JPH09204609A - Composite type magnetic head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic head in which a common core is used for a recording and reproducing head and an erasing head and also provide a manufacturing method for it. SOLUTION: This magnetic head 10 is provided with two sets of C-type cores 14, 17 and I-type cores 13, 16 which respectively form a recording and reproducing gap 15 and a erasing gap 18, and the I-type cores 13, 16 are constituted by being joined back to back with each other. The respective gap lengths of the recording and reproducing gap 15 and the erasing gap 18 are set for an identical dimension and an identical tolerance.

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 information on a magnetic recording medium, and more particularly to a magnetic head for a floppy disk and a method for manufacturing the magnetic head.

[0002]

2. Description of the Related Art Generally, a magnetic head used in a magnetic recording / reproducing apparatus for recording / reproducing a magnetic disk, for example, a floppy disk, has a composite head structure of a recording / reproducing head and an erasing head. For example, in FIG.
It is configured as shown in FIG. That is, in FIG. 5, the magnetic head 1 is composed of a magnetic head core 2, coils 4, 5 and a bridge bar 9 and a slider 3.

The slider 3 is a slider half 3 made of a non-magnetic material (for example, ceramic) having a substantially L-shaped cross section.
It is composed of a and 3b.

In assembling the magnetic head 1 having such a structure, the slider halves 3a and 3b are first joined to the magnetic head core 2 with epoxy resin or glass, and then the contact surface to be opposed to the magnetic disk. Polish A. Next, the coils 4 and 5 that form a magnetic circuit are mounted on the magnetic head core 2, and the bridge bar 9 that forms a magnetic path is mounted to complete the magnetic head 1.

As shown in FIG. 6, the magnetic head core 2 has a recording / reproducing gap 6 and an erasing gap 7. The gap 6 is an I-shaped core 2a or C.
The mold core 2b and the gap 7 are formed by the I-type core 2c and the C-type core 2d.

The I-type cores 2a and 2c and the C-type core 2
The abutting surfaces of b and 2d are abutted at predetermined intervals so that gaps 6 and 7 can be formed. In this case, generally, the erase gap 7 is used.
Is selected to be two to three times the gap length of the recording / reproducing gap 6 in consideration of the characteristics of the core material of the cores 2a, 2b, 2c and 2d. For example, the gap length of the recording / reproducing gap 6 is 1 ± 0.1 μm, and the gap length of the erasing gap 7 is 2.5 ± 1 μm.
As a result, for example, an erasing rate of -40 dB can be obtained.

[0007]

However, in the magnetic head 1 having such a structure, the gap lengths of the recording / reproducing gap 6 and the erasing head 7 are different from each other. The recording / reproducing head core composed of 2b and the erasing head core composed of the cores 2c and 2d are formed separately. Therefore, two types of head cores, that is, a recording / reproducing head core and an erasing head core, which are manufactured in almost the same manufacturing process, are required, resulting in a large number of parts, a complicated manufacturing process, and a high cost. There was a problem of being lost.

In view of the above points, it is an object of the present invention to provide a composite type magnetic head in which a common core is used for a recording / reproducing head and an erasing head, and a method for manufacturing the same.

[0009]

According to the present invention, the above object comprises two sets of a C-type core and an I-type core forming a recording / reproducing gap and an erasing gap, respectively.
In a composite magnetic head configured by joining the I-shaped cores back to back, the lengths of the recording / reproducing gap and the erasing gap are
This is achieved by a magnetic head characterized by having the same size and the same tolerance.

Further, according to the present invention, the above-mentioned object is to form a recording / reproducing gap and an erasing gap by abutting two sets of a C-type core and an I-type core, respectively. In a method of manufacturing a composite magnetic head, wherein cores are joined back to back, a C-shaped core and I for forming the recording / reproducing gap.
C-shaped core and I for forming the erase gap with the D-shaped core
This is achieved by a method of manufacturing a composite magnetic head, characterized in that the mold core is formed with a gap having the same process, the same size and the same tolerance.

According to the above structure, the C-type core and the I-type core forming the recording / reproducing head core and the C-type core and the I-type core forming the erasing head core have the same size and the same tolerance gap length. Since the gap is formed, the two sets of the C-shaped core and the I-shaped core can be commonly used before the track width regulating groove is processed.

Therefore, it is not necessary to prepare two types of C-type cores and I-type cores, and only one type of C-type core and I-type core is used to form gaps having the same size and the same tolerance gap length. A recording / reproducing head core and an erasing head core are formed by forming and then processing track limiting grooves corresponding to the recording / reproducing head core and the erasing head core, respectively. Then, finally, the I-shaped cores of the recording / reproducing head core and the erasing head core are joined back-to-back to each other to complete the magnetic head core.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 shows an embodiment of a magnetic head core incorporated in a magnetic head according to the present invention. In FIG. 1, a magnetic head core 10
Is a recording / reproducing head core 11 and an erasing head core 12.
It is composed of

The recording / reproducing head core 11 is an I-shaped core 1.
3 and C-type core 14, and these I-type core 13 and C
The abutting portion of the die core 14 forms a recording / reproducing gap 15.

Similarly, the erasing head core 12 is
It is composed of an I-type core 16 and a C-type core 17, and an erasing gap 18 is formed by the abutting portion of the I-type core 16 and the C-type core 17.

The above-mentioned structure is similar to the magnetic head core 2 of the conventional magnetic head 1 shown in FIG. 5, but in the magnetic head core 10 according to the embodiment of the present invention, the recording / reproducing gap 15 and the erasing gap are used. The gap length of the gap 18 is selected to have the same size and the same tolerance. That is,
The gap length of the erasing gap 18 is selected to be about 0.9 to 1.1 times, preferably the same as the gap length of the recording / reproducing gap 15. Here, 3.5 inch floppy disk (unformatted capacity is 2M
In the case of a magnetic head for B or 1 MB), the gap length of the recording / reproducing gap 15 and the erasing gap 18 is selected to be, for example, 1 ± 0.1 μm.

The magnetic head core 10 as described above is manufactured as follows. That is, first in FIG.
In (A), a first substrate 21 and a second substrate 22 made of a magnetic material such as ferrite are prepared. In this case, the first substrate 21 is relatively thin and is for forming the I-shaped core, and the second substrate 22 is relatively thick and is for forming the C-shaped core.

Next, as shown in FIG. 2B, after the winding groove 22b extending along the longitudinal direction is formed on the bonding surface 22a of the second substrate 22 facing the first substrate 21, As shown in FIG. 2C, the first substrate 21 and the second substrate 22 are bonded to each other. In this case, the opposing surfaces of the first substrate 21 and the second substrate 22 are butted so as to form a predetermined gap length. Thus, the head core 23 is constructed.

As shown in FIG. 3D, the head core 23 is provided with a read / write track width with respect to the bonding surface of the first substrate 21 and the second substrate 22. First substrate 2 so as to remove a part
The track width regulating groove 24 is formed on the upper surfaces of the first and second substrates 22.
Is processed. At this time, the track width regulating groove 24 is processed so that the width of the remaining gap 15 becomes the recording / reproducing gap width T1. As a result, the recording / reproducing gap bar 25 is formed.

On the other hand, using the same head core 23, as shown in FIG. 3 (E), with respect to the bonding surface of the first substrate 21 and the second substrate 22 so as to have an erase track width, The track width regulating groove 2 is formed on the upper surfaces of the first substrate 21 and the second substrate 22 so as to remove a part thereof.
6 is processed. At this time, the track width regulating groove 26 is
The width of the gap 18 in the remaining portion is processed so as to be the recording / reproducing gap width T2. As a result, the erase gap bar 27 is formed.

Thereafter, the recording / reproducing gap bar 25 is used.
The erasing gap bar 27 is filled with the bonding glass 28 in the track width regulating grooves 24 and 26, respectively, and the upper surfaces thereof are polished, and as shown in FIG. The substrates 21 are joined so that they are back to back.

The core foot portion 29 of each recording / reproducing gap bar 25 and erasing gap bar 27 is shown in FIG.
It is processed as shown in FIG. Thereby, the block 30 of the magnetic head is formed.

Finally, the block 30 of the magnetic head
However, the individual magnetic head cores 10 are completed by slicing the gaps 15 and 18 in the direction perpendicular to the longitudinal direction.

The magnetic head core 10 manufactured according to the embodiment of the present invention is configured as described above, and since the recording / reproducing head core 11 and the erasing head core 12 are formed from the same head core 23, the recording / reproducing head core 10 is formed. The gap lengths of the gap 15 and the erase gap 18 can be selected to have the same size and the same tolerance.

Therefore, when the magnetic head core 10 is manufactured, it is sufficient to prepare one kind of the head core 23, which facilitates the manufacture and the erase gap 18 has a shorter gap length than the conventional one. Therefore, the manufacturing time for forming the gap can be shortened.

In this case, the gap length of the erasing gap 18 is significantly narrower than that of the conventional one, but the erasing rate is, for example, about -30 dB, which is a standard value of -2.
Since it is within 6 dB, there is no problem in practical use.

[0027]

As described above, according to the present invention, the C-type core and the I-type core forming the recording / reproducing head core and the C-type core and the I-type core forming the erasing head core have the same size. And a gap having a gap length with the same tolerance is formed, the two sets of the C-type core and the I-type core can be formed before the track width regulation groove is processed.
Common ones can be used.

Therefore, it is not necessary to prepare two types of C-type cores and I-type cores, and only one type of C-type core and I-type core is used to form gaps having the same size and the same tolerance gap length. The head core to be formed is formed in the same step, and then the track regulation groove is processed corresponding to the recording / reproducing head core and the erasing head core, respectively, whereby the recording / reproducing head core and the erasing head core are configured. Finally, the magnetic head core is completed by joining the I-shaped cores of the recording / reproducing head core and the erasing head core back to back to each other, and combining this magnetic head core with the coil, the bridge bar and the slider in the conventional manner. Thus, the magnetic head is completed.

Thus, according to the present invention, it is possible to provide an extremely excellent magnetic head in which a common core is used for the recording / reproducing head and the erasing head, and a manufacturing method thereof.

[Brief description of drawings]

FIG. 1 is an enlarged plan view showing the vicinity of a gap of an embodiment of a magnetic head core incorporated in a magnetic head according to the present invention.

2A, 2B, and 2C are schematic perspective views sequentially showing the manufacturing process of the magnetic head core of FIG.

3 (D) and (E) are schematic perspective views sequentially showing the manufacturing process of the magnetic head core following FIG.

4 (F), (G), and (H) are schematic perspective views sequentially showing the manufacturing process of the magnetic head core following FIG.

FIG. 5 is a schematic perspective view showing an example of a conventional magnetic head.

6 is an enlarged plan view showing the vicinity of the gap in the magnetic head of FIG.

[Explanation of symbols]

 10 magnetic head core 11 recording / reproducing head core 12 erasing head core 13,16 I-type core 14,17 C-type core 15 recording / reproducing gap 18 erasing gap 21 first substrate 22 second substrate 23 head core 24, 26 track width Regulating groove 25 Gap bar for recording / reproducing 27 Gap bar for erasing 28 Glass for bonding 29 Core foot part

Claims (2)

[Claims] 1. A composite comprising two sets of a C-shaped core and an I-shaped core forming a recording / reproducing gap and an erasing gap, respectively, the I-shaped core being joined back to back. In the magnetic head, the composite magnetic head is characterized in that the gap lengths of the recording / reproducing gap and the erasing gap are set to have the same size and the same tolerance. 2. A pair of a C-shaped core and an I-shaped core are butted against each other to form a recording / reproducing gap and an erasing gap, and the two I-shaped cores are joined back to back. In the method of manufacturing a composite magnetic head, the C-type core and the I-type core forming the recording / reproducing gap and the C-type core and the I-type core forming the erasing gap are in the same step, with the same size and with the same tolerance. A method of manufacturing a composite magnetic head, characterized in that a gap having a gap length of 1 is formed.