JP2522614Y2 - Composite magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a composite magnetic head suitable for use in a magnetic disk drive or the like, and more particularly to a composite magnetic head obtained by integrating a recording / reproducing head and an erasing head. About the head.

[Outline of the invention]

The present invention relates to a composite magnetic head comprising a front core formed by abutting a recording / reproducing core portion and an erasing core portion on a front end side with a center core portion therebetween, and a back core disposed on a rear end side of the front core. The back core has a structure in which a pair of core members formed in a substantially U-shape corresponding to the respective head portions are integrated into a substantially E-shape via a non-magnetic material, so that a front core and a back core are formed. An object of the present invention is to provide a composite magnetic head which has a stable and strong bond with a core, has good electromagnetic conversion characteristics, and is excellent in productivity.

[Conventional technology]

For example, a magnetic disk such as a floppy disk is relatively easy to handle and can record a large amount of signal. Therefore, its use as an external storage device of a minicomputer, an office computer, a personal computer or the like is expanding.

In the above-mentioned floppy disk, information signals are stored in concentric tracks, and in order to ensure compatibility of the information signals, recording is performed with a track width slightly smaller than the track pitch of the disk. Has become.
That is, a so-called tunnel erase composite magnetic head in which a pair of erasing magnetic gaps are disposed on both sides behind the recording / reproducing magnetic gap as a magnetic head built in the magnetic disk device is used.

As shown in FIG. 4, this tunnel erase type composite magnetic head has a recording / reproducing core section (53) on both sides of a center core section (55) magnetically separated via a non-magnetic material (55a). each recording and reproducing gap g ₁ and erase gap g ₂ butt erase core portion (54) on the front gap side,
g ₂ is formed comprising the recording and reproducing head section (51) and the erase head section (52) (so-called front core (50)) is configured, the rear end side in the elongated back core of the front core (50) (58) is fixed using mechanical means such as a leaf spring (not shown) to form a closed magnetic path for each head. Also, the legs (53) of the cores (53), (54)
Drive coils (56) and (57) are fitted into (a) and (54a), respectively.

Thus, the magnetic head has a configuration for erasing both sides of the recorded signal in the recording and reproducing gap g ₁ in the erasing gap g _2, g _2, for example, the recording and reproducing head unit (5
Even if 1) is off-track (positional deviation) from the recording track, the interval between the recorded signals is guaranteed, and good recording / reproducing characteristics can be obtained.

[Problems to be solved by the invention]

In recent years, in the field of magnetic recording, high-density recording of information signals has been promoted. In response to this, in the above-described composite magnetic head, each magnetic gap g _{1 is} required to guarantee erasing timing at the time of driving. , it is necessary to reduce the distance a between g _2, i.e. the center core portion width (55). Therefore, the joining area between the back core (58) and the center core (55) is reduced, and this joining becomes unstable, causing deterioration of electromagnetic conversion characteristics.

Under such circumstances, it is conceivable to set the d dimension of the back core (58) and the l dimension of the front core (50) large to secure the above-mentioned joint area. However, when the l dimension is increased, there is a disadvantage that the front core (50) is easily damaged when handling. Also, the number of cores (50) and (58) obtained from one operation unit is reduced, and there is a problem in productivity and material cost.

Conversely, if the l dimension of the front core (50) is set to be small to solve the above-mentioned problem, the d dimension of the back core (58) must be reduced due to structural restrictions, and a sufficient bonding area can be obtained. I will not be able to.

Therefore, the present invention has been proposed in order to solve the above-mentioned drawbacks, and has made the joining between the front core and the back core stable and strong, has good electromagnetic conversion characteristics, and has excellent productivity. It is an object to provide a composite magnetic head.

[Means for solving the problem]

In order to achieve the above object, a composite magnetic head according to the present invention has a recording / reproducing head unit and an erasing unit in which a recording / reproducing core unit and an erasing core unit are joined to a center core unit which is magnetically separated via a nonmagnetic material. A front core constituting a head portion, and a back core formed by integrating a pair of core members formed in a substantially U-shape corresponding to the respective head portions into a substantially E-shape via a non-magnetic material. A closed magnetic path for the recording / reproducing head and the erasing head is formed by arranging the back core on the rear end side of the front core so that the legs of each core overlap inside the drive coil. Is what you do.

[Action]

As described above, the back core joined to the rear end side of the front core is formed of a pair of core members each formed in a substantially U-shape corresponding to the recording / reproducing head section and the erasing head section, and the leg thereof. Since the portions are overlapped in the drive coil, the bonding area of these cores is secured, and the bonding is stable and strong. Further, since the core member is integrated via a non-magnetic material, crosstalk between the heads is reduced.

〔Example〕

Hereinafter, an embodiment of a composite magnetic head to which the present invention is applied will be described with reference to the drawings.

In the composite magnetic head of this embodiment, as shown in FIG. 1, a recording / reproducing core section (13) and an erasing core section (14) are provided on both sides of a center core section (15) with gap spacers (not shown). butt through not), the recording and reproducing head unit (11) and the front core formed by forming an erase head portion (12) having an erase magnetic gap G _2, G ₂ having a recording reproducing magnetic gap G ₁ (10 ) And these heads (11),
A back core (20) in which a pair of core members (21) and (22) formed in a substantially U-shape corresponding to (12) are joined through a non-magnetic material (23) to form a substantially E-shape. Are superimposed, and drive coils (25) and (26) are inserted into the cores (13) and (14). The back core (20) is fixed to the front core (1) by a leaf spring or the like (not shown).
0).

Then, for example, the recording gap G ₁ is slightly larger than the predetermined track width, and so that the distance between the magnetic erase gap G ₂ provided behind either side of the gap G _1, G ₂ becomes a predetermined track width The magnetic disk contact surface (1
It is regulated by the track width regulating grooves (17) and (18) provided in 6). In addition, the center core (15)
Has a structure in which a pair of magnetic cores (15a) and (15b) are joined via a non-magnetic material (15c) while the heads (11) and (12) do not magnetically interfere with each other. Has become.

That is, the recording and reproducing head unit (11) and the erase head section (12) is independently a closed magnetic path is formed, the recording signals in the recording and reproducing gap G ₁ while rotating the magnetic disk in a first in the X-direction Immediately after the gap G ₂ , G ₂
To erase. Therefore, a guard band is formed between signals recorded on the magnetic disk, so that good recording / reproducing characteristics can be obtained even when off-track occurs.

As described above, the back core (20) has a substantially U-shaped core member (13) corresponding to each of the head portions (11) and (12).
(14), the gap G ₁ , G ₂ interval, that is, the width A of the center core (15) is increased with the increase in recording density.
Can be secured sufficiently without increasing the D dimension of the back core (20) or the L dimension of the front core (10). Therefore, the bonding is stable and strong, and the electromagnetic conversion characteristics can be improved. The front core (1
Since it is not necessary to increase the length of (0), the mechanical strength of the core (10) is ensured, and the core (10) is less likely to be damaged during work. Rather, even if the L dimension is set smaller than before, a sufficient joining area can be secured, so that the core (10) obtained from one working unit can be obtained.
Is increased, which is also advantageous in terms of material cost and productivity. Further, the magnetic path length can be shortened due to the narrowing of the L dimension, and the magnetic efficiency can be further improved.

In addition, the back core (20) includes the respective head portions (11),
A pair of substantially U-shaped core members (21) corresponding to (12),
Since (22) is joined and integrated via a non-magnetic material (23), the heads (11) and (12) are magnetically separated and crosstalk between the heads (11) and (12) is achieved. Is eliminated. The bonding method may be any method as long as the core members (21) and (22) are magnetically separated from each other, such as glass fusion or bonding using an adhesive such as epoxy.

As described above, in the present invention, the back core (20) has a substantially E-shape, so that the front core (10) and the back core (20) are located inside the drive coils (25) and (26). It can be joined and fixed by overlapping. As a fixing method, for example, (1) As shown in FIG. 2, the erasing core portion (14) and the core member (22) are overlapped inside the bobbin (26a), and a pressing spring (30) such as a leaf spring is used. ) Is press-fitted into a gap between the core member (22) and the bobbin (26a) (or a gap between the erasing core portion (14) and the bobbin (26a)).

(2) As shown in FIG. 3, a projection (26b) having a triangular pyramid shape or a flat plate shape is provided on the inner wall of the bobbin (26a) in advance.
A method of pressing and fixing the core member (22) to the erasing core portion (14) by the elasticity of the projection (26b).

And the like. Thus, the drive coils (25), (2
By joining and fixing the cores (10) and (20) inside 6), the magnetic efficiency can be further improved, the external noise resistance can be improved, and good recording / reproducing characteristics can be obtained.

[Effect of the invention]

As is clear from the above description, in the composite magnetic head of the present invention, a pair of core members in which the back core is formed in a substantially Since it has a substantially E-shape via the material, a sufficient bonding area between the front core and the back core is ensured. Therefore, this bonding becomes stable and strong, and the electromagnetic conversion characteristics are greatly improved.

As a result, even when the gap between the recording / reproducing gap and the erasing gap, that is, the width of the center core portion becomes narrower in response to the increase in the recording density, the bonding between the front core and the back core becomes stable and strong. A composite magnetic head having excellent electromagnetic conversion characteristics can be provided.

In addition, since it is not necessary to increase the length of the front core, breakage during operation is reduced and the yield can be improved, and a large number of cores can be obtained from one operation unit, which is advantageous in terms of material cost and productivity.

At the same time, it becomes possible to join the front core and the back core inside the coil, thereby improving external noise resistance and magnetic efficiency.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of a composite magnetic head to which the present invention is applied, and FIGS. 2 and 3 are sectional views showing a fixed state of a front core and a back core, respectively. FIG. 4 is a perspective view showing a conventional composite magnetic head. 10: Front core 11: Recording / reproducing head unit 12: Erase head unit 13: Recording / reproducing core unit 14: Erase core unit 15: Center core unit 15c: Non-magnetic material 20: Back core 21, 22 core member 23 non-magnetic material

Claims (1)

(57) [Scope of request for utility model registration] A front core comprising a recording / reproducing head unit and an erasing head unit, wherein a recording / reproducing core unit and an erasing core unit are joined to a center core unit which is magnetically separated via a non-magnetic material; A back core is formed by integrating a pair of core members formed in a substantially U-shape corresponding to each head portion into a substantially E-shape via a non-magnetic material. A composite magnetic head in which a back magnetic core of a read / write head and an erase head is formed by arranging a back core so that legs of each core overlap inside a drive coil.