JPH08194910A - Magnetic head - Google Patents

Abstract

PURPOSE: To obtain a magnetic head which has a small inductance and shows little feed-through by a method wherein the area of a rear side hole part which is formed in a surface opposite to a magnetic gap side is larger than the area of a surface side hole part which is formed in a surface on a magnetic gap side. CONSTITUTION: Two tapered surfaces 42g and 42g which increase the thickness of a tape slider 42 in accordance with the withdrawal from hole parts 42a and 42b are provided. Therefore, the surfaces of the tape slider 42 of which the hole parts 42a and 42b are composed are close to magnetic cores 2c and 2d on a magnetic gap 2a side and, further, the thickness of the tape slider 42 is L1. However, on the side opposite to the magnetic gap 2a side, the surfaces of the tape slider 42 of which the hole parts 42a and 42b are composed are the tapered surfaces 42g and 42g which withdraw gradually from the magnetic cores 2c and 2d and the hole parts 42a and 42b are gradually widened. As a result, the area M × N2 of the rear side hole part formed on the side opposite to the gap 2a side is larger than the area M × N1 of the surface side hole part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head.
More specifically, the present invention relates to an improvement of a magnetic head that can reduce the inductance of the magnetic head and can reduce feedthrough (magnetic noise due to a phenomenon of direct entry of recording magnetic flux into a reproducing core).

[0002]

2. Description of the Related Art U.S. Pat. No. 5,055,959
There is disclosed a magnetic head capable of minimizing the spacing loss between the magnetic gap and the tape sliding on the gap. Then, the applicant of the present invention has devised a magnetic head which is an improved embodiment of this technique.

As shown in FIG. 11 showing the magnetic gap and its periphery, this magnetic head is formed by a rod-shaped slider first member 42w made of ferrite and a notch 42e of a slider second member 42y also made of ferrite. A pair of magnetic core pieces 2c and 2d made of ferrite forming the magnetic gap 2a are inserted into the formed hole 42a, and the gap is filled with the non-magnetic material 12.

Here, the height H of the slider protrusion 42d of the slider second member 42y is set to be the same height surface as the core protrusions 2c1 and 2d1 of the magnetic core pieces 2c and 2d. The non-magnetic protrusions 12a and 12b, which are arranged on both sides of the core protrusions 2c1 and 2d1 in the tape width direction and have a trapezoidal shape, have the same height H as the slider protrusion 42d and the core protrusions 2c1 and 2d1. Is set to. On the other hand, the width W2 of the slider protrusion 42d is equal to the core protrusions 2c1 and 2d1.
The width is narrower than the total width W1. The non-magnetic protrusions 12a and 12b have a width W2 in the vicinity of the slider protrusion 42d, and become wider as they approach the core protrusions 2c1 and 2d1, and the portions in contact with the core protrusions 2c1 and 2d1 have the width W1. It is getting wider.

In this way, the slider protrusion 42d, the core protrusions 2c1 and 2d1 and the non-magnetic protrusions 12a and 12b are formed.
However, the tape sliding surface is formed. The wear characteristics of the non-magnetic material 12 are set to be substantially equal to those of the slider protrusion 42d and the core protrusions 2c1 and 2d1.

The wear condition when the magnetic head having such a structure is incorporated in a magnetic recording / reproducing apparatus and the magnetic tape is driven in the direction of arrow c will be described.

The tape sliding surface is initially (t = 0), as shown in FIG.
As shown in FIG. However, when the magnetic recording / reproducing apparatus operates and the tape slides on the tape sliding surface in the direction of arrow C, abrasion begins to occur. At this time, the pressure per unit area of the tape in the core protrusions 2c1 and 2d1 that form the tape sliding surface is smaller than that in the slider protrusion 42d that is another tape sliding surface. This is the width W1 obtained by adding the respective lengths of the core protrusions 2c1 and 2d1.
Is larger than the width W2 of the slider protrusion 42d. For this reason, the slider protrusion 42d is heavily worn, and the core protrusions 2c1 and 2d1 are in a state of little wear. As shown in FIG. 12, the core protrusions 2c1 and 2d1 are gradually worn.
2d1 is protruding (t = ta). The non-magnetic protrusions 12a and 12b are worn so as to connect the slider protrusion 42d and the core protrusions 2c1 and 2d1. The non-magnetic protrusions 12a and 12b are connected to the both protrusions 42d, 2c1 and 2c.
Even if a material having a higher wear resistance than d1 is used, the degree of the depression is slightly increased, but the wear in the form of joining is the same. This is because the widths of the non-magnetic convex portions 12a and 12b are formed to be relatively wide. In this way,
The convex portions 2c1 and 2d1 of the core gradually project. When the protrusion has a certain height or more, the friction with the tape becomes larger than that of other portions, and the protrusion is scraped. As a result, a protrusion having a constant height is generated in the gap 2a and its vicinity. FIG. 12 shows the state of the height of the tape sliding surface after a certain period of time (t = tx). In this way, a magnetic recording / reproducing apparatus with a small spacing loss between the tape and the magnetic gap 2a and a good tape touch is constructed.

In this magnetic head, in order to make the wear characteristics of the tape sliding surface the same and to prevent feed-through (magnetic noise due to the phenomenon that the magnetic flux of the recording magnetic head jumps directly into the core of the reproducing magnetic head). In addition, the magnetic core pieces 2c and 2d and the tape slider 42 are made of ferrite of the same material system. For this reason, if the two are directly joined, the inductance of the magnetic head rises,
There is a problem that the number of coil turns cannot be increased and the head sensitivity decreases. However, in this magnetic head, since it is fixed to the tape slider 42 via the non-magnetic material 12, magnetic coupling is weak and the inductance of the magnetic head does not increase.

[0009]

However, although this magnetic head has such an advantage, it still has the tape slider 4 as compared with the conventional general magnetic head.
Since the ferrite No. 2 is close to the magnetic core pieces 2c and 2d, the inductance of the magnetic head increases to some extent, and there is a problem that the number of coil turns of the magnetic head cannot be increased. On the other hand, if the tape slider 42 having the role of a shield is separated from the magnetic core pieces 2c and 2d, the inductance of the magnetic head decreases, but the feedthrough deteriorates. Such a relationship is as shown in FIG. 10, which shows the relationship between the distance L between the tape slider 42 and the magnetic core pieces 2c and 2d and the inductance of the magnetic head and the relationship between the distance L and the feedthrough. The longer the distance L, the lower the inductance but the more feedthrough. On the other hand, when the distance L is short, the feedthrough is small, but the inductance increases.

An object of the present invention is to provide a magnetic head which can reduce the inductance of the magnetic head and can reduce the feedthrough.

[0011]

In order to achieve the above object, the invention of claim 1 provides a pair of magnetic core pieces forming a magnetic gap at the abutting surfaces, and a tape slider supporting the magnetic core pieces so as to surround them. A magnetic head having a magnetic core piece put in a hole of the tape slider and joined to each other via a non-magnetic material surrounding the magnetic core piece, the magnetic core piece being formed on the surface opposite to the magnetic gap side. The hole area on the back surface side is larger than the hole area on the front surface side formed on the surface on the magnetic gap side. Here, it is preferable that the tape slider is made of the same material as the magnetic core piece or the same material having the same composition but different crystal structures.

According to a second aspect of the present invention, in the magnetic head according to the first aspect, at least a part of the periphery of the hole of the tape slider is thinner than a thickness other than the periphery of the hole.

Further, according to the invention of claim 3, in the magnetic head according to claim 1, there is provided at least two taper surfaces which gradually increase the thickness of the tape slider as the distance from the hole of the tape slider increases.

[0014]

Therefore, in the magnetic head constructed as described above, a pair of magnetic core pieces are butted to form a magnetic gap, and a tape slider made of the same material or of the same material as the magnetic core pieces is formed through a non-magnetic material. By fixing the pair of magnetic core pieces to the magnetic tape, the magnetic coupling between the magnetic core pieces and the tape slider is weakened, and the inductance of the magnetic head can be suppressed to some extent. Moreover, since the hole area on the back side formed on the surface opposite to the magnetic gap side is made larger than the hole area on the front side formed on the surface on the magnetic gap side, , The magnetic core piece and the tape slider are considerably close to each other, but on the surface opposite to the magnetic gap side, the two are separated from each other.

Further, at least a part of the thickness of the tape slider around the hole is made thinner than the thickness of the part other than the hole, or the thickness of the tape slider is gradually increased as the distance from the hole of the tape slider increases. Since it has a taper surface, a part of the surface of the hole of the tape slider facing the magnetic core piece is closer to the magnetic core piece on the magnetic gap side.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to the embodiments shown in the drawings. The members indicated by the same reference numerals as those in FIG. 11 are the same members as those in FIG. 11.

1 and 2 show the overall structure of the magnetic head of the present invention seen from the front and the bottom. This magnetic head is
The recording / reproducing head is composed of three magnetic head groups 1, 2 and 3 each having two magnetic gaps and magnetic core pieces. The main structure of the first magnetic head set 1 is composed of a tape slider 41 and two magnetic head chips forming two recording magnetic gaps 1a and 1b arranged in the holes 41a and 41b, respectively. . The main configurations of the second magnetic head set 2 and the third magnetic head set 3 are also
It is constructed similarly to the first magnetic head set 1. That is, the main structure of the second magnetic head set 2 is the tape slider 42.
And two magnetic head chips constituting two reproducing magnetic gaps 2a and 2b, one of which is arranged in each of the holes 42a and 42b. The third magnetic head group 3 is mainly composed of a tape slider. 43 and its hole 43a,
It is composed of two magnetic head chips forming two recording magnetic gaps 3a and 3b, one of which is arranged in the magnetic recording medium 43b.

A space member 51 is provided between the tape sliders 41 and 42, and the tape sliders 42 and 43 are provided.
A space member 52 is arranged between the two. Further, between the tape slider 41 and the case 7 and between the tape slider 43 and the case 7, outriggers 61 and 62 which are members for stably running the magnetic tape are arranged. Then, the three tape sliders 41, 42, 43 and the like are fixed to the head plate 8 while being fitted in the case 7. The magnetic head thus configured is incorporated in a magnetic recording / reproducing apparatus (not shown), and is positioned and fixed by the positioning pin 9 and the mounting holes 81, 81 formed in the head plate 8. The cross machine screws 10, 10 visible on the lower surface of the head plate 8 are used as a reference for positioning adjustment when assembling the magnetic head. Specifically, the image is captured by a camera and used.

3 to 7, three magnetic head groups 1,
The detailed configuration of the second magnetic head set 2 out of 2 and 3 is shown. Since the other magnetic head sets 1 and 3 have the same configuration as the second magnetic head set 2, the description thereof will be omitted.

In order to reduce field through, the tape slider 42 of the second magnetic head group 2 has the same material as the magnetic core piece or a material of the same material having the same composition but different crystal structure, for example, oxidation of ferrite or the like. It is composed of a rod-shaped slider first member 42w made of a magnetic material and a rod-shaped slider second member 42y made of an oxide magnetic material such as ferrite. Both members 4
Both 2w and 42y are annealed in a high temperature atmosphere of 600 to 800 ° C. to suppress an increase in magnetic inductance, and their magnetic characteristics are deteriorated, but the magnetic characteristics are not necessarily deteriorated. The second slider member 42y is provided with notches 42e and 42f for forming the holes 42a and 42b, and a convex slider protrusion 42d that slides on the tape.

The shapes of the holes 42a and 42b are as follows. That is, the tape slider 42 has a hole 42
Two taper surfaces 42g, 42g that gradually increase the thickness of the tape slider 42 as the distance from a, 42b increases.
Are provided respectively. That is, the holes 42a and 42b
On the magnetic gap 2a side, the surface of the tape slider 42 that forms the area is close to the magnetic core pieces 2c and 2d and has a thickness L1. However, on the side opposite to the magnetic gap 2a, the surface of the tape slider 42 has a tapered surface 42g, which gradually moves away from the magnetic core pieces 2c, 2d.
42g, and the holes 42a and 42b gradually widen. As a result, the hole area (M × N2) on the back surface formed on the surface of the tape slider 42 opposite to the magnetic gap 2a side is larger than the hole area (M × N1) on the front surface side. Therefore, the thickness of the tape slider 42 becomes L2 at the widest portion and is considerably thicker than L1.

The hole portions 42a, 42b are provided with a pair of magnetic core pieces 2c, 2d which form the magnetic gaps 2a, 2b at their abutting surfaces. In addition,
A metal magnetic film such as sendust is deposited on either one of the butting surfaces of the magnetic core pieces 2c and 2d. Also,
Each of the magnetic core pieces 2c and 2d is made of a magnetic material of the same material or of the same material as the slider first and second members 42w and 42y, and a coil (not shown) is wound around each of them.
A magnetic core piece 2e made of an oxide magnetic material such as ferrite is joined to the magnetic core pieces 2c and 2d so as to form a magnetic loop. These magnetic core pieces 2
c, 2d, 2e and magnetic head chips 21, 22
The magnetic head chips 21 and 22 are welded and supported by the slider first member 42w and the slider second member 42y via the non-magnetic material 12 such as glass.

This welding support is, as shown in FIG.
The two magnetic head chips 21 and 22 put in the holes 42a and 42b of the tape slider 42 are held in that state by the jig 11 and bonded by the melted non-magnetic material 12. That is, the molten non-magnetic material 12 is transferred to the tape slider 42 and the magnetic head chip 21,
Both are welded by putting them in a gap between 22 and cooling and solidifying. At this time, the non-magnetic material 12 is once placed on the two taper surfaces 42g, 42g of the tape slider 42 and then melted, and enters the gap between the tape slider 42 and the magnetic head chips 21, 22 to cause the tape slider 4 to move.
2 and the magnetic head chips 21 and 22 are fixed. For this reason, the non-magnetic material 12 does not roll to somewhere during this fixing.

The tape slider 42 has a non-magnetic material 1
Two magnetic head chips 2 welded and supported via 2
A shield case 2h is provided around the coils 1 and 22 so as to surround them, and a resin material is injected into the space inside the shield case 2h to seal the two magnetic head chips 21 and 22. are doing. The terminal portion 2g having a plurality of terminals for electrically connecting the outside and the coils or the like of the magnetic head chips 21 and 22 has a magnetic gap 2.
It projects to the side opposite to a and 2b.

Next, the peripheral structure of the magnetic gap 2a of the second magnetic head set 2 thus constructed will be described with reference to FIGS. 5, 7 and 11. Notch 42 of slider first member 42w and slider second member 42y
A pair of magnetic core pieces 2 is formed in the hole 42a formed by
c and 2d are put therein, and the gap between them is filled with the non-magnetic material 12. Thus, the appearance of the present invention is the same as that of FIG.

The height H of the slider protrusion 42d of the slider second member 42y is set to be the same height as the core protrusions 2c1 and 2d1 of the magnetic core pieces 2c and 2d. Also, the slider protrusion 42d and the magnetic core piece 2
The height of the non-magnetic material 12 filled between the core convex portions 2c1 and 2d1 of c and 2d is also formed to be the same height H as the both convex portions. On the other hand, the width W2 of the slider protrusion 42d
Is smaller than the width W1 obtained by adding the respective lengths of the core protrusions 2c1 and 2d1.

Here, the non-magnetic convex portions 12a and 12b, which are set to the same height as the both convex portions of the non-magnetic material 12, are formed in a trapezoidal shape. That is, the width of the vicinity of the slider convex portion 42d is W2, and the width becomes wider as it approaches the core convex portions 2c1 and 2d1, and the portion in contact with the core convex portions 2c1 and 2d1 has the width W2.
1 is the widest.

Thus, the slider protrusion 42d, the core protrusions 2c1 and 2d1, and the non-magnetic protrusions 12a and 12b form a tape sliding surface. The wear characteristics of the non-magnetic material 12 are as follows.
It is set to be approximately equal to c1 and 2d1.

The wear condition of the magnetic head constructed as described above is the same as that shown in FIG. 12, and the spacing loss between the tape and the magnetic gaps 1a, ... Become the head. On the other hand, the inductance and feedthrough of the magnetic head are shown in FIG.
As shown in, the feedthrough is slightly increased, but the inductance is greatly reduced. This is a phenomenon in which the feedthrough occurs in the space on the surface side where the magnetic gaps 2a and 2b are formed, so the surface side hole area formed on the surface of the tape slider 42 on the magnetic gap 2a and 2b side can be changed. Without it, the feedthrough is almost unchanged. On the other hand, the inductance of the magnetic head is
The magnetic core piece 2c of the hole 42a of the tape slider 42,
Since this is a phenomenon in which the entire surface facing 2d is involved, the back surface side hole area formed on the surface of the tape slider 42 opposite to the magnetic gaps 2a, 2b side becomes large, and as a result, This is because the inductance becomes correspondingly smaller when the part is moved away from the magnetic core pieces 2c and 2d.

As a result, as can be seen from FIG. 10, it is possible to reduce the feedthrough and the inductance by reducing the distance L.

The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the embodiment of FIG. 7, the tapered surface 4
Although there are two 2g, as shown in FIG. 8, a total of four tapered surfaces 42g, ..., 42g may be provided in four directions. Further, as shown in FIG. 9A, the tapered surface 4
2 g may be formed from the surface of the tape slider 42, or a step may be provided on the surface of the tape slider 42 facing the magnetic head chip 21 as shown in FIG. 9B. Further, as shown in FIG. 9C, the hole 42a has a rectangular parallelepiped shape, while the portion of the magnetic head chip 21 on the side opposite to the magnetic gap side is narrowed to reduce the tape slider 42 and the magnetic head chip. The distance to 21 may be made longer on the side opposite to the magnetic gap.

The above-described embodiment is an example of a magnetic recording / reproducing apparatus in which the tape side moves, but the magnetic head of the present invention is
It can also be used in a system driven by a magnetic head. Also,
As the tape, in addition to a normal magnetic tape, a magnetic medium such as a passbook or a credit card can be used. Furthermore, although the tape slider 42 is composed of two members, a slider first member 42w and a slider second member 42y, it may be a single member or the slider protrusion 42d may be a separate member. At that time, the slider protrusion 42d and the magnetic core piece 2c,
It is also possible that only 2d is made of the same material, and the other members of the tape slider 42 are made of a cheap material such as brass or iron.

Further, in the above-mentioned embodiment, the slider protrusion 4
By forming 2d, etc., the tape and the magnetic gap 1a, ..., 3b
The magnetic head has a small spacing loss and a good tape touch, but it is not applied only to such a magnetic head. That is, a pair of magnetic core pieces that form a magnetic gap at the abutting surfaces are put in the holes of the tape slider that is made of the same material or the same material system as the magnetic core pieces and that supports the magnetic core pieces, and surrounds the magnetic core pieces. It is generally applicable to a magnetic head in which both are joined via a non-magnetic material surrounding the.

[0034]

As is apparent from the above description, in the present invention, the hole area on the back surface side formed on the surface opposite to the magnetic gap side is equal to that on the front surface side formed on the surface on the magnetic gap side. Since it is wider than the hole area, the magnetic core piece and the tape slider are considerably close to each other on the surface on the magnetic gap side, and feedthrough can be suppressed. On the other hand, on the surface opposite to the magnetic gap side, the distance between the magnetic core piece and the tape slider becomes long, and the inductance of the magnetic head can be reduced. As a result, it is possible to obtain a magnetic head having a small inductance and a small feedthrough.

In addition, the thickness of at least a part of the periphery of the hole of the tape slider is made thinner than the thickness other than the periphery of the hole, or the thickness of the tape slider is gradually increased as the distance from the hole of the tape slider increases. Since it has two tapered surfaces, it is easy to process, and it is possible to easily obtain a magnetic head having a small inductance and a small feedthrough.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a magnetic head of the present invention as viewed from the front.

FIG. 2 is an overall configuration diagram of a magnetic head of the present invention viewed from below.

FIG. 3 is a front view of a second magnetic head set of the three magnetic head sets constituting the magnetic head of the present invention.

FIG. 4 is a side view of the second magnetic head set as seen from the arrow IV in FIG.

5A and 5B are a side view and a partially enlarged view of the second magnetic head set as seen from the arrow V in FIG.

FIG. 6 is an explanatory diagram of a method of welding a tape slider and a magnetic head chip.

FIG. 7 is a detailed exploded view of the periphery of the magnetic gap of the magnetic head of the present invention.

FIG. 8 is a view showing a second embodiment of the present invention and is a view showing the periphery of the hole portion of the tape slider.

9 (A), (B), and (C) are cross-sectional views of main parts showing other different embodiments.

FIG. 10: Distance L between tape slider and magnetic core piece
3 is a graph showing the relationship between the magnetic field and the inductance of the magnetic head, and the relationship between the distance L and the feedthrough.

FIG. 11 is a configuration diagram of a magnetic head previously devised by the applicant.

12 is a graph showing a wear state of a tape sliding surface of the magnetic head shown in FIG.

[Explanation of reference numerals] 1a, 1b, 2a, 2b, 3a, 3b Magnetic gap 2c, 2d Magnetic core piece 12 Non-magnetic material 41, 42, 43 Tape slider 41a, 41b, 42a, 42b, 43a, 43b Hole portion 42g Taper surface

Claims (3)

[Claims] 1. A pair of magnetic core pieces constituting a magnetic gap at the abutting surfaces, and a tape slider supporting the magnetic core pieces so as to surround the magnetic core pieces. The magnetic core pieces are inserted into the holes of the tape slider. In a magnetic head that joins the magnetic core piece and a non-magnetic material that surrounds the periphery of the magnetic core piece, the hole area on the back surface side formed on the surface opposite to the magnetic gap side is The magnetic head is characterized in that it is made wider than the surface area of the hole formed on the surface. 2. The magnetic head according to claim 1, wherein the thickness of at least a part of the periphery of the hole of the tape slider is smaller than the thickness of the part other than the periphery of the hole. 3. The magnetic head according to claim 1, further comprising at least two taper surfaces that gradually increase the thickness of the tape slider as the distance from the hole of the tape slider increases.