JPH10105937A - Magnetic head and rotary head device having the same - Google Patents

Abstract

(57) [Summary] [Object] To reduce the amount of magnetic flux from a recording magnetic head entering a reproducing magnetic head and improve the S / N of a reproducing signal. A ferrite cover (10e) as a magnetic flux absorbing member is formed in a U-shape, and is arranged on a head base (10b) so as to surround left and right side surfaces and a rear surface of a head chip (10a). The area on the front side of the cover 10e is
0a, the cover 10e is made thicker than the head chip 10a, and the magnetic impedance of the cover 10e is made lower than that of the head chip 10a. Head chip 10a of recording magnetic head 22
Of the unnecessary magnetic flux from the head 22
sucked into e. The head chip 1 of the head 22
Of the unnecessary magnetic flux from 0a, most of the magnetic flux 26 heading to the reproducing magnetic head 23 jumps into the cover 10e when approaching the head 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic head and a rotary head device having the same. More specifically, by arranging a magnetic flux absorbing member so as to surround all or a part of a surface other than the front surface of the head chip, an attempt was made to favorably reduce the amount of magnetic flux from the recording magnetic head that jumps into the reproducing magnetic head. It relates to a magnetic head and the like.

[0002]

2. Description of the Related Art A magnetic recording / reproducing apparatus using a magnetic tape has a characteristic that a large amount of information can be stored. Recently, there has been a demand for such a magnetic recording / reproducing apparatus to record / reproduce a signal at a high transfer rate so that a large amount of stocked information can be exchanged with an external device at a high speed.

In order to record and reproduce signals at a high transfer rate, it has been proposed to mount a large number of recording / reproducing heads on a rotating drum as a rotating head device constituting a magnetic recording / reproducing apparatus.

FIG. 8 shows such a rotary head device. That is, a plurality of recording magnetic heads 2 and reproducing magnetic heads 3 are alternately arranged on the rotating drum 1 in the circumferential direction, and are fixed by screws 4. A magnetic tape T is wound around the rotating drum 1 over a predetermined angular range.

In the rotary head device shown in FIG. 8, a signal is recorded on a magnetic tape T by a plurality of recording magnetic heads 2, and a signal recorded on the magnetic tape T is reproduced by a plurality of reproducing magnetic heads 3. You.

At present, the transmission rate of a signal that can be transmitted and received by one recording magnetic head 2 and one reproducing magnetic head 3 is 88M in clock frequency due to restrictions on the material of the magnetic head and the like.
Hz is the limit. Therefore, in order to further realize a high transfer rate of the magnetic recording / reproducing apparatus, the recording magnetic head 2 and the reproducing magnetic head 3
It is necessary to further increase the number of mounted.

[0007]

When the number of the recording magnetic heads 2 and the reproducing magnetic heads 3 mounted on the rotating drum 1 is increased, the recording magnetic heads 2 and the reproducing magnetic heads 3 inevitably come closer to each other. When the recording magnetic head 2 and the reproducing magnetic head 3 approach each other as described above, a signal is recorded on the magnetic tape T by the recording magnetic head 2 and, at the same time, a signal recorded on the magnetic tape T is reproduced by the reproducing magnetic head 3. At the time of simultaneous recording and reproduction, as shown in FIG. 9, as shown in FIG. 9, the magnetic flux 6 from the head chip 2a of the recording magnetic head 2 jumps into the head chip 3a of the reproducing magnetic head 3, thereby deteriorating the S / N of the reproduction signal. Will be.

The recording magnetic head 2 includes a relay board 2d for soldering a head chip 2a and a coil 2c wound on the head chip 2a to a head base 2b.
Are mounted and fixed. Similarly, the reproducing magnetic head 3 has a head base 3b and a head chip 3a.
And a relay board 3d for soldering the coil 3c wound around the head chip 3a.

Conventionally, as described above, in order to reduce the amount of magnetic flux from the recording magnetic head that enters the reproducing magnetic head, for example, a method of mounting a shield plate on the reproducing magnetic head (see Japanese Patent Application Laid-Open No. Sho 59-68804). ), A method of winding a short coil around a reproducing magnetic head (Japanese Patent Laid-Open No. 1-14300)
No. 5 publication) has been proposed.

However, these methods are methods for forcibly eliminating unnecessary magnetic flux from the outside by using a shield plate or the like. Has a small shielding effect and enters the reproducing magnetic head, so that the shielding effect is easily reduced, and it is very difficult to design and manufacture a shield plate and the like. Therefore, with these methods, the amount of diving can be reduced only by about 10 dB, and further improvement has been required.

Further, in order to reduce the amount of magnetic flux from the recording magnetic head entering the reproducing magnetic head, the recording magnetic head and the reproducing magnetic head are not alternately arranged on the rotating drum. A method of arranging the reproducing magnetic heads on the rotating drum in a concentrated manner is also conceivable.However, since the space between the magnetic heads cannot be reduced too much due to the structure, when the number of magnetic heads increases, the recording magnetic head group and the reproducing magnetic It is difficult to sufficiently separate the head group.

Further, a method of sufficiently isolating the recording magnetic head group and the reproducing magnetic head group from each other by using a multi-head configuration in which a plurality of head chips are mounted on one head base has been considered. The multi-head has problems such as an increase in cost.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a magnetic head and the like capable of reducing the amount of magnetic flux from a recording magnetic head that enters a reproducing magnetic head.

[0014]

In the magnetic head according to the present invention, a magnetic flux absorbing member is provided so as to surround all or a part of the surface other than the front surface of the head chip. And, for example, the end area of the front side of the head chip of the magnetic flux absorbing member is wider than the front surface area of the head chip, the thickness of the magnetic flux absorbing member is thicker than the thickness of the head chip, the magnetic impedance is lower than the head chip, The magnetic flux absorbing ability is made high. As the magnetic flux absorbing member, for example, ferrite which is a high magnetic permeability material is used.

[0015] Further, the rotary head device according to the present invention comprises:
A plurality of recording magnetic heads and reproducing magnetic heads are alternately arranged in the circumferential direction of the rotating drum, and either or both of the recording magnetic head and the reproducing magnetic head cover all or a part of the surface other than the front surface of the head chip. A magnetic flux absorbing member is provided so as to surround the same. For example, the magnetic flux absorbing member has an engaging convex portion or an engaging concave portion for preventing the rotating drum from jumping out during rotation, and the rotating drum is engaged with the engaging convex portion or the engaging concave portion of the magnetic flux absorbing member. In this case, an engaging concave portion or an engaging convex portion is provided.

In the present invention, the magnetic flux absorbing member is disposed so as to surround all or a part of the surface of the magnetic head other than the front surface of the head chip. Therefore, a part of the unnecessary magnetic flux from the head chip of the recording magnetic head is absorbed by the magnetic flux absorbing member provided in the recording magnetic head, so that the magnetic flux directed to the reproducing magnetic head is reduced. Further, a part of the magnetic flux heading toward the reproducing magnetic head is absorbed by the magnetic flux absorbing member of the reproducing magnetic head. In this case, in the reproducing magnetic head, when the magnetic flux absorbing member has a higher magnetic flux absorbing ability than the head chip, most of the magnetic flux directed to the reproducing magnetic head side is absorbed by the magnetic flux absorbing member. Therefore, even when the recording magnetic head and the reproducing magnetic head are close to each other, the amount of the magnetic flux from the recording magnetic head entering the reproducing magnetic head is greatly reduced.

In the present invention, the magnetic flux absorbing member is formed with an engaging projection or an engaging concave portion for preventing the rotating drum from jumping out during rotation. An engagement recess or engagement protrusion that engages the portion or engagement recess is formed. Therefore, when the magnetic head is disposed and fixed on the rotating drum, the engaging protrusion or the engaging recess of the magnetic flux absorbing member is engaged with the engaging recess or the engaging protrusion of the rotating drum. Therefore, even if the rotating drum rotates and a large centrifugal force is applied to the magnetic flux absorbing member, the magnetic flux absorbing member does not jump out of the rotating drum.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a magnetic head 1 according to an embodiment.
0 is shown. In the magnetic head 10, a head chip 10a and a relay board 10d for soldering a coil 10c wound around the head chip 10a are arranged and fixed on the upper surface of a head base 10b. , A ferrite cover 10e as a magnetic flux absorbing member is arranged and fixed.

The ferrite cover 10e is formed in a U-shape, is disposed on the head base 10b so as to surround the left and right side surfaces and the rear surface of the head chip 10a, and is attached to the head base 10b with an adhesive. Fixed.

The front end area (Sc1 + Sc2) of the ferrite cover 10e is wider than the front area (Sh1 + Sh2) of the head chip 10a, and the thickness Dc of the ferrite cover 10e is equal to the thickness Dh of the head chip 10a. Be made thicker. As a result, the magnetic impedance of the ferrite cover 10e becomes lower than the head chip 10a.
Is set so as to be lower than the magnetic impedance and to increase the magnetic flux absorbing ability.

FIG. 2 shows a rotary head device using the above-described magnetic head 10 as a recording magnetic head 22 and a reproducing magnetic head 23. That is, a plurality of recording magnetic heads 22 and reproducing magnetic heads 23 are alternately arranged in the circumferential direction on the rotating drum 21, and fixed by screws 24. A magnetic tape T is wound around the rotating drum 21 over a predetermined angular range.

In the rotary head device shown in FIG. 2, signals are recorded on the magnetic tape T by a plurality of recording magnetic heads 22, and the signals recorded on the magnetic tape T are reproduced by a plurality of reproducing magnetic heads 23. You.

In this case, since the magnetic impedance of the ferrite cover 10e of the recording magnetic head 22 (10) is lower than that in the air, as shown in FIG. 3, unnecessary magnetic flux from the head chip 10a of the recording magnetic head 22 is reduced. Some are
It is sucked into the ferrite cover 10e of the recording magnetic head 22, and returns to the head chip 10a of the recording magnetic head 22 through the ferrite cover 10e. Therefore, of the unnecessary magnetic fluxes from the head chip 10 a of the recording magnetic head 22, the magnetic flux 26 toward the reproducing magnetic head 23 is used.
Decreases.

Also, as described above, the reproducing magnetic head 23
The magnetic impedance of the ferrite cover 10e is lower than the magnetic impedance of the head chip 10a.
When 6 comes near the reproducing magnetic head 23, most of them jump into the ferrite cover 10e.

As described above, the magnetic head 1 shown in FIG.
By using 0 as the recording magnetic head 22 and the reproducing magnetic head 23, the amount of the magnetic flux from the recording magnetic head 22 jumping into the reproducing magnetic head 23 can be greatly reduced. S / N can be improved.

The curve a in FIG. 4 shows the measurement result of the plunge amount when a magnetic head with a ferrite cover (see FIG. 1) is used, while the curve b in FIG. 4 shows the result when a magnetic head without a ferrite cover is used. 3 shows the measurement results of the amount of diving. However, the measurement was performed with the distance between the recording magnetic head and the reproducing magnetic head being 10.9 mm. According to this measurement result, when the magnetic head with the ferrite cover is used, the amount of diving at, for example, 44 MHz is 25% less than that when the magnetic head without the ferrite cover is used.
It has decreased by about dB.

Further, as shown in FIG. 1, a ferrite cover 10e as a magnetic absorbing member is arranged to absorb unnecessary magnetic flux, thereby reducing the amount of unnecessary magnetic flux entering the head chip 10a. For example, there is an advantage that the arrangement position and the like can be roughly set as compared with a conventional method in which unnecessary magnetic flux is forcibly removed by a shield plate or the like. Therefore, as shown in FIG.
Even if 0e is formed into a U-shape and arranged so as to surround the left and right side surfaces and the rear surface of the head chip 10a, the effect of attenuating the amount of diving can be sufficiently obtained. The point is that the magnetic flux absorbing member may be arranged so as to surround all or a part of the surface other than the front surface of the head chip 10a. Of course, when the magnetic flux absorbing members are arranged on the entire surface other than the front surface of the head chip 10a, the effect of attenuating the diving amount is maximized.

If the head chip 10a of the recording magnetic head 22 and the ferrite cover 10e are very close to each other, the magnetic flux generated from the head chip 10a for recording signals on the magnetic tape T is originally generated by the ferrite cover. 1
However, since the position of the ferrite cover 10e can be roughly set as described above, the head chip 10a of the recording magnetic head 22 and the ferrite cover 10e can be sufficiently separated. ,
The original recording function of the recording magnetic head 22 is not hindered.

In the magnetic head 10 shown in FIG. 1, a ferrite cover 10e is arranged so as to surround the head chip 10a. However, a magnetic flux absorbing member using other high magnetic permeability material is arranged. It may be.
In the rotary head device shown in FIG. 2, the magnetic head 10 in which the ferrite cover 10e is disposed so as to surround the head chip 10a is used for both the recording magnetic head 22 and the reproducing magnetic head 23. Even if the magnetic head 10 is used as one of the magnetic head 22 and the reproducing magnetic head 23, the effect of attenuating the jump amount can be obtained.

Incidentally, in the magnetic head 10 shown in FIG. 1, the ferrite cover 10e is
b and is fixed by an adhesive. Further, as shown in FIG. 2, the rotating drum 21 on which a large number of recording magnetic heads 22 and reproducing magnetic heads 23 are mounted necessarily has a large diameter. Therefore, when the rotating drum 21 rotates, a centrifugal force of 2000 G to 3000 G is generated in the outer peripheral portion of the rotating drum 21 to which the recording magnetic head 22 and the reproducing magnetic head 23 are attached.

Each time the rotary drum 21 rotates, the above-described centrifugal force is repeatedly applied to the ferrite cover 10e of the magnetic heads 22 and 23, so that the amount of the adhesive and the aging of the adhesive change the ferrite cover 10e. And the ferrite cover 10e may fly out of the rotating drum 21. This is the same not only when the ferrite cover 10e is stuck to the head base 10b but also when it is stuck to the rotating drum 21 directly with an adhesive.

FIGS. 5 to 7 show a main part of a rotary head device 50 according to another embodiment of the present invention. 5 is a plan view, FIG. 6 is a sectional view taken along line AA of FIG. 5, and FIG. 7 is an exploded perspective view.

On the rotating drum 51, a plurality of recording magnetic heads and a plurality of reproducing magnetic heads are alternately arranged in the circumferential direction. Therefore, the rotary drum 51 has a screw portion of a fixing screw 53 for fixing the magnetic head 52 as a recording magnetic head or a reproducing magnetic head on the rotary drum 51, corresponding to the arrangement position of each magnetic head. And a groove 51b for disposing a ferrite cover 54 to be described later. Also, the groove 51
b is provided with a screw hole 51c.
A head height adjusting screw 55 is screwed into c.

In the magnetic head 52, a head chip 52a is arranged and fixed on a lower surface of a head base 52b, and a relay board 52d for soldering a coil 52c wound on the head chip 52a is arranged and fixed on an upper surface of the head base 52b. It is the structure which was done. And head base 5
2b is formed with a through hole 52e through which the screw portion of the fixing screw 53 described above passes.

The ferrite cover 54 is provided on the left and right side surfaces of the head chip 52a of the magnetic head 52 described above.
A substantially rectangular parallelepiped groove 54a is formed on the upper surface so as to surround the rear surface and the lower surface, and engaging protrusions 54b and 54 are formed on the left and right side surfaces to prevent projection by centrifugal force.
b is formed. As described above, the ferrite cover 54 is disposed in the groove 51b provided in the rotating drum 51, and the engaging protrusions 54b, 54b engage with the engaging recesses 51d, 51d formed in the groove 51b. Is done.

Further, on the rear surface side of the ferrite cover 54, a U-shaped relief groove 54c for releasing the head height adjusting screw 55 when disposed in the groove 51b provided on the rotary drum 51 is provided. ing. Such an escape groove 5
By providing 4c, the width t of the rear part of the ferrite cover 54 can be made relatively large, the strength can be increased, and the magnetic impedance can be reduced to increase the above-described attenuating effect of the diving amount.

The ferrite cover 54 has an end area on the front side larger than the front area of the head chip 52a and a thickness similar to that of the ferrite cover 10e shown in FIG. It is made thicker than the thickness of. Thus, the magnetic impedance of the ferrite cover 54 is set to be lower than the magnetic impedance of the head chip 52a, and the magnetic flux absorbing ability is set to be higher.

When the magnetic head 52 is mounted on the rotary drum 51, first, the ferrite cover 54 is attached to the rotary drum 51.
It is arranged in one groove 51b and is attached and fixed with an adhesive. In this case, the engaging projection 54 of the ferrite cover 54
The b and 54b are engaged with the engaging recesses 51d and 51d of the groove 51b, and the head height adjusting screw 55 is in a state where contact with the ferrite cover 54 is avoided by the clearance groove 54c.

Next, the screw portion of the fixing screw 53 is inserted into the through hole 52e formed in the head base 52b of the magnetic head 52.
The magnetic head 52 is fixed on the rotary drum 51 by screwing into the screw hole 51 a of the rotary drum 51 through the through hole. In this case, the head chip 52a of the magnetic head 52 enters the groove 54a formed on the upper surface of the ferrite cover 54,
The left and right side surfaces, the rear surface, and further the lower surface of the head chip 52a are surrounded by the ferrite cover 54.

With the magnetic head 52 attached to the rotary drum 51 as described above, the head height adjusting screw 5
By rotating the head 5 up and down, the head base 52b with which the tip of the head height adjusting screw 55 contacts moves up and down, and as a result, the height of the head chip 52a attached to the head base 52a is adjusted. You.

In the rotary head device 50 shown in FIGS. 5 to 7, similarly to the rotary head device shown in FIG. 2, the ferrite cover 54 transfers the magnetic flux from the recording magnetic head to the reproducing magnetic head. Can be greatly reduced, and the S / N ratio of a reproduced signal during simultaneous recording and reproduction can be improved.

The ferrite cover 54 is disposed in the groove 51b provided on the rotary drum 51, and at this time, the engaging projections 54b, 54b of the ferrite cover 54 are
1b is engaged with the engaging recesses 51d. Therefore, even if the rotary drum 51 rotates and a large centrifugal force as described above is applied to the ferrite cover 54, the ferrite cover 54
It will no longer jump out.

The ferrite cover 54 is sandwiched between the rotating drum 51 and the head base 52b of the magnetic head 52. Therefore, the ferrite cover 54
Even if the adhesive force of the adhesive that adheres to the rotating drum 51 decreases due to aging, this ferrite cover 54
Never jumps out to the outer periphery of the rotating drum 51.

Further, by forming the U-shaped relief groove 54c on the rear surface side of the ferrite cover 54, the width t of the rear portion of the ferrite cover 54 can be made relatively large as described above, and the strength can be increased. At the same time, the magnetic impedance can be lowered to increase the above-described effect of attenuating the diving amount.

In the above-described embodiment, the engaging projections 54b, 54b of the ferrite cover 54 are provided on the side surface of the ferrite cover 54, but the centrifugal force generated by the rotation of the rotary drum 51 is prevented. It is not necessary to provide the convex portion on the side surface as long as the convex portion is formed.

In the above-described embodiment, the engaging projections 54b, 54b are provided on the ferrite cover 54, and the engaging recesses 51d, 51d are provided in the groove 51b. Conversely, it is a matter of course that the ferrite cover 54 may be provided with an engaging concave portion and the groove 51b may be provided with an engaging convex portion.

[0048]

According to the present invention, the magnetic flux absorbing member is provided so as to surround all or a part of the surface of the magnetic head other than the front surface of the head chip. The amount of jumping into the head can be reduced satisfactorily, and the S / N of a reproduced signal during simultaneous recording and reproduction can be improved. Also, the magnetic flux absorbing member is provided with an engaging protrusion or an engaging recess for preventing the rotating drum from jumping out during rotation,
By engaging it with the engaging concave portion or engaging convex portion of the rotating drum, even if a large centrifugal force due to the rotation of the rotating drum is applied to the magnetic flux absorbing member, the magnetic flux absorbing member is disengaged from the rotating drum and pops out. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a magnetic head as an embodiment.

FIG. 2 is a plan view showing an example of a rotary head device using the magnetic head shown in FIG. 1 as a recording magnetic head and a reproducing magnetic head.

FIG. 3 is a diagram showing a flow of a magnetic flux from a recording magnetic head to a reproducing magnetic head for describing the magnetic head in the embodiment.

FIG. 4 is a diagram illustrating a diving amount suppression effect by a ferrite cover.

FIG. 5 is a plan view showing a main part of a rotary head device as another embodiment.

FIG. 6 is a cross-sectional view showing a main part of a rotary head device as another embodiment.

FIG. 7 is an exploded perspective view showing a main part of a rotary head device as another embodiment.

FIG. 8 is a plan view showing an example of a conventional rotary head device.

FIG. 9 is a diagram showing a flow of a magnetic flux from a recording magnetic head to a reproducing magnetic head for describing a conventional magnetic head.

[Explanation of symbols]

10: magnetic head, 10a: head chip, 1
0b: head base, 10e: ferrite cover, 21: rotating drum, 22: recording magnetic head, 23: reproducing magnetic head, 26: magnetic flux, 50
... Rotating head device, 51 ... Rotating drum, 51
a, 51c: screw hole, 51b: groove, 51d ...
Engaging recess, 52: magnetic head, 52a: head chip, 52b: head base, 52e: through hole, 53: fixing screw, 54: ferrite cover, 54a ... Groove, 54b ... Engaging projection, 54
c: relief groove, 55: head height adjustment screw

Claims (6)

[Claims] 1. A magnetic head, wherein a magnetic flux absorbing member is provided so as to surround all or a part of a surface other than a front surface of a head chip. 2. An end area of the magnetic flux absorbing member on a front side of the head chip is larger than a front area of the head chip, and a thickness of the magnetic flux absorbing member is larger than a thickness of the head chip. The magnetic head according to claim 1. 3. The magnetic head according to claim 1, wherein the magnetic flux absorbing member has an engaging protrusion or an engaging recess for preventing protrusion when the rotary drum is mounted. 4. The magnetic head according to claim 1, wherein the magnetic flux absorbing member is made of ferrite. 5. A plurality of recording magnetic heads and reproducing magnetic heads are alternately arranged in a circumferential direction of a rotary drum, and either or one of the recording magnetic head and the reproducing magnetic head is other than a front surface of a head chip. A whole or a part of the surface is surrounded by a magnetic flux absorbing member. 6. The magnetic flux absorbing member has an engaging protrusion or an engaging recess for preventing the rotating drum from jumping out during rotation, and the rotating drum has an engaging protrusion or an engaging protrusion of the magnetic flux absorbing member. The rotary head device according to claim 5, wherein an engagement concave portion or an engagement convex portion that engages with the engagement concave portion is provided.