JPS6240680A - Magnetic recording media - Google Patents

Abstract

PURPOSE:To decrease the deflection of a disk by providing a prescribed groove along the circumferential direction between an inner circumferential side fixing part and an outer circumferential side recording part. CONSTITUTION:Between an inner circumferential side fixing part 9 of a magnetic disk 1 and an outer circumferential side recording part 10, a cross sectional square groove 11 is concentricly formed along the circumferential direction. The disk 1 generates the deflection due to various causes. For example, when a sticking material 12 is mixed into a spacer 4 and a disk contacting surface, the groove 11 is provided, the side wall comes to be the free edge, and therefore, the side wall is deformed as shown by the broken line in the figure and the deformation is not transferred into the recording part 10. The fixing part 9 is the hard part, the groove 11 is a soft part and the deformation, which comes to be the cause for the deflection, can be absorbed by the groove 11. Consequently, the deflection of the disk 1 during the rotation is decreased, and the slider floating clearance can be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic recording medium that is mounted on a spindle of a magnetic disk device and driven to rotate.

[Technical background of the invention and its problems]

Recently, there has been an increasing demand for miniaturization of magnetic disk drives, in which a magnetic head with a slider bearing that functions as a hydrodynamic gas bearing faces the recording medium and stably maintains a minute gap for recording and reproduction. Magnetic recording media (hereinafter referred to as magnetic disks) are also becoming smaller in diameter and thinner.

On the other hand, a large storage capacity is desired despite the miniaturization of devices, and great efforts are being made to improve recording density (bit density and track density). Other effective means for increasing capacity include increasing the number of magnetic disks per device, narrowing the distance between the magnetic disks, and reducing the thickness of the magnetic disks.

Conventionally, the thickness of a magnetic disk has been reduced as the diameter has been reduced, taking into consideration that deformation due to centrifugal force due to rotation does not adversely affect recording and reproduction, but the following problems arise.

That is, as shown in FIG. 6, when the magnetic disks 1 are stacked and mounted, the undulation of the magnetic disk mounting surface 3 of the spindle 2, the thickness of the spacer 4, and the magnetic disk welding of the magnetic disk mounting surface 3 and the spacer 4 are caused. The magnetic disk 1 is damaged due to scratches, deposits, etc. on the surface 5. The way the magnetic disk bends at this time varies depending on the thickness of the magnetic disk, and the thinner the magnetic disk, the larger the curvature of the bending in the circumferential direction. In fact, the curvature of this deflection has a close relationship with the dynamic flying height fluctuation of the magnetic hend slider 6 flying above the magnetic disk.

In FIG. 7, when the magnetic disk 1 is magnetic and there is an undulation with a curvature half υρ in the direction of the foot of the toss slider 6, if the length of the flat part of the magnetic head slider 6 is t, then the magnetic disk 1 and The air film formed between the magnetic and Rad slider 6 changes by s (=t27sρ). However, the undulation frequency due to the rotation of the magnetic disk is several hundred H.
When z is small, the magnetic helide slider 6 assumes a flying posture that averages out the air film, and conversely, normally, the latter part of the slider with the gap 8 of the recording/reproducing core 7 approaches the magnetic disk 1 due to undulation. You will end up leaving. During steady rotation, the above phenomenon appears as a change in the signal output, so-called modulation, resulting in a decrease in signal reliability. Further, when the rotation of the magnetic disk stops, contact and collision between the magnetic head slider and the magnetic disk occur even at high circumferential speeds, and the life of the magnetic head slider and the magnetic disk is extremely shortened.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a magnetic recording medium that can reduce the deflection of a magnetic disk that occurs during rotation and stably set the flying clearance of a magnetic head slider.

[Summary of the invention]

In order to achieve the above object, the present invention provides a magnetic recording medium in which the inner fixed part is fixed to a spindle and a magnetic head runs in the outer recording part to record and reproduce information. Provided is a magnetic recording medium characterized in that a groove is provided along the circumferential direction of the magnetic recording medium between the magnetic recording medium and the outer peripheral side recording portion.

[Embodiments of the invention]

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

FIG. 1 is a sectional view showing an embodiment of the magnetic recording medium of the present invention. The magnetic disk 1 is provided with concentric grooves 11 having a substantially square cross section along the circumferential direction of the magnetic disk 1 between the inner fixed part 9 and the outer recording part 10 so as not to interfere with the recording of this signal. is formed. The grooves 11 are provided on both sides of the magnetic disk 1, and a plurality of grooves 11 may be provided as necessary. Further, it is also possible to provide the groove 11 only on one side, or to provide the groove 11 only in a part of the magnetic disk 1 instead of over the entire circumference. Further, the shapes are not limited to concentric circles, but may be substantially the same or polygonal.

FIGS. 2 and 3 show a magnetic disk l provided with grooves 11.
3 is a diagram showing the positional relationship between the spacer 4 and the spacer 4.

FIG. 2 shows an outer recording section 10 slightly outside the spacer 4.
A groove 11 is provided at a position that does not affect the recorded portion.

In FIG. 3, the magnetic disk 1 is pressed down so that the spacer 4 covers the groove 11.

When the contact surface l between the spacer 4 and the magnetic disk 1 is reduced in this way, there is an advantage that, for example, the influence of deflection caused by uneven thickness of the spacer 4 is reduced.

Next, the present invention in which grooves 11 are provided in the magnetic disk 1 will be explained in detail with reference to FIG. Usually, the spacer 4 has problems such as nonuniform thickness or irregularity of the magnetic disk contact surface 5. Furthermore, there is a possibility that undesired substances may be mixed into the contact surface between the spacer 4 and the magnetic disk 1. FIG. 4 shows the deformation of the magnetic disk 1 that occurs when the magnetic disk 1 is clamped via the spacer 4 when the foreign matter 12 is mixed in. This deformation occurs because the side wall of the groove 11 is a free end, so the side wall deforms as shown by the broken line in the figure.
The influence of deformation that causes deflection is not transmitted to the outer circumferential side recording portion IO.

Further, the cause of the deformation is at the contact surface with the spacer 4 that is further inner than the location where the groove 11 is provided. This inner circumferential fixing portion 9 is relatively rigid. When the grooves 11 are provided, the thickness of the magnetic disk 1 becomes thinner at the grooves 11.
The part is soft compared to the rigid part. The deformation that causes deflection occurring in the rigid part of the inner fixing part 9 is absorbed by the soft part provided with the groove 11, and its influence is not transmitted to the outer recording part.

Note that the width and depth of the groove 11 vary depending on the diameter of the magnetic disk, but the width is a width that does not affect the outer recording section 10, and the depth is a width that does not affect the outer recording section 10. It is sufficient that the thickness of the part has such strength that a creep phenomenon (plastic deformation increases with time even under a constant stress) does not occur even when rotated at a normal speed of 3000 to 3600 rpm. In this way, by providing the groove 11 between the inner fixed part 9 (!: outer recording part 10) of the magnetic disk 1, the unevenness of the magnetic disk mounting surface 3 of the spindle 2 and the uneven thickness of the spacer 5 can be prevented. , it is possible to reduce the deflection caused by the irregularity of the magnetic disk contact surface 5 of the spacer 5 from reaching the outer recording section 10.As a result, the fluctuation in the flying clearance of the magnetic herad slider 6 is reduced, and the magnetic disk when the rotation of the magnetic disk is stopped is reduced. The circumferential speed at which the disk 1 comes into contact with the magnetic head slider 6 is reduced, and the sliding distance of the magnetic head slider 6 during one magnetic disk rotation stop is shortened.Furthermore, sliding at high circumferential speeds can be avoided. ,
The life of the magnetic disk 1 and the magnetic hent slider 6 can be extended, and the reliability of the magnetic disk device is significantly improved.

FIG. 5 is a sectional view showing a modification of the groove 11.

In FIG. 5, (a) is a rectangular groove, (b) is a U-shaped groove, (C) is a 7-shaped groove, and (d) is a semicircular groove.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to reduce the influence of the deflection of the magnetic disk that occurs at the inner fixing part on the outer recording part, and to stably set the flying clearance of the magnetic rad slider. A recording medium is provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a magnetic recording medium showing an embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views showing the positional relationship between grooves and spacers according to the present invention, and FIG. 4 is a cross-sectional view of a magnetic recording medium according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing a modified example of the groove according to the present invention, FIG. 6 is a cross-sectional view of a conventional magnetic recording medium mounted on a spindle, and FIG. 7 is a magnetic recording medium. To the magnetism of medium circumferential waviness 7
FIG. 3 is an explanatory diagram illustrating the influence on the floating state of the slider. DESCRIPTION OF SYMBOLS 1... Magnetic disk (magnetic recording medium), 4... Spacer, 9... Inner circumference side fixing part, 10... Outer circumference side recording part, 11... Groove. Figure 4 (a) (b) (C) (d) Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] In a magnetic recording medium in which an inner fixed part is fixed to a spindle and a magnetic head runs to an outer recording part to record and reproduce information, the magnetic recording medium is located between the inner fixed part and the outer recording part. A magnetic recording medium characterized in that a groove is provided along the circumferential direction of the medium.