JPS6028011A - Magnetic head - Google Patents

Abstract

PURPOSE:To ensure the satisfactory magnetic recording/reproducing by providing a means which functions as a short ring to an AC recording signal around a main magnetic pole for erasion. CONSTITUTION:A short ring 20 consisting of a conductor having a prescribed form is provided around tips of main magnetic poles 9a and 9b for tunnel erasion. This ring 20 transmits only a DC magnetic flux to the poles 9a and 9b and prevents the easy transmission of a high frequency magnetic flux by means of an induced current. Then the ring 20 covers a nonmagnetic guard member 3b at the tunnel erasion side, a nonmagnetic material 4b and the periphery of tips of poles 9a and 9b which are adjacent to these member 3b and the material 4b. In this case, the ring 20 is set near tips of the poles 9a and 9b in order to obtain a larger effect.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head suitable for use as a recording/reproducing head of a flexible disk device that uses, for example, a flexible disk as a magnetic recording medium.

BACKGROUND TECHNOLOGY AND PROBLEMS Figure 1 and FIG. A magnetic head as shown in FIG. 2 has been proposed.

That is, in FIGS. 1 and 2, +11 indicates a main magnetic pole for recording and reproducing which is made of a thin film of soft magnetic material and has a predetermined width at one end that faces the magnetic recording medium (2), and this main magnetic pole for recording and reproducing +11 are integrally sandwiched and joined from both sides by non-magnetic guard members (3a) and (3h) of a predetermined thickness on the opposing surface of the magnetic recording medium (2), and this non-magnetic guard member (3
A magnetic core (4a) joined to the rear of a) and (3b) and integrally sandwiching and joining this recording/reproducing main magnetic pole +ll from both sides.
and a non-magnetic material (4b).

In this case, the magnetic core (4a) provided behind the non-magnetic guard member (3a) constitutes a return path for the magnetic flux of the main magnetic pole for recording and reproducing. An auxiliary magnetic pole part (near the main magnetic pole for recording and reproduction +11 on the side of the magnetic core (48) in contact with the non-magnetic guard member (3a)) is located near the main magnetic pole for recording and reproduction (1).
5a) and a return path portion (5b) that serves as a return path for the magnetic flux of this recording/reproducing main magnetic pole 11).
6). Further, a predetermined groove portion (7) is provided on the side of the non-magnetic material (4b) that is in contact with the non-magnetic guard member (3b), and 2
A recording/reproducing winding (8) is applied to the equal groove portion (61 (main magnetic pole for recording/reproducing +1 through 71). Here, the magnetic recording medium (2) used is, for example, placed on a synthetic resin base (2a). A high-level one layer (2b) is provided, and this high-level 1t4
(2b) A two-layer medium with a perpendicular recording layer (2c) provided thereon.

In addition, (9a) and (9b) each indicate a main magnetic pole for tunnel erasing, which is made of a thin film of soft magnetic material and arranged downstream of the main magnetic pole for recording and reproducing (1), and this main magnetic pole for tunnel erasing (
9a) and (9b) are arranged at an interval smaller than the width of the recording/reproducing main magnetic pole (1). In this case, the non-magnetic guard member (3b
) and the main magnetic pole for recording/reproducing (9a) (9b) of the non-magnetic material (4b) on the opposite side to the surface to which the main magnetic pole for recording/reproducing (11) is attached, with the width of the main magnetic pole for recording/reproducing (9a) (9b) being wider than the main magnetic pole for recording/reproducing (full). This main magnetic pole for erasing (9a) (9
b) with the non-magnetic guard member (3b) and the non-magnetic material (4b)
and a non-magnetic guard member (3c) and a magnetic core (4c) joined to the rear thereof, so as to be sandwiched from both sides.

This magnetic core (4c) is the main magnetic pole for tunnel erasure (9a)
(9b) constitutes a magnetic flux return path. An auxiliary magnetic pole section near the tunnel erasing main magnetic poles (9a) (9b) in the example in which the non-magnetic guard member (3a) of this magnetic core (4a) is in contact with the tunnel erasing main magnetic poles (9a) (9b). (10a) and this main magnetic pole for tunnel erasure (9a)
A groove portion (11) is provided to separate the return path portion (10b) serving as a return path for the magnetic flux (9h). The erasing winding (12) is applied to the tunnel erasing main magnetic poles (9a) and (9b) through this groove part (11) and the groove part (7) of the non-magnetic material (4b), and the tunnel erasing main magnetic poles (9a) and (
9b), both ends in the width direction of the track once recorded are erased by a predetermined width, that is, tunnel erased so as not to pass the DC magnetic flux, thereby preventing unerased signals from being reproduced.

In such a composite head, leakage flux between magnetic poles often becomes a problem. In particular, a single magnetic pole head has a configuration close to an open magnetic path, so leakage magnetic flux is particularly large. In addition, the main magnetic pole for recording and reproduction +11, the main magnetic pole for tunnel erasing (9a) and (
9b) should be as small as possible for ease of use, so this is especially true in this case. To prevent leakage of the tunnel erase magnetic field, either wrap a cancel coil around the main magnetic pole for recording and reproducing and connect it in series with the tunnel erase winding (in this case,
It is known that the effect of leakage can be completely removed by adjusting the number of turns in the canceling coil (just to cancel) or by adjusting the current in the canceling winding to cancel. 3 and 4 schematically show how the cancellation winding is wound. Since tunnel cancellation is performed using direct current, there are no problems such as phase rotation.

On the other hand, leakage from the recording/reproducing main magnetic pole Tll to the tunnel erasing main magnetic poles (9a) and (9b) will not be a problem if a sufficiently large tunnel erasing current is applied at the same time as recording starts, but when the recording operation starts. At this time, the main magnetic poles (9a) and (9b) for tunnel erasing are located at the 10th field or the previous sector where the sector number of the own sector is written, so the expansion and contraction of the medium etc. Therefore, if a track misalignment occurs, a part of the width of the track that has already been written is erased, resulting in the inconvenience of narrowing the effective track.

To prevent this, the timing at which the tunnel erase current flows can be delayed by the time that the recording/reproducing main magnetic pole +11 runs between the tunnel erase main magnetic poles (9a) and (9b).
Then, magnetic flux leaking from the recording/reproducing main magnetic pole il+ to the tunnel erasing main magnetic poles (9a) and (9b) became a problem.

In addition, the main magnetic poles (9a) and (9b) for tunnel erasure are:
Unlike the main magnetic pole for recording and reproduction (1), since reproduction is not performed, the thickness of the magnetic pole can be increased, and the recording sensitivity is high. Therefore, until the tunnel erase current flows, the main magnetic pole for recording and reproduction (
The main magnetic pole for tunnel erasure (9
There is a risk that a) and (9b) will be excited and recording will be performed.

As a method to prevent this, a method of winding a canceling coil in the same way as tunnel cancellation may be considered. However, the recording current has a pulse waveform (square waveform), and the leakage magnetic flux does not have flat frequency characteristics, and there is also phase rotation, so although it has some effect, it is difficult to completely cancel it, especially at high frequencies. There was a problem where recording and playback was not possible.

OBJECTS OF THE INVENTION In view of the above, an object of the present invention is to provide a magnetic head capable of performing good magnetic recording and reproduction.

Summary of the Invention The magnetic head of the present invention has a main magnetic pole for recording and reproducing made of a magnetic thin film excited by an AC recording signal, and a main magnetic pole for erasing made of a magnetic thin film excited by a DC erasing signal is arranged adjacent to the magnetic head. In this magnetic head, a means for functioning as a short ring for AC recording signals is provided around the main erasing pole to enable good magnetic recording and reproduction.

EMBODIMENT OF THE INVENTION An embodiment of the magnetic head of the present invention will be described with reference to FIGS. 5 and 6.

In FIG. 5, (20) is the main magnetic pole for tunnel erasure (9
A short ring made of a conductor is provided in a predetermined shape around the tip of (a) and (9b), and the meaning of providing this short ring (20) is as follows. That is, the main magnetic poles (9a) and (9b) for tunnel erasing only need to pass the tunnel erasing signal of DC magnetic flux, and it is not necessary that the frequency characteristics are good. Since the reproduced signal is a high-frequency magnetic flux, a short ring (20) made of a conductor is provided in the main magnetic poles (9a) and (9b) for tunnel erasure in order to pass only the DC magnetic flux and make it difficult for the high-frequency magnetic flux to pass through due to induced current. It is.

FIG. 6 shows this embodiment as a whole, and the short ring (20) is provided as described above.
The figure (excluding the winding in cross section) shows a non-magnetic guard member (3b) on the tunnel erase side, a non-magnetic material (4b),
It is arranged to be adjacent to the non-magnetic guard member (3c) and the magnetic core (4c), and to wrap a predetermined length around the tips of the main magnetic poles (9a) and (9b) for tunnel erasing. This short ring (2
0) is more effective when provided near the tip of the erasing soil magnetic pole. In addition, a non-magnetic guard member (3a) and a magnetic core (
4a) and the bonding interface between the non-magnetic guard member (3C) and the magnetic core (4c) by setting an angle and retreating;
Main magnetic pole for recording/reproduction +11 and main magnetic pole for tunnel erasing (9
a) and (9b) The length of the tip is shortened without causing problems in terms of strength, thereby improving the magnetic recording and reproducing efficiency. In addition to the short ring, the main magnetic pole for tunnel erasure (
In order to cancel the leakage of erase magnetic flux from 9a) and (9b) to the main magnetic pole for recording and reproducing (1), a canceling winding is provided in the main magnetic pole for recording and reproducing (1).

Here, as shown in Figures 3 and 4, a recording/reproducing signal leakage magnetic flux canceling winding is wound around the main magnetic pole for tunnel erasure, and low frequency components are canceled by the canceling winding. Another possible method is to use a short ring to prevent high frequency components that cannot be detected. Next, the manufacturing method of this embodiment will be explained with reference to FIG.

First, the non-magnetic block (21a) with the winding groove (21a)
21) and another non-magnetic block (22) are prepared, and the grooved surface and one surface of the other block are mirror-polished. It should be durable, hard and dense. For example, non-magnetic t! L
Ferrite (Zn ferrite).

forsterite, photoceram, crystallized glass, barium titanate, calcium titanate, 81203-TI
C or 81203- TiO2 based ceramic.

Examples include ZrO2-based ceramics. Next, the mirror-finished surfaces are bonded (glass fusion, bonding with an inorganic adhesive such as water glass, or an organic adhesive such as epoxy resin). Next, cuts are made at the midpoints m1, m2, . . . between the grooves. Next, the material is ground and mirror-polished so that the thickness up to the groove becomes a predetermined thickness. Next, on the side where the main magnetic pole for tunnel erasure is to be attached, insert m<2g> to attach a special body for the shoot ring (2o) at a position that will be near the tip of the main magnetic pole when completed. The depth of this groove (23) needs to be determined so that the short ring can operate sufficiently (it is preferable to make it deeper than the skin depth of the recording signal frequency). Furthermore, although the width of the groove (23) is shown only near the tip of the magnetic pole in the figure, it may be wider than ever and may extend to near the bottom. However, if it is completely expanded to the bottom, it will be difficult to polish it in the next step to create a rough surface after applying the guiding surface, so it is better to leave the bottom part intact.

Next, conductor 11Q (24) is applied to a depth greater than 1 (23) (sputtering, vapor deposition, ion blating).

plating or a combination of two or more of these), polishing to a flat surface. Next, on the side to which no conductor was attached, there was a magnetic thin film (permalloy) that would become the main magnetic pole (1) for recording and reproduction.

(25) with a thickness of about 0.05 μl and 11 to 2 μm is applied by sputtering, vapor deposition, ion blasting, plating, etc. This thickness is determined by taking into consideration the required reproducing resolution and recording/reproducing sensitivity. Next, photoetching is performed to form stripes with a predetermined track width and pitch.

Next, on the surface to which the conductor film (24) is attached, the magnetic film (26a) (2
6b) in the same manner to add about 0.1 to 3μ. next,
Photoetching is performed in a stripe pattern with a predetermined track width and a predetermined interval. At this time, the main magnetic pole for recording and reproduction (]
) and the main magnetic poles for tunnel erasure (9a) and (9b) must be aligned so that they have a predetermined positional relationship. Also, before attaching these magnetic poles, apply 5i0 to the surface where the magnetic poles will be attached.
If a protective film such as 2+5IsN4+^1203+ZrO2 is applied to a thickness of about 0.1 to 1 μm and then a magnetic film is applied, the magnetic properties of the magnetic films (26a) (26b) are improved. In that case, before attaching the conductor film (24) for forming the short ring (20), remove the protective film of the conductor 111-1 on the part where the main magnetic pole for tunnel erasing is not attached by photoetching and remove the short ring. (20) must be formed.

Next, for example, the conductor film (24
), a conductor film (24') having approximately the same width is attached on top of the conductor film (24').

The thickness is preferably greater than the skin depth of the recording signal frequency. Furthermore, keep both sides flat! Attach films (S10215isN4+ Al2O3+ ZrO2, etc.) (27) and (28).

Next, a composite substrate of non-magnetic material (29) and ferrite (30) is made (Fig. 10) and joined from both sides (Fig. 11). Next, the sliding surface is cylindrically polished until the main pole reaches a predetermined level and cut into each head, and the recording/reproducing winding (8) and the tunnel erasing winding (12) are wound around the head. Obtain a magnetic head. Here, the tunnel erasing S wire (12) is provided with a canceling winding for canceling the erasing magnetic field leaking to the recording/reproducing main magnetic pole side. The number of turns needs to be adjusted to just cancel.

Further, if the non-magnetic block (22) on the side where the winding groove (21) is not inserted is made of a material with high electrical conductivity, the conductor film (24) is not required. Non-magnetic block (22)
This is because it replaces this conductive film. In exactly the same way, main magnetic pole 1 (i! (25) (26a ) and (26b
) and a conductor film (24) (24'), a short ring can be formed by the conductor film (24) (24') and the nonmagnetic material (22). It is not preferable to use a highly conductive core as the lower magnetic core provided with the winding groove. This is because this core is placed inside the recording/reproducing winding (8), which is undesirable and causes a large loss.

This embodiment configured as described above is used, for example, as a recording/reproducing head of a flexible disk device, and when recording on a magnetic recording medium (2), the recording/reproducing main magnetic pole +1
A recording signal is supplied to the recording and reproducing winding (8) of the main magnetic pole for recording and reproducing +11, and perpendicular magnetic recording is performed by this main magnetic pole for recording and reproducing +11. ) is supplied with an erasing current (direct current) to erase both sides of this recording track.

Therefore, when installing the magnetic recording medium (2), there may be a slight difference in time.
Even if a track shift occurs due to expansion or contraction due to changes in temperature or humidity, previous data will not be left unerased during rewriting, and accurate data can be obtained during playback.

In particular, in this embodiment, a short ring (20) is provided around the tips of the main magnetic poles (9a) and (9b) for tunnel erasure, so that the main magnetic poles (9a) and (9b) for tunnel erasure Only direct current magnetic flux passes through, and high-frequency magnetic flux is difficult to pass through due to induced current, so leakage of recording signals (high-frequency magnetic field) from the main magnetic pole for recording and reproduction (+L) to the main magnetic poles for tunnel erasure (9a) and (9b) is reduced. be done.

As described above, according to this embodiment, the short ring (20) is connected to the main magnetic poles (9a) and (9b) for tunnel erasing.
), so that the main magnetic poles for recording and reproducing +11 are connected to the main magnetic poles for tunnel erasing (9a) and (9).
Magnetic flux leakage to b) can be reduced. Therefore, rewriting due to magnetic flux as a recording signal leaking to the main magnetic poles (9a) and (9b) for tunnel erasing can be prevented, and there is an advantage that good magnetic recording and reproduction can be performed.

Moreover, FIG. 12 shows another embodiment of the present invention.

In FIG. 12, parts corresponding to those in FIG. 6 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 12, (31a), (31b) and (31c) are respectively above the tunnel cancellation winding;
A conductor film provided at a predetermined position between the nonmagnetic material (4b) and the magnetic core (4c) and the nonmagnetic guard members (3b) and (3c) is shown, and the conductor films (31a) and (31b)
And on the upper layer of (31c), as shown in FIG.
1t! (32a), (32b) and (32c) are provided. Also, (33).

(34) is glass, and (35) is a protective shield for the main magnetic pole for tunnel erasure.

Next, the manufacturing method of this embodiment will be explained with reference to FIGS. 14 and 15.

First, as shown in Fig. 14, prepare a non-magnetic block (36), and groove (37) for attaching a conductive film to the side of the non-magnetic block (36) where the winding groove will be inserted (depth of several to several 1
04m) and apply a conductive film (38) thicker than the depth of 'a (37) (by sputtering, vapor deposition, ion blating, plating, or a combination of two or more of these) and polish it flat. Next, the winding groove (39) is inserted, and then the protective film (40) (S1021 Si3
N+ + 81203 t ZrO2 etc.) from 1 to 5
/l Add about I11. Next, the other non-magnetic blocks (21) and (22) are joined and cut in the same manner as shown in Fig. 9, and the cut surfaces are polished to a mirror finish so that the core thickness of the winding part becomes the specified thickness. , a conductor film (38) is attached to the tip of one of the winding cores. Then, the main magnetic pole films (25), <26a) and (26b) are made in the same manner as in FIG. 9, with this side becoming the main pole side for tunnel erasure.
) and short ring conductor <2c> and protective WL film (3
5) A weight-retaining film (41) is attached. Effectively the 9th
A central block is created in which means for functioning as a short ring, which functions in the same way as shown in the figure, is provided on the main magnetic pole side for tunnel erasing. Next, as shown in Fig. 15, for the non-magnetic/ferrite composite block on the tunnel erase side, first prepare a non-magnetic material block (42) and a ferrite block (43), and first prepare the - side of the ferrite block (43). Make it a mirror surface and attach conductor 1 (i+ (44)) on it.Winding groove (45)
Remove the conductive film (44) by photo-etching the area where the 100% conductive layer will be inserted, and then remove the conductive film (44) by photo-etching the area slightly wider than that.
Add (4B) to a thickness of about 1 to 5 μm. It is also possible to insert the winding groove (45) with the conductor film (44) still attached, but in this case, a part of the conductor film (near the groove) may peel off when making the groove, so do not etch it. It's better to be there. next,
Non-magnetic material block (42) and ferrite block (43)
), then cut and mirror-polish the cut surfaces. Next, on the main magnetic pole side for recording and reproduction of the central block made earlier,
If the same composite block as shown in the figure without the conductive film is joined to the block with the conductive film (44) made as shown in Fig. 15 on the tunnel erasing side and made into a head in the same manner as in the conventional method, this example is obtained. A magnetic head is made. In this example, the tunnel erase side is the tunnel erase main pole (9a) (9b)
In addition to the structure in which a short ring (24') is attached to the tunnel erase side, a conductor film is attached to the tip of the magnetic core on the tunnel erase side, which makes it difficult for high frequency magnetic flux to pass through due to eddy current, and allows leakage magnetic flux of recording signals to pass through. It is easy to understand that since the structure is made more difficult, the same effects as in the example shown in FIG. 5 described above can be obtained.

Further, FIG. 16 shows another embodiment of the present invention. In FIG. 16, parts corresponding to those in FIGS. 1 and 6 are given the same reference numerals, and detailed explanation thereof will be omitted.

This example has two main magnetic poles (9a) and (9b) for tunnel erasure.
The excitation direction is reversed. 21 as a recording medium
By using the magnetic recording medium (2) as the iii medium, the Hi-Mu 1m (2b) can also have a structure in which a closed magnetic path is formed through the two main magnetic poles for tunnel erasure (9a) (9b) as part of the magnetic path. It is characterized by low leakage magnetic flux and high efficiency. This main magnetic pole for tunnel erasure (9a)
A short ring (20) is formed near the tip of (9b). The manufacturing method of this example will be described with reference to FIG. 17. First, we will discuss how to make the main magnetic pole side for tunnel erasure. First, ferrite plate (
A V groove (50a) is placed in 50) and filled with glass. ■
A part of the bottom of the groove (50a) is cut at a plane n where the width (50b) of the cut glass is approximately equal to the distance between the main magnetic poles (9a) and (9b) for tunnel erasing, and mirror polished. Non-magnetic plate (51
) is polished to a mirror surface and a conductor 1it (52) is placed on it to a thickness of several to several 1.0. Add c+m. Furthermore, a protective film (53) is applied thereon. The conductive film (52) becomes part of the short ring. Join these two blocks, cut diagonally as shown by the dotted line p, and cut them into squares with a V groove (50 mm).
A shallower groove (54) is placed on the a) side to serve as the winding groove. Next, the side of the cut surface where the ferrite is wider is mirror-polished, and the main magnetic pole for tunnel erasure (9a) is placed on that side.
9b) Magnetic glands (permalloy).

Sendust, magnetic amorphous film, etc.) (55a) (55
b) is applied to a thickness of 0.1 to 3 μm by vapor deposition, sputtering, ion blating, plating, etc., and formed into a predetermined shape by photoetching. Next, use a method such as the lift-off method on top of this,
A conductive film (56) is attached to form a short ring between the two ends of the previously attached conductive film (52). Although this conductor film has a band shape in the figure, it may cover the entire ferrite layer below this. This is more effective in preventing crosstalk from the recording winding. This thickness is preferably thicker than the skin depth at the recording frequency. Historically, the front surface is almost flat with a protective film and pillow material (57)
Add (5102, 5isN4.81203,
Zr (h etc.).

On the other hand, a composite part of a ferrite core (58) serving as a winding part and a non-magnetic material (59) provided with a winding groove (59a) is made and joined. Next, the main magnetic pole for recording and reproducing (Tl) and the main magnetic pole for tunnel erasing (9a) (9b
) to separate the winding (8) of the main magnetic pole +11 for recording and reproducing and the tunnel erase winding (1
2) Insert a groove (61) for passage.

Next, a main magnetic pole film for recording/reproduction (25) and a block with a protective film on the ferrite/nonmagnetic composite substrate (62) (
62) and join these two blocks.

This example is completed by cylindrical polishing of the sliding surface, cutting into each head, and winding. In this example, a conductor film (52) is attached to the front surface of the magnetic core (50) on the magnetic recording medium (2) side of the main magnetic poles (9a) and (9b) for tunnel erasure, and the main magnetic pole (9a) for tunnel erase (9b) is formed with a short ring (20), so the recording winding (8)
Since the leakage magnetic flux from the is of high frequency, it is very difficult for the tunnel erase magnetic pole to pass through.
It is easy to understand that the leakage to 9a) and (9b) can be reduced and the same effects as the above-mentioned side can be obtained.

In addition, in the example shown in Fig. 16, the conductor film (52) is attached to the entire upper surface of the magnetic core, but it is also possible to attach the conductor film only around the main magnetic poles (9a) and (9b) for tunnel erasure. be.

Further, as shown in FIG. 18, a groove (51a) for forming a short ring by winding is provided at a predetermined position on the non-magnetic plate (51) or the ferrite plate (50).
As shown in FIG. 9, a short ring (20) made of wire may also be provided.

In addition, as shown in Fig. 20, the tunnel elimination winding (12)
Attaching the capacitor C to the tunnel eliminates the winding (1
2) can also be configured to operate as a short ring (20) for recording and reproducing signals. The capacitance of the capacitor C at this time needs to be such that the resonant frequency of the resonant circuit formed by the capacitor C and the tunnel erase winding (12) is lower than the recording signal frequency. here,
R1 is a resistor, R2 is a variable resistor, (63) is a power input terminal, (64) is a tunnel erase signal input terminal, (65)
is a transistor that becomes conductive in response to a tunnel erase signal and causes a predetermined current to flow through the winding. In this case, it is not preferable to connect the write-side transistor erase leakage magnetic flux canceling coil in series with the tunnel erase winding. This is because when connected in series, the signal core side also operates as a short ring. In this case, where it is necessary to drive separately as shown in Figure 18, the rise of the tunnel erase winding current is slow (because the LC resonance circuit C is formed), so if a tunnel erase signal that rises too quickly is input, it is canceled. Since the rise of the winding is fast, an unbalance may occur only at the time of rise and fall, which may have a negative effect. It is necessary to have a slow rise time (rise time slower than time 2, which is the reciprocal of the resonant frequency ω).

In addition, in the manufacturing process of the example in Fig. 12, the winding groove (39
) (see Figure 14) on the side where the non-magnetic block (3
6) Conductor II! (3B) was formed, but the non-magnetic block (22) joined to this non-magnetic block (36)
Conductor mirror (38) and protection S! on the side. A membrane (4o) may also be applied.

Further, the magnetic recording medium (2) is connected to the tunnel erase winding (12).
) It is also possible to make a short ring (2o) with a winding wire at the tip of the opposite surface side.

In addition, in the above example, a magnetic core (4c) on the tunnel erasing side is used to make it difficult for the signal magnetic flux to flow to the tunnel erasing magnetic pole side.
The metal magnetic material (e.g. Sendust).

It is also possible to make it difficult for the recording signal magnetic flux to flow toward the tunnel erase magnetic pole side by actively increasing the frequency loss by forming the recording signal magnetic flux from Permalloy. In this case, the structure of the head is the same, with the magnetic fIL core (4c) on the tunnel erasing side made of metal, and the magnetic core (4c) on the recording/reproducing side made of ferrite. It can be easily understood that the same effects as the example shown in FIG. 6 can be obtained in these examples as well.

Moreover, if a short ring (20) is provided and a metal magnetic core is combined, there is an advantage that even better magnetic recording and reproduction can be achieved.

The present invention also provides the above-mentioned main pole excitation type magnetic field for perpendicular recording.
・It can be applied not only to RAD but also to so-called auxiliary pole excitation type magnetic heads.

Note that the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations may be adopted without departing from the gist of the present invention.

Effects of the Invention According to the present invention, a means that functions as a short ring for AC recording signals is provided around the main magnetic pole for erasing, so that leakage magnetic flux from the main magnetic pole on the recording/reproducing side is diverted from the main magnetic pole on the tunnel erasing side. By making it difficult to pass through the main magnetic pole, it is possible to prevent erroneous rewriting due to alternating current magnetic flux as a recording signal leaking to the main magnetic pole for tunnel erasing, and there is an advantage that good magnetic recording and reproduction can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional magnetic head, FIG. 2 is a top view of the example shown in FIG. 6 is a perspective view of the example shown in FIG. 5, and FIGS. 7 and 8 are examples of the main parts of the example shown in FIG. 5, respectively. 9, 10, and 11 are manufacturing process diagrams of the example shown in FIG. 5, FIG. 12 is a sectional view showing another embodiment of the present invention, and FIG. 141121 and 15 are line diagrams showing an example of the main parts of the example, and FIG. 16 and 1
9 are perspective views showing other embodiments of the present invention, and FIG.
Figure 7A and Figure 17B are manufacturing process diagrams of the example in Figure 16;
8 is a diagram showing an example of the main part of the manufacturing process of the example shown in FIG. 19, FIG. 20 is a diagram showing another embodiment of the present invention, and FIG. 21 is a diagram showing the manufacturing process of another embodiment of the present invention. FIG. 3 is a diagram illustrating an example. tl) is a main magnetic pole for write/return, (9a) and (9b) are main magnetic poles for tunnel erase, respectively, and (20) is a short ring. Figure 1 Figure 2 Figure 4 Figure 3 Figure 4 Figure 8 Figure 8 Figure 18 Figure 20b Figure 21

Claims (1)

[Claims] A magnetic head having a main magnetic pole for recording and reproducing made of a magnetic A1 gland excited by an AC recording signal, and a main magnetic pole for erasing made of a magnetic thin film excited by a DC erasing signal arranged adjacent to each other. . A magnetic head, characterized in that means is provided around the main erasing pole to function as a short ring for the AC recording signal.