JPH02121172A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To obtain the high output and the high resolution with a magnetic head set at the inner circumferential side of a magnetic disk and to reduce the head crush probability with a magnetic head set at the outer circumferential side by giving the floating characteristics to the magnetic head of the inner circumferential side so as to secure the smaller floating height than the magnetic head of the outer circumferential side against the same peripheral speed of the disk. CONSTITUTION:The floating surface width Wa of a magnetic head 13 set at the outer circumferential side of a magnetic disk 1 is set larger than the floating surface width Wb of the magnetic heads 11 and 12 set at the inner circumferential side respectively. Therefore the floating height of the head 13 is larger than those of the heads 11 and 12 against the same peripheral speed of the disk 1. Thus the floating height H3 of the head 13 is larger than the floating height H3' obtained with use of a magnetic head having the same floating surface width of both heads 11 and 12. At the same time, the floating height H1 and H2 of both heads 11 and 12 are smaller than the floating height H1' and H2' obtained with user of the magnetic heads having the same floating surface width as that of the head 13. As a result, the head crush probability is reduced with the head 13 and the high output and the high resolution are obtained with the heads 11 and 12 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device in which a plurality of floating magnetic heads are arranged in the radial direction of a magnetic disk per magnetic disk.

[Prior Art] Fig. 4 is a schematic diagram showing a part of a conventional magnetic disk device of this type. In the figure, (1) is a magnetic disk which is a recording medium, (11), (12), ( A plurality of magnetic heads (13) are disposed in the radial direction on the same surface of the magnetic disc (1) that rotates once, facing the magnetic disc (1), and are floated by the air flow caused by the rotation of the disc (1). , (22).

(23) is a magnetic head (11), (12), (
13) is a suspension consisting of a spring plate that supports the.

These magnetic heads (11), (12), and (13) are in light contact with the magnetic disk (1) when they are at rest;
1) When it rotates, it floats due to the air flow generated by it and maintains a predetermined gap. Figure 5 shows the magnetic disk (1) at this time.
Magnetic head (11), (12), for the circumferential speed of
(13) A flying characteristic diagram showing the flying height of each magnetic head (11).

(12) and (13) are the circumferential speed of the magnetic disk (1) at its floating position (relative speed between the disk and the head) V
It will levitate to the respective heights H, H,, H, determined by V 2 y V 3.

By the way, when the magnetic disk is rotating and the magnetic head is floating, the flying height of the magnetic head must be set higher than a certain level so that it does not come into contact with the disk, or even if it does come into contact, it will not be damaged much. Must be.

[Problem to be solved by the invention] Conventional magnetic disk drives have an elliptical structure as described above.

Since a plurality of magnetic heads having the same flying characteristics are arranged in the radial direction of the magnetic disk, the flying height of each magnetic head is determined by the position in the radial direction of the disk, that is, the circumferential speed of the disk.

Now, at the outer periphery of the magnetic disc, the circumferential velocity, that is, the disc
The relative speed of the head is high, and when the magnetic disk or magnetic head moves or catches dust and comes into contact with it, so-called head crash can cause significant damage. For this reason, the flying level of the magnetic head must be made sufficiently high at the outer periphery. However, since conventional magnetic disk drives use magnetic heads with the same flying characteristics, the width of the air bearing surface and suspension pressure must be adjusted in order to obtain a sufficient flying height for the magnetic head (13) on the outer periphery. If this is determined, the flying height of the innermost magnetic head (11) will become too high, and its relative speed with the magnetic disk may be small, making it impossible to obtain sufficient output or resolution. There was a problem that this occurred.

This invention was made to solve the above-mentioned problems, and even when it is necessary to increase the flying height of the outer magnetic head to reduce the probability of head crash, it is possible to increase the flying height of the inner magnetic head. An object of the present invention is to obtain a magnetic disk device in which the flying height does not need to be increased more than necessary.

[Means for Solving the Problems] A magnetic disk device according to the present invention uses a magnetic head on the inner circumferential side using a magnetic head having a flying characteristic that has a lower flying height for the same circumferential speed of a magnetic disk than a head on the outer circumferential side. It is a head.

[Function] The magnetic disk device of the present invention can maintain the magnetic head on the outer side at a safe level and raise the flying height of the magnetic head on the inner side to an appropriate level without increasing it unnecessarily. High output and resolution can also be obtained from the magnetic head on the inner circumferential side.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a schematic configuration diagram showing a part of an embodiment of the present invention.
The figure is a flying characteristic diagram of the magnetic head used in this embodiment, and FIG. 3 is a characteristic diagram showing the probability of head crash occurring with respect to the magnetic disk rotation speed of each magnetic head.

In fig.

(1) is a magnetic disk which is a recording medium, (11), (1
2), (13) are magnetic heads, (21), (2
2) and (23) are suspensions, and unlike the conventional example, magnetic heads (11) and (12) have a different air bearing surface width wb, and magnetic head (13) has a larger air bearing surface @Wa. Two types of magnetic heads are used.

In FIGS. 2 and 3, A is the outer magnetic head (13
), B is the inner magnetic head (11), (12)
shows the characteristics of

As described above, in this embodiment, the outer magnetic head (1
3), the air bearing surface width Wa of the inner magnetic head (11), (
The flying height A of the magnetic head (13) for the same circumferential speed of the magnetic disk (1) is larger than the flying surface width wb of the magnetic head (12), so their flying characteristics are as shown in Fig. 2. It is larger than the flying height B of 11) and (12). Therefore, the flying height H1 of the outermost magnetic head (13) is the flying height H1' when it is assumed that a magnetic head with the same air bearing surface width as the innermost magnetic heads (11) and (12) is used. It becomes a dog, and the magnetic head (II) on the inner circumference side.

(12) Flying height H + Hz is the magnetic head (13)
The flying heights H' and H2' are smaller than the flying heights H' and H2' assuming that a magnetic head with the same air bearing surface width is used.

Conventional magnetic disk drives use magnetic heads with the same flying characteristics, so if a magnetic head with flying characteristics as shown in Figure 2B is used, for example, the outer magnetic head (I3) may crash. The probability of a head crash becomes extremely large as shown in Figure 3B, and if a type with flying characteristics as shown in Figure 2A is used, the flying height is large, so the head crash probability is shown in Figure 3A. However, the inner magnetic heads (11) and (12) cannot obtain sufficient output or resolution.

On the other hand, in this embodiment, since magnetic heads with different air bearing surface widths and air bearing characteristics are used as described above, the magnetic heads (11
) and (12), the flying height can be lowered, spacing loss can be reduced, and higher output and resolution can be obtained. can increase the flying height and reduce the probability of head crash.

In the above embodiment, the flying characteristics are changed by changing the width of the air bearing surface of the magnetic head.
1), (22), and (23) can be changed to change the floating characteristics. That is, by making the suspension pressure force Fi of the magnetic head closer to the inner circumference larger than the suspension pressure Fj of the magnetic head closer to the outer circumference, the flying height of the magnetic head closer to the inner circumference is lowered, and the suspension pressure force Fi of the magnetic head closer to the outer circumference is lowered. It is possible to increase the flying height of the magnetic head and obtain the same effect as in the above embodiment.

Further, the flying height of the magnetic head may be changed by applying other means.

[Effects of the Invention] As described above, according to the present invention, the magnetic head on the inner side of a plurality of magnetic heads has a flying characteristic in which the flying height for the same circumferential speed of the magnetic disk is lower than that of the head on the outer side. Since the magnetic head has the following characteristics, it is possible to obtain a magnetic disk device in which high output and resolution are obtained in the magnetic head on the inner circumferential side, and the probability of head crash is reduced in the magnetic head on the outer circumferential side.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a part of an embodiment of the present invention;
Fig. 2 is a flying characteristic diagram of the magnetic head used in this embodiment, Fig. 3 is a characteristic diagram showing the probability of head crash occurring with respect to the magnetic disk rotation speed of each magnetic head, and Fig. 4 is a diagram of a conventional magnetic disk. A schematic configuration diagram showing a part of the device, and FIG. 5 is a diagram showing the flying characteristics of a conventional magnetic head. In the figure, (1) is a magnetic disk, (11), (12)
, (13) is a magnetic head, (21), (22)
, (23) is the suspension. A is the characteristic of the outer magnetic head, and B is a characteristic of the inner magnetic head. The same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 3 Subb: Sub Yu+Su b2 Illa〉Sub Wa=Wa1+Wa2 Figure 2 Magnetic disk circumferential speed Magnetic disk circumferential speed Diagram procedural amendment (self-proposed) u1 trench 5・′0 Day

Claims (1)

[Claims] In a magnetic disk drive in which a plurality of magnetic heads are disposed in the radial direction on the same surface and are floated by airflow caused by the rotation of the magnetic disk, facing the surface of the magnetic disk, the inside of the plurality of magnetic heads is A magnetic disk device characterized in that the magnetic head on the peripheral side is a magnetic head having a flying characteristic that the flying height for the same peripheral speed of the magnetic disk is lower than that of the head on the outer peripheral side.