JPH0338645B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a composite magnetic head capable of high-density recording and reproducing, and more particularly to a bonding structure that increases the bonding strength between a recording/reproducing magnetic core and an erasing magnetic core.

"Prior art and its problems" In a recording method that forms recording tracks along the circumferential direction of a disc-shaped magnetic recording medium such as a magnetic disk, in order to increase the recording density, the track spacing is narrowed. , during recording, there is a crossfeed where adjacent recording tracks overlap, and during playback,
Leakage magnetic flux called crosstalk from adjacent recording tracks is likely to occur.

In order to solve this crosstalk problem, a composite magnetic head as shown in FIGS. 2 and 3 has been proposed. This composite magnetic head is
By scanning both sides in the width direction of the recorded track Tw recorded by the recording/reproducing gap 10, a guard band with almost no signal is created on both sides of the recorded track Tw.
It has the basic function of forming Te. By forming the guard bands Te on both sides of the recording track Tw in this way, even if the track spacing is narrowed,
No crossfeed or crosstalk between adjacent tracks occurs.

This conventional composite magnetic head consists of a magnetic core 11 on the recording/reproducing side and a magnetic core 21 on the erasing side, which are coupled via a non-magnetic layer 29 of ceramics, glass, etc. interposed between the two. . The recording/reproducing side magnetic core 11 and the erasing side magnetic core 21 are each
A pair of magnetic cores 12, 13 and magnetic cores 22, 2
The gaps between the two form the recording/reproducing gap 10 and the erasing gap 20, respectively. This recording/playback gap is 10
A non-magnetic material 14, 24, such as high melting point glass, is interposed in the erase gap 20.

Notch grooves 15, 15 are formed on both sides of the recording/reproducing gap 10 in the width direction, spanning between the magnetic cores 12 and 13. These notch grooves 15, 15 are for regulating the track width Tw, and inside thereof,
It is filled with a non-magnetic material (generally glass) 16.

In addition, in the center of the erasing gap 20 in the width direction,
Notch groove 2 with width Ew spanning between magnetic cores 22 and 23
5 is formed. This notched groove 25 regulates the erasing track width Te, and inside it,
Similarly, a non-magnetic material 26 is filled. The width Ew of the cutout groove 25 is set to be approximately the same as or smaller than the recording track width Tw. Further, the length Gl of the notched groove 25 in the track direction is usually set to be 20 times or more the gap interval of the normal erasing gap 20 in order to enable reliable erasing.

Coils 17 and 27 are wound around the magnetic core 13 on the recording/reproducing side and the magnetic core 23 on the erasing side, respectively.
Back bars 18 and 28 are bonded to the back surfaces of and 23, that is, the surfaces opposite to the running surface of the magnetic recording medium. The back bars 18 and 28 are both made of magnetic material, and the magnetic cores 12 and 13 and the back bar 18 constitute a closed magnetic circuit on the recording and reproducing side, and the magnetic cores 22 and 23 and the back bar 28 constitute a closed magnetic circuit on the erasing side. Configure.

However, in this conventional composite magnetic head, the recording/reproducing side magnetic core 11 and the erasing side magnetic core 21 are simply bonded via the non-magnetic layer 29, so there is a problem that the bonding strength between the two is weak. It was hot. Furthermore, since the back bars 18 and 28 on the recording/reproducing side and the erasing side face each other with a thin non-magnetic layer 29 interposed therebetween, they are extremely close to the erasing side magnetic core 21 and the recording/reproducing side magnetic core 11, respectively. A slight misalignment will result in insufficient isolation of the magnetic circuit between the magnetic circuit on the recording/reproducing side and the magnetic circuit on the erasing side.
This had a negative impact on both recording, playback, and erasure.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems with conventional composite magnetic heads and to increase the bonding strength between the recording/reproducing magnetic core and the erasing magnetic core. Another object of the present invention is to provide a magnetic head in which when backbars are provided on the recording/reproducing side and the erasing side, the backbars are less likely to have an adverse effect on both magnetic circuits, and furthermore, the workability of attaching the backbars is good. do.

"Summary of the Invention" The composite magnetic head of the present invention has a magnetic core on the recording and reproducing side and a magnetic core on the erasing side, on the joining surface of the magnetic core on the opposite side to the side on which the magnetic recording medium runs, between the two cores. A bonding reinforcing groove is formed that spans the entire length, and this bonding reinforcing groove is filled with a bonding material made of a non-magnetic material, and a back bar on the recording/reproducing side (or for) and a back bar on the erasing side (or for) are made of non-magnetic material. The joint width of the integrated back bar with the non-magnetic material interposed is the width of the joint reinforcing groove formed on the joint surface of the magnetic core on the recording/reproducing side and the magnetic core on the erasing side. It is characterized by being smaller than the width. By forming the bond reinforcing groove and filling it with the bonding material in this manner, the bonding area between both cores and the bonding material can be increased, thereby increasing the bonding strength. In addition, since the width of the bond reinforcing groove is larger than the conventional gap between both cores, the width of the bond reinforcing groove formed on the bonding surface of the magnetic head on the recording/reproducing side and the erasing side is greater than the width of the back bar. By making the joint width small, the tolerance of the joint can be increased, and the workability of attaching the back bar can be improved.

"Embodiments of the Invention" The present invention will be described below with reference to illustrated embodiments. FIG. 1 shows an embodiment of a composite magnetic head according to the present invention, and the same elements as those of the conventional product shown in FIGS. 2 and 3 are given the same reference numerals. This example is
The notched grooves 31 and 32 formed in the recording and reproducing side magnetic core 11 and the erasing side magnetic core 21 are formed not as a through type but as a bottomed type, thereby making the magnetic path of the magnetic cores 12 and 22 thicker and increasing the mechanical strength. The present invention is applied to an increased number of magnetic heads. The bottom walls of the notched grooves 31, 32 are deeper toward the joint surfaces of both cores 11, 21, and are open on the joint surface side. The cutout grooves 31 and 32 have the same function as the cutout grooves 15 and 25 of the conventional product in terms of magnetic recording and reproduction, and their insides are filled with a nonmagnetic material 33 such as glass. This non-magnetic material 33 extends from the communication hole in the bottom of the notch grooves 31 and 32 to the winding groove 34 and
35 also flows into the upper part of the magnetic cores 12 and 13,
and serves to join the magnetic cores 22 and 23 together.

The present invention also provides the above-mentioned recording/reproducing side magnetic core 1.
A bonding reinforcing groove 40 is formed on the bonding surface between 1 and the erasing magnetic core 21 on the side opposite to the running surface of the magnetic recording medium, and this bonding reinforcing groove 40 is filled with a bonding material 41 made of a non-magnetic material. It is characterized by This bonding material 41 is the magnetic core 1 to be bonded.
In consideration of the materials No. 2 and 22, a bonding material such as glass or resin is selected and used. Also, this bonding material 4
1 may be the same material as the non-magnetic layer 29 interposed between the recording/reproducing side magnetic core 11 and the erasing side magnetic core 21, or may be a different material.

By forming the bonding reinforcing groove 40 and filling it with the bonding material 41, the magnetic cores 11, 12
Since the bonding area with the magnetic cores 21 and 22 increases, the bonding strength between both cores can be increased. Furthermore, freedom in selecting the material of the bonding material 41 is also advantageous for increasing the bonding strength.

The present invention further includes a back bar 18 on the recording/reproducing magnetic circuit side and a back bar 28 on the erasing side magnetic circuit.
are integrated with a non-magnetic material 50 sandwiched between them to form an integrated back bar 51. The width w of this nonmagnetic material 50 is equal to the width w of the bonding reinforcement groove 4.
It is set smaller than the width W of 0.

The integrated back bar 51 in which the back bars 18 and 28 are integrated in advance in this way can be more easily fixed to the rear side surface of the magnetic cores 11 and 21 than when the back bars 18 and 28 are separate bodies. Furthermore, the widths W and w of the bonding reinforcing groove 40 and the non-magnetic material 50 are
By providing a difference in the integrated back bar 51
The permissible value of displacement in the longitudinal direction becomes larger.
That is, within the range of width W, the non-magnetic material 5 of width w
As long as 0 changes its position, the recording/reproducing side back bar 18 will not have an adverse effect on the erasing side magnetic circuit, and the erasing side back bar 28 will not have an adverse effect on the recording/reproducing side magnetic circuit, so the allowable value for positional deviation becomes large. . And this means that back bars 18 and 2
According to the present invention, the positioning of the back bars 18 and 28 is facilitated, and the possibility that the magnetic circuits on the recording/reproducing side and the erasing side are mutually adversely affected is reduced. .

In the above embodiment, the present invention is applied to a composite type magnetic head in which the cutout grooves 31 and 32 have a special shape, but the present invention is applicable to the conventional magnetic head shown in FIGS. , and other composite magnetic heads.

FIG. 1b shows a state in which sliders 60, 60 are joined to both sides of the composite magnetic head described above.

[Effects of the Invention] As described above, according to the present invention, in a composite magnetic head, the bonding strength between the recording/reproducing side magnetic core and the erasing side magnetic core can be increased. In addition, the positioning of the back bar that closes both the magnetic circuits on the recording and reproducing side and the erasing side is achieved by making the joint width of the back bar smaller than the width of the reinforcing groove formed on the joint surface of the magnetic cores on the recording and reproducing side and the erasing side. The tolerance for the combination can be increased, making it easier to assemble, and the tolerance for misalignment is increased, which eliminates the negative effect on the magnetic circuit caused by misalignment of the back bar.Furthermore, the back bar installation work can be simplified, making work easier. Sexuality improves.

[Brief explanation of the drawing]

FIG. 1a is a perspective view showing an embodiment of the composite magnetic head of the present invention, FIG. 1b is a perspective view of the slider attached, FIG. 2 is a plan view of a conventional composite magnetic head, and FIG. is a front view of the same. 10... Recording/reproducing gap, 11... Recording/reproducing side magnetic core, 12, 13... Magnetic core, 18...
Back bar, 20... Erasing gap, 21... Erasing side magnetic core, 22, 23... Magnetic core, 28...
...Back bar, 31, 32...Notch groove, 40...
Bonding reinforcement groove, 41... Bonding material, 50... Non-magnetic material, 51... Integrated back bar.

Claims (1)

[Scope of Claims] 1. A pair of magnetic cores constituting a recording/reproducing gap, a recording/reproducing back bar located on the back side of the pair of magnetic cores and forming a closed magnetic circuit with the pair of magnetic cores, and the above-mentioned recording/reproducing device. A recording/reproducing magnetic core having cutout grooves located on both sides of the gap to regulate the recording/reproducing track width, and a pair of magnetic cores located on the back side of the pair of magnetic cores forming a pair of erasing gaps located on both sides of the recording/reproducing track. The pair of magnetic cores are joined to an erasing back bar constituting a closed magnetic circuit and an erasing magnetic core having a notch for regulating the erasing track width by the erasing gap, and the recording/reproducing magnetic core and erasing magnetic core are connected to each other. A bonding reinforcing groove extending between both magnetic cores is formed at the joint surface with the core where the recording and reproducing back bar and the erasing back bar are located, and this bonding reinforcing groove is filled with a bonding material, and further the recording and reproducing back bar and the back bar for recording and reproducing are formed. In a composite magnetic head consisting of a back bar integrated with a back bar for erasing with a non-magnetic material interposed therebetween, the width of the joint of the integrated back bar with the non-magnetic material interposed is equal to the width of the magnetic core for recording/reproducing and the erasing core. A bonding structure for a composite magnetic head, characterized in that the width is smaller than the width of a bonding reinforcing groove formed on a bonding surface with a magnetic core.