JP2942114B2 - Magnetic head and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head incorporated in a magnetic recording / reproducing apparatus and the like, and more particularly to a magnetic head such as a combination head for a VTR or a single head and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIGS. 7 and 8 are a perspective view and a top view, respectively, showing an example of a conventional VTR video magnetic head.
(A), (b) is AA sectional drawing and BB sectional drawing which show the state after running a magnetic recording medium (magnetic tape) for a long time.

Magnetic cores 1a and 1b made of ferrite or the like
Is provided with a hollow portion (winding groove) 2 so that a closed magnetic path is formed in the cores 1a and 1b during recording and reproduction. The magnetic gap 3 is provided on the abutting surfaces of the cores 1a and 1b.
Are formed. The magnetic gap 3 is made of a glass layer, and the cores 1a and 1b are welded to the glass layer and glass 7 filled in the track groove 5.

Next, an example of a method of manufacturing this conventional magnetic head will be described with reference to FIGS . 10 and 11 to 19 . Incidentally, FIG. 10 is a perspective view showing a magnetic head manufactured by the manufacturing method of FIGS. 11 to 19.

[0005] 21a and 21b shown in FIG . 11 are a pair of core blocks formed by cutting a magnetic material such as ferrite into a desired rectangular parallelepiped shape. These core blocks 21a, 21b
12 , a plurality of track grooves 5 are formed at predetermined intervals along the longitudinal corners of the core block as shown in FIG. 12 , and the winding groove 8 and the reinforcing groove 6 are formed in one core block 21a. Form. Then, as shown in FIG. 13 , a low-melting glass rod 7 obtained by adding a Pb component to SiO ₂ , for example, is disposed at the track groove 5, the winding groove 8, and the reinforcing groove 6, and then the glass rod 7 is subjected to a heat treatment. Then, the glass 7 is filled in the track groove 5, the winding groove 8 and the reinforcing groove 6 by protruding outside as shown in FIG .

[0006] Next, as shown in FIG.
The glass 7 protruding from the winding groove 8 and the reinforcing groove 6 is removed by, for example, polishing, and the glass 7 in the winding groove 8 is cut using, for example, a forming grindstone to form a winding as shown in FIG. A mirror-like glass layer 7a is formed on the wall surface on which the line groove 8 is formed.
It is formed to a thickness of about 0 to 30 μm. And both blocks 21
A high-melting point glass such as SiO _{2 is applied} to each of the bonding surfaces a and 21b by vapor deposition, sputtering or equivalent means so as to have a thickness equal to a desired gap length . After covering the high melting point glass layer 4 shown in FIG.
a and 21b are joined. Then, heat treatment is performed at a low melting point glass melting temperature, and both blocks are joined by the filling glass 7 to form a combined body. Where the high-melting glass and the low-melting glass are in contact, the high-melting glass is assimilated into the low-melting glass.

[0007] Next, while sequentially cutting to a predetermined width at the portion shown by the two-dot chain line in FIG. 19 , that is, the track groove 5 portion of this combined body, unnecessary unnecessary lower portion is cut off from the reinforcing groove 6 The sliding surface is polished on an arc and wrapped. Further, the coil 9 is wound around the hollow portion 2 formed by the winding groove 8, thereby obtaining the magnetic head 1 having the cores 1a and 1b having a predetermined shape as shown in FIG.

[0008]

In the conventional magnetic head shown in FIGS. 7 and 8, when the magnetic recording medium is run for a long time, the glass is more abrasion-resistant than ferrite. In the AA section, as shown in FIG. 9A, the ferrite portion is almost uniformly worn, but in the BB section in FIG. 8, the ferrite portion is worn near the magnetic gap as shown in FIG. 9B. The glass part is locally worn. As a result, the running of the magnetic tape in the vicinity of the magnetic gap becomes unstable, causing a spacing loss between the magnetic tape and the magnetic gap, sometimes deteriorating the magnetic recording / reproducing characteristics.

In the conventional method of manufacturing a magnetic head, as shown in FIG.
As shown in FIG. 18 , both blocks are joined. Here, if the error of the predetermined distance between the track grooves becomes large, a track shift may occur at the time of joining the two blocks, and the yield may be significantly deteriorated.

The present invention solves the above-mentioned conventional problems, and provides a magnetic head capable of stabilizing the running property of a magnetic tape even after running for a long time and preventing deterioration of magnetic recording / reproducing characteristics. The purpose is to provide. It is another object of the present invention to provide a magnetic head which does not cause a track shift when manufacturing the magnetic head.

[0011]

According to the present invention, there is provided a magnetic head in which a core half on a magnetic recording medium introduction side and a core half on a magnetic recording medium lead-out side are butted via a magnetic gap. The abrasion property of the magnetic recording medium sliding surface is larger than that of the core half so as to continuously surround at least both ends in the width direction of the magnetic gap and portions other than the magnetic gap of the core half on the magnetic recording medium lead-out side. It is characterized in that a high non-magnetic material is provided.

Further, according to the present invention, a pair of core blocks each having a winding groove on at least one side are joined to form a combined body, and one end in the longitudinal direction of the combined body on the side of the magnetic recording medium sliding surface is chamfered. A step of machining track grooves intersecting with the joint surface of the combined body and extending on the side surface of the chamfered core half at a predetermined interval, and substantially based on the inside of the track grooves and the chamfered portion. Filling a non-magnetic material so as to return to the shape of the above, cutting and dividing each magnetic head chip by a cutting line passing through the groove, and polishing the magnetic recording medium sliding surface side of the magnetic head chip. It is characterized by consisting of.

[0013]

According to the magnetic head of the present invention, both ends in the width direction of the magnetic gap and portions other than the magnetic gap of the core half on the magnetic recording medium lead-out side are continuously surrounded on the magnetic recording medium sliding surface of the magnetic head. As described above, a non-magnetic material having higher abrasion than the core half is disposed. Therefore, even when the magnetic recording medium travels for a long time, not only the nonmagnetic material near the magnetic gap but also the nonmagnetic material on the magnetic recording medium lead-out side wears. For this reason, there is no local wear except at both ends of the sliding surface of the magnetic recording medium.

Further, in the method for manufacturing a magnetic head according to the present invention, a pair of core halves each having a winding groove on at least one of them are joined, and after the step of forming a joined body, it intersects with the joining surface of the joined body. In addition, since the method includes a step of processing the track grooves extending on the side surface of the chamfered core block at a predetermined interval, no track deviation occurs.
After the step of chamfering one longitudinal edge of the combined body on the side of the magnetic recording medium sliding surface, a track groove intersecting with the joint surface of the combined body and extending on the side surface of the chamfered core block is formed. Since the process is performed at intervals, the processing amount at the time of forming the track groove can be reduced by the chamfered amount.

[0015]

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

FIGS. 1 and 2 are a perspective view and a top view, respectively, showing an example of the magnetic head of the present invention, and FIGS. 3 (a) and 3 (b).
3A is a sectional view taken along the line AA and a sectional view taken along the line BB showing a state after the magnetic recording medium (magnetic tape) has been run for a long time.

Magnetic cores 1a and 1b made of ferrite or the like
Is provided with a hollow portion (winding groove) 2 so that a closed magnetic path is formed in the cores 1a and 1b during recording and reproduction. The magnetic gap 3 is provided on the abutting surfaces of the cores 1a and 1b.
Are formed. The magnetic gap 3 is made of a glass layer, and the cores 1a and 1b are welded to the glass layer and glass 7 filled in the track groove 5. At the time of normal recording / reproduction, the magnetic core 1a is on the magnetic recording medium introduction side, and the magnetic core 1b is on the magnetic recording medium lead side.

The sliding surface of the magnetic recording medium of the magnetic head 1 continuously surrounds both ends in the width direction of the magnetic gap 3 and the portion other than the magnetic gap of the magnetic core 1b on the magnetic recording medium lead-out side. Glass (non-magnetic material) 7 having higher abrasion than the core half is provided.

In the magnetic head of this embodiment shown in FIGS. 1 and 2, when the magnetic recording medium is run for a long period of time, glass is more wear-resistant than ferrite.
In the AA cross section of FIG. 2, as shown in FIG.
The glass part 7 of the magnetic core 1b on the magnetic recording medium lead-out side is worn. FIG. 3 shows a cross section taken along line BB of FIG.
As shown in (b), the glass part 7 of the magnetic core 1b mainly on the magnetic recording medium lead-out side is worn, and the wear area and the wear amount are larger than the AA cross section. Therefore, when the magnetic recording medium sliding surface of the magnetic head 1 is viewed as a whole, the glass portion 7 of the magnetic core 1b on the magnetic recording medium lead-out side wears out first. Therefore, it is possible to reliably prevent the running of the magnetic tape near the magnetic gap 3 from becoming unstable due to the local wear of only the glass part near the magnetic gap 3 as in the conventional example. In other words, even when the magnetic tape runs for a long time, the running of the magnetic tape in the vicinity of the magnetic gap 3 is extremely stabilized, and the magnetic recording / reproducing characteristics due to the spacing loss between the magnetic tape and the magnetic gap. Can be suppressed.

Next, one embodiment of a method of manufacturing a magnetic head according to the present invention will be described with reference to FIGS.

First, as shown in FIG. 4, 31a, 31b
Are a pair of core blocks formed by cutting a magnetic material such as ferrite into a desired rectangular parallelepiped shape. This core block 3
1a, 31b, one core block 3
A winding groove 8 is formed in 1a. At this time, a reinforcing groove may be formed as in the conventional example. And both blocks 31
a, 31b, for example, a SiO ₂
A high-melting glass such as that described above is applied by vapor deposition, sputtering or equivalent means so as to have a thickness equal to the desired gap length, and the blocks 31a and 31b are abutted to form a combined body. Next, as shown in FIG.
One end in the longitudinal direction of the magnetic recording medium sliding surface side of the combined body is chamfered. Then, as shown in FIG.
The track grooves 5 are machined at predetermined intervals so as to be orthogonal to and extend to the side surfaces of the chamfered core half, so that the inside of the track grooves and the chamfered portions are almost returned to the original shape. After a low-melting glass rod obtained by adding a Pb component to SiO ₂ is provided, the glass rod is subjected to a heat treatment to fill the glass 7 (in FIG. 6, a track groove is formed in a right part of the combined body). The shape is not filled with glass so that the shape can be understood.)

Next, the tape is sequentially cut at a predetermined width and a predetermined angle azimuth angle θ at a track groove 5 portion of the combined body, and the tape sliding surface is polished on an arc and wrapped to form a first tape. Core 1 having a predetermined shape as shown in the figure
A magnetic head 1 having a and 1b is obtained.

As described above, in the method of manufacturing a magnetic head according to the present invention, after the steps of joining a pair of core halves having at least one of the winding grooves and forming the joined body, the joining surface of the joined body is formed. And a track groove extending on the side surface of the chamfered core half, which is orthogonal to the above, is formed at a predetermined interval, so that no track deviation occurs. After the step of chamfering one longitudinal edge of the coupling body on the side of the magnetic recording medium sliding surface, a track groove intersecting with the joining surface of the coupling body and extending to the side surface of the chamfered core half is formed. Since the process is performed at a predetermined interval, the processing amount at the time of forming the track groove can be reduced by the chamfered amount. Further, as shown in FIG. 15 , the glass 7 protruded from the track groove 5, the winding groove 8, and the reinforcing groove 6 is removed by, for example, polishing, and the glass 7 in the winding groove 8 is further formed by a forming grindstone. Therefore, it is not necessary to perform a cutting process using the method, and the process can be greatly simplified.

In the magnetic head of the present invention, a magnetic head having an azimuth angle has been described. However, contrary to the manufacturing method of the embodiment, the azimuth angle is set at the time of processing the track groove, and at the time of cutting, the azimuth angle is perpendicular to the joint surface. You may cut so that it becomes. Also, a magnetic head having no azimuth angle may be used.

[0025]

According to the magnetic head of the present invention, at least both ends of the magnetic gap in the width direction and the core half of the core half on the magnetic recording medium lead-out side are continuously formed on the sliding surface of the magnetic head. A non-magnetic material having a higher abrasion than the core half is disposed so as to surround the core half. Therefore, even when the magnetic recording medium travels for a long time, not only the nonmagnetic material near the magnetic gap but also the nonmagnetic material on the magnetic recording medium lead-out side wears. For this reason, there is no local wear except at both ends of the sliding surface of the magnetic recording medium. Therefore, even when the magnetic tape is run for a long time, the running of the magnetic tape near the magnetic gap is greatly stabilized,
It is possible to suppress a decrease in magnetic recording / reproducing characteristics due to a spacing loss between the magnetic tape and the magnetic gap.

Further, in the method of manufacturing a magnetic head according to the present invention, a pair of core blocks each having a winding groove on at least one of them is joined, and after the step of forming a joined body, it intersects with the joining surface of the joined body. Since the track groove extending on the side surface of the chamfered core block is formed at a predetermined interval, no track deviation occurs at all. Therefore, the yield can be significantly improved.
After the step of chamfering one longitudinal edge of the combined body on the side of the magnetic recording medium sliding surface, a track groove intersecting with the joint surface of the combined body and extending on the side surface of the chamfered core block is formed. Since the process is performed at intervals, the processing amount at the time of forming the track groove can be reduced by the chamfered amount. Therefore, distortion to the magnetic core at the time of processing the track groove can be effectively suppressed, and a magnetic head having excellent magnetic characteristics can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a top view showing one embodiment of the magnetic head of the present invention.

3A and 3B are a sectional view taken along the line AA and a sectional view taken along the line BB, respectively, showing a state after a magnetic recording medium (magnetic tape) has been run for a long time on the magnetic head of the present invention.

FIG. 4 is a perspective view showing steps of a method of manufacturing a magnetic head according to the present invention.

FIG. 5 is a perspective view showing steps of a method for manufacturing a magnetic head according to the present invention.

FIG. 6 is a perspective view showing steps of a method of manufacturing a magnetic head according to the present invention.

FIG. 7 is a perspective view showing a conventional magnetic head.

FIG. 8 is a top view showing a conventional magnetic head.

9A and 9B are a sectional view taken along line AA and a sectional view taken along line BB, respectively, showing a state after a magnetic recording medium (magnetic tape) has been run for a long time on a conventional magnetic head.

FIG. 10 is a perspective view showing another example of a conventional magnetic head.

FIG. 11 is a view showing a part of a step showing a method of manufacturing the conventional magnetic head of FIG. 10;

FIG. 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

FIG. 13 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

FIG. 14 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

FIG. 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

FIG. 16 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

FIG. 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

FIG. 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

FIG. 10 shows a method for manufacturing the conventional magnetic head of FIG.
It is a figure showing a part of process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic head 2 Hollow part 3 Magnetic gap 5 Track groove 7 Glass part (nonmagnetic material)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/187 G11B 5/127

Claims (2)

(57) [Claims] In a magnetic head in which a core half on a magnetic recording medium introduction side and a core half on a magnetic recording medium lead-out side are butted via a magnetic gap, a sliding surface of the magnetic head on the magnetic recording medium is provided. A non-magnetic material having a higher abrasion than the core half is disposed so as to continuously surround at least both ends in the width direction of the magnetic gap and portions other than the magnetic gap of the core half on the magnetic recording medium outlet side. The non-magnetic material is
A magnetic head extending to the leading end of the magnetic recording medium . 2. A step of joining a pair of core blocks having at least one winding groove to form a combined body, chamfering one longitudinal edge of the combined body on the side of the magnetic recording medium sliding surface, A step of machining track grooves intersecting with the joint surface of the joined body and extending on the side surfaces of the chamfered core half at a predetermined interval, and making the inside of the track grooves and the chamfered portion substantially the original shape Filling a nonmagnetic material so as to return, cutting and dividing each magnetic head chip by a cutting line passing through the groove, and polishing the magnetic recording medium sliding surface side of the magnetic head chip. A method for manufacturing a magnetic head, comprising: