JPH0550043B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic head suitable for recording and reproducing, for example, a magnetic disk device, and a method for manufacturing the same.

Conventional Structures and Problems Conventionally, magnetic disk devices, especially flexible disk devices, have been mainly 8 inch (approximately 20 cm) in diameter and 5.25 inch (approximately 13 cm) in diameter, but recently, 3 inches (approx. 7.5cm) diameter ~ 4
Small flexible disk devices with an inch (approximately 10 cm) diameter have appeared. Generally, 8 inches (approximately 20
In tunnel erase type magnetic heads used for magnetic disks with a diameter of cm) or 5.25 inches (approx. It was corrected using the electrical circuit. If this can be reduced to 0.5 mm or less, the correction circuit can be simplified. However, in the conventional structure, this was not possible.
In addition, as a structure of the magnetic head to solve this problem,
There is a straddle erase type magnetic head, but as the recording density (track density) increases, this poses a problem in that it significantly increases production yield.

Here, a conventional magnetic head used in a flexible disk device will be explained with reference to FIGS. 1 to 6. FIG. 1 is an exploded perspective view of a tunnel erase type magnetic head for a flexible disk device, in which recording/reproducing cores 1 and 3 are erasing cores for tunnel erasing, respectively. Core members 4 to 6 are bonded to core members 7 to 9 with glass via magnetic gaps 10 to 12, and nonmagnetic materials 13 to 15 are bonded to core members 7 to 9 with resin or glass 1.
6 to 18. FIG. 2 is a plan view of a magnetic head constructed by assembling cores 1 to 3.

FIG. 3 is a plan view of a straddle erase type magnetic head. Reference numerals 19 and 20 are first and second cores constituting a magnetic circuit for recording and reproducing, which face each other with a magnetic gap 21 in between. 22a,2
Reference numeral 2b denotes an erasing core, which is placed at a predetermined position relative to the magnetic gap 21.

Fig. 4 is a perspective view of the magnetic head described in Japanese Patent Publication No. 51-9575, Fig. 5 is an enlarged plan view of the same main part,
FIG. 6 is a perspective view of a magnetic head described in Japanese Patent Application Laid-Open No. 57-44219, both of which are tunnel erase type magnetic heads. 4 and 5, 23 is a common core for recording/reproducing and erasing, 24 is a recording/reproducing core, 25 is an erasing core, 26 is a recording/reproducing gap, and 27 is an erasing gap. Note that the diagonally lined portions in the figure are portions made of nonmagnetic material. According to this, leakage magnetic flux is generated as shown by arrows A and B as shown in FIG. 5, and the effective track width is reduced by the leakage magnetic flux shown by arrow B. Further, in FIG. 6, 28 is a recording/reproducing gap, and 29 is an erasing gap. According to these, the distance _l1 between the recording/reproducing gap 28 and the erasing gap 29 cannot be made small.

OBJECT OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and provides a magnetic head in which the distance between the recording/reproducing gap and the erasing gap can be sufficiently reduced without deteriorating manufacturing yield, and An object of the present invention is to provide a method for manufacturing a magnetic head that allows the magnetic head to be manufactured easily.

Structure of the Invention In order to achieve the above object, the magnetic head of the present invention includes first and second cores forming a recording/reproducing gap, and third and fourth cores forming an erasing gap. , the second core and the third core have abutting surfaces that abut each other, and at least one of the abutting surfaces is provided with an inclined portion such that an opening is formed on the tape abutting surface side. It is.

Further, in the method for manufacturing a magnetic head of the present invention, a first core having a substantially U-shape and a second core having a substantially I-shape are adhered to each other to form a recording/reproducing gap; A third core and a substantially U-shaped fourth core are bonded together to form an erasing gap, and at least one of the abutting surfaces of the second core and third core is cut and inclined. After forming the parts, these abutting surfaces are adhered to each other, and an auxiliary core is further adhered over the first core and the fourth core.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

Figure 7 is a perspective view of the recording/reproducing head section.
1 is a first core, and 32 is a second core. 1st
After the core 31 is molded, the abutting surface with the second core 31 is mirror-finished. Further, the abutting surface of the second core 32 with the first core 31 is also mirror-finished. Next, the cores 31 and 32 are bonded to glass so that the recording/reproducing gap 33 has a predetermined gap length.
Next, record/playback track 3 with a predetermined track width
Grooving is performed leaving 4a, 34b, 34c...
Groove portions 35a, 35b, 35c... are obtained. Then, a non-magnetic material (for example, a ceramic material or glass suitable for the expansion coefficient of the ferrite used in the cores 31, 32) is inserted into the grooves 35a, 35b, 35c, etc. to make the surface height uniform. At this time, if the expansion coefficient of the non-magnetic material is not appropriate, resin may be filled.

FIG. 8 is a perspective view of the erasing head section, where 36 is the third core and 37 is the fourth core. After the fourth core 37 is molded, its abutting surface with the third core 36 is mirror-finished. On the other hand, the abutting surface of the third core 36 with the fourth core 37 is also mirror-finished, and the core 3
6 and 37 are bonded to glass to form a predetermined erasing gap 38. After that, groove processing is performed to form the groove part 3.
9a, 39b, 39c... are obtained, and erasing tracks 40a, 40b, 40c... are obtained. Then, a nonmagnetic material is inserted into the grooves 39a, 39b, 39c, and bonded. These operations are recorded and recorded as shown in Figure 7.
It can be made using the same manufacturing process as when making the regeneration head.

Next, the abutting surface of the second core 32 with the erasing head is mirror-finished, and as shown in FIG.
When the depth of a, 35b, 35c... is l ₂ , l ₃
An inclined portion (hereinafter referred to as a taper) is provided with a dimension _{l 4 such} that <l 4 and l ₆ ≦4l ₅ when the thickness of the second core 32 is l ₆ . Also, the third core 36
Similarly, the abutting surface with the second core 32 is mirror-finished and provided with a taper.

Further, as shown in FIG. 10, the recording/reproducing head section and the erasing head section are adhesively fixed with resin. The adhesion position at this time is set at a position where the track center of the recording/reproducing head section is shifted by ΔL from the track center of the erasing head section, as shown in FIG. The dimension of this ΔL varies depending on the diameter of the flexible disk used. Next, the bottom part is milled to give it a mirror finish.

Thereafter, as shown in FIG. 12, the head tip portion is completed by cutting at the positions indicated by chain lines A, B, C, etc. A recording/reproducing coil 41 and an erasing coil 42 are inserted into this head chip.
When inserting the coils, the recording/reproducing coil is inserted into the first core 31, and the erasing coil 42 is inserted into the fourth core 37, as shown in FIG. Next, a mirror-finished trapping core 43 shown in FIG. 13 is adhesively fixed to form a closed magnetic path, and the magnetic head is completed as shown in FIG. 16.

In this way, since the second core 32 forming the recording/reproducing gap and the third core 36 forming the erasing gap are shared, the gap distance can be reduced to 0.5 mm or less, and Can eliminate magnetic saturation of the core. Furthermore, the magnetic flux generated by the erasing coil 42 leaks from the fourth core 37 to the second core 32 and the leakage flux that reduces the track width is caused by the leakage flux generated by the second core 32 as shown in FIGS. 14 and 15. Due to the taper provided on the abutting surfaces of the core 32 and the third core 36, the distance between the fourth core 37 and the second core 32 can be increased by 2l ₅ . Therefore, the gap between the recording/reproducing gap 33 and the erasing gap 38 can be reduced accordingly, and can actually be reduced to 0.5 mm or less. Furthermore, there is a gap of 2l ₅ between the recording/reproducing magnetic circuit and the erasing magnetic circuit at the gap portion, and as shown in FIG. The resistance becomes large, and the recording/reproducing coil 41 is hardly interlinked, and its interference can be prevented. Also, depending on the size of the medium, it was difficult to record
The reproducing cores 31 and 32 were set at a small angle (azimuth), but in the magnetic head of this embodiment, the center line of the erasing track is shifted by ΔL from the center line of the recording/reproducing track. I can handle it. Further, according to the manufacturing method of this embodiment, all processing is performed with mechanical precision, so the work is stable and manufacturing is easy.

In the above embodiment, an example was described in which a taper was provided on both of the abutting surfaces of the second core 32 and the third core 36, but a taper may be provided on only one of them.

Effects of the Invention As explained above, according to the magnetic head according to the present invention, the second core of the recording/reproducing magnetic circuit and the third core of the erasing magnetic circuit are brought into contact with each other and used in common. In order to eliminate the feedthrough that occurs due to this, an inclined portion is provided on the abutting surfaces of the second core and the third core, so that the gap between the recording/reproducing gap and the erasing gap can be made sufficiently small. and the correction circuit can be simplified. Further, according to the method for manufacturing a magnetic head according to the present invention, the magnetic head described above can be easily manufactured, and there is no deterioration in yield due to improvement in recording density.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a conventional tunnel erase type magnetic head, Fig. 2 is a plan view thereof, Fig. 3 is a plan view of a conventional straddle erase type magnetic head, and Fig. 4 is yet another conventional example. 5 is an enlarged plan view of the same, FIG. 6 is a perspective view of another conventional tunnel erase type magnetic head, and FIG. 7 is an embodiment of the present invention. FIG. 8 is a perspective view of a recording/reproducing magnetic circuit with track processed and non-magnetic material bonded to it, and FIG. 8 is a perspective view of an erasing magnetic circuit in an embodiment of the present invention with non-magnetic material bonded after track processing. FIG. 9 is an explanatory diagram of the second inclined portion, FIG. 10 is a perspective view of the recording/reproducing core and the erasing core bonded together and the back side has been processed, and FIG. 11 is the recording/reproducing core. Fig. 12 is an explanatory diagram of the misalignment of the reproduction system head with respect to the track center; Fig. 12 is an explanatory diagram of the cut points when individually cutting heads made in multiple series; Fig. 13 is a perspective view of the auxiliary core; 15 is an explanatory diagram of the magnetic path of the magnetic head, and FIG. 16 is a perspective view of the magnetic head. 31...first core, 32...second core, 3
3... recording/reproducing gap, 36... third core, 37... fourth core, 38... erasing gap, 43... auxiliary core.

Claims (1)

[Scope of Claims] 1. First and second cores forming a recording/reproducing gap, and third and fourth cores forming an erasing gap, the second core and the third core forming a gap for erasing. A magnetic head having an abutting surface that abuts the core, and at least one of the abutting surfaces is provided with an inclined portion so that an opening is formed on the tape abutting surface side. 2. The magnetic head according to claim 1, wherein the inclined portion is provided only on the second core. 3. The magnetic head according to claim 1, wherein the inclined portion is provided only on the third core. 4. The magnetic head according to claim 1, wherein the inclined portion is provided on both the second core and the third core. 5 What are the recording/reproducing gap and the erasing gap?
5. A magnetic head according to claim 1, wherein the magnetic heads are constructed so that their track centers are shifted from each other. 6 A substantially U-shaped first core and a substantially I-shaped second core are adhered to each other to form a recording/reproducing gap, and a substantially I-shaped third core and a substantially U-shaped third core are bonded to each other. and a fourth core to form an erasing gap, and after cutting at least one of the abutting surfaces of the second core and the third core to form an inclined portion, these abutting surfaces are 1. A method of manufacturing a magnetic head, comprising adhering them to each other and further adhering an auxiliary core across the first core and the fourth core.