JPS62124617A - Multigap magnetic head - Google Patents

Abstract

PURPOSE:To facilitate work winding a divided signal coil and to reduce crosstalk by installing a notch whose back end is opened on a shared magnetic core and dividing the signal coil into a magnetic core and a shared magnetic core so as to wind. CONSTITUTION:Side magnetic cores 9a and 9b made of magnetic thin films and a center magnetic core 9c are installed on a glass substrate 8, and thereon a protective film 10 is installed. Including the glass substrate 8 and the protective film 10, the notch 11 is formed from the back end toward a sliding surface. The signal coil 6a crosses only a magnetic closed circuit made of head chips including a magnetic gap 2a, and is divided and wound. In the same way, the signal coil 6b passes through a coil window 5b and is wound on the side magnetic core 9b and further wound on the center magnetic core 9c through the coil window 5b and the other tapered part 11b of the notch 11. Thus the signal coils 6a and 6b are divided and wound by using the notch 11 whose back end is opened, whereby the winding work can be facilitated and the crosstalk is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a multi-gap magnetic head suitable for use as a rotary head or the like when making a video tape recorder multi-functional.

[Background of the invention]

In recent years, video tape recorders have developed many features such as standard recording/playback mode and long-time recording/playback mode selection, special playback such as field still playback, and audio signal recording/playback using a rotating head to enable high-quality audio playback. These functions are now being required, and these functions are being achieved by mounting dedicated magnetic heads, each with a predetermined track width and azimuth angle, on the same rotating cylinder. In order to save space on the rotating cylinder and to facilitate assembly, these magnetic heads are generally arranged close to each other so that they can be handled as one unit. Then, a unit consisting of a plurality of magnetic heads that can be handled integrally in this way.
This is called a multi-gap magnetic head.

As a multi-gap magnetic head, conventionally
As described in Publication No. 9-198518, etc.
It is known that adjacent head chips are integrated via a common magnetic core, and a signal coil is wound around each head chip.

FIG. 6(a) shows this type of multi-gap magnetic head, where la, lb are head chips, 2a,
2b is a magnetic gap, 3a and 3b are magnetic cores, 4 is a common magnetic core, 5a and 5b are winding windows, 6a and 6b are signal coils, and 7a and 7b are magnetic closed circuits.

In the figure, a head chip 1a has a magnetic core 3a and a common magnetic core 4 bonded together, and a magnetic gap 2a having a predetermined azimuth angle and a predetermined track width is formed at the bonded portion. A winding window 5a is formed surrounded by the core 4. Similarly, in the head chip 1b, the magnetic core 3b and the common magnetic core 4 are bonded,
A magnetic gap 2b having a predetermined azimuth angle and a predetermined track width is formed in these bonded parts, and a magnetic core 3
A winding window 5b is formed surrounded by the common magnetic core 4 and the common magnetic core 4. The width of the common magnetic core 4 is tightly regulated to a predetermined gap interval X, and the two head chips la and lb are integrated via the common magnetic core 4. The signal coil 6a is wound around the magnetic core 3a through the winding window 5a so as to cross the magnetic closed circuit 7a of the head chip 1a including the magnetic gap 2a, and similarly,
The signal coil 6b is connected to the winding window 5 so as to cross the magnetic closed circuit 7b of the head chip 1b including the magnetic gap 2b.
b and is wound around the magnetic core 3b.

In such a multi-gap magnetic head, each magnetic gap 2
The distance X between a and 2b can be set with high precision using the common magnetic core 4, and each head chip la and lb are attached together on a head base (not shown). , it has excellent mass productivity and easy assembly work. However, the signal coil 6a crosses the magnetic closed circuit 7a, 'Ib.

6b is wound around the magnetic cores 3a and 3b in a concentrated manner, there is a problem in that the inductance increases and the head reproduction voltage per inductance decreases.

Therefore, in order to improve the head reproduction voltage per inductance, each magnetic closed circuit 7a is connected.

It is conceivable that the signal coils 6a and 6b are wound separately around the signal coil 7b.

FIG. 6(b) shows an example of this, in which one signal coil 6a passes through the winding window 5a, passes through the magnetic core 3a, passes through both windings 5a and 5b, and connects to the common magnetic core 4. The other signal coil 6b is wound around the winding window 5b.
It is wound around the magnetic core 3b through the magnetic core 3b and the common magnetic core 4 through the two windings 5a and 5b. in this case,
Split winding can improve the head reproduction voltage per inductance, but since the signal coils 6m and 6b are wound across both magnetic closed circuits 7a and 7b, for example, the signal is read at one magnetic gap 2a. Sometimes, the magnetic flux picked up by the other magnetic gap 2b jumps into one magnetic closed circuit 7a, resulting in a drawback that magnetic interference between the head chips la and lb, that is, crosstalk increases.

Furthermore, a part of the signal coils 6a, 6b is connected to both windings Junchu 5a,
5b and around the common magnetic core 4, there is a drawback that the winding work becomes difficult.

In addition, as another example of split winding, as shown in FIG. The signal coil 6b is passed through the winding window 5b to the magnetic core 3a,
A possible method is to wind it across 3b. in this case,
Although the winding work is easy, as in the above example, the signal coils 6a and 6b are wound so as to cross both magnetic closed circuits 7a and 7b, respectively, so there is a drawback that crosstalk becomes large.

Furthermore, as another example, as shown in FIG. The other signal coil 6b is wound around the magnetic core 3a and the common magnetic core 4, and the other signal coil 6b is connected to the magnetic core 3 by passing through both windings 5b and 5c.
b and a method of winding it around the common magnetic core 4 is conceivable. In this case, since the signal coils 6a and 6b can be divided and wound into independent magnetic closed circuits 7a and 7b, it is possible to improve the head reproduction voltage per inductance without increasing crosstalk, but the magnetic gap 2a , 2b is narrow, it is practically impossible to further form an auxiliary winding window 5C in the common magnetic core 4, and even if the winding window 5C could be processed, the winding work would be extremely difficult. It becomes difficult.

[Object of the Invention] An object of the present invention is to provide a multi-gap magnetic head that eliminates the drawbacks of the above-mentioned prior art, allows easy divisional winding of the signal coil, and reduces crosstalk.

[Summary of the invention]

In order to achieve this object, the present invention integrates adjacent head chips so that they share one magnetic core, and provides a notch with an open rear end in the shared magnetic core, so that each head chip The present invention is characterized in that when the signal coil is divided into a magnetic core and a shared magnetic core and wound, the signal coil on the shared magnetic core side is wound between the winding window and the notch.

[Embodiments of the invention]

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

FIG. 1(a) is a front view showing an embodiment of a multi-gap magnetic head according to the present invention, and FIG. is the center magnetic core, 10 is the maintenance #! In the membrane, 1) is a notch, 12 is a head perse, 13 is an adhesive, and 14 is a reinforcing material, and parts corresponding to those in FIG. 6 are given the same reference numerals. In this embodiment, a case will be described in which there are two head chips constituting a multi-gap magnetic head, similar to the conventional example described above.

In these figures, side magnetic cores 9a, 9b and a center magnetic core 9 made of a magnetic # film are disposed on a glass substrate 8.
A protective film 10' is provided on these magnetic cores 9a, 9b, and 9c. A magnetic gap 2a is formed at the joint between one of the side magnetic cores 9a and the center magnetic core 9c, and a winding window 5a is formed passing through these joints, the glass substrate 8, and the protective film 1o. ing. Similarly, a magnetic gap 2b is formed at the joint between the other side magnetic core 9b and the center magnetic core 9c, and a winding window 5b is formed through the joint, the glass substrate 8, and the protective film 1o. It is formed. Also,
The center magnetic core 9c, including the glass substrate 8 and the protective film 1o laminated on both the front and back surfaces, has a wedge-shaped notch 1) tapered upward toward the sliding surface from the rear end thereof.

The signal coil 6a is wound around the side magnetic core 9a through the winding window 5a, and around the center magnetic core 9c through the winding window 5a and one tapered portion 1)a of the notch If. has been done. Therefore, 1. The signal coil 6a is wound in sections across only the magnetic closed circuit of one head chip including the magnetic gap 2a.

Similarly, the signal coil 6b is wound around the side magnetic core 9b through the winding window 5b, and is also wound around the center magnetic core through the winding window 5b and the other tapered part 1) b of the notch 1). 9c, and is wound in sections so as to cross only the magnetic closed circuit of the other Herad tip including the magnetic gap 2b.

In the multi-gap magnetic head configured in this way, the glass substrate 8 on the side of one side magnetic core 9a is attached onto the head base 12 using an adhesive 13, and the glass substrate 8 on the side of the other side magnetic core 9b is attached. The substrate 8 is fixed onto the head base 12 by a reinforcing agent 14 made of adhesive or the like, and the notch 1] is closed by the reinforcing material 14, so that the substrate 8 is firmly fixed onto the head base 12.

Next, the manufacturing method of this example will be explained in Figs. 2 and 3.
This will be explained using figures.

First, as shown in FIG. 2(a), the winding window 5a.

5b and a wedge-shaped notch 1) are prepared, and on this glass substrate 8 both side magnetic cores 9a and 9b are formed. These side core magnetic 9a,
9b is formed by sputtering a Co--Nb--Zr based amorphous material or the like to form a grinding gear film with a thickness of about 20 μm, and the shape thereof is obtained by patterning by a mask sputtering method or the like. These side magnetic cores 9a.

When forming the magnetic gaps 2a and 2b, the side magnetic gaps 2a and 2b are formed by mirror-finishing one side of the side magnetic cores 9a and 9b into a tapered shape by ion milling, etc., and then using a non-magnetic material such as Sin. A film (not shown) is formed as a gap spacer with a thickness of about 0.25 μm, and then, as shown in FIG.
This is obtained by forming a center magnetic core 9c made of Co--Nb--Zr amorphous material between a and 9b.

Next, as shown in FIG. 2(c), each of the cores 9a.

A protective film 10 is formed on 9b and 9c. This protective film 10
40μ by vapor-depositing oxide such as MgO・5ift.
After that, the winding window 5
a, 5b and the amorphous material wrapped around the notch 1) and MgO.S10. By removing the system oxide by ion milling or the like, a magnetic head chip in which two Herad chips are integrated can be obtained.

Next, the magnetic herad chip thus obtained is pasted onto the head base 12 using an adhesive 13. In this case, only one side magnetic core 9a side is attached to the head base 12, and the notch 1) is opened through the gap formed between the other side magnetic core 9b and the head base 12. Make it.

Thereafter, as shown in FIG. 3, for one head chip, the signal coil 6a is connected between the side end of the side magnetic core 9a and the winding window 5a, and between the winding window 5a and the tapered part 1 of the notch 1). ) Divide and wind the windings between the space a and the other head chip in the same way, that is, between the side end of the side magnetic core 9b and the winding window 5b, and between the winding window 5b and the tapered part of the notch 1). 1) Divide each part between b and wind. The number of turns of the signal coils 6a and 6b is the same as that of the side magnetic core 9a.
, 9b and the center magnetic core 9c, for example, 10 turns each, and the total number of turns is 20 for each head chip.
It was a turn. (The illustrated signal coil has a smaller number of turns than the actual number for simplification.) Finally, the lower end of the side magnetic core 9b and the head base 12
The magnetic head chip is firmly fixed onto the head base 12 (see FIG. 1). As the reinforcing material 14, an appropriate member made of a non-magnetic material may be bonded to the side magnetic core 9b and the head base 12 using an adhesive, or a highly viscous adhesive may be bonded to the lower end of the side magnetic core 9b and the head base. Possible methods include filling and solidifying the material between 12 and 12 hours.

In the multi-gap magnetic head according to the above embodiment, each signal coil 6a, 6b can be wound in sections without interfering with the adjacent magnetic closed circuit, so the signal coil can be wound in one place for each head chip. Compared to the case where the
The inductance in the video signal frequency band is approximately 2~
It was reduced by 4dB. Therefore, if the inductance is equal to the head reproduction voltage and E is the head reproduction voltage, the value of the head reproduction voltage per inductance, that is, the value of ``'/4-'' was improved by 1 to 2 dB by the divided winding.

In addition, the shape of the notch 1) is such that the width t1 at the rear end is approximately the same as the core width of the center magnetic core 9c, and the depth t8 is the same as that of the center magnetic core 9c, as shown in FIG. core 9c
The height is approximately 1/2 of the height L, and the width gradually narrows in the depth direction.
does not reach Junchu 5a and 5b for both volumes, and considering the effect of reducing inductance, it is preferably within the range of 3 < t, < L, /2, in order to reduce inductance and crosstalk. It has been confirmed that the same effect as above can be obtained. Furthermore, the shape of the notch 1) is not limited to a wedge shape, and may have another shape, such as a base shape, which has a tapered part that narrows upward from the rear end toward the sliding surface. We have confirmed that similar effects can be obtained.

FIG. 4 is a front view showing another embodiment of the multi-gap magnetic head according to the present invention, in which 5c is a winding window, 6C is a signal coil, 9'c and 9''c are side magnetic cores, and 1)' ,
1) "" indicates a notch, and parts corresponding to those in FIG. 1 are given the same reference numerals. In this embodiment, a case will be described in which there are three head chips constituting a multi-gap magnetic head.

In the case of this embodiment, between the side magnetic core 9a and the center magnetic core 9'c that constitute each head chip, between both the center magnetic cores 9'c and 97c, and between the center magnetic core 9//c and the side magnetic core 9b. winding windows 5a, 5c, 5 respectively.
b is formed, and the signal coils 6a and 6b in the left and right head chips are dividedly wound as in the first embodiment, but the signal coil 6C in the center head chip
is dividedly wound between the winding window 5c and the notch 1)' and between the winding window 5C and the notch 1)'. Therefore, even in a multi-gear magnetic head having three magnetic gaps as in this embodiment, each of the signal coils 6a, 6b,
Since 6c is divided into windings without interfering with the adjacent magnetic closed circuit, the same effect as in the first embodiment can be obtained, and this also applies to a multi-gap magnetic head with four or more magnetic gaps. It is.

FIG. 5 shows still another embodiment of the multi-gap magnetic head according to the present invention, in which FIG. 5(a) is a perspective view in the middle of the manufacturing process, and FIG. 5(b) is a perspective view in the completed state.

This embodiment differs from the first and second embodiments described above in the method of forming the magnetic core. That is, in the first and second embodiments, each magnetic core was formed using thin film technology;
In this embodiment, as shown in FIG. 5(a), the magnetic core 15
a, 15b, and 15c are each two nonmagnetic substrates 16a.
, 16b, 16c sandwich three blocks 17a,
17b and 17c are prepared, and then, as shown in FIG. 5(b), they are butted together and bonded and integrated to form a gap junction type multi-gap magnetic head.

The magnetic gaps 2a, 2b are the blocks 17a.

When bonding 17b and 17c, the winding windows 5a and 5b are formed at the joints between the left and right blocks 17a and 17b.
is defined by a pre-formed groove and a central block 17c. Moreover, the notch 1) is for each block 17a,
After bonding 17b and 17c, the rear end of the central block 17c is formed by dicing using a wedge-shaped blade.Finally, the signal coils 6a and 6b are divided and wound in the same manner as in the first embodiment. do.

In this embodiment as well, the notches 1) can be used to divide and wind each signal coil 6a, 6b without interfering with the adjacent magnetic closed circuit, so the same effect as in the first embodiment can be obtained. . It goes without saying that the present invention can also be applied to such a gap junction type multi-gap magnetic head having three or more magnetic gaps.

〔Effect of the invention〕

As explained above, according to the present invention, the signal coil can be dividedly wound using the notch with the rear end open, which facilitates the winding work, and also allows the magnetic closed circuit to be connected to each head chip. Since the signal coil can be divided and wound so as to cross only the
An excellent multi-gap magnetic head can be provided by eliminating the drawbacks of the prior art described above.

[Brief explanation of drawings]

FIG. 1(a) is a front view showing a first embodiment of a multi-gap magnetic head according to the present invention, FIG. 1fb) is a side view thereof, FIGS. FIG. 4 is a front view showing a second embodiment of the multi-gap magnetic head according to the present invention, and FIGS. 5 (a) and (b) are multi-gap magnetic heads according to the present invention. FIG. 6(a) is a perspective view showing a third embodiment of the head. fb), (cl), (d) are front views showing a conventional multi-gap magnetic head. 2a, 2b... Magnetic gap, 5a, 5b. 5c... Winding window, 6a, 6b, 6c...
・Signal coil, 8...Glass substrate, 9a, 9b
...Side magnetic core, 9c, 9'c, 9'c・
... Center magnetic core, 10 ... Protective film, 1
)...Notch, lla, llb...Taber part, 12...Head base, 13...
・・Adhesive, 14 ・= ・・Reinforcement material, 15a, 15
b, 15c...magnetic core, 16a, 16I),
16c...Nonmagnetic substrate, 17a, 17b, 17
c...Block. Ink;r Figure 1

Claims (2)

[Claims] (1) Consisting of a plurality of head chips arranged on the same plane, the head chip has a winding window formed by a first magnetic core and a second magnetic core, and a winding window is formed between the first magnetic core and the second magnetic core. In a multi-gap magnetic head in which a signal coil is wound around two magnetic cores, the adjacent head chips share one magnetic core, and the shared magnetic core is provided with a notch with an open rear end, A multi-gap magnetic head characterized in that the signal coil is divided and wound for each head chip through the notch and the winding window. (2) A multi-gap magnet according to claim (1), wherein the notch has an upwardly tapering shape from the rear end of the shared magnetic core toward the sliding surface. head.