JPH0421907A - Magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To decrease the generation of heat by an eddy current loss by providing plural slits or spacers between plural magnetic gaps. CONSTITUTION:This magnetic head is produced by cutting magnetic gaps G1, G2 in a front core 1 integrally molded by using a grind stone having a small thickness and simultaneously cutting slits 5 thereon. A magnetic flux is generated in a front core 1 and a back core 3 and the eddy current loss arises in the front core 1 when a current is passed to a coil 2 at the time of erasing of the information recorded on a tape. The eddy current loss is, however, decreased and the generation of heat is suppressed, since the constitution to divide the center core 1c is adopted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head for erasing information recorded on, for example, a magnetic card or tape.

[Prior Art] Conventionally, a magnetic head for erasing information on a magnetic card or magnetic tape has a structure as shown in FIG.

FIG. 2 is a diagram showing the configuration of a conventional magnetic head.
) is a plan view, and (b) is a front sectional view.

In Fig. 2, l is the front core of the composite type head, 2 is a coil for generating magnetic flux, 3 is a hack core,
4 is a mask block, and the front core l has a structure having two magnetic gaps Gl and G2. Other conventional examples include a double gap type as shown in FIG. 3 and a semi-double gap type as shown in FIG.

In Figures 3 and 4, 6 and 8 are side cores, 7 and 9
2 is a center core, and the same reference numerals as in FIG. 2 indicate the same or corresponding parts.

However, to erase high Hc (coercive force) media,
A composite type head that uses high saturation magnetic flux density (such as Sendust) in the front core is required.

[Problem to be solved by the invention] Since the conventional magnetic heads of the type shown in FIGS. 3 and 4 have poor erasing efficiency and require a large amount of current, a composite head as shown in FIG. The front core shown in FIG. 2 is made of a material with high magnetic induction, such as sendust, to improve the erasing efficiency. However, the conventional magnetic head as shown in FIG. 2 has the disadvantage that heat generation increases due to eddy current loss occurring inside the front core. Additionally, there is a method of laminating the core to reduce eddy current, but laminating the core has the problem of making it troublesome to align the gap lines and also being expensive. .

The present invention was made to solve these conventional problems, and provides a magnetic head that has good erasing efficiency and does not generate much eddy current inside the core, thus reducing heat generation due to eddy current loss. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above object, the magnetic head of the present invention is provided with a plurality of slits or spacers between a plurality of magnetic gaps, and these slits are used when machining the magnetic gaps. At the same time, slits are processed.

[Function] According to the present invention, a slit of a certain arbitrary width or a non-magnetic material filled in this slit is placed at an arbitrary position between the plurality of magnetic gaps Gl and G2 that does not cause deterioration of the magnetic properties.
By providing a non-conductive spacer, the eddy current loss generated inside the front core is reduced and heat generation is suppressed.In addition, as a method for creating the slits, the magnetic gaps Gl and G2 are When processing using a grindstone, processing can be done at the same time, making it possible to reduce costs.

[Example] Figures 1 (a), (b), and (C) are a surface view, a front cross-sectional view, and a side view of a magnetic head showing an example of the present invention, respectively, and best illustrate the features of the present invention. FIG.

In Figure 1, l is the front core of the integrally formed composite head, 2 is a wound coil for generating magnetic flux, 3 is the back core of the composite head, and 4 is the part pasted on the part that will not be erased. The non-magnetic block 5 is a slit for magnetically and electrically separating Gl and G2, and this slit 5 is made of a non-magnetic, non-conductive material, and is designed to control the magnetic properties of the front core. A spacer that does not deteriorate may be used.

Next, when a current is passed through the coil 2 when erasing information recorded on the tape, magnetic flux is generated in the front core 1 and the back core 3, and eddy current loss occurs in the front core 1. Here, the magnetic flux flowing to the center core lc compared to the magnetic gaps Gl of the front core l and the side cores la and lb outside G2 is approximately doubled as shown in FIG. 8(a), and the eddy current loss is also In lc, when the erase current is 10 AT, the temperature rise is as large as 35° C., and the heat generation is the largest.

However, in this embodiment, since the center core lc is divided, the eddy current loss is reduced as shown in FIG. 8(b), and the temperature rise is 23°C with an erase current of 10 AT, suppressing heat generation. Ru.

Furthermore, FIGS. 5(a) to 5(Ce) are diagrams for explaining the process of manufacturing the magnetic head shown in FIG. Gl, G2. At the same time, the slit 5 is cut (FIGS. 5(a) to 5(C)).

In addition, as another method, the cut slit 5
A large, non-magnetic, non-conductive filler is provided in the spacer 15 (FIG. 1(d)).

(e)) is also possible.

6 is a front cross-sectional view of a magnetic head according to another embodiment of the present invention, and FIG. 7 is a front cross-sectional view of a magnetic head according to still another embodiment of the present invention. respectively indicate slits, and the same reference numerals as in FIG. 1 indicate the same or corresponding parts.

The magnetic head shown in FIG. 6 has an increased number of slits, such as slits 11 and 12, within a range that does not cause deterioration of magnetic properties.

Further, the magnetic head shown in FIG. 7 has a slit shape such as the slit 13 in a tapered shape to suppress heat generation within the core.

The above-mentioned slits can be formed by irradiating a laser beam or the like onto the part of the front core 1 where the slit will be inserted to thermally damage the part, or by oxidizing and etching the part. can be provided.

[Effects of the Invention] As described below, the present invention reduces heat generation due to eddy current loss in the core by providing a slit groove between the gaps in the front core of an integrally formed composite erase head. Furthermore, since the front core is integrally formed, there is no need to make the gap grooves and slits match linearly, as is the case with laminated products.

[Brief explanation of drawings]

FIGS. 1(a), (b), and (c) respectively show -
・Surface view, front sectional view, and side view of a magnetic head showing an example; FIG. 2 is a diagram showing the configuration of a conventional magnetic head, where (a) is a plan view and FIG. 2(b) is a front sectional view. Figure 3 (a
) and (b) are a plan view and a front view of a conventional double gap type erasing head, and 4th (a) and 4 (b) are a plan view and a front view of a conventional semi-double gap erasing head. 5(a) to (e) are diagrams for explaining the process of manufacturing the magnetic head of FIG. 1, FIG. 6 is a front cross-sectional view of a magnetic head of another embodiment of the present invention, and FIG. FIG. 8 is a front cross-sectional view of a magnetic head according to still another embodiment of the present invention, and is a diagram showing the erase rate and temperature rise with respect to the erase current.
1A shows a conventional example, and FIG. 1B shows a magnetic head according to the present invention. In the figure. l: Front core of composite head la, lb: Side core 1c: Center core 2: Coil for magnetic flux generation 3: Back core of composite head 4: Non-magnetic block 5 Nislit 6°8: Side core of doubler gap type 7: Center core 9: Semi-double gap type center core 15 spacer Gl, G2: Magnetic gap

Claims (2)

[Claims] (1) A magnetic head having a plurality of magnetic gaps in an integrally formed front core, characterized in that a plurality of slits or spacers are provided between the plurality of magnetic gaps. (2) A method for manufacturing a magnetic head having a plurality of magnetic gaps in an integrally formed front core, characterized in that a slit is formed between the plurality of magnetic gaps at the same time as the magnetic gap is formed. Method.