JPS62140206A - magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a high-density recording/reproducing magnetic head used in fixed head video tape recorders, still video cameras, etc., and a method for manufacturing the same, and particularly relates to a magnetic head for high-density recording/reproduction used in fixed head video tape recorders, still video cameras, etc., and a method for manufacturing the same. The present invention relates to a magnetic head suitable for use with tapes and metal sheets.

[Background of the invention]

These various conventional magnetic heads, particularly magnetic heads having two magnetic gaps on the same straight line (referred to as in-line heads), have had a serious problem of crosstalk between the two magnetic head cores. For example, when recording is performed with one magnetic head gap, a leakage magnetic field is generated in the other magnetic head gap, and the gap contacts the recording medium, causing a minute recording action.

Additionally, if you try to read from a recording track where two magnetic gaps have been recorded at the same time, there is a problem that even if you try to obtain a reproduced signal from only one recording track, the signal from the other recording track will be mixed in. .

In-line heads of various structures have been proposed to reduce the occurrence of such losstalk. A typical example thereof is disclosed in Japanese Patent Application Laid-Open No. 60-5410. FIG. 3 is a diagram showing an example of the magnetic head core arrangement of a conventional in-line head. In Figure 3, 1.0, 1.1
are each magnetic head core, 12.13 is the adhesive part of the magnetic head core, 14.15 is each winding coil, 1
6.17 is the magnetic gap of each magnetic head core,
18 is a shield member made of a non-magnetic material, and 19 is a winding groove provided in the shield member. As shown in FIG. 4, such magnetic head forming parts are bonded together at portions 12 and 13 to form a magnetic head.

Note that this magnetic head core is configured in a dogleg shape or an inverted dogleg shape.

According to the magnetic head having such a configuration, the distance between the head cores increases as the distance from the magnetic gap increases,
Crosstalk occurring between both cores 10 and 1.1 can be suppressed to a small level.

However, with such a magnetic head core configuration, ■
It is difficult to process magnetic head cores shaped like a square or an inverted square with high dimensional accuracy. ■It is difficult to ensure dimensional accuracy when joining together with the shield member. ■Since the coil must be wound around the magnetic head core and then bonded, highly reliable bonding of glass, etc. cannot be performed.

(2) The process of joining individual magnetic head cores is very complicated and has drawbacks such as not being suitable for mass production. Furthermore, it is weak against the mechanical strength of the magnetic head core for narrow track heads of 100 μm or less required for high-density recording. Furthermore, when the distance Q between the two magnetic head cores is set to 50 μm or less, the mechanical strength of the shielding member is weak, making it extremely difficult to manufacture. Therefore, we applied for
No. 103,710 proposed a new in-line head that solved the above-mentioned drawbacks. FIG. 5 is a perspective view showing an example of an in-line head. In FIG. 5, 30, 30. '
is each core half, and this core half is a core base body 31 made of a non-magnetic material. ．． 31. 'consisting of magnetic gap 3
2. It has a projecting inclined surface toward the 32' direction. A magnetic thin film with high saturation magnetic flux density and high magnetic permeability 33.33
' and 34.34' are formed. The thicknesses are defined as track widths tw and tw1. The core halves 30° 30' formed in this way have their magnetic gap abutting surfaces ground and polished to obtain a predetermined guard band α, and are abutted through a predetermined non-magnetic gap film to create a magnetic field. A gap 32,32' is formed. 3
5 is a non-magnetic material such as glass, which joins the two core halves. Reference numeral 36 is a window for coil winding, and coil-wound high permeability ferrite pieces 37 and 37' are joined to both sides of the magnetic head core to form an in-line magnetic head having two magnetic gaps. At this time, the first magnetic head core has a closed magnetic path formed by the magnetic thin film 33, 33' and the ferrite piece 37, and the second magnetic head core has a closed magnetic path formed by the magnetic thin film 33, 33' and the ferrite piece 37.
．． 34' and the ferrite piece 37' form a closed magnetic path. By adopting such a structure, the first magnetic head core and the second magnetic head core are arranged at a predetermined interval of Q near the magnetic gap, and the structure is such that the interval increases in the longitudinal direction, resulting in less crosstalk. Recording and playback can be performed.

However, this structure has the disadvantage that it is not suitable for mass production because it is necessary to cut the magnetic head core into one chip and then bond the ferrite pieces to both sides of the head core. It wasn't given enough consideration.

[Purpose of the invention]

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and provide an in-line magnetic head suitable for high-density recording. Furthermore, it is an object of the present invention to provide a magnetic head that can form two magnetic head cores simultaneously and integrally using thin film forming technology, and that has high dimensional accuracy and is excellent in mass production.

[Summary of the Invention] In order to achieve the present invention, a plurality of protrusions having both inclined side surfaces are formed on the surface facing the magnetic gap of a core half made of a non-magnetic material, and both sides of the protrusion are formed. A magnetic thin film made of a magnetic material having a high saturation magnetic flux density is provided from the surface to the other slopes.

Further, the two magnetic head cores are separated by a predetermined width at the operating magnetic gap surface of the core halves, and the pair of core halves are joined to form an integral structure, and a closed magnetic path is formed only by the magnetic thin film. The magnetic head is configured so that In this way, the distance between the head cores becomes larger as the distance from the operating magnetic gap increases in the longitudinal direction, and a closed magnetic path is formed at the same time as the pair of core halves are joined, resulting in a high-performance integrated structure. In-line heads can be easily obtained.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 are perspective views illustrating one embodiment of the present invention, and the same parts in each figure are given the same reference numerals, and the explanation thereof will be omitted. The part indicated by the dotted line is a perspective view of the inside of the head.

In FIG. 1, 20 and 20' are core halves, and these core halves are core bases 21 and 21 made of non-magnetic material.
', and has a projecting inclined surface toward the working magnetic gap 22, 22' and the back gap 26, 26'. On this inclined surface, magnetic thin films 23.degree. 23' and 24.24' having high saturation magnetic flux density and high magnetic permeability are formed. Let the thickness be the track width tw and 1,/. In order to define the gap depth ga, a predetermined portion of the magnetic thin film from the recording medium sliding surface to the gap depth exposed on the surface facing the working gap is left, and a predetermined portion other than this is removed. FIG. 2 is an exploded view of the core halves before they are brought together. The Bd portion is a portion where a gap depth gci portion is left and other unnecessary magnetic thin films are removed. As a method for removing the magnetic thin film, for example, an ion milling method is used in which the magnetic thin film is irradiated with a laser beam and vaporized at a high temperature. Uses ultrasonic etching method. Cut and remove with a hard and sharp tool such as a diamond cutting tool. It is preferable to use a method such as cutting and polishing using a dicer. Furthermore, when an amorphous material is used in the magnetic thin film, it is not necessarily necessary to remove it; for example, it is sufficient to significantly deteriorate the magnetic properties of only a predetermined portion by irradiating it with a laser beam and heating it above the crystallization temperature. . The thus formed core halves 20° and 20' are ground and polished so that the magnetic gap abutting surfaces have a predetermined guard band width, and are butted together via a predetermined non-magnetic gap film, thereby forming an operating magnetic gap. 22.22' and back gap 26.26'
are formed simultaneously. 25 is a non-magnetic material such as glass, and is used to join the two core halves. 27.27
' is a coil winding window opening surface, which is formed at a predetermined distance n from the recording medium sliding surface 28.

With this structure, the first magnetic head core and the second magnetic head core are arranged at a predetermined interval Q in the vicinity of the magnetic gap, and the interval is widened in the longitudinal direction, so recording with less crosstalk can be achieved.・Can be played. Also, at the same time as joining the two core halves, the working magnetic gap 22.22' and the back gap 26.
Since a closed magnetic path is formed by 26', there is no need to join a ferrite core or the like for forming the magnetic path afterwards, and it is also excellent in mass productivity.

In addition, in FIG. 1, a core base 21 made of a non-magnetic material,
21' is non-magnetic ferrite (Zn ferrite), forsterite, photoceram, crystallized glass, barium titanate, calcium titanate, AQzOa-Ti
It is made of C-based ceramic or the like.

〔Effect of the invention〕

As explained above, according to the present invention, (1) two adjacent magnetic head cores can be integrally formed on a non-magnetic basis, and an in-line magnetic head with a narrow spacing between the magnetic head cores can be formed with high dimensional precision; It is effective in manufacturing.

(2) Since the structure is such that the magnetic head core can be formed using the slope of the non-magnetic base portion, the distance between the cores increases as the distance from the magnetic gap portion increases, which is effective in reducing crosstalk.

(3) The slope portion of the nonmagnetic substrate is composed of a V-shaped protrusion,
Since the magnetic film is deposited using a thin film formation technique, two magnetic head cores each having a narrow track can be arranged at a narrow interval, and a magnetic head with high recording and reproducing efficiency can be obtained.

(4) At the same time as the two core halves are joined, a closed magnetic path is formed by the operating magnetic gap and back gap, so
There is no need to join a ferrite core for forming a magnetic path afterwards, and it is also excellent in mass production.

[Brief explanation of drawings]

1 and 2 are perspective views of a magnetic head showing an example of the present invention, FIGS. 3 and 4 are assembled parts diagrams of a magnetic head and a perspective view of a magnetic head showing a conventional example, and FIG. 5 is a perspective view of another magnetic head. FIG. 2 is a perspective view of a magnetic head showing a conventional example. 20.20'...Magnetic core half, 21.21'...
Non-magnetic substrate, 22.22'...Magnetic gap of each magnetic head core, 23.23', 24.24'
...Magnetic thin film, 25...Nonmagnetic material, 26.26'
... Back gap, 27.27'... Coil winding window opening surface, 28.28'... Recording medium sliding surface, 29°29'... Coil winding.

Claims (1)

[Claims] 1. A magnetic head having two magnetic gaps on the same straight line, in which two core halves made of non-magnetic materials are joined via the magnetic gaps, and the core halves face the magnetic gaps. A core base having a protruding portion having both side faces inclined with respect to the side faces of the direction, and a magnetic thin film made of a magnetic material having a high saturation magnetic flux density deposited on the side face of the core base facing the magnetic gap. , the two magnetic head cores are separated by a predetermined width at the magnetic gap surface, and the magnetic head is configured as an integrated type, characterized in that the closed magnetic path is configured only by the magnetic thin film. magnetic head.