JP2836031B2 - 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 for recording or reproducing mounted on a device such as a video tape recording / reproducing device, an audio tape recording / reproducing device, an audio / video soft tape duplicating device or a digital recording / reproducing device. About.

[0002]

2. Description of the Related Art A conventional magnetic head comprises two cores 100 and 101 and a winding 102 as shown in FIG.
The core 100 and the core 101 are bonded or welded so that a necessary gap length is formed in the magnetic gap 103. The cores 100 and 101 are formed of a single magnetic material such as a single crystal ferrite or a polycrystal ferrite, and are used for a magnetic head such as a magnetic tape recording / reproducing machine and a soft tape duplicator for audio / video.

[0003]

In the prior art, the core is formed of the same material. For example, in the case of using single crystal ferrite, the magnetic tape and the tape sliding surface having a magnetic gap are not provided. There has been a problem that frictional noise easily occurs due to friction, and the S / N ratio at the time of recording and reproduction is reduced. Also, when using polycrystalline ferrite, there are unstable elements that are liable to cause chipping of particles due to remaining vacancies and grain boundaries. There is a problem of having an unstable element that significantly impairs the performance of the device.

Further, there are proposals in which the entire ring core is laminated with a thin-plate magnetic alloy, one in which the magnetic tape contact side is a laminated core with a thin-plate magnetic alloy, and one in which the back core side is formed of a ferrite material. Also in the case of (1), the sliding surface of the magnetic tape is a metal core, and has a problem that the abrasion resistance is inferior to that of ferrite and the life of the head is short.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to improve abrasion resistance to a magnetic tape, reduce sliding noise, and provide a wide band. It is an object of the present invention to provide a magnetic head capable of obtaining high sensitivity.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a magnetic circuit in which a core contacts a magnetic tape.
Divided into a front core and a back core
The front core is the tape contact core
Is a single crystal ferrite and the back core contact side core is polycrystalline
It is made of ferrite, and the tape contact side core and
Joint with the core on the hot side
Made of ferrite, and the back core is a thin magnetic plate with high magnetic permeability
It is formed of a laminated core made of alloys, and this laminated core is
Most of the circuit is composed of three types, including the back core.
The magnetic circuit is made of a material.

[0007]

[0008]

[Function] The back core is laminated with a thin magnetic alloy with high magnetic permeability.
The core of the magnetic circuit
By configuring the components and combining the core material, the magnetic resistance of the magnetic circuit is reduced, the magnetic permeability is increased, and the frequency characteristic of the magnetic permeability is broadened. Further, the recording / reproducing sensitivity of the magnetic head is high and the band is wide, and at the same time, the abrasion and sliding noise due to friction with the magnetic tape are reduced.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a schematic perspective view of a magnetic head according to the present invention , FIG. 2 is a schematic perspective view of a magnetic head of another embodiment according to the present invention, and FIG. 3 is an audio magnetic head to which the magnetic head according to the present invention is applied. It is sectional drawing of a head.

[0010] As shown in FIG. 1, magnetic head 1, two using a magnetic material, the front core piece 2a of two pieces formed by strong wear single crystal ferrite, a front core 2 consisting 2b, magnetic Back core 3 formed by laminating thin plate alloys to obtain high magnetic permeability over a wide band as a circuit
And a winding 4 applied to the back core 3. 4a and 4b are ends of the winding 4.

The back core 3 is formed by molding a thin plate-shaped alloy into a back core shape by etching or die-cutting, and insulating the surface of the alloy to form a multilayer, or by laminating multiple layers by vacuum evaporation. After laminating the shape alloy in multiple layers, it is formed into a back core shape.

The back core 3 is bonded to the front core 2 so that two front core pieces 2a and 2b form a predetermined magnetic gap 5. At this time, the joint surface 6 where the front core 2 and the back core 3 face each other forms a mirror surface.

[0013] a description of the operation of the magnetic head 1, which is configured as described above. By reducing the thickness of the front core 2, it is possible to reduce the sliding noise that is easily generated by the sliding of the magnetic tape. In particular, when the thickness of the front core 2 is polished to 0.5 mm or less, the effect is large.

Also, two pieces of front core pieces 2a, 2
The front core 2 has low noise by being adhered to the back core 3 or welded with glass or other non-magnetic material so that b forms a predetermined magnetic gap 5.

Also, since the joint surfaces 6 of the front core 2 and the back core 3 are both mirror surfaces, the magnetic resistance can be reduced, and the front core 2 made of single crystal ferrite and the laminated thin plate alloy are formed. The whole magnetic circuit composed of the back core 3 can have a high magnetic permeability and a wide band.

As shown in FIG. 2, a magnetic head 10 of another embodiment uses three types of magnetic materials,
A front core 14 composed of two pieces of front core pieces 13a and 13b formed of single crystal ferrites 1a and 11b and polycrystalline ferrites on the back core contact side cores 12a and 12b, and obtains high magnetic permeability over a wide band as a magnetic circuit. A back core 15 formed by laminating sheet-like alloys,
And a winding 16 applied to the back core 15. Note that 16a and 16b are ends of the winding 16.

The two pieces of front core pieces 13a and 13b constituting the front core 14 are composed of tape contact side cores 11a and 11b formed of single crystal ferrite and back core contact side cores 12a and 12b formed of polycrystal ferrite.
Are magnetically tightly joined at the hot pressing joint surface 17 by mutual diffusion.

The back core 15 is formed by molding a thin plate-shaped alloy into a back core shape by etching or punching, and insulating the surface of the alloy to form a multilayer, or by laminating an insulating layer on the surface by vacuum evaporation. After laminating the shape alloy in multiple layers, it is formed into a back core shape.

The back core 15 is bonded to the back core contact side cores 12a and 12b constituting the front core 14 so that the two front core pieces 13a and 13b form a predetermined magnetic gap 18. At this time, the joint surface 19 where the back core contact side cores 12a and 12b and the back core 15 face each other forms a mirror surface.

The operation of the magnetic head 10 according to another embodiment configured as described above will be described. The tape contact side cores 11a and 11b which are in contact with the magnetic tape are formed of a single-crystal ferrite having high wear resistance, and the back core contact side cores 12a and 12b behind the cores are formed of a polycrystalline ferrite having little sliding noise. They are formed and joined by mutual diffusion by joining by hot pressing. For this reason,
The ferrite materials are welded to each other and mechanically and magnetically tightly coupled, and at the same time, only the magnetic gap 18 can be formed of ultra-thin single crystal ferrite, further reducing sliding noise. .

Further, since the back core 15 formed by laminating thin plate-like alloys constitutes most of the magnetic circuit including the winding 16, the conventional single crystal ferrite and polycrystal ferrite are hot-rolled. Compared to pressure-bonded magnetic heads
Further, the overall magnetic permeability is increased, and a magnetic head having a wide band and high sensitivity is configured.

Further, when the magnetic heads 1 and 10 according to claim 1 or 2 using a plurality of magnetic materials are mounted on a video signal recording / reproducing apparatus or a digital signal recording / reproducing apparatus, the mounting structure is as follows. If the size of the head 10 itself is reduced, when the head is mounted on the rotary drum, the head may be temporarily mounted on the pedestal and then fixed to the rotary drum.

FIG. 3 shows an audio magnetic head 30 using the magnetic head 1 according to the present invention . The audio magnetic head 30 includes a magnetic head 1 and a spacer 3.
1 and the front core 2
The terminal 4 is provided through a terminal plate 33 fixed to the head body 32 on the opposite side to the terminal 34 and the terminal 4 is connected to the winding 4 via a lead wire 35. Reference numeral 36 denotes an adhesive.

[0024]

According to the present invention as described above, according to the present invention, Ba
Laminated core made by laminating a thin magnetic alloy with high magnetic permeability
This core forms the majority of the magnetic circuit
And the core material is compounded, so the magnetic resistance of the magnetic circuit
Is small, the magnetic permeability is high, and the frequency characteristic is wide.
High sensitivity recording and reproduction characteristics can be obtained. Also magnetic
Reduce wear and sliding noise caused by friction with the tape.
Can be.

[Brief description of the drawings]

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

FIG. 2 is a schematic perspective view of a magnetic head according to another embodiment of the present invention .

FIG. 3 is a sectional view of an audio magnetic head to which the magnetic head according to the present invention is applied;

FIG. 4 is a schematic perspective view of a conventional magnetic head.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/133 G11B 5/147 G11B 5/255

Claims (1)

(57) [Claims] 1. A magnetic head core constituting a magnetic circuit is divided into a back core winding the front core and the conductor in contact with the magnetic tape, before SL front core, a tape contact side core in a single-crystal ferrite, the back core The contact-side core is formed of polycrystalline ferrite, and the tape-contact-side core and the back-core contact-side core are formed of a bonded ferrite in which the core and the back core are bonded to each other by hot pressing, and the back core is a thin plate having a high magnetic permeability. Laminated magnetic alloy
It is formed by a laminated core, and this laminated core forms most of the magnetic circuit.
Magnetic head is characterized in that configuration, and constitutes a magnetic circuit in three core materials, including pre-SL back core.