JPS581820A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain the high efficiency of reproduction, by providing a continuous alloy material layer having high magnetic flux density ranging from a magnetic tape contact surface through a rear gap part on the butted surface of the core half body at the play side of the tape among a pair of core half bodies and forming a working gap between said alloy material layer and a core half body of the other side. CONSTITUTION:A pair of core half bodies 11 and 12 are formed with a ferrite material. An alloy material layer 14 (such as ''Sendust '',) of the saturation magnetic flux density higher than said ferrite material is formed to the core 12 at the play side[toward arrow (a)]of a magnetic tape 13 and on the surface to be butted to the other core 11. The layer 14 is continuous with at least a distance (l) a 3-10mu thickness and ranging from the tape contact surface through a rear gap 16 over a winding groove 15. As a result, the loss of current is reduced in the reproduction mode with an increment of the reproduction efficiency compared with a conventional head, and the recording is possible in the same way as conventional. Thus a recording/reproducing head is obtained to be suitably used to a tape having high resistance to magnetism.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording/reproducing magnetic head used in a magnetic recording/reproducing device.

Conventionally, magnetic heads for recording and reproducing Takamakura magnetic tapes have a specific resistance of 111, as shown in TFJll&l 5.
) Otakuia! material (Mn-Zn system, Ni-Z
In addition to forming the main core bodies (1) and (2) from K (n type) K, only the vicinity of the working gap g, which is likely to be magnetically saturated, is made of an alloy magnetic material with a large saturation magnetic flux density Bs, such as Sendas l [13JK]. There is something configured. (4) is a winding hole. In addition, it is 511m as shown in Figure 2.

Both core housings (1) and + including the part of the working gap g
A magnetic head having a mK sendust film (3) coated on the entire mating surface of No. 27, or a core half hole provided with a winding hole (4) among a pair of core half holes as shown in FIG. (2)
A magnetic head has been proposed in which a sendust film (3) is deposited only on the alignment ff1k.

All of these magnetic heads based on composite cores are suitable for use with high-strength magnetic tapes. However, during playback, the ferrite core (1 bar 2) and sendust film (3)
1113)
No. 5, there was a drawback that the regeneration efficiency deteriorated due to the large current loss. Incidentally, the above-mentioned magnetic head has a deterioration of -3 dB compared to a single ferrite head, so it is difficult to use it for both recording and reproducing Al and coercive tapes.

In view of the above-mentioned points, the present invention provides a magnetic head which is suitable for application to a dual-purpose recording/reproducing head for, for example, a magnetic tape, which eliminates the magnetic saturation of the head and improves reproduction efficiency. It is to do.

The magnetic head of the present invention will be explained below using examples.

In the present invention, k as shown in FIG. 4, for example.

A pair of core halves Iυ and αat are formed of a ferrite material (for example, Mn-Zn system, N1-Zn system, etc.) K, and among the core halves aυ and 0, the escape of the magnetic tape αJ running in the direction of arrow a. In addition to the core half-closed A, an alloy high magnetic flux material layer A4V is formed on the surface that abuts against the core housing αυ, and an operating gap G is formed between this material layer Q4 and the other core half-closed all. For the 0 alloy high flux density material layer a, a material having a higher flux density Bs than the ferrite # constituting the core halves uu and aat, such as a Sendust film, can be used. In this case, the alloy high magnetic flux density material layer, ie, the sendust film I, is 41! Continuously extend at least the distance beyond I hole A3 to the rear gear part 4, in this example the entire length of the core half! Form continuously. The thickness d of the sendust film a4 is 3 to 10 microns, preferably 5 to 7 microns. If the film thickness d is thinner than 3^, the magnetic saturation cannot be improved and the output decreases.

According to the magnetic head having such a configuration, only one core half αaK (where the magnetic tape escapes) is formed with a continuous and uniform high saturation magnetic flux density material such as the Sendust film α4, so that the Sendust film α oozes out during playback. eddy current loss is low,
In addition, since the raw magnetic flux aη passes through the continuous and uniform sendust film α4, the influence of the large magnetic resistance at the sendust-ferrite interface is reduced, and the reproduction efficiency is improved compared to the conventional head. Also, recording is determined by the magnetic field finally applied to the magnetic tape (13).
Since the sendust film I is formed on the core half α2 of No. 13, there is no magnetic saturation here (recording can be performed in the same way as in the conventional case).

The jIs diagram shows the recording characteristics of the present invention and the conventional magnetic head, and the 6th Ia shows the self-recording and reproducing characteristics of the present invention and the conventional magnetic head.
These are the results when only recording No. 1 up to 9 MHz and when self-recording and reproducing. In the same figure, -1! (f) (1') is the main magnetic head (configuration shown in Figure 4), - line (1)
(1') is the conventional magnetic head shown in Fig. 2;
1') is a conventional 3rd IiltI) magnetic head, curve (N
) (Me is a magnetic head made of a single ferrite.This fifth
From the figures and Fig. 1s6, it can be seen that the magnetic head of the present invention can record on high-magnetic magnetic tape and has the same reproduction efficiency as ferrite alone. Therefore, the magnetic head of the present invention is suitable for use as a recording/reproducing head for a magnetic tape.

FIG. 7Bk shows an example of the manufacturing method of the magnetic head shown in FIG. First, as shown in No. 711A, a pair of half-core blocks ab and az made of 7-elite material are provided, and one of the half-core blocks is machined using a QIJK machine (grindstone) *t.
A Ti groove αR and a pack groove αS for glass insertion are formed. Next, after mirror-finishing the abutting surface (12d) of the other half-core block o4 by mechanocareal polishing, sputtering device a9 shown in FIG. 7Bk
A sendust film α thick is formed on the mirror-finished surface (12!1) of the core cow body block i. C
O is the sendust source. Next, both; a half body push α
υ and az are butted together through a gap spacer, and for example, a winding groove acJ and a back groove α8V and a low melting point gas 2s @ are inserted, heat treated, joined by glass fusion, and then cut to a predetermined width. and chain 11-. The tape contacting surface is polished to the position indicated by '61, and the rear part is cut off to obtain a head chip, that is, a desired magnetic head.

Conventionally, the two core halves are simultaneously fused together by placing glass having the same melting point in the winding groove and the pack 111Q. In this case, the grip part (operating gap side) also pack part (
The reliability of the core bond is good, but the glass (211) is the ferrite core part and the block (121 and Sendust II (
141, KlfC oozes out, a pseudo gap occurs, and the amount of crosstalk becomes poor. Although the pseudo gap is slightly improved by keeping the fusion temperature low, the reliability of the bond deteriorates and chip peeling occurs.

Therefore, in the present wA, the above-mentioned problem is improved by: *Glass having different softening points are inserted into the line groove α9 and the back groove αIK, respectively, and the glass is fused.

That is, as shown in FIG. 8, the winding groove α9 and the back groove a8
After butting the ferrite core semi-dead block (111) with the ferrite core semi-dead block (111) and the ferrite core semi-dead block a3 coated with the sendust film a4 against each other, a glass with a high softening point, for example, 385C, is placed in the winding groove i. A glass c3 with a low softening point, for example, Boor, is inserted into the back groove α seconds and simultaneously fused.In this way, the flow of the glass in the front part is as shown in Figure K119 and As shown in FIG.
It is cooled without reaction or diffusion. That is, in the front part, the glass Ω does not enter the track width regulating groove (2). On the other hand, since the glass of the back part has a low softening point, it is in a liquid state and reacts and diffuses as shown in FIGS. 11 and 12 to form a strong glass bond.

In addition, the difference in the softening points of glass and glass is allowed to be in the range of 5C to 50C. When cutting out the block completed in this way as a head chip, the 5-sit property is sufficiently high and the yield is improved.

No. 1311 shows the pseudo-gap state of the magnetic head obtained by conventional glass fusing, and No. 14 WJ shows the pseudo-gap state of the magnetic head obtained by glass fusing according to the present invention.・As shown in this $13 cabinet, in the conventional glass fusion method, if the output level at the working gap is OdB, -1
Although a pseudo-gap output (up to) of dBQ degree is generated, according to the glass fusion method of the present invention, the pseudo-gap output drops to less than -30 dB as shown in FIG. 14, and is greatly improved. In addition, even in the case of the magnetic head shown in FIG. 2, for example, in which the butt mfK of both ferrite cores is coated with a sendust film, the conventional glass fusion bonding causes a drop of -14 dB to -15 dB on the left side of the 13th WJ. However, if the glass fusion of the present invention is used, the pseudo-gap output of 100 dB is reduced to less than -30 dB, which is an improvement of 15 bB@ degree.

In addition to clay figurines, the present invention is also applicable to g 151KJK.As shown in FIG. Including 5:' It can also be constructed by forming a continuous uniform sender) l[Q4) of the abutment IIK of the cow body α2.

In addition, as shown in Fig. 16, the tape contacting surface that forms the working gap g is made of single crystal 7E2ite 3υ, and the other parts forming the main magnetic path are made of polycrystalline ferrite.
In the head core formed by , the tape relief is similar to the clay figurine on the mating surface of the core half-closed a3).
It can be configured by forming l(1◆). In this configuration, it is possible to record and play with K and Takamura magnetic tapes like clay figurines, and at the same time, the tape pair 11! plane is made of single crystal ferrite on ll#. ) Because of C311, there is less wear, and because the crystal plane can be selected, uniform characteristics can be achieved.Also, because the main magnetic path is made of polycrystalline ferrite (2), a high-output magnetic head with little sliding noise can be obtained.

As mentioned above, the present WAK can prevent magnetic saturation of the head core and improve playback efficiency, and is therefore suitable for application to, for example, a ginkgo head for high coercive force tapes. .

[Brief explanation of drawings]

111 to 8311 are cross-sectional views showing examples of conventional magnetic heads, FIG. 1114 is a cross-sectional view showing an embodiment of the magnetic head according to the present invention, and FIG. 6 is a theory of the present invention @
Recording characteristics diagram and self-recording characteristics diagram provided for, No. 711 ~
D is the 4th! Elf) Fig. 1M showing an example of the manufacturing method of a magnetic head, Fig. 8 is a sectional view showing an example of the glass fusing method that can be applied to the present invention, Fig. 189 and Fig. 10 are glass fusing of the front part. Figures 11 and 12 are 11th and 11th views showing the state of glass fusion in the back part, a sectional view on B-Bll, and a sectional view on B-Bll.
Figures 3 and 14 show the state of the pseudo gap of the magnetic head obtained by the conventional glass fusion method, respectively. A characteristic diagram representing the state of the pseudo gap of the magnetic head obtained by the glass fusing method of the present invention, and FIG. 15 and FIG. 16 are cross sections showing other embodiments of the magnetic head according to the present invention, respectively. It is a diagram. , Oυα is the core half-hole, Q41 is the alloy high magnetic density material layer, and a9 is the IIk wire hole. Figure 2 Figure 3 Figure 13 Figure 14 Figure 1S Figure 18

Claims (1)

[Claims] It has a pair of core half-holes that are butted against each other, and one tape is attached to the surface of the pair of core half-holes on the escape side of the magnetic tape and the other core half-hole is connected to the other core half-hole from the opposing surface to the rear. gap S
<A magnetic head comprising a continuous layer of alloy high magnetic flux dense material, and an operating cap formed between the layer of material and the other half of the core.