JPH0370853B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head, and more particularly to a magnetic head that slides into contact with the surface of a magnetic disk, which is a magnetic recording medium, for reproducing information from a recording path.

This type of magnetic head is included in magnetic disk devices that are widely used as external storage devices for electronic computers, microcomputers, measuring instruments, and the like.

The structure of such a magnetic head is as shown in FIGS. 1 and 2.

As shown in FIG. 1, a magnetic disk 1 that is a magnetic recording medium (a protective cover of the magnetic disk 1 is omitted and not shown for simplicity of explanation) has a disk shape with an opening 1a formed in the center. It rotates in the direction of arrow 2 by the rotation of a rotating shaft of a drive means (not shown) fitted into the opening 1a.

A magnetic head 3 is disposed on the bottom side of the magnetic disk 1, and a magnetic head 6 supported on the bottom of an arm 5 is disposed on the top side.When recording and reproducing information, a magnetic gap 4 formed on each side is disposed on the magnetic disk 1. The magnetic disk is moved onto one surface of the magnetic disk so as to come into sliding contact with the surface of the magnetic disk.

Tracks 3a formed on the surface of the magnetic disk 1 by sliding contact of the magnetic gap 4 of the magnetic head 3
and recording information on a track 6a formed by sliding contact of a magnetic gap (not shown) of the magnetic head 6;
Reproduction and erasure are performed. Tracks 3a and 6a
are not opposed to each other, but are formed with an interval of four tracks between them.

FIG. 2 shows the detailed structure of the magnetic heads 3 and 6 that are in sliding contact with the magnetic disk 1, as viewed from the direction of arrow 8 in FIG. 1 (arm 5 is omitted for clarity).

The magnetic head 6, which is placed in contact with the upper surface of the magnetic disk 1, is assembled above and below an elastic plate 9 made of copper alloy or stainless steel as a substrate, and the elastic plate 9 is connected to an arm 5 (not shown) at its end. It also serves as a support for the magnetic head. The front core halves 10a and 11a holding the spacer 12a are inserted through the elastic plate 9, and the portions protruding toward the lower surface of the elastic plate 9 are connected to the mask block 14 and the mask block 1 fixed to the elastic plate 9.
It is held in 3. A coil 15 is attached to the portions of the front core halves 10a and 11a that protrude to the upper surface side of the elastic plate 9, and the end of the coil 15 is formed on a flexible printed board 16 with one end fixed to the elastic plate 19. It is connected to the connected portion 17a by soldering.

A recess 14a is formed in a portion of the mask block 14 adjacent to the front core 11a, and the mask block 14 presses the magnetic disk 1 downward with the bottom surface of the portion excluding the recess 14a, and presses the magnetic disk 1 downward at a position opposite to the pressed portion. Since the magnetic gap 4 of the magnetic head 3 is placed in the
is formed.

On the other hand, the magnetic head 3 disposed in contact with the lower surface of the magnetic disk 1 has a front core and coil (not shown) housed in a case 3b, and a magnetic gap 4 ( (not shown in FIG. 2) is formed. Further, the left side portion of the upper surface faces a magnetic gap (not shown) of the magnetic head 6 and presses the magnetic disk 1 upward, so that a track 6a is placed on the upper surface of the magnetic disk 1.
is formed.

However, the magnetic heads 3 and 6 with the above structure
Now, when a magnetic disk drive is installed with other related equipment, the transformers and coils installed in the magnetic disk drive and related equipment generate magnetic noise, and electrostatic noise is also generated due to other factors. The noise is picked up by the front cores and coils of the magnetic heads 3 and 6.

This results in inconveniences such as malfunctions occurring during recording and reproduction by the magnetic disk device, and abnormal recording due to noise.

To prevent this, magnetic heads 3, 6
It is effective to cover and shield the front core and coil with a shielding member made of a high permeability material such as permalloy.

Conventionally, for the magnetic head 3, the case 3b itself was formed of a shielding member, or the case 3b
A shielding material is provided inside the magnetic head 6 to shield the front core and the coil, and a shielding material is provided in the arm 5 of the magnetic head 6 to protect the part of the magnetic head 6 above the elastic plate 9. shielding is being done.

However, shielding the front core halves 10a, 11a, etc. of the portions of the magnetic head 6 that protrude toward the magnetic disk 1 from the elastic plate 9 has not been done because it is technically difficult.

Therefore, the magnetic head 6 picks up magnetic noise and electrostatic noise in this unshielded portion, and the above-mentioned drawbacks have not been resolved.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a magnetic head that does not pick up magnetic noise or electrostatic noise in a magnetic disk device.

To achieve this objective, according to the invention:
A magnetic device comprising: a core holding portion; an elastic plate having an opening except for a portion bridged by the core holding portion; a core held by the core holding portion of the elastic plate; and a shield member surrounding the core. In the head, a structure is adopted in which the shield member is made of a high magnetic permeability material fixed to the core holding portion of the elastic plate.

The details of the present invention will be explained below based on the embodiments shown in the drawings. Components in each figure that correspond to those in FIGS. 1 and 2 are given the same reference numerals.

FIG. 3 shows an elastic plate 9 which is both a substrate and a support plate of the magnetic head of the present invention. Elastic plate 9
is copper alloy (Be-Cu) or SUSU material thickness 50μm
It is formed from a roughly rectangular plate, with a tongue protruding at the front and mounting holes 9a, 9b, and 9c formed at the rear for attachment to the aforementioned arms. Further, in the front part, a substantially rectangular core holding part 20 with both ends bridged is formed by punching out the periphery. Two rectangular holes 20a and 20b are formed in the front part of the core holding part 20, through which a core and a spacer, which will be described later, are inserted.
Note that the surface of the elastic plate 9 shown in the figure is the surface facing the magnetic disk.

As shown in FIG. 4, the core holding portion 2 of the elastic plate 9
A rectangular frame-shaped shield portion 21 made of a high magnetic permeability material such as permalloy is fixed along the side edge of 0 by pasting or the like. A front core, a spacer, a mask block, etc., which will be described later, are arranged in a space 21a partitioned by the shield part 21.

5A and 5B show the assembly structure of all parts of the magnetic head.

Reference numerals 10a, 10b, 11a, 11 are shown in Fig. 5A.
Those indicated by b, 18a, and 18b are front core halves, respectively, which are made of a high magnetic permeability material such as ferrite and have a substantially L-shaped plate shape. Further, the front core halves 10a and 11a are similar to each other, and the front core halves 10b and 11b are also similar to each other. Further, those indicated by reference numerals 12a, 12b, and 12c are ceramic spacers.

Front core halves 10a and 11a with spacer 12a sandwiched therebetween, and front core half 18 between them.
The front core halves 10b and 11b holding the core a are butted against each other, and magnetic gaps g and g for erasing are formed on the lower side.

On the other hand, the front core half 18a is butted against the front core half 18b, and a magnetic gap g' (not shown) for recording and reproduction is formed on the lower side. The lower sides of the front core halves 18a, 18b are held between spacers 12b, 12c.

Furthermore, a ceramic rectangular plate-shaped mask block 13 is fixed by abutting against the lower part of the front core halves 10a, 10b and the side surface of the spacer 12b.
A rectangular trapezoidal ceramic mask block 14 with a recess 14a formed in the lower part of the front core halves 11a, 11b and the side surface of the spacer 12c.
Abut and fix.

On the other hand, as shown in FIG. 5B, the rear end of the core holding part 20 on the opposite side of the surface to which the shield part 21 of the elastic plate 9 is fixed, that is, the adhesive part 1 shown by diagonal lines in the figure.
6a, the front end portion of the flexible printed board 16, on which the connecting portion 17a of the wiring portion 17 is formed, of the rectangular flexible printed board 16 having the steel-plated wiring portion 17 formed on the surface thereof, is adhered with epoxy resin or the like (as indicated by the dashed dot line in the figure). ) After this, insert the front core half 1 of the front core assembly into the hole 20a of the core holding part 20.
0b, 11b, 18a, 18b from the direction of arrow C in the figure, and insert the front core half 1 into the hole 20b.
0a, 11a and the spacer 12a, and the fourth
The assembly is fitted into the space 21a in the figure, and the upper surfaces of the mask blocks 13 and 14 are fixed to the bottom surface of the core holding section 21a.

Further, a coil 15 for generating an erasing magnetic field is fitted into the front core halves 10a, 11a and the spacer 12a protruding from the hole 20b. Then, an L-shaped back core 10 made of ferrite is fixed in contact with the upper surfaces of the front core halves 10a, 11a and the spacer 12a, and the side surfaces of the front core halves 10b, 11b, 18a protruding from the holes 20a.

On the other hand, a coil 19 for generating recording and reproducing magnetic fields is fitted into the front core half 18b protruding from the hole 20a. Then, a rectangular plate-shaped back core 18 made of ferrite is connected to a front core half 18a,
It is fixed by coming into contact with the side surface of 18b.

Finally, the ends 15a, 15b of the coil 15 and the ends 19a, 19b, 19c of the coil 19 are connected to predetermined connections 17a of the flexible printed circuit board 16 by soldering.

FIG. 6 shows the structure of the portion of the magnetic head of the present invention, which has the assembly structure described above, that protrudes from the elastic plate 9 toward the magnetic disk.

That is, the front core halves 10a, 10b, 11a, 11b, forming the gaps g, g',
18a, 18b and spacers 12a, 12b, 12
c and the mask block 13 that holds them;
14 has a structure in which the entire periphery is surrounded by the shield part 21.

FIG. 7 shows a magnetic head 6' of the present invention which slides on the magnetic disk 1. As shown in FIG.

In other words, the lower ends of the front core halves 10a, 11a, the spacer 12a, and the mask blocks 13, 14 (the portions that slide against the magnetic disk 1) are spaced from the lower end of the shield part 21 by a very small clearance t.
The magnetic disk 1 is brought into sliding contact with only a dimension of .

The dimension of this clearance t is the magnetic disk 1
In order to prevent the shield portion 21 from coming into contact with and causing damage, the dimensions may be set to the minimum required size.

Therefore, the front core halves 10a, 11a (including not shown 10b, 11b, 18a, 18b)
Most of the portion protruding from the elastic plate 9 toward the magnetic disk is shielded by the shield portion 21. The dimension of the exposed portion is only a very small clearance dimension t.

Therefore, most parts of the front core half that pick up magnetic noise and electrostatic noise generated in the magnetic disk device are magnetically shielded by the shield 21, so the front core half picks up magnetic noise and electrostatic noise. The amount of electrostatic noise picked up is extremely small.

In addition, in this embodiment, the shield part 21 was fixed to the elastic plate 9 in advance, but the shield part 21
may be fixed to the elastic plate 9 after being fixed to the front core half, spacer/mask block assembly in advance.

Further, in the embodiment, the shield part 21 was provided only on the magnetic disk side of the elastic plate 9, but by providing it on the opposite side as well and shielding the front core half and coil on that side, the entire magnetic head can be further protected. You can also increase the shield effect of.

As is clear from the above description, according to the present invention, there is provided a core holding part, an elastic plate in which an opening is formed except for a portion bridged by the core holding part, and a core holding part of the elastic plate held in the core holding part. In the magnetic head having a core that surrounds the core, and a shield member that surrounds the core, the shield member is made of a high magnetic permeability material fixed to the core holding portion of the elastic plate. The core can be shielded stably and well, and the magnetic noise and electrostatic noise picked up by the core in a magnetic recording/reproducing device can be minimized.

That is, according to the present invention, when the core holding portion swings due to the sliding contact state between the magnetic recording medium and the core, the shield member swings integrally with the core, so that the opening of the opening facing the core of the shield member swings integrally with the core. The difference in dimension between the end and the tip of the core does not change due to the swinging of the core holding part, and is always constant, so that there is no fluctuation in the shielding effect.

In addition, since the difference between the open end of the shield member and the tip of the core is constant regardless of the swinging of the core holder, as long as the difference exists, the shield member can be moved to the medium by swinging the core holder. There is no risk of accidental contact, the difference dimension can be set extremely small, leakage magnetic flux from the open end of the shield member can be minimized, and the shielding effect is enhanced.

Further, according to the present invention, the shield member does not need to cover the entire elastic plate, but may be formed in a size that can surround the core in a core holding portion formed on a part of the elastic plate, so it can be small. The material requires only a small amount of high permeability material. Moreover, the shielding material can be fixed very easily by simply fitting it around the core and fixing it to the core holding portion of the elastic plate by adhesive or the like during the core installation process.
Therefore, in manufacturing the magnetic head, the cost associated with the shield member is not so great, and the magnetic head can be manufactured at a correspondingly low cost.

[Brief explanation of drawings]

1 and 2 are perspective views and side views for explaining the conventional structure, FIGS. 3 to 7 are for explaining the embodiments of the present invention, FIG. 3 is a perspective view of an elastic plate, and FIG. The figure is a perspective view of the elastic plate with the shield attached.
Figures 5A and B are perspective views illustrating the assembly structure of the entire parts, Figure 6 is a perspective view showing the structure of the part that protrudes from the elastic plate toward the magnetic disk, and Figure 7 is the magnetic field that slides into contact with the magnetic disk. FIG. 3 is a side view of the head. 1... Magnetic disk, 3, 6, 6'... Magnetic head, 9... Elastic plate, 10a, 10b, 11a,
11b, 18a, 18b...Front core half,
12a, 12b, 12c...Spacer, 13, 1
4...mask block, 21...shield part.

Claims (1)

[Claims] 1. It has a core holding part, an elastic plate in which an opening is formed except for the part bridged by the core holding part, a core held in the core holding part of the elastic plate, and a shield member surrounding the core. 1. A magnetic head, wherein the shield member is made of a high magnetic permeability material fixed to the core holding portion of the elastic plate.