JPS6251012A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To reduce the deterioration of symmetricalness of a record/ reproduction waveform that is caused by the fact that an erasion magnetic field is picked up by a back core which forms a closed magnetic circuit for record/reproduction, by attaching the back core to a back end face of a record/ reproduction core at the side opposite to the rubbing surface to a recording medium. CONSTITUTION:A square bar-shaped back core 2 the same in thickness as a record/reproduction core 1 is fixed to a back end face 11 of the core 1 via an adhesive or a spring, etc. These cores 1 and 2 form a closed magnetic circuit for record/reproduction. While the erasion cores 3 forming erasion gaps 6 are set at the places near a record/reproduction gap 5 at both sides of the core 1 as if they were set orthogonal to the head 1. The inner sides of both ends of a U-shaped erasion yoke core 4 are welded to the faces at both ends of the core 3 as if they enclosed an approximately T-shaped bar of the core 1 by means of an adhesive. Then a front panel is attached to both side faces of the front part of the core 1 by an adhesive, etc. so that the front panel of a nonmagnetic substance is positioned on the same surfase as the front end face of the core 1. Thus a magnetic head is completed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head used, for example, in a floppy disk device, and a method for manufacturing the same, and particularly relates to a magnetic head used in a floppy disk device, etc., and particularly to a recording/reproducing core (hereinafter referred to as a recording/reproducing core). This invention relates to a back core mounting structure and its mounting method.

[Conventional technology]

To give an overview of the conventional manufacturing method of this type of magnetic head, for example, as shown in FIGS. 6 and 7, a recording/reproducing core bar (not shown) is joined to form a recording/reproducing gap 5 on the front surface. The recording/playback core 1 is sliced to obtain a recording/playback core 1, taking into consideration the mirror polishing margin on the side surface of the recording/playback core 1.The recording/playback core 1 is arranged one by one on a flat plate, etc. Each side surface 10 of the magnetic material was subjected to a mirror polishing process (see FIG. 8) by rasping, etching, etc., in order to remove a degraded layer of the magnetic material that was generated during processing such as cutting. Next, the back core 2 is fixed to the mirror-polished side surface 10 with an adhesive, a spring, or the like. In this way, the recording/reproducing core 1 and the bank core 2 form a closed magnetic circuit for recording/reproducing. Then, a recording/reproducing coil 7 is wound around one side of the recording/reproducing core 1. Further, in the vicinity of the recording/reproducing gap 5 on both sides of the recording/reproducing core 1, an erasing core 3 having an erasing gap 6 formed therein is arranged. A U-shaped erasing yoke core 4 is fixed to both ends of the erasing core 3 with an adhesive or the like so as to surround one side of the recording/reproducing core 1. An erasing coil 8 is wound around the erasing yoke core 4. Then, the front plate 9 is bonded to both sides of the front part of the recording/playback core 1 with an adhesive or the like so that the front plate 9 made of a non-magnetic material is located on the same plane as the front end surface of the recording/playback core 1, and the magnetic recording medium is to run stably on the magnetic field. In this way, a magnetic head is obtained.

[Problem that the invention seeks to solve]

In the conventional magnetic head described above, since the back core 2 is attached to the side surface 10 of the recording/reproducing core 1, the back core 2 comes close to the erasing core 3 and the erasing yoke core 4, and the back core 2 spreads the erasing magnetic field. , a phenomenon occurred in which the symmetry of recording and reproducing waveforms deteriorated, and there was a problem in terms of reliability.

In addition, in the conventional magnetic head manufacturing method, the recording/reproducing cores l are arranged on a flat plate or the like and the side surfaces 10 of the recording/reproducing cores l are polished to a mirror finish, which takes time and increases costs. It was also a cause. Moreover, in order to obtain the recording/reproducing core 1 by slicing the recording/reproducing core bar, the side surface 10 of the recording/reproducing core 1 must be cut in advance.
It is necessary to take into account the mirror polishing allowance for slicing, which reduces the number of recording/reproducing cores 1 per recording/reproducing core par, which also causes high costs.

An object of the present invention is to provide a highly reliable magnetic head that reduces or eliminates deterioration of the symmetry of recording and reproducing waveforms.

Another object of the present invention is a method for manufacturing an inexpensive magnetic head by reducing the time required for mirror polishing per recording/reproducing core and increasing the number of recording/reproducing cores per recording/reproducing core. The purpose is to provide

[Means for solving problems]

In the magnetic head according to the present invention, in a magnetic head in which erasing cores are arranged on both sides of a recording/reproducing core, the back core forming a closed magnetic circuit for recording/reproducing is opposite to the recording medium sliding surface of the recording/reproducing core. It is attached to the rear end surface of the side.

The rear end face is mirror polished.

Further, in the method for manufacturing a magnetic head according to the present invention, in the method for manufacturing a magnetic head in which erasing cores are disposed on both sides of a recording/reproducing core, the rear end surface of the recording/reproducing core bar is mirror-polished by lapping, etching, etc. Next, the recording/reproducing core bar is sliced to obtain a recording/reproducing core, and then a back core is fixed to the rear end surface of the recording/reproducing core using an adhesive, a spring, or the like.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a magnetic head according to the present invention. In the figure, reference numeral 1 denotes a recording/reproducing core, one of which is an L-shaped piece and the other approximately a T-shaped piece, and both are butted and joined to form a recording/reproducing gap 5 on the front surface. The rear end surface 11 of the recording/reproducing core l on the opposite side to the recording medium sliding surface is mirror-polished.

A rectangular bar-shaped bank core 2 having the same thickness as the recording/reproducing core 1 is fixed to the rear end surface 11 of the recording/reproducing core 1 with an adhesive, a spring, or the like. 7
is a recording/reproducing coil wound around the L-shaped piece of the recording/reproducing core 1. The upper recording/reproducing core I and the back core 2 form a closed magnetic circuit for recording and reproducing. Furthermore, in the vicinity of the recording/reproducing gap 5 on both sides of the recording/reproducing core 1, an erasing core 3 having an erasing gap 6 formed therein is arranged perpendicularly to the recording/reproducing head l. The inner surfaces of both ends of a U-shaped erasing yoke core 4 are fixed to both end surfaces of the erasing core 3 with an adhesive or the like so as to substantially surround the T-shaped piece of the recording/reproducing core 1. Reference numeral 8 denotes an erasing coil wound around the erasing yoke core 4. and,
Although not shown, the front plate of a non-magnetic material is fixed to both sides of the front part of the recording/playback core 1 with adhesive or the like so that the front plate of non-magnetic material is located on the same plane as the front end surface of the recording/playback core 1. Obtain a magnetic head.

FIG. 2 shows another embodiment of the present invention, in which the recording/reproducing core 1
The approximately T-shaped piece that makes up the piece is thick except for the part where it butts with the other L-shaped piece, and the rectangular bar-shaped piece is formed to have the same width as the thick T-shaped piece. The only difference is that the back core 2 is fixed to the rear end surface 11 of the recording/reproducing core l, and the rest is the same as the above embodiment.

FIG. 3 shows a third embodiment of the present invention, in which a groove (2a) is formed along the longitudinal direction of the front surface of a rectangular bar-shaped back core 2 that is wider than the thickness of the recording/reproducing core 1. Then, fit the rear end of the recording/playback core 1 into this groove (2a), and then insert the recording/playback core 1 into the groove.
The second embodiment differs from the first embodiment in that the rear end surface 11 is fixed to the inner bottom surface of the groove (2a), but otherwise the configuration is the same.

Next, the method for manufacturing the magnetic head of the present invention, particularly the recording/reproducing core 1.
The processing method and the method of attaching the back core 2 to the recording/reproducing core 1 will be explained.

As shown in FIG. 4, with the recording/reproducing core bar 12 joined to form the recording/reproducing gap 5 on the front surface, the rear end surface (12a) of the core bar 12 is polished to a mirror surface by means such as pinning or etching. Polishing is performed to remove the damaged layer of the magnetic material. Next, the recording/reproducing core bar 12 is sliced into a predetermined thickness to obtain a recording/reproducing core 1 as shown in FIG. Then, the back core 2 is fixed to the rear end surface 11 of the recording/reproducing core 1 with an adhesive, a spring, or the like. Thereafter, the magnetic head is manufactured by conventional methods.

(Effects of the Invention) As can be seen from the above description, the present invention has a back core that forms a closed magnetic circuit for recording and reproduction, which is attached to the rear end surface of the recording and reproduction core opposite to the recording medium sliding surface. As the back core can be moved away from the erase core and the erase yoke core, it is possible to reduce or eliminate the phenomenon of deterioration of the symmetry of recording and reproducing waveforms due to the back core absorbing the erase magnetic field that existed in the conventional method. This provides an excellent effect in that a magnetic head with high trajectory can be obtained.

Further, according to the method for manufacturing a magnetic head of the present invention, since mirror polishing can be performed on the recording/reproducing core in the state of the recording/reproducing core, the time required for mirror polishing per recording/reproducing core can be reduced, resulting in low cost. A magnetic head with excellent properties can be obtained. Furthermore, since mirror polishing is performed on the rear end surface of the recording/reproducing core, there is no need to provide an allowance for mirror polishing the side surface of the recording/reproducing core in conventional manufacturing methods. Therefore, the number of recording/reproducing cores per recording/reproducing core can be increased compared to conventional manufacturing methods, and from this point of view as well, a unique effect is achieved in that an inexpensive magnetic head can be obtained.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a perspective view of a magnetic head showing one embodiment of the present invention, FIG. 2 is a perspective view of a magnetic head showing another embodiment of the present invention, and FIG. 3 is a perspective view of a magnetic head showing another embodiment of the present invention. , a perspective view of a magnetic head showing a third embodiment of the present invention, FIG. 4 a perspective view showing a method of processing a recording/playback core bar according to the present invention, and FIG. 5 a perspective view of a magnetic head according to a third embodiment of the present invention. FIG. 6 is a perspective view of a conventional magnetic head; FIG. 7 is an exploded perspective view of a conventional magnetic head; FIG. 8 is a conventional recording/reproducing core. FIG. 3 is a perspective view showing a state where the side surface has been mirror-polished. In the figure: ■...Recording/reproducing core, 2...Back core, 3...Erasing core, 11...Rear end surface, 12...Recording/reproducing core bar. be. Patent applicant Katama, representative of Alps Electric Co., Ltd.
Katsudaibe Figure 1 Figure 2 Redemption-Koma Figure 3 Figure q 1 Kinto Re-Core No. 51!1

Claims (3)

[Claims] (1) In a magnetic head in which erasing cores are arranged on both sides of a recording/reproducing core, a back core forming a closed magnetic circuit for recording/reproducing is attached to the rear end surface of the recording/reproducing core on the opposite side from the recording medium sliding surface. A magnetic head characterized by: (2) The magnetic head according to claim 1, wherein the rear end surface of the recording/reproducing core is a polished mirror surface. (3) In a method of manufacturing a magnetic head in which erasing cores are arranged on both sides of a recording/reproducing core, the rear end surface of a recording/reproducing core bar is mirror-polished by lapping, etching, etc., and then the recording/reproducing core bar is sliced to perform recording. A method of manufacturing a magnetic head, comprising: obtaining a reproducing core; and then fixing a back core to the rear end surface of the recording/reproducing core using an adhesive, a spring, or the like.