JPH0540913A - Magnetic head - Google Patents

Abstract

PURPOSE:To avoid various cross-talks and the cost-up by eliminating an additional working process only for working each of magnetic head confronting faces being arranged closely to avoid the various cross-talks to the shape reducing a pseudo gap action between them, for example nearly a circular shape. CONSTITUTION:In plural adjacent magnetic heads such as a combination head of double azimuth head, etc., provided along the traveling direction of the magnetic head, the tape sliding face 14 side in each of the magnetic confronting faces 5.5' is formed from a non-magnetic material.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a combination head used for a home-use VTR, for example, as shown in FIG. 6, two head chips 21, 21 'have respective gaps 27.2.
The heads 7'are parallelly opposed to each other and are closely attached on one base 22. In the case of a VHS type base, the gap distance X'is set to, for example, 0.74 mm. The chips 21 and 21 'are in a positional relationship that causes crosstalk between them.

There are various reasons for using such a combination head. For example, separate magnetic heads for standard mode and long time mode are required, and simultaneous recording on two channels is required due to the problem of recording density. In the case of the VHS method, the former reason is used.

For example, as shown in FIG. 7, the sliding surface of each head chip 21, 21 'in the combination head has a bonding glass 24, 24 in which each magnetic core 23, 23' constituting a magnetic circuit is a non-magnetic material. The track width is regulated by 'and each magnetic core 2
Ferrite, which is a magnetic material, is used for 3 '.

In such a combination head,
Head chip facing edges 25, 25 'are formed on the head chips 21, 21', respectively, and a slit 26 is formed as a space therebetween.

Incidentally, gaps 27 and 27 'are formed in the head chips 21 and 21', respectively.
・ The track width determined by 27 'is Tw' and the magnetic core 23
The thickness of the sliding surface at 23 'is called Cw', the distance between the slits 26 is called G ', and the length of the gap 27, 27' is called g '.

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

Considering a case where such a combination head is run on a recorded magnetic tape,
For example, as shown in FIG. 8, a track pattern (hereinafter referred to as a track) R1, L1, R2, L2 is formed on the magnetic tape 28.
・ R3 ・ L3 ・ R4 ・ L4… are recorded. Where R and L
Indicate different azimuth angles, and their track pitch is called Tp.

In the long-time (triple-time) mode of the VHS system, Tp = 19 μm. Therefore, when Cw = 160 μm, the track which is the main track being reproduced is, for example, the track R3, and other than that. As a track, the slit 26 is a track R1, L1, R2, L2, L3, R4.
It will pass through 7 neighboring tracks of L4 at the same time.

Further, since the gap G ′ of the slit 26 is 10 ² to 10 ³ times the gap length g ′, there is no influence on the luminance signal, which is the short wavelength side in the recording / reproducing signal, and almost on the long wavelength side. It will affect a certain color signal. In particular, it is easily affected by the same azimuth track that has the same phase, and in the above case, the signals from tracks R1, R2, and R4 are simultaneously reproduced for track R3, which is the main track being reproduced, It becomes a crosstalk component.

Next, the reason why the above-mentioned crosstalk occurs will be described. Head chips 21, 21 'which are combination heads during reproduction of the magnetic tape 28.
As shown in FIG. 9, which is a conceptual diagram showing the flow of magnetism inside,
A magnetic flux Φ ₁ is generated in the magnetic core 23 by the reproduction medium remanent magnetization 29 serving as a main signal traced by the gap, and an electromotive force is generated in the coil due to the change of the magnetic flux Φ ₁ , while the slit 26 traces a neighboring track. Therefore, the residual medium remanent magnetization 29 ′ which becomes a crosstalk signal
As a result, a magnetic flux Φ ₂ is generated in the magnetic cores 23 and 23 ′, and an electromotive force is generated in the coil due to the change of the magnetic flux Φ ₂ .

Therefore, since the magnetic fluxes of the reproducing medium remanent magnetization 29 and the neighboring medium remanent magnetization 29 'simultaneously pass through the coil, the signal from the neighboring track interferes with the reproduced signal of the main track due to the gap 27, which is called crosstalk. There was a problem that signals were overlapped and output.

That is, in the combination head using such a conventional ferrite head, the crosstalk caused by the pseudo gap action by the slit 26 can be classified into two types. However, when the slit 26 becomes a pseudo gap with respect to the gap 27, 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 adjacent tracks described above is called a problem, and when these crosstalks occur, a color signal is particularly displayed on the monitor. The problem is vertical stripes due to burst signal crosstalk, and the problem is color flicker.

Further, as a magnetic head having another shape, for example, in a ferrite / alloy composite type head as shown in FIG. 10, the magnetic cores 23/23 'are ferrite except the alloy films 30/30'. Therefore, since the head chip facing side edges 25 and 25 'are formed of ferrite which is a magnetic material, problems and occur.

Further, in a thin film laminated head as shown in FIG. 11, for example, the magnetic cores 23.
Substrate 3 formed of 0'and other parts made of non-magnetic material
The magnetic head is formed of 1.31 ′, and there is a limitation that the larger track width Tw at the head chip facing side edge 25 · 25 ′, that is, the reproduction track width Tw cannot be made too large. The problem of crosstalk from can be solved geometrically. However, the problem of crosstalk within the main track cannot be solved.

In order to solve the above problems, therefore, as shown in FIG. 12, a magnetic head in which the edges 25, 25 'on the head chip facing side of the slit 26 are formed into a substantially circular arc shape (Japanese Patent Laid-Open No. SHO11-29200). No. 60-182006), and as shown in FIG.
The magnetic heads having 5'inverse azimuths with respect to the azimuths of the gaps 27, 27 'are produced, and the slits 26 between the head chip facing side edges 25, 25' are formed.
It has been proposed to reduce the pseudo-gap effect of the above.

[0018]

However, in order to obtain the magnetic head as described above, the edge 2 on the side facing the head chip is used.
A process of processing 5.25 'into a substantially arcuate shape or reverse azimuth is required, and the number of processes increases, which causes a problem of increasing cost.

[0019]

The magnetic head of the present invention comprises:
In order to solve the above-mentioned problems, a plurality of magnetic heads, such as a combination head such as a double azimuth head, which are arranged close to each other along the traveling direction of the magnetic head and have a gap by a magnetic core, are close to each other. The magnetic tape sliding surface side of the facing surface is made of a non-magnetic material.

[0020]

With the above structure, since the magnetic tape sliding surface side of the adjacent magnetic head facing surfaces is made of a non-magnetic material, a pseudo gap is not formed between the magnetic head facing surfaces. .. Therefore, the problem of crosstalk in the main track portion due to the pseudo gap can be avoided, and similarly, the problem of crosstalk from adjacent tracks can be avoided.

Therefore, in the past, in order to avoid the above-mentioned problems and, it was necessary to perform an additional processing step only for forming the facing surfaces of the magnetic heads close to each other so as to reduce the pseudo gap action between them. With the above configuration, it is possible to eliminate the above-mentioned problems and to eliminate the conventional additional processing steps and obtain a magnetic head.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS. In the case of a combination head such as a double azimuth head, as shown in FIG.
Head chips 1.1 'are attached to 2', and the head chips 1.1 'are provided close to each other along their traveling direction. In the figure, X represents the distance between the gaps of the adjacent head chips 1.1 ', and G
Indicates the distance between the facing surfaces of the adjacent head chips 1.1 '. If the distance between the head chips 1.1 'is small as described above, the same applies even if the head chips 1.1' are attached to one head base 2.

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

The magnetic core 3 is formed by laminating soft magnetic alloy magnetic thin films 10 via an insulating layer 9 as shown in FIG. 1 which is a view of the head chip 1 seen from the magnetic tape sliding surface 17 side. , Is generally called an alloy laminated thin film. As the alloy magnetic thin film 10, sendust alloy, amorphous alloy,
An iron-based microcrystalline alloy or the like is used, and the insulating layer 9 is generally made of silicon dioxide (SiO ₂ ) or alumina (Al ₂ O ₃ ). The substrate 11 is made of a non-magnetic material, and usually ceramics or crystallized glass is often used.

Further, the magnetic cores 3, 3 in the head chip 1 are positioned obliquely with respect to the magnetic head traveling direction A, and the mountain-shaped portion having the wall surface 8 on which the magnetic cores 3, 3 are respectively formed. The apex angle θ of 6 is generally 45 to 60 °.

The manufacturing method of such a head chip 1 is as follows.
Although not shown, a cross section V is formed on the surface of the substrate having a substantially rectangular parallelepiped shape.
After forming the V-shaped groove continuously by dicing, etc., a soft magnetic thin film (magnetic core) is formed on one wall surface of the mountain-shaped portion formed between the adjacent grooves to produce a one-sided substrate block. Then, as shown in FIG. 4, the pair of one-sided substrate blocks 13 are aligned so that the magnetic cores 3 are located linearly and a predetermined gap 7 is formed between them, and the bonding glass The substrate block 14 is manufactured by bonding with 4.

In the substrate block 14, the gap surface 13 in one of the substrate blocks 13 on one side is
the gap facing outer surface 13b, which is the back side of
Alternatively, the distance between the ground surface and the gap 7 may be made small by grinding in parallel with. However, the magnetic core 3 is ground to such an extent that the magnetic core 3 is not exposed on the ground surface, which will be described later, facing the magnetic head.

After that, the substrate block 14 is cut at a predetermined pitch X. When the substrate block 14 is cut in this way, the cutting plane direction is set 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 with respect to both end faces in the longitudinal direction according to the desired azimuth angle. In this way, the head chip 1 as shown in FIG. 3 is manufactured.

When such a head chip 1 is applied to a combination head, as shown in FIG. 1, the head chips 1 and 1'have different functions, for example, one head chip 1 for recording in the normal mode. The reproducing head chip 1'is used for reproduction, and the other head chip 1'is used for reproducing for long time mode. Therefore, the reproducing head chip 1'for long time mode is for improving the reproduction efficiency. , The gap 7'of the head chip 1 ', that is, the track width Tw is set wide.

In each of the head chips 1.1 'arranged in proximity as described above, the magnetic head facing surface 5'of them is made of the substrate 11, 11' which is a non-magnetic material, and each magnetic chip The cores 3 and 3'are not exposed on the magnetic head facing surfaces 5 and 5 ', so that each gap 7
Parallel to 7 ', track width, ie length l ₁ · l' ₁
The magnetic head facing surfaces 5 and 5'corresponding to are made of a non-magnetic material.

By the way, conventionally, since the facing surfaces between the head chips are made of a magnetic material such as ferrite, in order to reduce the obstacles due to the pseudo gap phenomenon between them, the facing surfaces are formed in a substantially arc shape. It was necessary to additionally provide a labor-intensive processing step such as forming into a sheet or forming into a reverse azimuth angle.

However, in the above structure, even if such an additional processing step is omitted, since the magnetic head facing surfaces 5, 5'of the head chips 1, 1 ', which are adjacent to each other, are made of a non-magnetic material, the slits between them are formed. It is possible to prevent the pseudo-gap effect of 15 and thus avoid the problem of crosstalk in the main track portion, and also avoid the problem of crosstalk from adjacent tracks.

In this way, a magnetic head is provided which prevents color flicker on the monitor due to vertical stripes on the monitor due to crosstalk of burst signals due to various crosstalks, that is, crosstalk of the burst signal due to the problem. The above configuration can avoid the cost increase due to the additional processing step which has been conventionally required.

Further, in the above structure, the magnetic head facing surface 5 side of the head chip 1 may be ground to the extent that the magnetic core 3 is not exposed. Therefore, such a head chip 1 is combined head such as a double azimuth head. When applied to, the distance between the gaps 7 and 7 ′ in the adjacent head chips 1.1 and 1 ′ can be set small. Thereby, each head chip 1 in the combination head
・ It becomes possible to improve the trackability of 1 '.

In the structure of the above embodiment, an example in which the magnetic core 3 is provided on one wall surface 8 of the mountain-shaped portion 6 has been described.
The present invention can also be applied to a magnetic head in which the magnetic cores 3 are provided on both wall surfaces 8 of the mountain portion 6, as shown in FIG.

Further, in the configuration of the above-mentioned embodiment, the example in which the magnetic head facing surface 5 is made of the non-magnetic material is given, but the magnetic head facing surface is formed by using the substrate in which the magnetic material and the non-magnetic material are laminated. A magnetic head in which the magnetic tape sliding surface 17 side of No. 5 is made of a non-magnetic material and the other magnetic head facing surface 5 portion is made of a magnetic material may be used.

[0037]

As described above, the magnetic head of the present invention has the following features.
In a magnetic head such as a combination head such as a double azimuth head which is arranged in proximity to each other in the magnetic head traveling direction and has a gap by a magnetic core, a magnetic tape sliding surface on a magnetic head facing surface which is close to each other. The side is made of a non-magnetic material.

Therefore, in the past, in order to avoid the above problems and, it was necessary to perform an additional processing step only to make the adjacent magnetic head facing surfaces into a shape that reduces the pseudo gap action between them. However, in the above configuration,
It is possible to eliminate the above-mentioned problems and to obtain a magnetic head by omitting an additional processing step as in the related art.

As a result, the above structure has an effect that it is possible to avoid an increase in cost due to an additional step which has been conventionally required for a magnetic head with reduced crosstalk.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram of the magnetic head mounted on a rotary 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-sided 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 schematic configuration diagram of a conventional magnetic head mounted on a rotary drum as a combination head.

FIG. 7 is a front view of each of the magnetic heads provided close to each other.

FIG. 8 is an explanatory diagram showing how each of the magnetic heads slides on a magnetic tape.

FIG. 9 is a conceptual diagram illustrating crosstalk that occurs when the magnetic heads slide on a magnetic tape.

FIG. 10 is a front view of another conventional magnetic head.

FIG. 11 is a front view of still another conventional magnetic head.

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

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

[Explanation of symbols]

 3 Magnetic core 5 Magnetic head facing surface 7 Gap 17 Magnetic tape sliding surface

Claims (1)

[Claims] 1. A magnetic head, such as a combination head such as a double azimuth head, which is disposed in close proximity along the direction of travel of the magnetic head and has a gap formed by a magnetic core. A magnetic head characterized in that the sliding surface side of the magnetic tape is made of a non-magnetic material.