JP2801435B2 - Magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head such as a combination head mounted on a magnetic recording / reproducing apparatus such as a video tape recorder (VTR).

[0002]

2. Description of the Related Art In a combination head used in a home VTR, for example, as shown in FIG. 8, head chips 21 and 21 'are formed with respective gaps 27 and 27'.
Are attached close to one base 22 along the traveling direction of the head chips 21 and 21 ′,
In the case of the base of the VHS system, the gap interval X ′ is 0.
The head chips 21 and 21 'are in a positional relationship that causes crosstalk between them. In addition,
When the head chips 21 and 21 ′ are attached on one base 22, if the distance between them is the same as above, there is a similar relation that crosstalk occurs.

There are various reasons for using such a combination head. For example, there are cases where independent magnetic heads are required for the standard mode and the long-time mode, and two-channel simultaneous recording is required due to the problem of recording density. However, in the case of the VHS system, the former reason is used.

As shown in FIG. 9, for example, the sliding surfaces of the head chips 21 and 21 'of the combination head are bonding glasses 24 and 24 in which the magnetic cores 23 and 23' constituting a magnetic circuit are made of a nonmagnetic material. The track width is regulated by ', and the gaps 27' and 27 'are formed, and the magnetic cores 23 and 23' are made of ferrite, which is a magnetic material.

In such a combination head,
Head chip facing sides 25 and 25 'are formed in each of the head chips 21 and 21', and a slit 26 is formed as a space between them. The track width determined by the gaps 27, 27 'of the head chips 21, 21' is represented by Tw ', the thickness of the sliding surface of each magnetic core 23, 23' by Cw ', and the interval between the slits 26 by G'. The length of the gap 27, 27 'is called g'.

In such a magnetic head, since the magnetic cores 23, 23 'made of ferrite, which is a magnetic material, are formed except for the bonding glass 24, 24', which is a non-magnetic material, the head chip-facing side edge 25, 23 'is formed. 2
5 'is also ferrite. Therefore, the slit 26
Is a gap 27 on the recording / reproducing signal, especially on the long wavelength side.
-A pseudo gap is formed for 27 'due to the shape effect.

When such a combination head is run on a magnetic tape on which a combination is recorded, for example, FIG.
As shown in the figure, track patterns (hereinafter referred to as tracks) R1, L1, R2, L2, R3, L3,
R4, L4... Are recorded, where R and L indicate different azimuth angles, and their width is called a track pitch (Tp).

In the case of the long-time (3 times) mode of the VHS system, Tp = 19 μm, so when Cw = 160 μm,
Assuming that the main track being reproduced is, for example, track R3, in addition to this, the slit 26 has tracks R1, L1, R2, and
It will pass through seven neighboring tracks L2, L3, R4 and L4 simultaneously. Further, since the gap G between the slits 26 is 10 ² to 10 ³ times the gap length g, there is no effect on the luminance signal on the short wavelength side of the recording / reproducing signal, but on the color signal on the long wavelength side. Will be given. In particular, it is easily affected by the same azimuth track having the same phase, and in such a case, the signals from tracks R1, R2, and R4 are reproduced simultaneously with track R3, which is the main track being reproduced, and the It becomes a talk component.

Next, the reason why the above-described crosstalk occurs will be described. Head chips 21 and 21 'which are combination heads for reproducing magnetic tape 28
As shown in FIG. 11 which is a conceptual diagram showing the flow of the magnetic field inside, a magnetic flux Φ ₁ is generated in the magnetic core 23 by the reproducing medium residual magnetization 29 which is a main signal traced by the gap 27, and the change in the magnetic flux Φ ₁ At the same time, an electromotive force is generated in the coil, and at the same time, since the slit 26 traces a neighboring track, a magnetic flux Φ ₂ is generated in the magnetic cores 23 ′ by the neighboring medium residual magnetization 29 ′ that becomes a crosstalk signal, and the magnetic flux Φ ₂ is generated. _An electromotive force is generated in the coil by the change of ₂ .

Therefore, the magnetic flux of the reproduction medium remanent magnetization 29 and the neighboring medium remanent magnetization 29 'pass through the coil at the same time, so that the signal from the adjacent track interferes with the reproduction signal of the main track due to the gap 27, which is called crosstalk. There is a problem that the signals are output overlapping each other.

As described above, the crosstalk caused by the pseudo gap effect by the slit 26 of the combination head in the conventional ferrite head can be classified into two types. In addition to the above-described problems, the track R3 in FIG. When the slit 26 forms a pseudo gap, there is a problem that crosstalk occurs in the main track portion.

Here, while the crosstalk in the main track portion is called a problem, the crosstalk from the near-adjacent track described above is called a problem. When these crosstalks occur, the color signal is particularly displayed on a monitor. The problem is vertical stripes due to the crosstalk of the burst signal, and the problem causes color flicker.

In a ferrite / alloy composite type head as shown in FIG. 12, for example, the magnetic cores 23 and 23 'are ferrite except for the alloy films 30 and 30'. Therefore, since the head chip opposing edges 25 and 25 'are formed of ferrite, which is a magnetic material, problems arise.

On the other hand, for example, in a thin film laminated head as shown in FIG.
Substrate 3 made of non-magnetic material.
The magnetic head is constituted by 1.31 '. Therefore, in the case of this magnetic head, the head chip facing side edge 25
In 25 ', the larger track width Tw, that is, the track width Tw for reproduction cannot be made so large, but the problem of crosstalk from a near adjacent track can be solved in shape. However, the problem of crosstalk in the main track cannot be solved.

Therefore, in order to solve the above-mentioned problem, as shown in FIG. 14, the shape of the edge 25, 25 'on the side facing the head chip in the slit 26 is made substantially arc-shaped. As shown in FIG. 15, the head chip-facing edges 25 and 25 'are made to be azimuths opposite to the azimuths of the gaps 27 and 27', respectively.
A proposal has been made in which the pseudo gap action of the slit 26 between the 25 'is reduced.

[0016]

However, in order to obtain the above-described magnetic head, it is necessary to use the head chip-facing side edge 2.
An additional step of processing 5.25 'into a substantially arc shape or an inverted azimuth is required, which causes a problem that the cost is increased.

[0017]

According to a first aspect of the present invention, there is provided a magnetic head in which a gap is formed to solve the above problems .
In a magnetic head in which a plurality of head chips each having a magnetic core are disposed close to each other along the direction of travel of the magnetic head, such as a combination head such as a double azimuth head, a magnetic head facing surface of each head chip adjacent to each other The magnetic core is exposed on one of the opposing surfaces.
And the other opposing surface thereof is made of a non-magnetic material.

[0018]

[0019]

According to the structure of the first aspect, each of the adjacent heads
Since either one of the magnetic head opposing surfaces of the chip is made of a non-magnetic material, a pseudo gap is not formed between the magnetic head opposing surfaces as in the related art. Therefore, the problem of crosstalk in the main track can be avoided,
In addition, the problem of crosstalk from tracks adjacent to each other can be avoided.

Therefore, conventionally, in order to avoid the above problems and the like, an additional processing step of forming the adjacent magnetic head facing surfaces into a shape that reduces the pseudo gap action between them has been required. In the configuration, for example, by using a non-magnetic material for the substrate and performing a normal manufacturing process,
It is possible to provide a magnetic head which avoids the above problems and eliminates the conventional additional processing step.

In addition, a magnetic head pair made of a non-magnetic material
The other magnetic head facing surface facing the facing surface has a magnetic core
Because the shape was exposed, the adjacent head chip
The distance between the gaps can be reduced, and the distance between the gaps is set smaller.
it can. As a result, the combination head
The track following of each head chip can be improved.
it can.

[0022]

[0023]

[0024]

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. For a combination head such as a double azimuth head, for example, FIG.
As shown in FIG. 2, head chips 1.1 'are respectively attached to independent head bases 2.2' of the rotating drum 12, and the head chips 1.1 'approach each other along their running directions. It is provided. In the drawing, X indicates the distance between the gaps of the adjacent head chips 1.1 ′, and G indicates the distance between the opposing surfaces of the adjacent head chips 1.1 ′. If the distance between the head chips 1.1 'is small as described above, the head chips 1.1'
It may be attached to one head base 2.

In such a head chip 1, as shown in FIG. 3, a mountain portion 6 is provided on a substrate 11, and a magnetic core 3 made of a soft magnetic thin film is provided on one wall surface 8 of the mountain portion 6. The pair of substrates 11 provided with the magnetic cores 3 are joined by the bonding glass 4 which is a non-magnetic material so that the respective magnetic cores 3 are linear and form the gap 7.

As shown in FIG. 1, which is the magnetic tape sliding surface 17 side of the head chip 1, the magnetic core 3 sandwiches an insulating magnetic layer 10 with a soft magnetic alloy magnetic thin film 10 having a high saturation magnetic flux density. And is generally called an alloy laminated thin film. As the alloy magnetic thin film 10, a sendust alloy, an amorphous alloy, an iron-based microcrystalline alloy, or the like is used.
The insulating layer 9 is made of silicon dioxide (SiO ₂ ) or alumina (Al
₂ O ₃ ) is commonly used. On the other hand, the substrate 11 is made of a non-magnetic material, and usually, ceramics and crystallized glass are often used.

Further, each magnetic core 3.3 in the head chip 1 is positioned obliquely to the magnetic head traveling direction A, and has a mountain-shaped portion 6 having a wall surface 8 on which the magnetic cores 3.3 are formed. Is generally 45 to 60 degrees.

The method for manufacturing such a head chip 1 is as follows.
Although not shown, a groove having a V-shaped cross section is continuously formed on the surface of the substrate made of a substantially rectangular parallelepiped nonmagnetic material by dicing or the like, and then the above-described alloy laminated thin film (magnetic core) is formed on one wall surface of the groove. ) To form a one-sided substrate block, and then, as shown in FIG. 4, a pair of one-sided substrate blocks 16 are formed by positioning each magnetic core 3 in a straight line and forming a predetermined gap 7 between them. Align to form,
The substrate block 14 is bonded by the bonding glass 4.
Is prepared.

The one side substrate block 16 of the substrate block 14 has a gap-facing outer surface 16b, which is on the back side of the gap surface 16a, ground in parallel with the gap 7, so that the ground surface and the gap 7 The magnetic core 3 is ground to such an extent that the magnetic core 3 is not exposed to the magnetic head facing surface described later, which is the ground surface thereof, and the magnetic core 3 is ground to the magnetic head facing surface described later, which is the ground surface thereof. And ground until it is exposed.

Thereafter, the substrate block 14 is cut at a predetermined pitch X. In this cutting, the direction of the cut surface is set so as to form an azimuth angle in the gap 7.
The substrate block 14 is not parallel to both end faces in the longitudinal direction, but is provided with an angle to the both end faces in the longitudinal direction according to a desired azimuth angle. Thus, the head chip 1 as shown in FIG. 3 is manufactured.

In the head chip 1 applied to the combination head, the above-described magnetic head facing surface 5 ground to such an extent that the magnetic core 3 formed oblique to the gap 7 is not exposed is formed. The other head chip 1 'has the above-described magnetic head facing surface 5' ground until the magnetic core 3 is exposed. Therefore, in a combination head such as a double azimuth head, as shown in FIG. 1, the distance between the head chips 1 and 1 'that are close can be set small.

In these head chips 1.1 ′,
Each function is different, for example, one head chip 1
Are used for recording / reproducing for the normal mode, and the other head chip 1 'is used for reproducing for the long-time mode. Therefore, the reproducing efficiency of the head chip 1' for the long-time mode is reproduced. The gap 7 'of the head chip 1', that is, the track width Tw is set to be wide in order to improve the head width.

In each of the head chips 1 and 1 'arranged close to each other as described above, the opposing surface 5 of one of the head chips 1 is made of a substrate 11 made of a non-magnetic material. The magnetic core 3 is exposed on the facing surface 5 'of the other head chip 1', but the magnetic core 3 does not face between the facing surfaces 5 and 5 '.

Therefore, the magnetic head facing surface 5, which is a projection of each of the gaps 7, 7 'in the direction of travel of the magnetic head.
Since the 5 'portion is made of a non-magnetic material, a pseudo gap effect due to the slits 15 therebetween is prevented, and the problem of crosstalk in the main track portion can be avoided. There is only one magnetic material, and a pseudo gap effect by the slits 15 between them is prevented, so that the problem of crosstalk from a track adjacent to the track can be avoided.

Conventionally, the opposing surfaces between the head chips are made of a magnetic material such as ferrite. In order to avoid problems such as crosstalk due to a pseudo gap phenomenon between the head chips, the opposing surfaces are opposed to each other. It is necessary to additionally provide a complicated processing step of forming a substantially arc-shaped or an inverted azimuth angle.

However, in the configuration of the above-described embodiment, the process in the ordinary manufacturing method of grinding the gap-facing outer surface 16b on the back side of the gap surface 16a of the one-side substrate block 16 in parallel with the gap 7 is used. Since the magnetic head as described above can be used, an additional processing step as in the related art can be omitted.

Thus, a magnetic head for preventing vertical stripes on the monitor due to various kinds of crosstalk, ie, vertical flicker on the monitor due to the crosstalk of the burst signal due to the problem and color flicker on the monitor due to the problem. The above configuration can avoid the cost increase that has conventionally occurred.

In the above configuration, the magnetic core 3 may be ground on the magnetic head facing surface 5 side of the head chip 1 so that one is not exposed, and the other is exposed until the other is exposed.
When such a head chip 1.1 ′ is applied to a combination head such as a double azimuth head, each gap 7.7 ′ in the adjacent head chip 1.1 ′ is applied.
The distance between them can be set small. This makes it possible to improve the track followability of each of the head chips 1 and 1 'in the combination head.

In the above-described configuration, an example in which the magnetic core 3 is provided on one wall surface 8 of the chevron 6 has been described. However, as shown in FIG. The present invention can be applied to a magnetic head provided with a core 3.

In the above embodiment, the magnetic head facing surface 5 is entirely made of a non-magnetic material. However, the magnetic head facing surface 5 is formed by using a substrate on which a magnetic material and a non-magnetic material are laminated. The magnetic head 5 may have a magnetic tape sliding surface 17 side made of a non-magnetic material, and the other magnetic head facing surface 5 may be made of a magnetic material.

Next, another embodiment of the present invention will be described with reference to FIGS. In the above-described embodiment, the magnetic core 3 is exposed on one of the opposing surfaces 5, 5 'of the head chips 1 and 1' in the combination head. In this embodiment, as shown in FIG. Until the magnetic core 3 is exposed on the opposing surface 5, the magnetic head opposing surface 5
The side substrates 11 are ground in parallel to the gaps 7, respectively.

In addition, in one head chip 1 ′, the exposed portion of the magnetic core 3 ′ on the magnetic head facing surface 5 ′ is further ground so that the magnetic core exposed facing surface 5 ″ is connected to the upper end side and the other side. Magnetic head facing surface 5 as head chip 1
It is formed so as to angle theta ₁ of the upper end side of the 30 degrees or more.

As shown in FIG. 7, the method of forming the exposed surface 5 ″ of the magnetic core is such that the back surface of the gap surface 16a is ground and the magnetic core 3 ′ is formed on the ground surface 5 ′. Opposite surface grooves 13 having a substantially V-shaped cross section are formed in the exposed substrate block 14 by, for example, a dancing process so as to include the magnetic cores 3 ′ downward from the upper end of the opposing surface 5 ′. A magnetic core exposed facing surface 5 "having a predetermined angle with respect to the upper end of the surface 5 'is formed.

The exposed surface 5 ″ of the magnetic core may be formed on the magnetic tape sliding surface 17 which is the upper surface of the substrate block 14 and in the vicinity thereof. It is not necessary to pass to the lower end, and the depth of the facing surface groove 13 is formed to be shallower downward, and the precision of forming the facing surface groove 13 is not so required.

Therefore, when the magnetic head manufactured as described above is applied to a combination head such as a double azimuth head, as shown in FIG. 6, each of the magnetic cores 3, 3 'exposed on the opposing surfaces 5.5 "is provided. average distance G ₂ of, can be increased by providing the magnetic core exposed opposing surface 5 ".

Further, the angle θ between the magnetic cores 3 and 3 '
₁ is set to be 30 degrees or more, and since the azimuth angle of each gap 7.7 ′ is, for example, 6 degrees in the VHS system, when the head chip 1 ′ is used for reproduction, The magnetic core 3 ′ on the magnetic core exposed facing surface 5 ″ is 42
The magnetic core 3 'has an azimuth angle of 30 degrees or more with respect to a track adjacent to the main track and a reverse azimuth, and the magnetic core 3' has an azimuth angle of 30 degrees or more with respect to a track adjacent to the main track. Greatly attenuates due to azimuth loss. Therefore, the problem of crosstalk from a near-adjacent track is avoided.

In addition, each magnetic core 3, 3 'is formed obliquely with respect to each of the gaps 7, 7', and since the oblique angle is sufficiently larger than each of the azimuth angles, the gaps 7 'are formed. Each of the magnetic head facing surfaces 5, 5 'on the track being reproduced by the magnetic head is made of a non-magnetic substrate 11.
11 'to avoid the problem of crosstalk in the main track.

By the way, in order to avoid various crosstalks which have conventionally occurred between the facing surfaces of the conventional combination head, the step of processing the head chip facing side edge of each magnetic head into a substantially arc shape or reverse azimuth. Needed.

However, in the configuration of the above embodiment, one back side of the gap surface 16a of the substrate block 14 is
After grinding in parallel with the gap surface 16a or grinding the gap back surface 16b of the one-sided substrate block 16 in parallel with the gap surface 16a, the facing surface 5 ', which is the ground surface, is provided with a facing surface that does not require much precision. By simply adding a simple step of providing the groove 13 to one of the head chips 1 ', various crosstalks occurring between the opposing surfaces of the magnetic heads can be avoided as in the related art.

Thus, a magnetic head for preventing vertical stripes on the monitor due to various kinds of crosstalk, ie, vertical flicker on the monitor due to the crosstalk of the burst signal due to the problem and color flicker on the monitor due to the problem. Therefore, it is possible to reduce the cost increase that has conventionally occurred.

In addition, since the distance between the gap 7 and the opposing surface 5 can be made smaller than in the prior art, even if the distance between the respective magnetic head opposing surfaces 5, 5 'in the combination head is the same as in the prior art, each gap 7.7 The distance between the magnetic heads can be reduced, and the trackability of the magnetic head in the combination head can be improved.

[0053]

As described above, the magnetic head according to the first aspect has a head chip having a magnetic core forming a gap.
In a magnetic head in which a plurality of magnetic heads are arranged close to each other along the magnetic head traveling direction, such as a combination head such as a double azimuth head, each of the heads adjacent to each other
One of the opposing surfaces of the magnetic head of the chip
The above magnetic core is exposed and opposed to it.
The other facing surface is made of a non-magnetic material.

Therefore, since one of the magnetic head opposing surfaces of each head chip is made of a non-magnetic material, the problem of crosstalk in the main track portion can be avoided, and the crosstalk from a near adjacent track can be avoided. Can also be avoided.

Therefore, conventionally, in order to avoid the above problems and the like, it has been necessary to perform an additional processing step of forming the opposing surfaces of the magnetic heads adjacent to each other into a shape for reducing the pseudo gap effect. It is possible to provide a magnetic head in which the above problems and the like are avoided in the manufacturing process, and it is possible to omit a conventional additional processing step.

As a result, there is an effect that it is possible to reduce the cost increase conventionally caused for avoiding various crosstalks.

Moreover, a magnetic head pair made of a non-magnetic material
Other magnetic head pair Komen opposite the facing surfaces, the magnetic core
Because the shape was exposed, the adjacent head chip
The distance between the gaps can be reduced, and the distance between the gaps is set smaller.
it can.

Thus, a combination head or the like can be used.
Track tracking of each head chip in the
It also has the effect that it can be done.

[0059]

[0060]

[0061]

[0062]

[Brief description of the drawings]

FIG. 1 is a front view of a magnetic head according to the present invention.

FIG. 2 is a schematic configuration diagram of the magnetic head mounted on a rotating drum as a combination head.

FIG. 3 is a perspective view of the magnetic head.

FIG. 4 is a perspective view of a substrate block obtained by joining a pair of one-side substrate blocks when manufacturing the magnetic head.

FIG. 5 is a front view of another magnetic head of the present invention.

FIG. 6 is a front view of still another magnetic head according to the present invention.

FIG. 7 is a perspective view of a substrate block obtained by joining a pair of one-side substrate blocks when manufacturing the magnetic head.

FIG. 8 is a schematic configuration diagram of a conventional magnetic head mounted on a rotating drum as a combination head.

FIG. 9 is a front view of each of the magnetic heads provided close to each other.

FIG. 10 is an explanatory diagram showing how each of the magnetic heads slides on a magnetic tape.

FIG. 11 is a conceptual diagram illustrating crosstalk generated when each of the magnetic heads slides on a magnetic tape.

FIG. 12 is a front view of another conventional magnetic head.

FIG. 13 is a front view of still another conventional magnetic head.

FIG. 14 is a front view of a conventional magnetic head proposed to avoid the problem of the magnetic head.

FIG. 15 is a front view of still another conventional magnetic head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head chip 3 Magnetic core 5 Magnetic head facing surface 7 Gap 17 Magnetic tape sliding surface

Claims (1)

(57) [Claims] 1. A magnetic head having a plurality of head chips having a magnetic core forming a gap, such as a combination head such as a double azimuth head, which is disposed close to each other in a magnetic head traveling direction. A magnetic head wherein the magnetic core is exposed on one of the magnetic head opposing surfaces of each head chip, and the other opposing surface thereof is made of a non-magnetic material.