JPS6232524B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head suitable for use in audio cassette tape decks, etc. More specifically, the present invention relates to a magnetic head suitable for use in audio cassette tape decks, etc. The present invention relates to a method of manufacturing a multi-element magnetic head arranged close to each other, a so-called recording-reproduction combination head (hereinafter referred to as an R&P combination head).

The design of this kind of R&P combination head,
One of the technical problems in manufacturing is the crossfeed, or leakage of magnetic flux from the recording head element to the reproduction head element.

When the playback function is operated to determine whether magnetization on the tape is appropriate during recording, if the crossfeed is large, the output NCF due to the crossfeed becomes the damage prevention output in contrast to the playback output S due to the magnetization on the tape. Especially for audio use, for playback output S
NCF is required to be smaller than 50dB.

In order to improve this crossfeed, it is preferable to integrate a recording head 10 and a reproducing head 20, which are completely independent, as shown in FIG.

However, if each head is made separately and integrated, the parallelism of the gaps 113 and 213 will not be sufficient and the yield will be extremely poor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing an R&P combination head that can improve the crossfeed and ensure gap parallelism in recording and playback, making it easy to mass-produce.

Embodiments of the present invention will be described below based on the drawings. FIG. 2 is an exploded perspective view of an R&P combination head showing an embodiment of the present invention, and FIG. 3 is a diagram showing its manufacturing process. In FIG. 2, reference numeral 10 indicates a recording head element, which includes recording head cores 11, 11 made of ferrite.
Head cores 11, 11 have gaps 113, 113
Front core 111 and coil 11 formed by
Rear core 112, 11 formed by winding 4,114
2, and these cores are held by the holding part 311 of the front holding tool 31.
13 is a channel shield plate interposed between the head cores 11, 11, and 14 is a U-shaped shield case made of permalloy that houses these recording parts. Reference numeral 20 denotes a reproducing head element, which includes reproducing head cores 21, 21 made of ferrite. Head core 21,2
1 is composed of a front core 211 formed by forming gaps 213, 213, and rear cores 212, 212 formed by winding coils 214, 214, and these rear cores are held by a holding part 321 of a rear holding tool 32. ing. 23 is head core 2
A channel shield plate 24 is interposed between 1 and 21, and 24 is a U-shaped shield case made of permalloy that accommodates the recycled parts. 33
is the terminal board.

Next, the manufacturing method will be explained. FIG. 3 is a process diagram showing the manufacturing process of the R&P combination head of the present invention. First, as shown in FIG. 3a, three head core materials 100, 200, and 300 are prepared, and these head core materials are glued together as shown to form one front core block. As a result, the recording gap 113 and the playback gap 213
is formed. Next, core block gap 11
The front surface on the 3, 213 side is ground into a W shape, for example, as shown in FIG. 3b. Here, the core block is ground into a W shape, but the grinding shape does not have to be W shape.
Moreover, this step may be omitted. Next, a groove 301 for inserting a shield case is formed in the head core material 300 at the center of the core block, as shown in FIG. 3b.
Next, as shown in FIG. 3c, it is cut into a size and a channel shield plate insertion groove 123 is formed. Next, this front block is held by the front holder 31 as shown in FIGS. 3d and 3e, and then the front core block is cut into a predetermined size as shown in FIG. 3f to form the front cores 111 and 211. Form. The front holder 31 consists of two holding parts 311 and 312 that hold the front core for recording and playback, and a connecting part 313 that connects them.
Maintains playback gap parallelism. Next, the U-shaped rear core 11 is formed separately from the front core.
2, 212 and the rear holder 32 holding the rear core are butted against the front cores 111, 211 and the front holder 31 as shown in FIG. Fix it with etc. The rear holder 32 has two holding parts 321 and 3 that hold the rear core for recording and playback.
22 and a shield case insertion groove 324.
Next, a shield case insertion groove 314 that communicates with the shield case insertion groove 324 of the rear holder 32 is formed in the front holder 31, and these head cores are then joined into a drawn U-shape as shown in FIG. Insert it into the shield cases 14, 24 of
Thereafter, the front surface of the head core is polished to form a tape sliding surface to complete the R&P combination head. Here, the connecting portion 31 of the front holder 31
3 may be integrally made of the same material as the front holder 31, or may be connected to each other using an easily cutable material such as plastic or soft metal.

Further, the front holder 31 and the rear holder 32 may have a central partition wall removed as shown in FIG. 4, in which case the head cores 11 and 21 can be brought closer to each other.

The R&P combination head shown in FIG. 4 is manufactured in accordance with FIG. 5, and since the manufacturing process is the same as that shown in FIG. 3 described above, detailed explanation thereof will be omitted.

According to the present invention described above, an R&P combination head which integrates completely magnetically independent recording and reproducing heads and has good gap parallelism can be manufactured with good mass productivity and a high yield.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an R&P combination head for explaining the present invention, FIG. 2 is an exploded perspective view of the R&P combination head showing an embodiment of the present invention, and FIG. 3 is a diagram of its manufacturing process. FIG. 4 is an exploded perspective view of an R&P combination showing another embodiment of the present invention, and FIG. 5 is a manufacturing process diagram thereof. 111,211...Front core, 112,21
2... Rear core, 31... Front holder, 32... Rear holder, 14, 24... Shield case.

Claims (1)

[Claims] 1. A recording head core formed by butting together a front core forming a recording gap and a rear core around which a coil is wound, and a playback head core formed by butting a front core forming a playback gap and a rear core around which a coil is wound. In a multi-element magnetic head in which head cores are arranged close to each other on the same track and both of the head cores are shielded separately, the distance between the recording front core and the reproduction front core each having an operating gap and the distance between the front cores A front holder that maintains parallelism and a rear holder that holds each rear core together have grooves that separate the recording rear core and playback rear core, and the front holder and rear holder are butted together. A method of manufacturing a multi-element magnetic head, characterized in that a rear front holder is separated into a recording side and a reproduction side, and a part of a shield case is inserted into the separating groove.