such a magnetic head and the increase in head output when compared with the conventional magnetic head without the auxiliary core 9 will be described below.

FIG. 12 shows the relationship between the auxiliary core thickness A and the head output increase when the apex angle C is 45 degrees.
A conventional example in which the distance B is set to 1 mm by the magnetic head having the auxiliary core 9 and this example in which the distance B is reduced to 0.4 mm are shown in comparison. In each case, the head output increases as the auxiliary core thickness A increases, but it can be seen that the head output increases more in the present embodiment in which the distance B is reduced. here,
In order to secure the winding window 8 for inserting the practical coil 7, the auxiliary core thickness A can be increased only up to about 0.4 mm. However, in the present embodiment, the auxiliary core thickness A is set to 0.15 mm or more.
The output can be increased by 5% or more.

FIG. 13 shows the relationship between the distance B and the head output increase when the auxiliary core thickness A is 0.25 mm and the apex angle C is 45 degrees. The solid line portion in the figure is the range of the present embodiment, but by adopting the structure of the present embodiment, the distance B can be easily shortened to 0.6 mm or less.
Head output in the range of 0.15 mm or more and 0.6 mm or less is 15 in comparison with the conventional magnetic head without the auxiliary core 9.
High output of over% is obtained.

FIG. 14 shows the relationship between the apex angle C and the head output increase when the auxiliary core thickness A is 0.25 mm and the distance B is 0.4 mm. The solid line portion in the figure is the range of this embodiment, but with the structure of this embodiment, at least the head output in the range where the apex angle C is 40 degrees or more and 70 degrees or less is a conventional magnetic head without an auxiliary core. An output as high as 15% or more can be obtained as compared with.

Therefore, the distance B between the tip portion 12 of the auxiliary core and the apex portion 6 is close to each other, and the distance B is from 0.15 mm to 0.6 m.
In the magnetic head of the present invention, the apex angle C is in the range of 40 degrees to 70 degrees, and the auxiliary core tip surface 10 and the apex vicinity portion 11 of the second core 4 are parallel to each other. The output is increased by 15% or more as compared with the conventional magnetic head for 4 megabytes without the core 9, and the head efficiency is as high as that of the magnetic head for 1 megabyte or the like.

The magnetic head of this embodiment described above can be easily manufactured by the following method of manufacturing a magnetic head. 2 to 5 are views showing a method of manufacturing the magnetic head in the first embodiment of the present invention.

First, as a first step, as shown in FIG. 2, an inclined apex groove 15 is formed by using a parallel blade on one side surface of a strip-shaped ferrite to prepare a half core. The apex groove 15 is for forming the apex vicinity portion 11, and the direction of groove processing is such that a side surface of the ferrite is a horizontal plane having an angle of 0 degree, and an angle C of 40 degrees or more and 70 degrees or less with respect to the horizontal plane. The direction is inclined with. By doing so, in the finally obtained head chip, the auxiliary core tip surface 10 and the second core 4 are
It is possible to make the apex vicinity portion 11 and the apex portion 11 in parallel state with a constant interval. Here, the parallel blade may be any blade whose both side surfaces are parallel, and the tip portion of the blade may have any shape. 10 for parallel blades
A grindstone or the like to which abrasive grains having a grain size of 00 or more are attached is useful, and such a blade having a blade thickness of 0.1 mm or more can be easily used in mass production.

Next, as shown in FIG. 3, in a second step, a core block in which a magnetic gap is formed is produced by using the core half and the first core 3 made of a substantially I-shaped ferrite. To do. For this, a gap facing surface obtained by mechanically polishing the grooved surface of the core half body and a gap facing surface of the substantially I-shaped first core 3 with Si-
It can be manufactured by attaching a gap material such as O-based material, butting them together, and performing heat bonding using the bonding glass 14. Further, as a second step, as shown in FIG. 4, the substantially I-shaped first cores 3 of the pair of recording / reproducing and erasing core blocks are joined together to form a head block. After that, as a third step, the groove processing for the winding window 8 is performed from the rear surface side of the head block. Grooving for this winding window 8 is performed by broken lines xx and yy in FIG.
The portion surrounded by is deleted, and as a result of this groove processing, the auxiliary core 9 can be attached to the substantially I-shaped first core 3 to obtain the substantially L-shaped second core 4. . Thereafter, as a fourth step, the head block obtained through the third step is cut along a broken line zz or the like in FIG. 4 to form a substantially I-shaped shape as shown in FIG. It is possible to obtain a head chip including the first core 3, the substantially L-shaped second core 4, the auxiliary core 9 and the like. Here, in order to form the closed magnetic path, the back core 5 may be bonded to this head chip as shown in FIG.

The magnetic head manufacturing method according to the present embodiment is different from the conventional manufacturing method in that the groove processing for the apex vicinity portion 11 by the parallel blade in the first step and the like are performed.
Although the groove processing for the winding window 8 in the process of (1) is characteristic, it can be easily mass-produced by machining, and thus it is excellent in mass productivity. Further, the distance B between the auxiliary core tip portion 12 and the apex portion 6 and the distance between the auxiliary core tip surface 10 and the second core 4 obtained by such processing are stable ones determined by the blade thickness of the parallel blades. The reduction of the magnetic resistance of the one core 3 and the reduction of the magnetic flux leakage from the auxiliary core 9 to the second core 4 become stable.

(Second Embodiment) A second embodiment of the present invention will be described with reference to the drawings.

FIG. 6 is a side view of the magnetic head according to the second embodiment of the present invention. The magnetic head of FIG. 6 is a magnetic head for a 4 megabyte floppy disk having a magnetic gap 1 for recording / reproducing and a magnetic gap 2 for erasing,
A substantially I-shaped first core 3 is disposed between both magnetic gaps, and a substantially L-shaped second core 4 and back core 5 form a closed magnetic circuit. Further, these magnetic gaps are joined by a bonding glass 14, and the recording / reproducing magnetic core and the erasing magnetic core are integrated via an adhesive layer 13. Here, the gap between the recording / reproducing magnetic gap 1 and the erasing magnetic gap 2 is defined to be a small value of 0.19 mm, and therefore the thickness of the first core 3 on the recording / reproducing side is about 0.1 mm, which is extremely thin. Has become. In the case of such a magnetic head, the apex portion 6 is formed by the substantially I-shaped first core 3 and the substantially L-shaped second core 4, and the coil is formed so as to surround the substantially L-shaped second core. 7 is arranged and the hole in the closed magnetic circuit serves as the winding window 8. However, a characteristic of the magnetic head of FIG. 6 of the present embodiment is that
An auxiliary core 9 is provided on the first core 3, the auxiliary core tip portion 12 and the apex portion 6 are close to each other, and the staircase portion 16 continuous with the apex vicinity portion 11 of the second core 4 in the winding window 8 is provided. Is provided, and the step portion 16 is parallel to the auxiliary core tip surface 10. With such a structure around the apex portion 6, even if the auxiliary core 9 is thick, the auxiliary core tip portion 12 and the apex portion 6 can be brought close to each other, and the auxiliary core 9 can be moved to the second portion.
Since the leakage of the magnetic flux to the core 4 can be stably reduced, the head efficiency can be improved.

When the auxiliary core thickness A is 0.3 mm, the distance B between the auxiliary core tip surface 10 and the apex portion 6 is 0.5 mm, and the apex angle C is 45 degrees in the magnetic head shown in FIG. 15 for conventional magnetic heads without
As much as a% increase in head output was obtained. In order to obtain such a high output increase, the distance B between the auxiliary core tip portion 12 and the apex portion 6 is 0.15, as in the above-described (Embodiment 1).
It is close to the range of mm to 0.6 mm, and the apex angle C is in the range of 40 degrees to 70 degrees. Therefore, as in the case of (Example 1), the magnetic head of this example also provides an output increase of 15% or more as compared with the conventional magnetic head for 4 megabytes without the auxiliary core 9 and is for 1 megabyte. The head efficiency is as high as a magnetic head.

The magnetic head of this embodiment described above can be easily manufactured by the following magnetic head manufacturing method. 7 to 11 are views showing a method of manufacturing a magnetic head according to the second embodiment of the present invention.

First, as a first step, as shown in FIG. 7, one side surface of a strip-shaped ferrite is attached to this side by four steps.
The apex groove 15 is formed in a direction inclined at an angle of 0 degree or more and 70 degrees or less, and as shown in FIG. 8, a part of the apex groove 15 is formed on both sides in a direction substantially perpendicular to the ferrite side surface. The stepped groove 17 is processed by using a parallel blade having parallel surfaces to form a core half. By doing so, in the finally obtained head chip, the auxiliary core tip surface 10 and the step portion 16 in the vicinity of the apex of the second core 4 can be in a parallel state with a constant interval. Here, the parallel blade may be any blade whose both side surfaces are parallel, and the tip portion of the blade may have any shape. For the parallel blade, a grindstone or the like to which abrasive grains having a grain size of 1000 or more is attached is useful, and such a blade having a blade thickness of 0.1 mm or more can be easily used in mass production. Thereafter, as in (Example 1), as shown in FIG. 9 as a second step, a core block in which a magnetic gap is formed using this core half body and the substantially I-shaped first core 3 is formed. The head block is manufactured by joining the first cores 3 in the pair of core blocks to each other as shown in FIG. Then, as a third step, a groove for the winding window 8 is removed to remove the portion surrounded by the broken lines xx and yy in FIG. 10, and the substantially I-shaped first portion is formed.
The auxiliary core 9 is attached to the core 3, and the substantially L-shaped second core 4 is attached.
To get Then, as a fourth step, the head block obtained through the third step is changed to a broken line zz in FIG.
By cutting along the lines, etc., a head chip composed of the substantially I-shaped first core 3, the substantially L-shaped second core 4, the auxiliary core 9 and the like can be obtained as shown in FIG.
Here, in order to form the closed magnetic path, the back core 5 may be bonded to this head chip as shown in FIG.

The magnetic head manufacturing method according to the second embodiment of the present invention is different from the conventional manufacturing method in that a groove is formed for the step portion 16 near the apex by the parallel blade in the first step, and the like. The groove processing for the winding window 8 in the process of 3 is characteristic, but these processings are excellent in mass productivity because they can be easily carried out in a large amount by mechanical processing.
Further, the auxiliary core tip surface 1 obtained by such processing
The distance between 0 and the second core 4 is stable depending on the blade thickness of the parallel blades, and the reduction of the magnetic resistance of the first core 3 and the reduction of the magnetic flux leakage from the auxiliary core 9 to the second core 4 are stable. It will be done.

[0036]

The magnetic head of the present invention is a magnetic head having improved head efficiency by bringing the auxiliary core provided in the I-shaped first core close to the apex portion. Further, in the method of manufacturing the magnetic head of the present invention, in order to improve the head efficiency, it is possible to easily and stably bring the auxiliary core provided in the I-shaped first core close to the apex portion. Therefore, the magnetic head and the manufacturing method thereof according to the present invention have high industrial utility value.

[Brief description of drawings]

FIG. 1 is a side view of a magnetic head according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a method of manufacturing a magnetic head according to the first embodiment of the invention.

FIG. 3 is a diagram showing a method of manufacturing a magnetic head according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a method of manufacturing a magnetic head according to the first embodiment of the invention.

FIG. 5 is a diagram showing a method of manufacturing the magnetic head according to the first embodiment of the invention.

FIG. 6 is a side view of a magnetic head according to a second embodiment of the invention.

FIG. 7 is a diagram showing a method of manufacturing a magnetic head according to the second embodiment of the present invention.

FIG. 8 is a diagram showing a method of manufacturing a magnetic head according to a second embodiment of the invention.

FIG. 9 is a diagram showing a method of manufacturing a magnetic head according to the second embodiment of the present invention.

FIG. 10 is a diagram showing a method of manufacturing a magnetic head according to a second embodiment of the invention.

FIG. 11 is a diagram showing a method of manufacturing a magnetic head according to the second embodiment of the present invention.

FIG. 12 is a graph showing dependency of head efficiency on auxiliary core thickness.

FIG. 13 is a graph showing the dependency of head efficiency on the auxiliary core tip position.

FIG. 14 is a graph showing the dependence of head efficiency on the apex angle.

FIG. 15 is a side view of a conventional magnetic head.

[Explanation of symbols]

 1 Magnetic Gap for Recording / Reproducing 2 Magnetic Gap for Erasing 3 First Core 4 Second Core 5 Back Core 6 Apex Part 7 Coil 8 Winding Window 9 Auxiliary Core 10 Auxiliary Core Tip Surface 11 Apex Vicinity 12 Auxiliary Core Tip 13 Adhesion Layer 14 Bonding glass 15 Groove for apex 16 Step portion 17 Groove for step portion

Claims (8)

[Claims] 1. An approximately I-shaped first core, which is joined to the first core via a magnetic gap, and in which an apex portion for determining the gap depth is formed by an inclined apex vicinity portion and a gap facing surface. Two cores and an auxiliary core provided on the first core are provided, and the angle formed by the first core and the portion near the apex in the apex portion is set to 40 degrees to 70 degrees, and on the first core. A magnetic head characterized in that a distance between the apex portion side of the auxiliary core and the apex portion is 0.15 mm to 0.60 mm. 2. The magnetic head according to claim 1, wherein a portion near the apex and an end surface of the auxiliary core on the apex portion side are parallel to each other. 3. A magnetic head according to claim 2, wherein a step portion is provided continuously in the vicinity of the apex. 4. A substantially I-shaped first core, an inclined apex portion near the apex portion that determines the gap depth, and a second core formed by a gap facing surface are joined together through a magnetic gap, and the first core is formed. A magnetic head in which a pair of core constituents provided with auxiliary cores on cores are joined so that the first cores face each other, and at least one of the core constituents of the pair of core constituents is first in an apex part. The angle between the core and the portion near the apex is set to 40 degrees to 70 degrees, and the distance between the apex portion side of the auxiliary core and the apex portion on the first core is 0.15.
A magnetic head having a size of mm to 0.60 mm. 5. The magnetic head according to claim 4, wherein the portion near the apex and the end surface of the auxiliary core on the apex portion side are parallel to each other. 6. A magnetic head according to claim 5, wherein a step portion is provided continuously in the vicinity of the apex. 7. A core in which parallel blades are used, both sides of which are parallel to each other, and a groove is formed to form a portion near an apex in a direction inclined at an angle of 40 degrees or more and 70 degrees or less with respect to a strip-shaped ferrite side surface. For the recording / reproduction, a first step of forming a half body and a first core made of a substantially I-shaped ferrite and the polished half of the core are joined to produce a core block having a magnetic gap. And a second step of joining a pair of the core blocks for erasing to form a head block, and a groove for a winding window is formed from the rear surface side of the head block, and an auxiliary core is attached to the first core. And a third step of obtaining a substantially L-shaped second core, and a fourth step of cutting the head block to obtain a head chip. 8. A groove for an apex portion is formed in a direction inclined at an angle of 40 degrees or more and 70 degrees or less with respect to a strip-shaped ferrite side surface, and the ferrite side surface is substantially formed in a part of the apex portion groove. A first step of forming a core half by processing a step portion groove using parallel blades whose both sides are parallel to each other in a vertical direction, and a first step of forming a substantially I-shaped ferrite
The core and the polished half of the core are joined to form a core block having a magnetic gap, and a pair of the recording / reproducing and erasing core blocks are joined to form a head block. And a third step of performing a groove processing for a winding window from the rear surface side of the head block and attaching an auxiliary core to the first core to obtain a substantially L-shaped second core, and the head block A method of manufacturing a magnetic head, comprising a fourth step of cutting the substrate to obtain a head chip.