JPH04243005A - Composite type magnetic head - Google Patents

Abstract

PURPOSE:To provide a magnetic head having a normal magnetic gap showing an equal or higher recording/reproducing output efficiency compared to the level of a MIG type magnetic head. CONSTITUTION:For the composite type magnetic head has a R/W gap and Er gap on both sides of the center core part, and a nonmagnetic layer is provided in the center core part, the position of the nonmagnetic layer is shifted to the Er gap side so that the distance between the nonmagnetic layer and the Er gap is about 33% of the distance between both gaps.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a magnetic head for a floppy disk, in particular a magnetic gap for recording/reproducing (R/W gap) and a magnetic gap for erasing (Er/W gap) on both sides of the center core portion.
The present invention relates to a pre-erase type composite magnetic head in which a gap is formed and a nonmagnetic layer is interposed between the center core portions.

0002

2. Description of the Related Art In this type of advance erase type magnetic head, the Er gap is formed at a position preceding the R/W gap (on the upstream side in the running direction of the magnetic medium), and the Er gap is formed prior to recording information on the medium. The old information is erased at the Er gap. In this type of magnetic head, in order to reduce crosstalk between signals due to the Er gap, a nonmagnetic material is interposed approximately at the center of the center core between the R/W and Er gaps, or slightly closer to the Er gap. FIG. 3 is a partial side view of a pre-erase type floppy head with a nonmagnetic layer interposed therebetween, and FIG. 4 is a partial front view of the floppy head viewed from the floppy disk sliding surface side. A non-magnetic layer 2 is sandwiched approximately in the middle of a center core section 1 disposed at the center of the front part of the head core, and C-shaped cores 3 and 4 are disposed on both sides of the center core section 1, with an R/W gap 5, Er A gap 6 is formed in each case. The distance L between both gaps 5 and 6 is 300 μm
In the illustrated example, the thickness is set to 205 μm, and the nonmagnetic layer 2
The thickness is 15 μm. The recording/reproducing core section is formed by the center core 1a on one side of the non-magnetic layer 2 and the C-shaped core 3, and the center core 1 on the other side is formed from the non-magnetic layer 2.
b and the C-shaped core 4 constitute an erase core section.

In this type of magnetic head, as shown in the examples of FIGS. 3 and 4, the gap distance L between the R/W gap and the Er gap tends to be reduced in order to accommodate larger capacities.
Furthermore, as recording density has become higher in recent years, the thickness of the gap itself has become narrower. In the conventional floppy head, the non-magnetic layer is located approximately at the center of the gap distance which has been reduced as described above, so the distance between the non-magnetic layer and the R/W gap is also narrow, making it difficult to read and write data. This results in a decrease in output efficiency. In order to improve the output while ensuring high-density recording, a so-called MIG (metal-in-gap) type magnetic head is already known in which a metal magnetic thin film of a high Bs material is attached to the magnetic gap portion.

0004

[Problem to be solved by the invention] R/W gap and Er
In a conventional advance erase head in which a non-magnetic layer is provided in the center core portion between the gaps, the non-magnetic layer is provided at approximately the center of the center core portion or slightly closer to the Er gap. As density recording increases, the distance between the gaps becomes smaller, and therefore the core portion between the R/W gap and the nonmagnetic layer also becomes narrower, resulting in a decrease in output efficiency. On the other hand, although the above-mentioned MIG type magnetic head can improve the output, it is more complicated to manufacture than one in which a normal magnetic gap is formed between the cores, and there are many steps such as attaching a metal magnetic thin film and processing the film thickness. There is a problem in terms of mass production.

Accordingly, the present invention provides a composite type magnetic head having a normal R/W gap and an Er gap on both sides of the center core portion, which improves the recording/reproducing output efficiency to approximately the same level as the MIG type. The purpose is to provide a magnetic head.

[0006]

[Means for Solving the Problems] According to the present invention, R/W
A composite magnetic head in which a nonmagnetic layer is interposed between a gap and an Er gap, wherein the distance between the R/W gap and the nonmagnetic layer is about 33% or less of the distance between both gaps. is provided.

[0007]

[Operation] In the present invention, by arranging the position of the nonmagnetic layer interposed in the center core portion largely toward the Er gap side, the thickness of the center core portion on the R/W gap side becomes large even with the same gap distance. , the output increases because the magnetic resistance of this part decreases. In one side of the center core part that constitutes the erase core part, the width of the erase track is wider than the width of the recording/reproduction track, so the core width is large, and even if the nonmagnetic layer is moved toward the Er gap side, the erase characteristics are affected. There is no.

[0008]

Embodiments Next, embodiments of the present invention will be explained with reference to the drawings. FIG. 1 is a partial side view of a pre-erase type magnetic head according to an embodiment of the present invention, FIG. 2 is a view seen from the magnetic medium sliding surface side of FIG. 1, and FIG. 3 of the conventional example, respectively.
, corresponds to FIG. As explained in the conventional example, the center core portion 1 is divided by the nonmagnetic layer 2 into the R/W gap side center core 1a and the Er gap side center core 1b, which are joined to the C-shaped cores 3 and 4, respectively, and the R/W gap side center core 1b is joined to the C-shaped cores 3 and 4, respectively. A W gap 5 and an Er gap 6 are formed. The Er gap side center core 1b and the C-shaped core 4 are
As shown, R/W gap side center core 1a and C
The width dimension D is larger than that of the shaped core 3.

As is clear from the figure, the position of the non-magnetic layer 2 is much closer to the Er gap 6 side than in the conventional example, and specifically, the distance T between the Er gap 6 and the non-magnetic layer 2 is is approximately 33% or less of the distance L between the R/W gap 5 and the Er gap 6. The region from the non-magnetic layer 2 to the R/W gap 5 is correspondingly wider compared to the conventional one, and the output is increased due to a decrease in magnetic resistance.

To give a specific example, the gap distance L is 2
05 μm, and the thickness t of the nonmagnetic layer is 15 μm. When the distance T between the center of the nonmagnetic layer 2 and the Er gap 6 is 97.5 μm (100×T
/L=47.5%), the effect of improving the output efficiency is 0%, and when the distance T is 90.5 μm (100×T/L=44%), the effect of improving the output efficiency is 6%. On the other hand, the distance T is 67
．． When the distance T is 5 μm (100 x T/L = 33%), the output efficiency improves by 21%, and when the distance T is 62.5 μm (
100×T/L=30%), it was recognized that the output efficiency improved by 27%. This is at a level equivalent to or higher than that of the MIG type in which a metal magnetic thin film is provided in the gap portion.

[0011]

[Effects of the Invention] As explained above, according to the present invention, R
In a magnetic head in which a nonmagnetic layer is sandwiched between the /W gap and the Er gap, by moving the position of the nonmagnetic layer toward the Er gap side, the efficiency of recording and reproducing output can be improved by more than 20%, which is different from the MIG type. A magnetic head with output efficiency equal to or higher than that can be easily obtained. M
Unlike the IG type, there is no difficulty in manufacturing, and there are no problems in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a partial side view of a pre-erase type composite magnetic head according to an embodiment of the present invention.

FIG. 2 is a partial front view of the embodiment shown in FIG. 1, seen from the magnetic medium sliding surface side.

FIG. 3 is a partial side view of a conventional advance erase type composite magnetic head.

FIG. 4 is a partial front view of the conventional example shown in FIG. 3;

[Explanation of symbols]

1 Center core part 2 Non-magnetic layer 3, 4 C type core 5 R/W gap 6 Er gap

Claims (1)

[Claims] 1. A composite magnetic head in which a non-magnetic layer is interposed between a recording/reproducing core portion having a magnetic gap for recording/reproducing and an erasing core portion having a magnetic gap for erasing, wherein the magnetic gap for erasing and the magnetic gap for erasing are A composite magnetic head characterized in that the distance to the nonmagnetic layer is approximately 33% or less of the distance between both gaps.