JP3160977B2 - Magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for recording and reproducing used in a magnetic tape device.

[0002]

2. Description of the Related Art Generally, a magnetic head has recording, reproducing and erasing functions, and a recording / reproducing magnetic head (write / read head) comprises 1, 2, 4 and 8 channels. By doing as a multi-track head,
Recording of information on a magnetic recording medium such as a magnetic tape, and
The information recorded in advance is read and reproduced. As the magnetic material, a metal magnetic material (for example, permalloy)
And non-metallic magnetic materials (eg, ferrite).

A conventional recording / reproducing magnetic head will be described below. As shown in FIG. 6, reference numerals 1a and 1b denote magnetic head cores for recording, 2a and 2b denote magnetic head cores for reproduction, and 3 and 4 denote recording gaps and reproducing gaps made of a nonmagnetic material such as glass, and 5a, 5b and 5c. A side shield block 6 made of a magnetic material such as ferrite, and 6 is a center shield block made of a magnetic material such as ferrite. The side shield blocks 5a, 5b, 5c
The magnetic head cores 1a, 1b, 2a, 2b are disposed in parallel with the gaps of the magnetic head cores 1a, 1b, 2b.
The center shield block 6 is arranged perpendicularly to the gaps between the magnetic head cores 1a, 1b, 2a, 2b. The center shield block 6 serves to prevent the influence of the leakage magnetic flux generated from the magnetic head cores 1a, 1b, 2a, 2b. It plays the role of preventing the effect of leakage magnetic flux.

For example, as shown in FIG. 9, a part 14 of a magnetic flux generated from a gap 3 on a magnetic head core 1a for recording is converted into a gap 4 of a magnetic head core 2b for direct reproduction.
On the other hand, the center shield block 6 calls into itself like the leakage magnetic flux 15 from the gap 3,
It serves to reduce the other magnetic flux 14. Since there is a gap 27 between the center shield block 6 and the side shield block 5b, the magnetic resistance increases and a new leakage magnetic flux 16 is generated.

[0005] Spacers 7a, 7b, 7c, 7d made of a non-magnetic material such as ceramic are used to magnetically separate the recording or reproducing magnetic head core 1a, 1b or 2a, 2b from the side shield blocks 5a, 5b, 5c. Play a role in ensuring. The holder 8 made of aluminum alloy or the like serves as a pedestal for bonding and fixing each component.

As shown in FIGS. 7 and 8, a recording / reproducing core chip 9 includes a recording magnetic head core 1a (or 1b) and a reproducing magnetic head core 2b (or 2a).
Are bonded to each other via a center spacer 10 made of a nonmagnetic material such as ceramic so as to be magnetically separated.

Hereinafter, a conventional method for manufacturing a magnetic head will be described. Each component as shown in FIG. 10A is bonded with an epoxy resin or the like as shown in FIG. 10B. The conventional magnetic head has two channels,
Since the reproducing head has a so-called "alternate" configuration, two recording / reproducing core chips 9 are used, and their end faces are bonded in the opposite directions. After bonding, as shown in FIG.
The coil 11 is inserted, and the back bar 12 is bonded. Then, as shown in FIG. 11 (b), after bonding and fixing to the holder 8, the groove 2 processed for the center shield block is formed.
The center shield block 6 is inserted into and bonded to 6.

The operation of the magnetic head configured as described above will be described. Normally, information is written on a magnetic tape, which is a magnetic recording medium, by a recording magnetic head core 1a, 1b, and immediately thereafter, information is reproduced from a reproducing magnetic head core 2a, 1b.
In general, a read-after-write method is used in which information is written in the read magnetic head core 2a, and immediately after that, the correctness of the information written in the read magnetic head cores 2a and 2b is checked. When using the magnetic heads 2a and 2b, in addition to the information written on the magnetic medium, the leakage magnetic flux generated in the recording magnetic head cores 1a and 1b jumps directly into the reproducing magnetic head cores 2a and 2b, or At the same time, it is necessary to consider a feed-through phenomenon, which is a phenomenon that is influenced by a magnetic flux that is further generated in another magnetic body due to a leakage magnetic flux. As a value indicating the degree of feedthrough, there is a ratio of a reproduced output value to a noise due to a leakage magnetic flux. For preventing a data error from occurring, it is necessary to reduce the fordthrough to 5% or less from the request of the circuit side.

[0009]

In the above-mentioned conventional structure, since there is a gap 27 between the center shield block 6 and the side shield block 5b, the magnetic resistance becomes large, and a new leakage magnetic flux 16 is generated. The magnetic head core 2b has a problem that the field-through value deteriorates to about 20% and a data error occurs when predetermined data is read by the read-after-write method.

An object of the present invention is to provide a recording / reproducing magnetic head in which the field-through value is reduced to 5% or less and the occurrence of a data error at the time of read-after is prevented. Aim.

[0011]

In order to achieve the above object, a magnetic head according to the present invention includes a shield block disposed so as to surround a magnetic head core, and a gap between the shield blocks 7 is formed in the magnetic head core. It is configured to be located outside the gap.

[0012]

According to this configuration, a part of the leakage magnetic flux generated from the gap of the recording magnetic head core jumps into the shield block surrounding the recording magnetic head core, and another part of the leakage magnetic head core reproduces. Although it jumps into the surrounding shield block, the effect of the magnetic flux generated from the break in the shield block on the magnetic head core for reproduction is reduced, and a good field-through value is obtained.

[0013]

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

In FIGS. 1 to 5 showing one embodiment of the present invention, the same parts as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, 17a, 17b, 18, 1
9 is a shield block made of a magnetic material such as ferrite,
Reference numeral 20 denotes a center block made of a nonmagnetic material such as ceramic. In the conventional example, the center shield block 6 made of a magnetic material is used at the position of the center block 20, but in the present embodiment, the center block 20 is made of a non-magnetic material, and each of the magnetic head cores 1a, 1b, 2a, 2b is formed. The space between the shield blocks 17a, 17b, 18, 19 is filled with glass 21.

Hereinafter, a method of manufacturing the magnetic head of this embodiment will be described. As shown in FIG. 3A, after forming a gap on the opposing surfaces of the magnetic cores 22 and 23 formed by processing a ferrite material into a predetermined shape, a film is formed.
As shown in FIG. 3B, the magnetic cores 22 and 23 are adhered to each other with glass 24, and the gap bar 2 shown in FIG.
5 is formed.

Next, outer shape processing is performed, and track processing for determining a track width is performed as shown in FIG.
In this embodiment, one pair of a magnetic head core 1a for recording and a magnetic head core 2a for reproduction was manufactured from one gap bar 25. In this embodiment, two-channel recording
Since it is a magnetic head for reproduction, alignment is performed using a gap bar 25 on which two tracks have been processed as shown in FIG. 3E, and then, as shown in FIG.
Using the shield blocks 17a, 17b, 18, and 19, the center block 20, and the glass 21, FIG.
As shown in (2), after taking in and filling the glass 21, unnecessary portions of the glass 21 are removed. At this time, the cuts 13 of the shield blocks 17a, 17b, 18, 19 are
Embed so that it is outside the gap. FIG. 5 (a)
As shown in FIG. 7, after the front surface is shaped, the coil 11 is inserted and the back bar 12 is bonded. Then, as shown in FIG. 5B, it is fixed by bonding to a holder 8 which is a mounting base.

The operation of the recording / reproducing magnetic head configured as described above will be described with reference to FIG.
A part 14 of the leakage magnetic flux generated from the gap 3 of the magnetic head core 1a for recording jumps into the gap 4 of the magnetic head core 2a for reproduction.
Jumps into the shield block 17b and leaks again at the cut 13 of the shield block 19.
However, since the heat is transmitted through the ferrite having a high specific resistance, a part of the ferrite is converted into Joule heat, the amount is reduced, and the effect on the reproducing magnetic head core 2a is also reduced. The shield blocks 17a, 17b, 18, 1
9 is disposed so as to surround the magnetic head cores 1a, 1b, 2a, 2b, and the function of inviting a part of the leakage magnetic flux is increased, so that it is effective as a magnetic shield. Thereby, the value of the field through can be reduced to 5% or less of the target.

[0019]

As is apparent from the above embodiments, the present invention includes a shield block provided so as to surround the magnetic head core, and the gap between the shield blocks is formed by the gap of the magnetic head core. With the configuration located on the outside, the value of the field through can be reduced to 5% or less, and an excellent magnetic head which can prevent the occurrence of a data error at the time of read-after can be realized.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a magnetic head according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ of FIG. 1;

FIG. 3 is a perspective view illustrating each step of a method of manufacturing a magnetic head according to an embodiment of the present invention;

FIG. 4 is a perspective view of each step following FIG. 3;

FIG. 5 is a perspective view of each step following FIG. 4;

FIG. 6 is an external perspective view of a conventional magnetic head.

FIG. 7 is a plan view of a recording / reproducing core chip of the magnetic head.

8 is a sectional view taken along the line CC ′ of FIG. 7;

FIG. 9 is a sectional view taken along line BB ′ of FIG. 6;

FIG. 10 is a perspective view illustrating each step of a conventional magnetic head manufacturing method.

FIG. 11 is a perspective view of another step following FIG. 10;

[Explanation of symbols]

 1a, 1b Magnetic head core 2a, 2b Magnetic head core 13 Break 17a, 17b Shield block 18 Shield block 19 Shield block

Claims (1)

(57) [Claims] 1. A magnetic head having a plurality of pairs of magnetic head cores for recording and reproduction on the same track, comprising: a shield block disposed so as to surround the magnetic head core; A magnetic head in which a cut is located outside the magnetic head core.