JPS6376104A - Magnetic head - Google Patents

Abstract

PURPOSE:To miniaturize the device by arranging the center axis direction of the coil of a 1st magnetic head in a direction different from the center axis direction of the coil of a 2nd magnetic head so as to reduce the effect of the leakage magnetic flux from the magnetic head arranged adjacently. CONSTITUTION:The coil 7 of a servo head 6 is placed in such a manner that its center axis 13 is on a tangent of the circle 12 which has an optional radius (r) and is on a plane perpendicular to the center axis 11 of the coil 2 of a data head and the center of which is situated on the axis 11. That is, the coil 7 is arranged on a position where the interlinkage between the leakage magnetic flux 5 from the data head 1 and the magnetic flux of the coil 7 is minimized. Thus, the induced voltage in the servo head 6 caused by the leakage magnetic flux 5 is lowered, then noise is reduced and the magnetic heads 1, 2 can be arranged adjacently. Thus, the magnetic disk device is miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head, and particularly to the structure of coils of two adjacent magnetic heads in a magnetic head mounted on a magnetic disk device or the like.

[Conventional technology]

Conventionally, magnetic disk drives have magnetic disks, which are magnetic recording media, stacked coaxially at regular intervals, and are equipped with magnetic heads that write and read information on the disk surfaces. Regarding such a magnetic head, Japanese Patent Laid-Open No. 57-143717 and the like can be cited. In general, the narrow laminated spacing (for example, 3 to 6 mm) of disks
As shown in FIG. 3, two magnetic heads are installed adjacent to each other. When a recording current is passed through the recording or reproducing coil 2 of the magnetic head 1, a magnetic flux 9 is generated. This magnetic flux 9 flows through the magnetic circuit 10, but part of it leaks from places where magnetic flux easily leaks, such as core corners, and becomes magnetic flux 5, flows into the magnetic circuit 10' of the adjacent magnetic head 6, and flows into the coil 7. According to
For example, this may cause problems such as magnetic coupling between coils. This problem is particularly noticeable between two adjacent magnetic heads that operate simultaneously, such as a servo head and a recording head.

[Problem that the invention seeks to solve]

The above conventional technology does not take into consideration the magnetic coupling between the coils of adjacent magnetic heads, and noise is serious in the servo head due to the influence of leakage magnetic flux from the data head. There was a problem that a servo head could not be provided. This has been an obstacle to miniaturization of the device.

SUMMARY OF THE INVENTION An object of the present invention is to solve such conventional problems and provide a magnetic head that reduces the influence of leakage magnetic flux from adjacent magnetic heads in a magnetic disk device and allows for miniaturization of the device. It is in.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a magnetic disk drive having first and second magnetic heads each having a coil for recording or reproducing, in which the direction of the central axis of the coil of the first magnetic head is The magnetic head is characterized in that it is arranged in a direction different from the central axis direction of the coil of the second magnetic head installed adjacent to the first magnetic head.

[Effect]

The coil of the servo head is arranged at a position where the magnetic flux leakage from the data head and the magnetic flux linkage with the coil of the servo head are minimal. As a result, the induced electromotive force in the servo head due to leakage magnetic flux is reduced, reducing noise and allowing magnetic heads to be installed adjacent to each other, contributing to the miniaturization of magnetic disk drives. can.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, the present invention will be explained in detail.

FIG. 4 is a diagram for explaining the present invention in detail. The present principle will be explained below using FIG. 4.

The coil 7 of the servo head (see FIG. 1 described below) is arranged at an arbitrary radius r centered on the central axis 11 of the coil 2 of the data head (see FIG. 1 described later) in a plane perpendicular to the central axis 11.
The coil 7 of the servo head is placed (arranged) so that the central axis 13 of the coil 7 of the servo head is located on the circle 12 of the circle 12 and the central axis 13 of the coil 7 of the servo head is tangential to the circle 12. Here, the distance from the upper end of the data head's coil 2 to the center of the circle 12 where the servo head's coil 7 is located is Q.
, the coil length of the data head is a, the coil length of the servo head is s, and the angle between the x-axis and the servo head coil is θ.

By adopting the above-described coil structure, the flux linkage between the coil of the servo head and the leakage flux from the data head adjacent thereto can be reduced.

FIG. 1 is a longitudinal cross-sectional view of core sliders of magnetic heads installed adjacently, showing an embodiment of the present invention, and FIG.
The figure is a diagram for explaining the operation of this embodiment.

In FIG. 1, 1 is a data recording/reproducing magnetic head (hereinafter referred to as a data head), 2 is a recording/reproducing coil, and 3 is a data recording/reproducing magnetic head.
4 is a magnetic core gap, 4 is a magnetic disk, 5 is leakage magnetic flux from the magnetic head I, 6 is a servo magnetic head (hereinafter referred to as servo head), and 7 is a coil of the servo head 6.

In the data head 1, when writing data, a current is passed through the recording/reproducing coil 2, and information is recorded on the magnetic disk 4 by leakage magnetic flux generated in the gap 3 of the magnetic core made of a magnetic material such as Mn-Zn. .

At this time, as described above, leakage magnetic flux 5 is generated from the data head 1 toward the servo head 2.

5(a) and 6(a) show the positional relationship between the coil 2 of the data head 1 and the coil 7 of the servo head 6. FIG. The total leakage flux from the data head 1 is the flux linkage 15. which interlinks with the coil 7 of the servo head. This results in leakage magnetic flux '14 that does not interlink.

As shown in Fig. 7(a) and (b), this interlinkage magnetic flux 1
5, an induced electromotive voltage (2) is generated between the terminals of the coil 7 of the servo head. As shown in FIG. 5(b) and FIG. 6(b), the distance between the coils is d, where the distance between the coils is d.
The relationship between the induced electromotive force
Shown in c). Comparing these figures, we see that in the former case d
=o″7: V shows a maximum value, and becomes smaller as the two coils are separated from each other.

As a result, in order to reduce the magnetic coupling between the coils, it is necessary to increase the distance d between the coils, which cannot be said to be an effective means due to problems such as miniaturization of the device and accuracy of position information reading. However, in the latter case, d=o
In the vicinity, the induced electromotive force ■ draws a curve indicating the value of O.

This is because, as shown in Figure 7(b), the components of the interlinkage magnetic flux 15 in the central axis direction of the servo head coil are different, so the induced electromotive force ■ is the induced electromotive force ■3 on the left side of the coil and the induced electromotive force ■3 on the right side of the coil. This is because the difference with the electromotive voltage V is V = V, -V. Therefore, by adjusting the coil structure and the coil spacing d, the induced electromotive force due to leakage magnetic flux can be reduced to O without increasing the coil spacing d, and magnetic interference between adjacent magnetic heads can be reduced. can be prevented.

The above-mentioned FIG. 1 shows the reading coil 7 of the servo head 6.
on the central axis of coil 2 of the data head (r=
By setting d=o in FIG. 6(b), the induced electromotive voltage becomes 0, and magnetic interference can be prevented. Another example is shown in Fig. 2(a).
, shown in (b). This is a case where the coil 7 of the servo head is arranged at the position Q=-(a/2) in FIG. 4, and is a sectional view seen from six directions in FIG. 3. Figure 2(a)
2(b) shows the case where adjacent magnetic heads record and reproduce data on the upper and lower surfaces of the magnetic disk, and FIG. 2(b) shows the case where they are installed on the same surface. With such a structure, magnetic interference can also be reduced.

The structure of the magnetic head described in this embodiment or other embodiments is effective in reducing magnetic interference between heads having a coil structure, such as a monolithic head, a composite head, an inductive thin film head, etc. .

In this way, in this embodiment and other embodiments, the influence of leakage magnetic flux from the data head on the servo head can be reduced, so the heads can be arranged adjacently.

[Effects of the Invention] As explained above, according to the present invention, in a magnetic disk device, the influence of leakage magnetic flux from adjacently installed magnetic heads can be reduced, so the device can be made smaller, and furthermore, leakage can be reduced. Various harmful effects caused by magnetic flux can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a core slider of a magnetic head installed adjacently, showing one embodiment of the present invention, and FIG. 2 is a cross-sectional view of a core slider of a magnetic head, showing another embodiment of the present invention. , FIG. 3 is a structural diagram of core sliders and coils of conventional magnetic heads installed adjacently, and FIG. 4 is an explanatory diagram of the positional relationship between coils of adjacent heads, which is a feature of the present invention.
Figure 5. FIG. 6 is a diagram showing the relationship between the positional relationship of adjacent coils, the distance between the coils, and the induced electromotive voltage, and FIG. 7 is a diagram showing the interlinkage magnetic flux and the induced electromotive voltage. 1.6: Magnetic head, 2,7 Coil, 3: Gap,
4: Magnetic disk, 5, 14・Leakage magnetic flux, 9: Magnetic flux, 1
0.10': Magnetic circuit, 11.13: Central axis, 12
: Circle, 15: Interlinkage magnetic flux. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 He-,-=

Claims (1)

[Claims] 1. A magnetic disk device having first and second magnetic heads each equipped with a coil for recording or reproducing,
A magnetism characterized in that the central axis direction of the coil of the first magnetic head is arranged in a different direction from the central axis direction of the coil of the second magnetic head installed adjacent to the first magnetic head. head.