JPH0386956A - Magneto-optical storage device - Google Patents

Abstract

PURPOSE:To obtain a magneto-optical storage device where head crush hardly occurs and which has high reliability by providing at least two slider rails which have specified width to a magnetic head slider. CONSTITUTION:A magnetic head 1012 is arranged on a recording film side by facing to an optical head 1011 so as o interpose a disk 1, constituted of a coil part which impresses a magnetic field on the recording film and a slider part which makes the whole head float and made to float by air pressure caused by the rotation of the disk while the disk is rotated. Then, at least two slider rails, one of which has the width of at least 2mm or more, are provided to the magnetic head slider. Thus, the head crush is avoided and the magneto- optical storage device having the high reliability is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a magnetic head for magnetic field modulation mounted on a slider, which is levitated above the medium to maintain the necessary magnetic field strength while improving the sliding resistance, especially against dust, etc. This invention relates to a magneto-optical storage device that is less susceptible to contamination.

[Conventional technology]

It is effective to place the magnetic field modulation coil for a magneto-optical disk as close to the recording film as possible in order to obtain a high C/N.

However, the surface runout of a recording medium that rotates at high speed is up to ±10
In the case of a medium exchange type device where the thickness reaches 0 μm, the fixed modulation magnetic field coil needs to be separated from the medium surface by at least 1100p. Therefore, in Japanese Patent Laid-Open No. 63'-217548, an attempt was made to employ a floating magnetic head as a means of stably bringing the magnetic field modulation coil close to the recording film surface while maintaining a constant distance.

[Problem M to be Solved by the Invention] However, the above technique has a weakness in that reliability cannot be ensured against the incorporation of dust from outside the device. That is, the flying of the magnetic head becomes unstable due to the incorporation of dust or the like or adhesion to the slider surface, and the magnetic head comes into contact with the medium surface. There is a great risk of causing a so-called head crash.

An object of the present invention is to provide a highly reliable magneto-optical recording device that employs a floating magnetic head and is less prone to head crashes.

[Means to solve the problem] The structure of the present invention is to achieve this objective.

a magnetic head for applying a magnetic field to a magneto-optical disk; a light source and an optical system for irradiating a laser into a magnetic field application area of the magneto-optical disk; a rotating means for rotating the magneto-optical disk; A magneto-optical recording device comprising: a magnetic head slider equipped with the magnetic head that flies above the magneto-optical disk; and a modulation means for modulating at least l of the laser and magnetic field in accordance with a signal to be recorded. The head slider is a magneto-optical recording device characterized in that the magnetic head is lifted above the disk so that the distance between the magnetic head and the magneto-optical recording medium is 10 micrometers or more during the operation of the modulation means.

Further, another configuration of the present invention includes a magnetic head that applies a magnetic field to a wider range than the minimum bit area to be recorded on the magneto-optical recording medium to form a magnetic field area, and a laser spot that defines the minimum bit area. a light source and an optical system that form on the magneto-optical recording medium; a means for modulating at least one of the magnetic field or the laser according to the signal to be recorded even if the laser spot is formed within the range of the magnetic field region; In the magneto-optical recording device having a mechanical means for relatively moving the magnetic field region and the laser spot on the magneto-optical recording medium during the modulation operation, the distance between the magnetic herad and the magneto-optical recording medium is 1 during the operation of the
This is a magneto-optical recording device characterized by a diameter of 0 micrometer or more.

That is, in a magneto-optical recording device in which the recording density is determined by a laser spot, recording and reproduction can be performed while avoiding head crashes even when the spacing between the magnetic head and the medium is 10 μm or more, as will be explained later in FIG. 4. . In view of the characteristics of such a magneto-optical recording device, the present invention has the following features:
In particular, the present invention relates to a magneto-optical recording device with a large distance between the head and the medium, which is suitable for a magneto-optical recording device that is of a medium replaceable type and has a high possibility of head crash due to dust or the like.

More specific configurations of the present invention include a magnetic head for applying a magnetic field to a magneto-optical disk, a light source and an optical system for irradiating the magneto-optical disk with a laser, a means for rotating the magneto-optical disk, and a magnetic head for rotating the magneto-optical disk. In the magneto-optical recording device, the magnetic head slider has at least two slider rails, each of which has a width of at least 2 mm or more. be.

For non-adhesive dust such as sand and dust, the flying height of the flying head is increased to avoid the dust from getting caught between the head and the disk. In a preferred embodiment, for sticky dust such as cigarette smoke,
The contact start/stop (C8/S) operation ensures flying stability by peeling off adhering dust.

In a magnetic head slider having one or more flying rails, it is very effective to increase the slider width in order to increase the flying height and to reduce the magnitude of the load supporting the slider. In this case, the flying height and flying stability can be ensured by optimizing the taper length and taper angle for a flat slider, and the size and position of the protrusion of the convex part for a curved slider. .

C action] A slider with an optimal shape has a diameter of μm-500, which is larger than the maximum diameter of floating dust in a normal indoor environment.
Because it has a flying height of μm, 1. In normal usage environment,
Infiltrated dust will not get caught between the slider and the medium surface. Further, dust adhering to the medium surface and the slider surface is peeled off when the slider surface and the medium surface come into contact in a low speed region due to the contact start/stop operation.

〔Example〕

In FIG. 1(a), reference numeral 1 denotes a magneto-optical disk which is a rotating record carrier, and is placed on a disk-shaped transparent substrate 1003.
Magneto-optical recording medium 1001 with magneto-optic effect and protective film 1
002. For example, light emitted from a light source made of a semiconductor laser is converted into a parallel beam by a collimator lens 3, and enters a focusing lens 5 via a beam splitter 4. The light beam focused by the lens 5 enters the disk from the disk substrate 1003 side and forms a minute spot with a diameter of about 1 μm on the recording film 1001. The aperture lens 5 follows the vertical vibration of the disk so that the focus is always on the recording film, and the actuator 6 follows the eccentricity of the information recording track on the disk so that the spot is always on the desired track. is attached to.

The reflected light from the disk 1 passes through the aperture lens 5, is reflected by the beam splitter 4, and is sent by the beam splitter 7 to the magneto-optical signal detection optical system 8 and the optical point control signal detection optical system 9, which detects defocus and track deviation. be guided.

An example of the magneto-optical signal detection system 8 is shown in the figure. This is a differential signal detection method using a λ/2 plate 801 and a polarizing beam splitter 803. The light incident on the magneto-optical detection optical system 8 passes through a λ/2 plate 801 and a lens 802, is separated into S+P polarization components by a polarization piece splitter 803, and is focused on photodetectors 804 and 805, respectively. . The signals converted into electrical signals by both photodetectors are differentiated by a differential amplifier 10 and obtained as a magneto-optical signal.

The magnetic head 1012 sandwiches the disk l and the optical head 10
In FIG. 1a, the magnetic head is rotated 90 degrees within the disk surface from its actual arrangement and is shown enlarged as a close-up view for illustrative purposes. The magnetic head 1012 is composed of a coil portion that applies a magnetic field to the recording film and a slider portion that levitates the entire head, as will be described later.During the disk rotation, the magnetic head 1012 is levitated by the air pressure generated by the disk rotation.

The magnetic head 1012 is also pressed against the disk 1 by a support spring 1013 with a load that will be described later. And when replacing disk 1.

A moving mechanism 1016 is required to move the magnetic head 1012 up and down.

The magnetic head 1012 is further integrally connected to the optical head 1011 by a support arm 1015 so as to be able to operate in conjunction with the optical head, so that the magnetic head is always placed directly above the optical spot on the disk.

The optical head 1011 is moved in the radial direction of the disk by, for example, a linear motor or a step motor.

When recording information on a medium, it is sufficient to modulate and open either the magnetic head 1012 or the optical head 1011 depending on the information, but in this embodiment, the magnetic head drive circuit 101
4 to drive the magnetic head.

FIG. 1(b) is a diagram showing the basic shape of a head slider used in the present invention. 11 produces air pressure;
The slider surface 12 that contributes to floating is a tapered surface that guides air to the slider surface, and in this embodiment, it is a two-rail slider type having two slider surfaces. By optimizing the slider 111ii S w, pressing load W, slider length Lx, taper length t, taper angle θ, etc., it is possible to obtain predetermined flying characteristics.

FIG. 2 is a diagram schematically showing the effect of high flying height. If the flying height is secured, even if dust 22 from the outside enters under the slider surface, it is expected that it will pass through without being urged by the slider 21 or the medium 23 surface.

Figure 3 shows the actual measurement of the particle size distribution of suspended dust in a general room. The number of dust particles with a diameter exceeding 1 μm is extremely small. From this, as an example, the number of dust particles with a particle size of 10 μm or more passing under the surface of a slider with a slider area of 50Iff112 is at most 8:44 per 3000 rotations of the disk.

FIG. 4 is a graph showing the relationship between the distance between the magnetic head and the recording film and the magnetic field strength. In the magneto-optical disk device of the present invention, as a writing method, recording is performed by modulating a magnetic field at a location irradiated with a laser spot, and as a reading method, a signal is detected by irradiating a medium with a laser spot. During recording, the magnetic field is applied at intervals (magnetic field area) that are wider than the area of the laser spot, and the minimum unit of recording density is determined by the diameter of the laser spot, and the magnetic field area does not affect the recording density.However, 402 has a characteristic. In magnetic disk devices for magnetic writing and magnetic reading, the recording density is determined by the magnetic field area itself, so it is necessary to make the magnetic field area small (for example, on the order of 20 μm x 1 μm).A magnetic head with such a small magnetic field area As shown at 402 in FIG. 4, if the distance between the head and the recording surface is widened, the magnetic field strength decreases and recording becomes impossible. However, as shown in 401, in a magnetic head used in a magneto-optical disk device that does not require a small magnetic field area (for example, a magnetic field area of 0.1 mm or more.
), even if the distance between the head and the recording surface is increased to 10 μm or more, the magnetic field strength does not change much, and it is possible to record on the recording surface while maintaining this distance. In the example shown in FIG. 4 401, the magnetic field area corresponding to a predetermined optical spot diameter is 0.1
It can be seen that in the case of a magnetic head of "mm", the magnetic field strength hardly deteriorates even if the distance is 50 μmli from the recording surface.

As can be considered from FIGS. 2 to 4, in order to obtain a highly reliable magnetic head slider without compromising its performance as a magneto-optical recording device, the flying height must be set at 10 μm or more.
It can be seen that the thickness is preferably 10 μm to 50 μm.

FIG. 5 shows the results of a computer simulation study of the influence of the slider width Sw of the magnetic head on the flying height. Here, slider length Lx = 5, 7 m,
The pressing load w=6.0 gw. As a simple means of increasing the flying height, the slider width has a great effect. In reality, for example, when floating on a 5-inch diameter disk,
If the slider area becomes large, the data area will not be used effectively. Further, as the slider @Sw becomes larger, the head @Ly becomes larger, and the difference in linear velocity between the inner slider and the outer slider increases on the inner peripheral side of the disk, causing the flying to be tilted.

Therefore, there is a limit to the size of the head width, and in the case of a 5-inch disk, the head width Ly is 15 mm (see FIG. 1(b)).

FIG. 6 shows the results of a computer simulation study of the relationship between the pressing load W of the support spring and the flying height.

Here, slider length Lx = 5.7 kaku, slider @ S
w = 7, 6 nu. It can be seen that the effect of pressing load is also large as another means of increasing the flying height. Theoretically, a relationship of 2 holds between the pressing load W, the linear velocity V, and the flying height. Therefore, when the linear velocity is constant, the pressing load is inversely proportional to the square of the flying height. However, there is a relationship h between the pressing load W and the stiffness of the air film under the slider surface, and as the pressing load W becomes smaller, the floating 1h becomes larger, and therefore the stiffness of the air film inevitably becomes smaller. This means that the force of the air film supporting the slider surface has weakened, making it unstable against fluctuations during floating. Therefore, the length of pressed seedlings in the current support spring system is limited within a certain range, taking floating stability into account, and is optimally around 5 gW.

FIG. 7 shows the results of investigating the relationship between the slider length Lx and the flying height by computer simulation. Although it depends on the slider width, it can be seen that the slider length does not have much effect on the flying height. However, if the slider length is shorter than the head width, flying stability in the pitching direction will deteriorate, so the slider length must be at least as long as the head width.

FIG. 8 shows the results of a computer simulation study of the flying height when the length of the tapered part at the air inflow end of the plane slider was changed. There is also an optimum value for obtaining a high flying height, which is 0.1 to 0.5 in terms of slider total length ratio. Similarly, the flying height relative to the taper angle has an optimum value as shown in FIG. 9, and when the angle becomes larger than 1°, the flying height decreases and the flying stability deteriorates.

FIG. 10 is a diagram showing the basic shape of the slider of the present invention. In this example, the slider surface has a quadratic curved surface that draws a quadratic curve in a plane perpendicular to the width direction of the slider.
If the distance of the apex of the following curve from the front end of the slider is X1 and the amount of protrusion from both ends is δ, then the flying height changes depending on the amounts of X and δ.

FIG. 11 is a diagram showing the relationship between the flying height and x/Lx. Although it depends on the size of the slider, when the position of the apex is at a position where the slider total length ratio x/Lx is 0.1 to 0.6, the flying height shows the highest value.

FIG. 12 is a diagram showing the relationship between the flying height and the protrusion amount δ.

Regardless of the size of the slider, the amount of protrusion of the apex above is 1~
It can be seen that the flying height reaches its maximum value when it protrudes by ↓0 μm, preferably 4 to 8 μm.

A high flying height can be achieved by any of the above methods, and by combining them with each other, a flying height of 10 μm or more can be obtained depending on the design of the disk device. As a result, dust entering from the outside passes under the slider surface, so that the floating head and the disk do not slide. However, even if the particle size is small, sticky dust may be forced to adhere to the slider surface or the medium surface.

For this, contact start/stop (C3
/S) A method of forcibly peeling off the adhered dust by introducing an action can be considered. At this time, the slider surface inevitably comes into contact with the medium surface, but reliability is improved if a lubricant is applied or adhered to the slider surface. A similar effect can be obtained by making a slider using a porous sintered body such as 3AI220°2SiO□, SiC, etc. and impregnating it with a lubricant.

FIGS. 13(a) to 13(c) are views of the slider 131 on which the magnetic head element 132 is mounted, viewed from the rear. (
A) is a conventional slider support method, with a round pivot 13
3, the contact is close to point contact, so there is a large degree of freedom in pitching, rolling, yawing, etc. However, in order to ensure stability during floating with the slider according to the present invention,
It is effective to restrict the degree of freedom in the rolling direction by providing line contact support using the pivot 134 as shown in (b). It is also effective to restrict the degree of freedom in the pitching direction by providing line contact support using the pivot 135 as shown in (c).

Although it is effective to optimize each of the above parameters separately, the most desirable embodiment is to optimize them in combination with each other.

Now, among the various parameters, the pressing load is desirably about 5.0 gw from the viewpoint of floating stability as described above.

Further, the range of selection for the taper angle is narrow, and a value of around 0.8° at the peak position shown in FIG. 9 will be used. As described above, the reliability of the device can be ensured if the flying height of the slider is 10 μm or more within the range of regular use of the device based on the particle size distribution of indoor airborne dust. Figure I5 is.

This diagram illustrates the relationship between the slider width and the taper length at a linear velocity of 10 m/s at the innermost circumference of the disk surface of a 5.25-inch device. The optimal point under the conditions of a flying height of 10 μm or more and a minimum slider width is at point A in the figure.

FIG. 14 shows an investigation of the flying characteristics of the slider near the above-mentioned point A.

FIG. 14 shows an example in which stable and high flying height is achieved under optimal conditions by combining the above techniques. When applying this method to 3.5-inch disks, or 5- and 25-inch disks, the size of the magnetic head slider is limited due to disk surface utilization efficiency, and in this example, the slider length is 10 mm as shown in the figure. , head @ 10 rm
Front and rear, slider width 5m+a, taper angle 0.83,
When designing with a load of 5gf, each parameter can be optimized in consideration of the flying height and stability. The slider shown in FIG. 14 has a slider width value that is floated so that points a and c are respectively set on the inner circumferential side of the disk. From this figure, it can be seen that a flying height of 10 μm or more can be secured at a linear velocity of 10 m/s to 20 m/s, which is the range in which a 5.25-inch disk is used, for example.

〔Effect of the invention〕

According to the present invention, after the recording characteristics of a magneto-optical disk are sufficiently grooved, the expected decrease in reliability due to the use of a floating magnetic head can be reduced by optimizing the flying height of the slider, etc. can be minimized. This greatly contributes to improving the performance of magneto-optical disk devices.

[Brief explanation of drawings]

is a diagram schematically representing the effect of high flying height, Figure 3 is a diagram showing the actual measurement results of suspended dust particle size distribution in a general room, and Figure 4 is the relationship between the distance between the magnetic head and the recording film and the magnetic field strength. Figure 5 shows the effect of the magnetic head slider @Sw on the flying height. Figure 6, which shows the results of a computer simulation, shows the relationship between the pressing load W of the support spring and the flying height.
Diagram showing the results of computer simulation,
Figure 7 shows the results of a computer simulation of the relationship between the slider length Lx and the flying height, and Figure 8 shows the flying height when the length of the tapered part at the air inlet end of the planar slider is changed. , FIG. 9 is a diagram showing the results of a computer simulation of the flying height with respect to the angle of the taper, and FIG. 10 is a perspective view showing an embodiment of the present invention.
Fig. 11 is a diagram showing the results of a computer simulation of the flying height with respect to the position of the apex of a quadratic curved slider, Fig. 12 is a diagram showing the results of a computer simulation of the flying height with respect to the protrusion of the vertex, and Fig. 13
The figure is a conceptual diagram for explaining a method of supporting a support spring. FIG. 14 is a graph showing the relationship between the distance between the magnetic head and the recording film and the linear velocity according to the present invention. FIG. 15 is a graph showing the relationship between the distance between the magnetic head and the recording film, the slider width, and the taper length according to the present invention. Explanation of symbols 11...Slider surface, 12...Tapered surface, 13...
・Magnetic field generating coil, 21...Flying head, 22...
External dust, 23... magneto-optical disk, 101... slider surface. 131... Slider back surface, 132... Head element,
133...Point contact pivot, 134,135...Line contact pivot. Gi 1 Figure/ρρJ 71171 Saichi Figure 2 Moutel Summer 3 Figure Library 懺Ne Sai to CP fee) Kaya 4 Figure Hough 1 page and 1ts->irs 5E Ml (μless) Figure S 1 mat 1) Boo 9 bow rW (1w) Figure 10 ρl /θ7 χh2 Rush amount 5 (C) Figure 14 θ 1θ /s 7θ tJjL7F < m/s ) 3

Claims (1)

[Claims] 1. A magnetic head that applies a magnetic field to a magneto-optical disk, a light source and an optical system for irradiating the magneto-optical disk with a laser, means for rotating the magneto-optical disk, and a magnetic head that In a magneto-optical recording device having a magnetic head slider mounted thereon, the magnetic head slider has 1
A magneto-optical recording device characterized in that the book has at least two slider rails each having a width of at least 2 millimeters or more. 2. The magneto-optical storage device according to claim 1, wherein the pressing load of the support spring supporting the magnetic head slider is 6 gw or less. 3. The magneto-optical storage device according to claim 1, wherein the length of the slider is 5 mm or more. 4. The magneto-optical storage device according to claim 1, wherein the taper length of the air inflow portion for generating lift in the slider is set to 0.1 to 0.5 in terms of slider total length ratio. 5. The magneto-optical storage device according to claim 1, wherein the taper angle of the air inflow portion for generating lift on the slider is 1° or less. 6. The vertex of the magneto-optical disk facing surface of the slider having a quadratic curved surface is 0.1 to 0 from the front end in terms of slider total length ratio.
．． 6. The magneto-optical storage device according to claim 1, wherein the magneto-optical storage device is configured to be located at position 6. 7. The vertex of the magneto-optical disk facing surface of the slider having a quadratic curved surface is 1 μm from the edge of the front and rear ends of the slider.
2. The magneto-optical storage device according to claim 1, wherein the magneto-optical storage device protrudes by ~10 μm. 8. The magneto-optical storage device according to claim 1, wherein the slider is made of a dense or porous sintered body, and has means for retaining lubricant on the slider surface. 9. The magneto-optical storage device according to claim 1, wherein the contact start/stop operation is performed when the device is started or stopped or at predetermined time intervals during operation of the device. 10. The magneto-optical storage device according to claim 1, wherein the support point of the support spring that supports the magnetic head slider is structured to form a line contact. 11. The magneto-optical recording device according to claim 1, wherein the magnetic head performs the recording operation by flying 10 to 50 micrometers above the magneto-optical disk by the magnetic head slider. 12. The magneto-optical recording device according to claim 1, wherein the magneto-optical disk is replaceable. 13. The magneto-optical recording device according to claim 1, wherein the magnetic head applies a magnetic field area of about 0.1 square millimeters or more to the magneto-optical disk. 14. A magnetic head that applies a magnetic field to a wider range than the minimum bit area to be recorded on the magneto-optical recording medium to form a magnetic field area, and a laser spot that defines the minimum bit area on the magneto-optical recording medium. means for forming the laser spot within the magnetic field region and modulating at least one of the magnetic field or the laser according to the signal to be recorded; In a magneto-optical recording device having a mechanical means for relatively moving a laser spot on a magneto-optical recording medium, the distance between the magnetic head and the magneto-optical recording medium is 10 micrometers during operation of the mechanical means. A magneto-optical recording device characterized by the above. 15. Claim 15, wherein the magnetic head is mounted on a magnetic head slider having at least two slider rails, each of which has a width of at least 2 mm, and the slider flies above the recording medium by air pressure. 15. The magneto-optical recording device according to 14. 16. The magneto-optical storage device according to claim 15, wherein the pressing load of the support spring supporting the magnetic head slider is 6 gw or less. 17. The magneto-optical recording device according to claim 15, wherein the magnetic head applies a magnetic field area of about 0.1 square mm or more to the magneto-optical recording medium. 18. A magnetic head that applies a magnetic field to the magneto-optical disk;
A light source and an optical system for irradiating a laser into a magnetic field application area of a magneto-optical disk, a rotating means for rotating the magneto-optical disk, and a magnetic head that flies above the magneto-optical disk as the disk rotates. In a magneto-optical recording device having a magnetic head slider mounted thereon and a modulation means for modulating at least one of the laser and a magnetic field according to a signal to be recorded, the magnetic head slider is configured to combine the magnetic head and the magneto-optical recording medium. 1. A magneto-optical recording device, characterized in that the magnetic head is floated above the disk so that the distance is 10 micrometers or more during operation of the modulation means. 19. The magneto-optical recording device according to claim 18, wherein the magnetic head performs the recording operation by flying 10 to 50 micrometres above the magneto-optical disk by the magnetic head slider. 20. The magneto-optical storage device according to claim 18, wherein the contact start/stop operation is performed when the device starts or stops, or at predetermined time intervals during device operation. 21. The magneto-optical storage device according to claim 18, wherein the support point of the support spring supporting the magnetic head slider has a line contact structure. 22. A magnetic head slider equipped with a magnetic head having a plurality of slider rails each having a width of at least 2 mm to obtain lift. 23.Claim 2, wherein the length of the slider is 5 mm or more.
2. The magnetic head slider according to 2. 24. The magnetic head slider according to claim 22, wherein the taper length of the air inflow portion for generating lift in the slider is set to 0.1 to 0.5 in terms of slider total length ratio. 25. The magnetic head slider according to claim 22, wherein the taper angle of the air inflow portion for generating lift in the slider is 1° or less. 26. The vertex of the magneto-optical disk facing surface of the slider having a quadratic curved surface has a ratio of 0.1 to 0.1 to
23. The magnetic head slider according to claim 22, wherein the magnetic head slider is configured to be located at a position of 0.6. 27. The vertex of the magneto-optical disk facing surface of the slider having a quadratic curved surface is 1μ from the front and rear edges of the slider.
The magnetic head slider according to claim 22, wherein the magnetic head slider protrudes by m to 10 μm. 28. The magnetic head slider according to claim 22, wherein the slider is made of a dense or porous sintered body.