JPS599412Y2 - Composite magnetic head - Google Patents

Description

[Detailed description of the invention] The present invention relates to a composite magnetic head in which a recording head and a playback head are integrally coupled, and a signal recorded by the recording head is reproduced by the playback head immediately after recording. .

When manufacturing such a composite magnetic head, it is necessary to keep the gap between the recording head and the playback head parallel to each other, and to reliably prevent the recording signal from the recording head from leaking to the playback head during recording. There must be.

There are two types of leaks: inductive leaks,
This is called capacitive leakage.

Inductive leakage is caused by changes in magnetic flux, and as a countermeasure to this problem, a method is known in which the recording head and the reproducing head are each covered with a magnetically shielding case and each head is provided with a magnetic field.

Capacitive leakage occurs because there is a potential difference between the recording head and the playback head during recording, so a method is often used to electrically insulate the record head and playback head and ground each head to a board, etc. ing.

For this reason, manufacturing of composite magnetic heads has traditionally been technically difficult.

In other words, inductive leakage can be prevented by shielding the recording head and playback head with magnetic shield cases, but capacitive leakage can be prevented by shielding the recording head 1 as shown in Figure 1.
and a shield case 3 that magnetically shields the playback head 2.
, 4 to electrically insulate the recording head 1 from the reproducing head 2. However, due to the parallelism of the joining side walls 19 of both magnetic shielding cases, assembly errors, etc., the recording head 1 Since the parallelism between the gap 7 of the read head 2 and the gap 6 of the read head 2 is not good, a significant loss of playback angle occurs.

To prevent this, as shown in Figure 2, the recording head 1
A core holder made of a conductive material provided on the side wall side of the connection side with the reproducing head 2 is integrally formed, and the cores 5 and 5 are respectively attached to this core holder 10 to form a core block 18. , both sides 5a, 5b, 5C,
If the composite magnetic head shown in FIG. 3 is manufactured by polishing 5d parallel to each other as shown by arrows A and B, the gaps 6 and 7 between the recording head 1 and the reproducing head 2 can be accurately parallel.

However, in this case, since the core holder 10 is integrally formed over the recording head 1 and the reproducing head 2, insulation cannot be achieved and capacitive leakage becomes significantly large.

In this way, there is a seeming contradiction between maintaining the parallelism of the gaps 6 and 7 between the recording head 1 and the playback head 2 and electrically insulating the recording head 1 and the playback head 2. There is a relationship.

The present invention solves these two technical problems by providing at least two protrusions on the joining side wall of each core holder on the joining side wall side of the recording head and playback head, and attaching the core to each of the two core holders. installed, both sides of the core block are parallel, and the one core block is housed in one magnetically shielded case,
The protrusions of the one core block are fitted into at least two guide holes drilled in the side wall of the joining side so as to protrude into the other magnetic shield case, and the protrusions of the other core block housed in the other magnetic shield case are fitted. A surface of the protrusion and a surface of the protrusion of the one core block are fixed in contact with each other via an insulator to electrically insulate both core blocks, and at least one of the core holders provided with the protrusion This is an organic solution to this problem by separating the joint from the side wall on the joining side.

The present invention organically solves the technical problem of keeping the gap between the recording head and the playback head parallel, and the technical problem of preventing the recorded signal from the recording head from leaking to the playback head during recording. It's something to look out for.

Embodiments of the present invention will be described below based on FIGS. 4, 5, and 6.

FIG. 6 is a diagram showing the side wall side of the joint portion of the shield case 3 or shield case 4 of the recording head 1 and playback head 2, and shows the guide hole 16. 16 are drilled.

These shield cases 3 and 4 are interposed with a conductive plate 15 having guide holes so that the guide holes are engaged with each other.
Connect integrally by current welding or the like as appropriate.

In this way, the shield case of the composite magnetic head equipped with the joining side wall 19 is integrally made.

On the other hand, as shown in FIG. 4, it is provided with protrusions 20, 20, and as is well known, by grounding itself, the S/N is improved.
In order to improve the performance, a core is attached to a core holder 12 made of a conductive material and fixed with an adhesive or the like to form a core block 17.

Surfaces 12a, 12 of the protrusions of the core block 17 like this
b and its flat surfaces 5a and 5b are polished parallel to each other as shown by arrows A and B.

(This polishing is performed appropriately using a jig.) This core block 17 is inserted into the shield case 3, and its protrusions 20, 20 are inserted into the other shield case 4 through the guide holes 16, 16 of the joint side side wall 19. is made to protrude, and a core block 21 having a predetermined shape is mounted inside the shield case 3.

In this way, the recording head 1 is manufactured.

In addition, the core block 1 shown in FIG. 4 is attached to the shield case 4.
7 is inserted and the surface of the protrusion 12 a, 1 is polished in parallel.
2b and an insulator 13. The reproducing head 2 is constructed by placing the core blocks 22 in contact with each other with the core block 13 interposed therebetween, and inserting the core block 22 having a predetermined shape into the shield case 4.

That is, the coils 11, . By interposing an insulator 13 between the coils 11, the capacitance between the coils that generates a potential difference is prevented from flowing into the reproducing core 5 via the core holder 12.

In addition, the installation of coil 11 etc. is done using core block 21.22.
This can be done at the same time as the other equipment.

Further, spacers for forming the effective gaps 6 and 7 are then installed using an appropriate jig.

after that. Seal the shield cases 3 and 4 with resin etc.
By polishing the tape sliding surface side, the composite magnetic head of the present invention is completed.

In this way, the present invention shields the core blocks of the recording head and playback head made of conductive material with their respective magnetic shielding cases, and in a composite magnetic head in which the recording head and playback head are integrally combined, the shielding case is used. at least two guide holes are provided in the side wall of the joint side of the recording head and the playback head, and at least two protrusions are provided in the side wall of the joint side of each core holder on the side wall of the joint side of the recording head and the playback head. , both sides of the core block are parallel to each other, one of the core blocks is accommodated in one of the magnetic shield cases, and at least two
The protrusion of the one core block is passed through the two guide holes and protruded into the other magnetic shielding case, and the surface of the protrusion of the other core block housed in the other magnetic shielding case and the one core block The surfaces of the protrusions are fixed in contact with each other via an insulator to electrically insulate both core blocks, and at least one of the core holders provided with the protrusions is separated from the joining side wall. By constructing a composite magnetic head, it is possible to accurately achieve parallelism between the gaps between the recording head and the playback head, and an insulator is interposed between the core holders of both heads to create a parallelism between the coils of both heads. The capacitance between the coils that generates a potential difference does not flow into the playback core via the core holder, which reduces capacitive leakage and improves the parallelism of the gap between the recording head and playback head. This has the effect that it is possible to simultaneously achieve the functions of maintaining the recording head and electrically insulating the recording head and the reproducing head.

This has the effect of making it easier to manufacture the composite magnetic head.

Furthermore, if the capacitance between the coils is dissipated to the ground via the shield case, as is conventionally known, it is possible to further prevent capacitive leakage.

It has been confirmed through experiments that capacitive leakage has been reduced.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional example, Figs. 2 and 3 are explanatory diagrams for achieving parallelism of the gap between the recording head and the playback head,
FIG. 4 is a sectional view of the core block of the present invention, FIG. 5 is a sectional view showing a temporarily assembled composite magnetic head, and FIG. 6 is a side view of the shield case. 1... Recording head, 2... Playback head, 3, 4... Shield case, 5...
Core, 6... Gap of playback head, 7...
... Recording head gap, 8 ... Insulator, 9 ... Mounting base, 10 ... Core holder, 11, 11 ... Coil , 12...
... Core holder 13 ... Insulator, 14.
... air gap, 15 ... conductive plate, 16 ...
... Guide hole, 17 ... Core block, 18
... Core block, 19 ... Joint side wall, 20 ... Protrusion, 21 ... Core block, 22 ... Core block, 5a, 5
b, 5C, 5d... Core block surface, 12
a, 12 b... Surface of the protrusion.

Claims (1)

[Scope of utility model registration request] In a composite magnetic head in which core blocks of a recording head and a reproducing head made of conductive material are shielded by respective magnetic shielding cases, and the recording head and the reproducing head are integrally coupled, the joining side of the shielding case is A core is formed in each of the two core holders, the core holder having at least two guide holes formed in the side wall, and at least two protrusions formed in the joining side side wall of each core holder of the joining side side wall of the recording head and the reproducing head. are mounted, both sides of the core block are parallel, the one core block is accommodated in one shield case, and the one core block protrusions are inserted into at least two guide holes drilled in the side wall on the joint side. the part penetrates and protrudes into the other magnetic shielding case, and insulates the surface of the protrusion of the other core block housed in the other magnetic shielding case from the surface of the protrusion of the one core block. A composite type characterized in that both core blocks are electrically insulated by being fixed to each other through bodies, and at least one of the core holders provided with the protrusion is separated from the joining side side wall. magnetic head.