JPS61217919A - Back bar joint structure of composite type magnetic head - Google Patents

Abstract

PURPOSE:To execute easily positioning, and to improve the workability by integrating a back bar at a recording/reproducing side and a back bar at an erasing side, aligning its non-magnetic material with the joint surface position of a recording/reproducing magnetic core and an erasing magnetic core, and joining said unified back bar to the joint body of both the cores. CONSTITUTION:The back bar 18 of a recording/reproducing magnetic circuit, and the back bar 28 of an erasing side magnetic circuit are integrated in advance in a state that a non-magnetic material 40 is inserted and attached between both said bars, and this unified back bar 41 is joined to the side face of the rear part of magnetic cores 11, 21. Also, on the joint surface of the recording/reproducing magnetic core 11 and the erasing side magnetic core 21, a joint reinforcing groove 50 is formed at the side opposite to the running surface of a magnetic recording medium, and this joint reinforcing groove 50 is packed with a joining material 51 consisting of a non-magnetic material. When the joint reinforcing groove 50 is formed in such a manner and it is packed with the joining material 51, the joint area of the magnetic core 11 (12) and the magnetic core 21 (22) increases, therefore, the joint strength of both the cores can be strengthed.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a composite magnetic head capable of high-density recording and reproduction, and particularly to a joining structure of a back bar that closes a recording/reproducing side magnetic circuit and an erasing side magnetic circuit.

"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, the track spacing is narrowed to increase the recording density. ,
During recording, crossfeed where adjacent recording tracks overlap, and during reproduction, leakage magnetic flux called crosstalk from adjacent recording tracks tends to occur.

In order to solve this crosstalk problem, a composite disk magnetic head as shown in FIGS. 2 and 3 has been proposed. This composite magnetic head covers both sides of the recording track ↑ in the width direction recorded by the recording/reproducing gap lO.
As the pair of erasing heads 20 and 20 scan,
On both sides of the recording track Tw, there are guard I with no signal.
By forming the guard bands To on both sides of the recording track Tw, which have the basic function of forming a guard band, crossfeed and crosstalk between adjacent tracks can be prevented even if the track spacing is narrowed. It will no longer occur.

This conventional composite magnetic head has a magnetic core 1 on the recording/reproducing side.
1 and an erase-side magnetic core 21 are coupled through a non-magnetic layer 29 of ceramics, glass, etc. interposed between the two. The recording and reproducing side magnetic core 11 and the erasing side magnetic core 21 are each constructed by coupling a pair of magnetic cores 12.13 and 22.23, and the air gap between them is the above-mentioned recording and reproducing gap lO. and an erase gap 20 is formed. A non-magnetic material 14, 24 such as high melting point glass is interposed in the recording/reproducing gap 10 and the erasing gap 20, for example.

On both sides of the recording/reproducing gap lO in the width direction, there are magnetic cores 1
A cutout groove 15.15 is formed spanning between 2 and 13. This notch groove 15.15 regulates the above-mentioned track width Tw, and the inside thereof is made of non-magnetic material (generally glass).
16 is filled.

Further, a notch groove 25 having a wide width Ew is formed in the widthwise center of the erasing gap 20 so as to span between the magnetic cores 22 and 23 . This cutout groove 25 regulates the erase track width Te, and the inside thereof is similarly filled with a nonmagnetic material 26. The width Ew of the notch 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 normally 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 and reproducing side and the magnetic core 23 on the erasing side, respectively, and the back surfaces of the magnetic cores 12 and 13 and the magnetic cores 22 and 23, that is, the running surface of the magnetic recording medium. on the opposite side, back par 18
and 28 are joined. The backpers 18, 28 are both made of magnetic material, and the magnetic core 12, 13 and the backer 18 form a closed magnetic circuit on the recording and reproducing side, and the magnetic core 22, 23 and the backer 28 form a closed magnetic circuit on the erasing side. Configure a magnetic circuit.

However, this conventional composite magnetic head
8 and 28 are separate bodies, and individually between the magnetic cores 12 and 13,
Since it must be fixed between the magnetic cores 22 and 23, not only is the fixing work complicated, but it is also difficult to fix it in the correct position. For example, if the backper 18 on the recording/reproducing side protrudes toward the magnetic core 22 on the erasing side, the magnetic circuit on the recording/reproducing side and the magnetic circuit on the erasing side will not be sufficiently cut off, and the recording/reproducing and erasing There were negative effects on both sides.

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 provide a joining structure that can easily join backers on the recording and reproducing side and the erasing side. Another object of the present invention is to provide a magnetic head that increases the tolerance for positional deviation of the backper and that even a slight positional deviation is unlikely to have an adverse effect on both the recording/reproducing and erasing magnetic circuits.

"Summary of the Invention" In order to achieve the above object, the composite magnetic head of the present invention integrates a backper on the recording and reproducing side and a backper on the erasing side with a nonmagnetic material sandwiched between them. This integrated back bar is characterized in that the non-magnetic material is joined to the joined body of the recording/reproducing magnetic core and the erasing magnetic core, with the non-magnetic material aligned with the joining surface position of the magnetic core for recording and reproducing and the magnetic core for erasing.

"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. In this embodiment, the notch grooves 31 and 32 formed in the recording/reproducing side magnetic core 11 and the erasing side magnetic core 21 are formed not as a through type but as a bottomed type, and the magnetic path of the magnetic core 12 and 22 is made thicker. , the present invention is applied to a magnetic head with increased mechanical strength. The bottom wall of this notched groove 31.32 is deeper toward the joint surface of both cores 11.21, and is open on the joint surface side. This notch groove 31.32 is
Regarding magnetic recording and reproduction, the conventional notched groove 15.
25, and its inside is filled with a non-magnetic material 33 such as glass. This non-magnetic material 33 is inserted into the winding groove 34 from the communication hole at the bottom of the cutout groove 31, 32.
It also flows into the upper part of the magnetic core 12 and 13 and serves to join the magnetic cores 12 and 13 and the magnetic cores 22 and 23.

The present invention also provides a backper 18 on the recording/reproducing magnetic circuit side.
and the back part 28 of the erase side magnetic circuit are integrated in advance with a non-magnetic material 40 sandwiched between them, and this integrated back part 41 is joined to the rear side surfaces of the magnetic cores 11 and 21. There is.

The present invention further includes forming a bonding reinforcing groove 50 on the bonding surface of one or more of the recording/reproducing side magnetic cores 11 and the erasing side magnetic core 21 on the side opposite to the running surface of the magnetic recording medium, and in this bonding reinforcing groove 50, It is filled with a bonding material 51 made of a non-magnetic material. By forming the bonding reinforcing groove 50 and filling it with the bonding material 51 in this way, the bonding area between the magnetic core 1l (12) and the magnetic core 21 (22) increases, thereby increasing the bonding strength between both cores. I can do it. The radius W of this bond reinforcing groove 50 is set larger than the width W of the non-magnetic material 40 of the integrated backper 41.

The integrated backper 41 in which the backpers 18 and 28 are integrated in advance in this way is easier to fix to the rear side surface of the magnetic cores 11 and 21 than when the backpers 18 and 28 are separate. Further, by providing a difference between the widths W and W of the bond reinforcing groove 50 and the non-magnetic material 40, the allowable value for displacement of the integrated back par 41 in the longitudinal direction becomes larger.

That is, as long as the non-magnetic material 40 of width W changes its position within the range of width W, the recording/reproducing side backper 18 becomes the erasing side magnetic circuit, and the erasing side backer 28 becomes the recording/reproducing side magnetic circuit. Since there is no adverse effect on each, the permissible value of positional deviation becomes large.

Note that when the bonding reinforcing groove 50 is not formed on the bonding surface of the magnetic cores 11 and 21, that is, when the thin non-magnetic material 29 with a thickness S is only interposed on the bonding surface, the integrated backper 41
If the width W of the non-magnetic material 40 is made sufficiently larger than the width S, positioning of the integrated backper 41 becomes easy as well. That is, since it is sufficient to position the non-magnetic material having the width S within the width W of the non-magnetic material 40, positioning is similarly easy and the tolerance to positional deviation is similarly high.

In the above embodiment, the present invention is applied to a composite magnetic head in which the notch grooves 31 and 32 are shaped in a special shape. , and other composite magnetic heads as well.

FIG. 1(b) shows a state in which sliders 60 and 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, it is possible to easily attach a backper that closes the magnetic circuit on the recording/reproducing side and the magnetic circuit on the erasing side to form a closed magnetic circuit. , positioning becomes easier. Therefore, workability can be improved and costs can be reduced. Further, since the tolerance to positional deviation can be increased, it is possible to eliminate the adverse effect on the magnetic circuit caused by the positional deviation of the backper.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing an embodiment of the composite magnetic head of the present invention, FIG. 1(b) is a perspective view of a state in which a slider is joined, and FIG. 2 is a plan view of a conventional composite magnetic head. FIG. 3 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... Non-magnetic material,
41...Integrated back bar, 50...Joint reinforcement groove,
51...Joining material.

Claims (3)

[Claims] (1) A pair of magnetic cores forming a recording/reproducing gap, a 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 a back bar located on both sides of the recording/reproducing gap. a recording/reproducing magnetic core having a notched groove for regulating the recording/reproducing track width; a pair of magnetic cores forming a pair of erase gaps located on both sides of the recording/reproducing track; and a pair of magnetic cores located on the back side of the pair of magnetic cores; In the composite magnetic head formed by joining the pair of magnetic cores, a back bar constituting a closed magnetic circuit, and an erasing magnetic core having a notched groove regulating the erasing track width by the erasing gap, the above-mentioned recording A back bar on the reproduction side and a back bar on the erasing side are integrated with a non-magnetic material sandwiched between them, and this integrated back bar is connected to the magnetic core for recording and reproduction and the magnetic core for erasing. A back bar bonding structure for a composite magnetic head characterized by bonding to a bonded body of both cores in accordance with the bonding surface position of the cores. (2) In claim 1, the joint surface between the recording/reproducing magnetic core and the erasing magnetic core located in the non-magnetic material portion of the integrated back bar has a joint reinforcing groove extending between the two cores. A back bar bonding structure of a composite magnetic head in which bonding material is filled in the bonding reinforcing grooves. (3) The back bar joint structure of a composite magnetic head according to claim 2, wherein the width of the nonmagnetic material of the integrated back bar is set smaller than the width of the joint reinforcing groove of the joint core.