JPH0845048A - Magnetic head - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a magnetic head that can accurately control the magnetic gap depth of a recording / reproducing magnetic core and reduce variations in recording / reproducing characteristics at low cost. A magnetic core 16 is arranged adjacent to a ski groove 20 of a slider 17, and a first apex portion 23 forming a closed magnetic path of a recording / reproducing head and a depth of the apex portion are the same. If the second apex portion 24 that does not contribute to the reproduction is provided, the second apex portion 24 is exposed inside the ski groove 20, and the depth 28 of the second apex portion 24 is monitored, The depth of the magnetic gap can be controlled accurately. Further, by accurately controlling the depth of the magnetic gap, it is possible to inexpensively supply a magnetic head with little variation in recording / reproducing characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head mainly used in a floppy disk drive device.

[0002]

2. Description of the Related Art An example of a magnetic head generally used in a conventional floppy disk drive will be described below with reference to FIGS. The magnetic head shown in FIG. 8 is called a tunnel erasing type magnetic head. In FIG. 8, reference numeral 1 is a magnetic core, which is formed by joining a recording / reproducing head 2 and an erasing head 3. The magnetic core 1 is sandwiched between non-magnetic sliders 4 and 5 and constitutes a ski surface 6 which is a sliding surface with respect to a magnetic recording medium. In addition,
A ski groove 7 is provided on the ski surface 6. In the magnetic head having such a structure, the magnetic core 1 and the sliders 4 and 5 are bonded to each other with glass or resin, and then the ski surface 6
It is manufactured by lapping so as to eliminate the step between the magnetic core 1 and the sliders 4 and 5 above. FIG. 9 shows the magnetic core 1
The recording / reproducing head 2 is composed of a center core 9 and a side core 10 facing each other with a recording / reproducing magnetic gap 8 in between, and a back core 11 connecting the two, and the magnetic gap depth 12 is equal to the side core 10. It is regulated by the apex 13 provided in the. Since the erasing head 3 is structurally similar to the recording / reproducing head 2, detailed description of its structure will be omitted, but as shown in the figure, the center cores of both heads are joined together to form the magnetic core 1. There is.

Reference numeral 14 is a recording / reproducing coil, and 15 is an erasing coil. The operation of the magnetic head thus configured will be described with reference to FIG. First, at the time of recording, a recording current is passed through the recording / reproducing coil 14 to generate a magnetic field in the recording / reproducing magnetic gap 8 to record information on the medium. Next, an erasing current is passed through the erasing coil 15 to generate a constant magnetic field in the erasing head to erase both sides of the previously recorded information with a certain width. On the other hand, at the time of reproduction, the magnetic field generated from the medium is sensed in the recording / reproducing magnetic gap 8 and information is taken out as voltage from the recording / reproducing coil 14.

[0004]

Generally, the recording and reproducing characteristics of a magnetic head are greatly affected by the dimensions of the length and depth of the magnetic gap, and in order to obtain good recording and reproducing characteristics, these dimensions should be adjusted. Accurate control is required.
In the conventional magnetic head, the magnetic core 1 and the slider 4,
It is necessary to perform lapping after the adhesion of 5 to eliminate the step between the two on the ski surface 6, and the depth 12 of the magnetic gap 8 also changes depending on the grinding amount. However, since this magnetic head has a structure in which the magnetic core 1 is sandwiched between the sliders 4 and 5, and the magnetic core 1 is exposed only on the ski surface 6, the magnetic gap 8 is formed after the sliders 4 and 5 are bonded.
You cannot see the depth of 12 directly. Therefore,
The depth 12 of the magnetic gap 8 after the sliders 4 and 5 are bonded is
Since it can be grasped only by indirect means such as measurement of the inductance of the magnetic core 1 and the depth 12 of the magnetic gap in the completed magnetic head cannot be accurately controlled, there is a problem that the recording / reproducing characteristics of the magnetic head vary. there were.
In order to solve this problem, the magnetic core is placed outside the slider, a dummy track is provided on the outermost surface of the magnetic core, and the entire magnetic field is lapped while observing the magnetic gap depth of the dummy track. Control the gap,
A magnetic head has been proposed in which, when completed, the dummy track is removed by grinding. However,
This magnetic head has a problem that the volume of the magnetic core is increased and the cost is increased accordingly.

The present invention solves these problems, and an object thereof is to provide a magnetic head which can accurately control the magnetic gap depth of a recording / reproducing magnetic core and reduce variations in recording / reproducing characteristics at low cost. I am trying.

[0006]

In order to achieve these objects, a first apex which forms a closed magnetic path of a recording / reproducing head by a side core, a center core and a back core, and regulates the depth of a magnetic gap in the side core. And a second apex portion having the same dimensions as the first apex portion and not contributing to recording and reproduction, and a slider having a ski groove is joined to the side surface of the second apex portion. The second apex portion is exposed inside the ski groove.

[0007]

With the above structure, the magnetic head of the present invention has
A second apex portion having the same magnetic gap depth as the first apex portion forming the closed magnetic path of the recording / reproducing head and not directly involved in the closed magnetic path is exposed inside the ski groove. Therefore, even after the slider is bonded, the depth of the magnetic gap can be measured by observing the second apex portion from the ski groove direction, and the depth of the magnetic gap can be accurately controlled until the magnetic head is completed. In addition, since the portion adjacent to the ski groove of the magnetic core is used without adding a track for controlling the magnetic gap to the magnetic core, the volume of the magnetic core can be made the same as that of the conventional magnetic head, and the increase in the magnetic core volume It is possible to prevent the cost from rising.

[0008]

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

FIG. 1 is a perspective view showing a first embodiment of the magnetic head of the present invention. In the figure, 16 is a magnetic core, which is sandwiched by non-magnetic sliders 17 and 18, and is adjacent to a ski groove 20 provided on a ski surface 19 of the slider 17. 2 is an enlarged view of the magnetic head shown in FIG. 1 in the vicinity of the magnetic gap in the recording / reproducing head portion. In this magnetic head, the depth of the magnetic gap 21 of the recording / reproducing head is controlled by the first apex portion 23 provided on the side core 22 similarly to the conventional magnetic head shown in FIG.
A second apex portion 24 having the same depth dimension of the magnetic gap 21 as the first apex portion 23 is provided inside the side core 22 on the side of the ski groove 20. The second apex portion 24 is separated from the magnetic gap 21 and the center core 25 by the mold glass 26 and does not contribute to recording / reproduction. The depth 27 of the ski groove 20 is equal to that of the second apex portion 24.
The depth is set deeper than 28.

FIG. 3 shows a method of manufacturing the recording / reproducing head, which will be described below. FIG. 3A shows the side core 22 in a bar state before the magnetic gap is formed.
And the center core 25. The side core 22 is formed with a first apex portion 23, and the center core 25 is formed with notches 29 such as chamfered grooves at regular intervals. The depth 30 of the cutout portion 29 is set to be about 100 μm deeper than the depth 31 of the first apex portion 23. The center core 25 and the side core 22 are bonded together via a gap material, and grooves are formed parallel to the longitudinal direction of the magnetic head to perform track processing, which is the bar shown in FIG. 3 (b). As shown in the figure, the track machining is alternately performed on the portion where the notch portion 29 of the center core 25 exists and the portion where the notch portion 29 of the center core 25 does not exist. A second apex portion 24 for measuring the magnetic gap is formed in a portion where the notch portion 29 of 25 exists. Similar to this bar, a bar-shaped erasing head that has been subjected to magnetic gap formation and track processing is adhered to the recording / reproducing head on the side of the center core, and after inserting a coil insertion groove, cut along the dashed-dotted line 32. The magnetic core is made.

With the above structure, the magnetic gap depth can be controlled by measuring the second apex portion 24 even after the slider is bonded. In the magnetic head of the present embodiment, the depth of the magnetic gap of the recording / reproducing head can be controlled within a range of ± 2 μm, and the variation in reproduction output is less than half that of the conventional magnetic head of the same specification. Yield is 5%
The degree was improved.

As described above, in this embodiment, the magnetic gap depth can be accurately controlled until the completion of the magnetic head, the variation in the recording / reproducing characteristics can be suppressed, and the defect rate can be reduced. In this embodiment, the main purpose is to accurately control the magnetic gap depth until the completion of the magnetic head. After the final adjustment of the magnetic gap depth, the second apex portion is deleted to complete the magnetic head. Even if it does, it does not go against the gist of the present invention.

FIG. 4 shows a second embodiment of the magnetic head of the present invention and is an enlarged view of the recording / reproducing head portion thereof. The magnetic head of the present embodiment has substantially the same structure as the magnetic head of the first embodiment shown in FIG. 1, except for the structure of the recording / reproducing head. That is, the recording / reproducing head 33 in the present embodiment has a structure in which the first apex portion 34 and the second apex portion 35 are provided in the center core 36, and the configurations of the center core and the side core in the above-described first embodiment are exchanged. With such a structure, the same effect as that of the magnetic head of the first embodiment can be obtained.

FIG. 5 is a perspective view showing a third embodiment of the magnetic head of the present invention. In the figure, 37 is a magnetic core which is sandwiched between non-magnetic sliders 38 and 39, and a ski surface 40 of this slider 38.
It is adjacent to the ski groove 41 provided above. FIG. 6 is an enlarged view near the magnetic gap of the recording / reproducing head.
The depth of the magnetic gap of the recording / reproducing head of this embodiment is
It is controlled by an apex section 43 provided in the center core 42. Further, the track width 44 is restricted only on the side core side, and the apex portion 43 of the center core 42 has the ski groove 41.
Is exposed inside. The depth 45 of the ski groove 41 is
It is set deeper than the depth 46 of the apex portion 43. In addition, the ski surface 40 is attached to the ridgeline of the magnetic core 37 on the ski groove 41 side.
And a taper 47 whose angle in the direction of the ski groove 41 is 10 μm deeper than the depth 46 of the apex portion 43. FIG. 7 shows a method of manufacturing the recording / reproducing head, which will be described below. FIG. 7A shows the center core 42 and the side core 48 in a bar state before the magnetic gap is formed. The center core 42 is provided with an apex portion 43 and the side core is subjected to track processing. The center core 42 and the side cores 48 are adhered to each other via a gap material to form a bar shown in FIG. 7 (b). Similar to this bar, a bar-shaped erasing head in which a gap has been formed and track processing has been performed is adhered to the recording / reproducing head on the side surface of the center core, and after inserting a coil insertion groove, the magnetic core is cut according to the broken line 49. Is created.

In the magnetic head of this embodiment, it is needless to say that the magnetic gap depth can be controlled by direct measurement even after the slider is bonded.
Since the apex portion exposed at the ski groove is tapered at 45 °, the magnetic gap depth can be easily measured by tilting the magnetic head at 45 °. In practice, the magnetic head of the present embodiment can control the depth of the magnetic gap of the recording / reproducing head within a range of ± 2 μm, and the variation in reproduction output is less than half that of the conventional magnetic head of the same specifications. The final yield was also improved by about 4%.

As described above, in the magnetic head of this embodiment, the magnetic gap depth can be accurately controlled until the completion of the magnetic head, the variation in the recording / reproducing characteristics can be suppressed, and the defective rate can be reduced.

[0017]

Since the magnetic head of the present invention has a structure in which the second apex portion is exposed inside the ski groove of the recording / reproducing head, the second apex portion is measured until the magnetic head is completed. By doing so, the magnetic gap depth can be accurately controlled. Further, since the portion adjacent to the ski groove of the magnetic core is used without adding a track for gap control to the magnetic core, the volume of the magnetic core can be made the same as that of the conventional magnetic head, and the cost due to the increase of the magnetic core volume is increased. Can be prevented from rising. Therefore, it is possible to inexpensively supply a large amount of magnetic heads with little variation in recording / reproducing characteristics, which is of high industrial utility value.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a magnetic head of the present invention.

2 is a partially enlarged view of a magnetic gap in a recording / reproducing head portion of the magnetic head shown in FIG.

FIG. 3 is a perspective view showing a method of manufacturing a recording / reproducing head.

FIG. 4 is a partially enlarged perspective view showing a second embodiment of the magnetic head of the present invention.

FIG. 5 is a perspective view showing a third embodiment of the magnetic head of the present invention.

6 is a partially enlarged view of the magnetic head shown in FIG.

FIG. 7 is a perspective view showing a method of manufacturing a magnetic head.

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

9 is a cross-sectional view of the magnetic core shown in FIG.

[Explanation of symbols]

1, 16, 37 ... Magnetic core, 2, 33 ... Recording / reproducing head,
3 ... Erasing head, 4,5,17,18,38,39 ... Slider, 6,19,40 ... Ski surface, 7,20,41 ... Ski groove, 8,21 ... Magnetic gap, 9,25,36 , 42 ... Center core, 10, 22, 48 ... Side core, 11 ... Back core, 12 ... Magnetic gap depth, 13, 43 ... Apex, 14 ... Recording / reproducing coil, 15 ... Erase coil,
23, 34 ... First apex part, 24, 35 ... Second apex part, 26 ... Molded glass, 27, 45 ... Ski groove depth, 28 ... Second apex depth, 29 ... Notch part,
30… depth of notch part, 31,46… depth of apex part,
32, 49 ... Cutting position, 44 ... Track width, 47 ... Taper.

Claims (3)

[Claims] 1. A side core, a center core, and a back core constituting a closed magnetic path of a recording / reproducing head, a magnetic gap of a predetermined size formed by track processing on the side core and the center core, and the magnetic provided on the side core. A first apex portion that regulates the depth of the gap; a second apex portion that is arranged in parallel with the first apex portion and has the same depth as the first apex portion; A slider provided with a notch portion provided in a center core facing the apex portion of the second apex so that a magnetic path including the second apex portion does not contribute to recording and reproduction, and a ski groove joined to a side surface of the second apex portion. And a magnetic head configured such that the second apex portion is exposed inside the ski groove. 2. A side core, a center core, and a back core forming a closed magnetic path of a recording / reproducing head, a magnetic gap having a predetermined size formed by track processing on the side core and the center core, and the magnetic provided on the center core. A first apex portion that regulates the depth of the gap; a second apex portion that is arranged in parallel with the first apex portion and has the same depth as the first apex portion; Slider provided with a notch portion provided on a side core facing the apex portion of the second apex so that a magnetic path including the second apex portion does not contribute to recording and reproduction, and a ski groove joined to a side surface of the second apex portion. And a magnetic head configured such that the second apex portion is exposed inside the ski groove. 3. A side core, a center core, and a back core which constitute a closed magnetic path of a recording / reproducing head, a magnetic gap of a predetermined size formed by a cutout portion provided in the side core, and the magnetic core provided in the center core. A magnetic head comprising an apex portion for controlling a depth of a magnetic gap and a slider having a ski groove joined to a side surface of the apex portion, the apex portion being exposed inside the ski groove.