JPH052793A - Magnetic head slider - Google Patents

Abstract

PURPOSE:To prevent a dust from being stuck to the edge face of the air inflow side of a slider. CONSTITUTION:A taper part 25 which is made thin toward an edge part is formed at one face of a slider 21, the pertinent one face is opposed to a rotating disk, and the slider 21 is moved to a direction separating from the above mentioned disk by the dynamic pressure of air flowing from the above mentioned edge part into the above mentioned taper part 25 by the rotation of the disk. An edge face 26 at the air inflow side of the slider 21 is formed so that one face close to the disk and the other side far from the disk can be respectively formed so as to be curved surfaces curving to the air outflow side in the direction opposed to the disk, and the radius of curvature at the above mentioned one side is made smaller than that of the above mentioned other side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a magnetic disk drive device,
The present invention relates to a slider used as a flying mechanism of a magnetic head of a disk drive device such as a magneto-optical disk drive device.

[0002]

2. Description of the Related Art As a bias magnetic field generator for applying a bias magnetic field for a magneto-optical disk, one having a structure similar to that of a magnetic head slider used in a hard disk device has been conventionally known (for example, INTERRNATI).
ONAL SYMPOSIUMON OPTICAL
MEMORY, 1987 Sep, T.M. NAKAOet
al. ).

FIG. 5 is an enlarged perspective view showing a structure around a magnetic head slider of a conventional magneto-optical disk drive device.
In the figure, reference numeral 1 denotes a disk-shaped magneto-optical disk (hereinafter referred to as a disk), and a magnetic head slider which floats on the upper surface of the disk 1 by several μm by a dynamic pressure generated by the rotation of the disk 1 in the direction of the white arrow 2 is facing. The magnetic head slider 2 has a rectangular flat plate shape, and its air inflow side is several μm.
The slider 21 thinned to some extent, and the U-shaped core 22 and the core 22 embedded in the center of the outflow side end of the slider 21.
And a bulkhead 24 which is a bias magnetic field generating unit including a coil 23 wound around one side.

The slider 21 of the magnetic head slider 2 is attached to a support arm 5 via a gimbal spring 4,
With a pivot (not shown) formed on the gimbal spring 4 as a fulcrum, the magnetic head slider 2 moves with respect to the support arm 5 by pitching (oscillation of the disk 1 in the radial direction) and rolling (oscillation of the disk 1 in the circumferential direction). It is movably supported and can follow the surface wobbling of the disk 1 by these swings. Further, the magnetic head slider 2 can be moved in the radial direction of the disk 1 by the forward / backward movement of the support arm 5. Further, the optical head 3 faces the lower surface of the disk 1 facing the bias magnetic field generation position of the bulk head 24, and heats the bias magnetic field generation region at the time of recording or erasing to form a reversed magnetic domain.

FIG. 6 is a schematic enlarged view showing the structure of a conventional slider 21, and FIG. 6 (a) is a side view thereof and FIG.
FIG. 6B shows the air inflow side (arrow A in FIG. 6A).
The front view seen from each is shown. The slider 21 has a flat plate shape, and the air flows into the slider 21 from the direction indicated by the hollow arrow by the rotation of the disk 1. On the bottom surface of the slider 21, a taper portion 25 formed at an angle θ is provided over substantially the entire width from a position facing the outflow side a predetermined distance from the end surface 27 on the air inflow side toward the end surface 27.

[0006]

In the slider 21 constructed as described above, the air flows into the taper portion 25, so that the air flow is restricted and the slider 21,
Dynamic pressure is generated between the disks 1, and buoyancy in the direction of separating from the disks 1 is generated. However, the end face 27 on the air inflow side of the slider 21 provided with the taper portion 25 formed at the angle θ is a flat surface and its thickness is on the order of several hundreds of μm. On the other hand, as shown in FIG. 7, the flow velocity of the inflow air has a velocity distribution that becomes smaller as it separates from the disc 1, and the thickness at which the flow velocity becomes almost zero (boundary layer thickness δ) is several hundred μ.
m, and the flying height of the slider 21 is 10 μm
Most of the air flowing toward the slider 21 on the slider inflow side due to the small amount is almost from the lower surface (closer to the disk 1) to the upper surface of the slider 21 as shown in FIG. The flow direction is changed in the vertical direction (the remaining minute amount flows into the minute gap region between the slider 21 and the disk 1 and the slider 21 is levitated). At this time, in the vicinity of the lowest point of the air inflow side end surface 27 of the slider 21, there is a place where the flow stagnates (double circled portion in FIG. 7). Therefore, dust contained in the air is first present in this portion. 10 is attached. Further, at the upper end angle of the slider 21 on the air inflow side (the circled portion in FIG. 7), the flow is separated, so that the dust 10 also adheres to this portion. When it is used for a longer period of time, as shown by hatching in FIGS. 8 and 9, a large amount of dust 10 in the air adheres from above and below the inflow side end surface 27 as time passes. FIG. 7 is a schematic view showing the air flow around the inflow end of the conventional slider 21 immediately before dust adhesion, FIG. 8 is a schematic side view of the conventional slider 21 showing the adhesion state of dust 10, and FIG. 9 is adhesion of dust 10 FIG. 9 is a schematic front view of the conventional slider 21 showing the situation, and FIGS.
FIG. 8A shows a sample example of the adhesion state of the dust 10 about 100 hours after the use of the magneto-optical disk drive device, and FIG.
And FIG. 9B shows the use of the magneto-optical disk drive device for about 20 minutes.
FIG. 8C and FIG. 9C show sample examples of the adhered state of the dust 10 after 0 hours, and FIGS. There is.

As shown in FIGS. 8 (a) and 9 (a), the dust 10 is attached around the lower end and the upper end of the inflow side end surface 27 of the slider 21. The thickness of the dust 10 is
Dust class (total number of dust particles having a size of 0.5 μm or more per 1 cubic foot) in an indoor environment of about 1 to 8 million, 0.05 mm after about 100 hours of use, and about 0.1 after about 200 hours of use. 15 mm, about 0.25 mm after about 300 hours of use, and the protruding height of the dust 10 from the upper end of the slider 21 to its upper portion is about 20 mm.
0.05 mm after 0 hours, 0.1 after about 300 hours of use
The experimental result of 0 mm is obtained, and the dust 10 adheres to almost the entire end surface of the slider 21 after about 300 hours of use. Further, the amount of dust 10 attached is larger at the lower end than at the upper end, as is typically shown in FIGS. 8 (a) and 9 (a). This is because the air flow velocity on the disk 1 is large on the side closer to the disk surface as described above, and as a result, an air flow as shown in FIG. 7 is generated, so that the air flow rate colliding with the lower end of the slider 21 per unit time. Is larger, air containing more dust arrives at the lower end portion, and dust adheres thereto. Although the upper end is a separation point, the flow velocity here is considerably high in the vertical upward direction as shown in FIG.
Since a large proportion is carried away by this flow, the amount of dust attached is smaller than that at the lower end.

As a conventional slider other than the slider having the above-mentioned shape, there is a slider shown in FIG. 10 (for example, National Institute of Electronics, Information and Communication Engineers Spring National Convention 5-38, Yasuda et al., 1990).
This is done by improving the front / rear end surfaces of the slider to improve the landing on / off characteristics to the disk. In this kind of slider, the air flow colliding with the lower end surface of the slider is Since it is more difficult to flow upward than the one shown in the conventional example, it becomes easier to stagnant, and it is not effective for removing and attaching dust.

The amount of dust 10 thus attached increases with the passage of time as shown in FIGS. 8 and 9,
Due to the increase in the amount, the dust 10 easily falls. Especially when disturbance vibration is applied to the slider 21 in such a state,
The dust 10 drops on the disk 1, and the dropped dust 10 is sandwiched between the slider 21 and the disk 1 to cause the slider 2 to move.
1 and the disk 1 did not properly float.

The present invention has been made to solve the above-mentioned problems, and provides a magnetic head slider which prevents the adhesion of dust and the like to the slider by forming the end surface on the air inflow side into a curved surface. The purpose is to

[0011]

In the magnetic head slider according to the present invention, the end surface on the air inflow side of the magnetic head slider has air on one side close to the disk and on the other side far from the disk in the direction facing the disk. The curved surface is curved toward the outflow side. Further, the radius of curvature on one side of the end face on the air inflow side is made smaller than the radius of curvature on the other side.

[0012]

In the first aspect of the invention, the end surface on the air inflow side has curved surfaces that are curved toward the air outflow side on the side facing the disk and on one side near the disk and on the other side far from the disk. Therefore, since the inflow air flows to the air outflow side without stagnating at the end face, the dust contained in the inflow air flows to the air outflow side without adhering to the end face.

Further, as described above, most of the air flows vertically upward at the slider inflow end, but in the second aspect of the invention, one side of the air, which is closer to the disk, is far from the disk. At the end surface on the air inflow side where the other side and the curved surface are respectively bent to the air outflow side, the radius of curvature of the other side is larger than the radius of curvature of the one side. Most of the air that has flowed into the air flows out more smoothly along the curved surface having the large radius of curvature toward the outflow end side, so that the inflow air hardly stagnates at the inflow side end surface. Further, the point where the flow separates at the upper end of the inflow end surface also moves to the outflow end side as compared with the conventional case, so that even if dust adheres, there is almost no risk of it growing or falling on the disc. .

[0014]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged perspective view showing a structure around a slider of a magneto-optical disk drive device using a magnetic head slider of the present invention.

In the figure, reference numeral 1 denotes a disk-shaped magneto-optical disk (hereinafter referred to as a disk), and the dynamic pressure generated by the rotation of the disk 1 in the direction of the hollow arrow is several μm to several tens on the upper surface of the disk 1. The magnetic head slider 2 that is flying by μm faces. The magnetic head slider 2 has a rectangular flat plate shape, and has a slider 21 having an air inflow side thinned by several μm to several tens of μm, a U-shaped core 22 and a core embedded in the center of the end of the slider 21 on the outflow side. 22 and a bulkhead 24, which is a bias magnetic field generation unit including a coil 23 wound around one side.

The slider 21 of the magnetic head slider 2 is attached to a support arm 5 via a gimbal spring 4, and the magnetic head slider 2 is pitched with respect to the support arm 5 with a pivot (not shown) formed on the gimbal spring 4 as a support. The disk 1 is supported so as to be capable of oscillating around the radial direction) and rolling (oscillating around the circumferential direction of the disk 1). This swinging can follow the surface runout of the disk 1. Further, the magnetic head slider 2 can be moved in the radial direction of the disk 1 by the forward / backward movement of the support arm 5. In addition, the bulkhead 24
The optical head 3 faces the lower surface of the disk 1 opposed to the bias magnetic field generation position, and heats the bias magnetic field generation region at the time of recording or erasing to form a reversed magnetic domain.

FIG. 2 is a schematic enlarged side view showing the structure of an embodiment of the slider 21 of the present invention. The slider 21 has a flat plate shape, and the air flows into the slider 21 from the direction indicated by the hollow arrow by the rotation of the disk 1. On the bottom surface of the slider 21, a taper portion 25 formed at an angle θ is provided over substantially the entire width from a position facing the outflow side a predetermined distance from the end surface 26 on the air inflow side toward the end surface 26. In the slider 21 configured as described above, when the air flows into the taper portion 25, the flow of the air is narrowed to generate dynamic pressure, and buoyancy in the direction of separating from the disk 1 is generated. The upper portion 26a of the end face 26 is an arcuate curved surface having a predetermined first diameter R ₁ and the lower portion 26b of the end face 26 has the same diameter as the first diameter R _1. It is an arcuate curved surface having a predetermined second diameter R ₂ which is smaller than R ₁ . That is, the lower portion 26b of the end face 26
The radius of curvature of the curved surface is smaller than that of the curved surface of the upper portion 26a.

The slider 21 thus constructed floats by the inflow of air generated by the rotation of the disk 1. Although dust is contained in the inflowing air, the end surface 26 of the slider 21 is a curved surface as described above, and the air hitting the end surface 26 flows from the end surface 26 in the outflow direction without stagnating. The dust contained in the inflowing air does not adhere to the end surface 26. Further, the velocity of the air on the surface of the disk 1 has a velocity distribution that becomes smaller as it moves away from the disk 1, so that the first diameter R ₁ of the curved surface of the upper portion 26a of the end surface 26 is set to the lower portion as described above. If there was greater than the second diameter R ₂ of 26b, the proper flow corresponding to the velocity distribution can be formed around the slider 21, it can be properly prevented adhesion of dust. That is, even if the flow separates on the curved surface of the upper portion 26a of the end face 26, the position moves to the outflow end side as compared with the conventional case, and therefore the dust adhesion position also moves to the outflow end side correspondingly. There is no problem. Most of the dust adhering to the slider 21 is contained in the inflowing air, but other than this, the following second embodiment for canceling the influence of the dust present on the disk 1 will be described. .

Example 2. Next, a second embodiment of the present invention will be described. FIG. 3 is a schematic enlarged view showing the structure of the slider 21 of the second embodiment. The slider 21 has a flat plate shape, and the air flows into the slider 21 from the direction indicated by the white arrow by the rotation of the disk 1. . From the position facing the outflow side by a first distance from the air inflow side end surface 26 of the slider 21,
From the end surface 26 to a position facing the outflow side by a second distance shorter than the first distance, a first inclined surface 25a is formed at a first taper angle θ ₁ , and from there, toward the end surface 26, Second taper angle 25b with 2 taper angle θ ₂ (θ ₂ > θ ₁ )
Are formed respectively, and the taper portion 25 is constituted by them. The end surface 26 has the same curved surface shape as that of the first embodiment as described above.

When the slider 21 thus constructed floats due to the rotation of the disk 1 and makes a pitching motion due to its surface wobbling and the tip comes into contact with the disk 1, the dust present on the disk 1 has the first inclined surface 25a. Hardly adheres to the second inclined surface 25b and adheres to the second inclined surface 25b. At this time, the flying characteristic of the slider is predominantly determined not by the second inclined surface 25b but by the first inclined surface 25a. Since the first inclined surface 25a has the same shape as before the dust adheres, the flying characteristic of the slider 21 is It will hardly change. The other structures and the floating characteristics for dust are substantially the same as those in the first embodiment, and therefore the description thereof will be omitted.

Example 3. Next, a third embodiment of the present invention will be described. FIG. 4 is a schematic enlarged view showing the structure of the slider 21 of the third embodiment. The slider 21 is in the form of a flat plate, into which air flows from the direction indicated by the hollow arrow by the rotation of the disk 1. . The shape of the upper portion of the air inflow end surface 26 of the slider 21 is different from that of the first embodiment, and the arcuate curved surface does not reach the upper surface on which the slider 21 is supported, and forms a straight portion 21c from the middle. However, the position where the arc changes to a straight line is formed on the slider outflow side behind the peeling position.

The slider 21 thus constructed is floated by the rotation of the disk 1 in the same manner as in the above-mentioned embodiment, and most of the dust-containing air is blown along the arc-shaped curved surface of the inflow end face 26. It moves to the outflow side and peels off at the position before the end face shape changes from a circular arc to a straight line. The slider 21 having such a shape is easier to manufacture than the first embodiment and is advantageous in cost. The characteristics other than the slider shape for dust and the like are the same as those in the first embodiment, and the description thereof will be omitted.

In the above description, the present invention has been described by taking the magneto-optical disk drive device as an example, but the present invention is not limited to this, and it can be applied to a fixed magnetic disk drive device open to the atmosphere. There is no end. Further, the shape of the inflow side end surface 26 of the slider is shown as an example in which the R shape is constant on the upper end side and the lower end side, but the present invention is not limited to this, and the radius of curvature of the upper end portion is larger than that of the lower end portion. If the radius is relatively large, the radius of curvature may be gradually changed (including an arc envelope curve such as a parabola) or a combination thereof. Further, the case where the bias magnetic field generating unit is a bulk has been described as an example, but it goes without saying that a thin film head having a reduced inductance may be used in order to speed up the change in magnetic field strength. Further, the mounting position of the bulkhead 24 has been described by taking the case where the slider 21 is at the center of the outflow side end as an example, but is not limited to this and may be any other position on the flat surface of the slider 21 facing the disk 1. In addition, the rotation direction of the disc 1 is described as counterclockwise, but it goes without saying that the rotation direction of the disc 1 is similarly established.

[0024]

As described above, in the first aspect of the invention, the end surface on the air inflow side has one side near the disk and the other side distant from the disk in the air-outflow side facing the disk. Since the inflowing air flows toward the air outflow side without stagnating at the end face, it is possible to prevent dust contained in the inflowing air from adhering to the end face. Further, in the second aspect of the present invention, the one side near the disc and the other side distant from the disc respectively have curved surfaces that are curved toward the air outflow side, and the curvature radius of the one side is the same as that of the other side. It is smaller than the radius of curvature, and depending on the velocity distribution of the inflowing air, one side of the end face allows the inflowing air to the lower surface of the slider to flow without stagnating, and the other side flows into most of the sliders other than the above. Since the air flows without stagnation, it is possible to further prevent the dust contained in the inflowing air from adhering to the end surface. As described above, the present invention has an effect of suppressing adhesion of dust to the end surface on the air inflow side.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view showing a structure around a magnetic head of a magneto-optical disk drive device using a magnetic head slider of the present invention.

FIG. 2 is a schematic enlarged view showing the structure of an embodiment of the magnetic head slider of the present invention.

FIG. 3 is a schematic enlarged view showing the structure of a magnetic head slider of a second embodiment of the invention.

FIG. 4 is a schematic enlarged view showing a structure of a magnetic head slider according to a third embodiment of the present invention.

FIG. 5 is an enlarged perspective view showing a structure around a magnetic head slider of a conventional magneto-optical disk drive device.

FIG. 6 is a schematic enlarged view showing the structure of a conventional slider.

FIG. 7 is a schematic diagram showing a flow of air near a conventional slider inflow end.

FIG. 8 is a schematic side view of a conventional slider showing a dust adhesion state.

FIG. 9 is a schematic front view of a conventional slider showing a dust adhesion state.

FIG. 10 is a schematic enlarged view showing the structure of another conventional slider.

[Explanation of symbols]

1 Magneto-optical disk 2 Magnetic head slider 21 Slider 25 Tapered part 26 Edge

Claims (2)

[Claims] 1. A taper portion having a thin wall is formed on one surface thereof toward an end portion, the one surface is opposed to a rotating disk, and air flowing from the end portion to the taper portion is caused by rotation of the disk. In the magnetic head slider that moves and flies away from the disk due to the dynamic pressure of, the end surface on the air inflow side has one side near the disk and the other side far from the disk in the direction facing the disk. A magnetic head slider, each having a curved surface curved toward the air outflow side. 2. The magnetic head slider according to claim 1, wherein a radius of curvature on one side of the end face on the air inflow side is smaller than a radius of curvature on the other side.