JP4298934B2 - Disk unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk device. The disk in this specification means a disk as a data storage medium such as a magnetic disk, an optical disk, or a magneto-optical disk. Accordingly, the disk device in the present specification means a device for performing at least one of processing of recording and reproduction of data on a predetermined disk such as a magnetic disk, an optical disk, or a magneto-optical disk.
[0002]
[Prior art]
Conventionally, as an example of this type of disk device, there is one described in Japanese Patent Laid-Open No. 2000-348456. As shown in FIG. 4, this conventional device includes a slider 90 having components such as an electromagnetic coil or a lens for recording and reproducing data to / from a disk D, and a suspension 91 that supports the slider 90 at the tip. And have. When the disk D rotates at high speed around the spindle axis C, the slider 90 floats to the disk through an air layer when air flows between the slider 90 and the disk D. ing. Further, this disk device measures the electrostatic capacitance between the conductor layer 90a provided on the slider 90 and the conductor layer of the disk D, and based on this measured value, the slider 90 and the disk D It is comprised so that the distance between can be detected. The base end portion of the suspension 91 is supported via a piezoelectric element 92, and the height of the slider 90 can be changed by controlling voltage application to the piezoelectric element 92.
[0003]
According to such a configuration, when the disk device in which the disk D is not rotating is stopped, the slider 90 is lifted using the piezoelectric element 92 so that the slider 90 does not contact the disk D. A so-called ramp loading method can be employed as the slider loading method. In addition, since the height of the slider 90 can be adjusted in accordance with the measured value while measuring the distance between the slider 90 and the disk D, the slider 90 is caused by a change in environmental temperature or the like. Even if the spring characteristics change, it is possible to control the distance so as not to fluctuate greatly due to this.
[0004]
[Problems to be solved by the invention]
However, in the above conventional apparatus, there is a possibility that the slider 90 may come into contact with the disk D when the disk device is started and when the drive is finished as described below.
[0005]
That is, when starting the disk device, as shown in FIG. 5A, the slider 90 is gradually lowered from a state where the slider 90 is separated from the disk D by a relatively large size. In this case, the slider 90 may be inclined with respect to the disk D by an appropriate angle θ. Such a tilt occurs due to, for example, dimensional error or deformation of the slider 90, the suspension 91, and other members that support the suspension 91, and the disk device is manufactured so as to completely eliminate this tilt. It is difficult. On the other hand, as described above, when the slider 90 is inclined, as shown by the phantom line in the figure, when the slider 90 is brought close to the disk D, the slider 90 floats between them. An air layer having a stable air flow is not immediately formed, and a part of the slider 90 may come into contact with the disk D. After such contact, the slider 90 floats through the air layer 93 in a posture parallel to the disk D, as shown in FIG.
[0006]
When the drive of the disk device is finished, the slider 90 is raised together with the suspension 91 from the state shown in FIG. 5B, but the flying force of the slider 90 by the air layer 93 is greatly reduced immediately after the start of the rise. . Therefore, the slider 90 returns to the original tilted posture as shown in FIG. 5A at a stage where the slider 90 is not sufficiently separated from the disk D. May come into contact with the surface of the disk D. The height of the air layer 93 may be set to a very small size, for example, on the order of μm. However, when the air layer 93 is made minute in this way, the contact between the slider 90 and the disk D occurs more. It becomes easy.
[0007]
The contact of the slider 90 with the disk D as described above damages them to shorten their life, and generates wear powder. Conventionally, a portion of the disk D that is damaged by contact with the slider 90 cannot be used as a data storage area. Therefore, there has been a problem that the storage capacity of the disk D is small in the prior art.
[0008]
Conventionally, unlike the above, for example, when the disk is not rotated, the slider is brought into contact with the disk, and when the disk starts to rotate, the slider floats by the action of airflow. There is also a so-called contact start / stop type. However, even in such a case, the slider eventually comes into contact with the disk in the same manner as the above-described prior art. Therefore, there was a problem similar to that described above.
[0009]
The present invention has been conceived under such circumstances, and a disk device that can appropriately prevent the slider and the disk from contacting each other at the time of starting and at the end of driving. The issue is to provide.
[0010]
DISCLOSURE OF THE INVENTION
In order to solve the above problems, the present invention takes the following technical means.
[0011]
  From this applicationClearlyThus, the provided disk device is provided with a slider that is disposed at a position facing the disk and that can float with respect to the disk via an air layer when the disk rotates.ThisAnd a suspension that is movable in a direction in which the slider and the disk face each other.,UpDetecting means capable of detecting the inclination of the slider relative to the disk;,UpAn actuator that can change the inclination of the suspension so that the inclination of the slider can be corrected;The actuator includes: an upper plate portion that supports a base end portion of the suspension and is supported on a lower plate portion via a plurality of support columns having a spring property; and the upper plate portion. Four magnets attached to the outer peripheral edge of the plate portion, and four electromagnets attached to the outer peripheral edge of the lower plate portion and arranged corresponding to the four magnets, By selectively driving, a function of rotating the slider around two axes orthogonal to each other in a plane substantially parallel to the disk, and reciprocating the suspension in a direction in which the slider and the disk face each other. Function andIt is characterized by that.
[0012]
According to such a configuration, at the time of starting the apparatus or at the end of driving, the detecting means detects the tilt of the slider, and then controls the actuator based on the detection data, whereby the slider is The posture can be made with no or little tilt with respect to the disc. Therefore, unlike the prior art, the slider is prevented from coming into contact with the disc when the slider is brought close to the disc at the start of the device or when the slider is moved away from the disc at the end of driving of the device. be able to. As a result, it is possible to extend the life of these sliders and disks so as not to be damaged greatly, and to prevent generation of wear powder. Further, since it is possible to avoid that a part of the data recording area of the disk is damaged by contact with the slider, the data storage capacity of the disk can be substantially increased as compared with the conventional case.
[0013]
In a preferred embodiment of the present invention, there is provided control means capable of controlling the actuator so as to reduce the inclination based on the data of the inclination of the slider detected by the detection means. The control means is configured to move the slider from the set position to the set position where the slider floats through the air layer from a release position separated from the disk by a certain distance or more. When moving to the position, control is performed to correct the tilt of the slider.
[0014]
According to such a configuration, the control means appropriately executes control in which the slider is brought into a parallel or substantially parallel posture with respect to the disk at an appropriate timing when the apparatus is started and when the drive is finished. .
[0015]
In another preferred embodiment of the present invention, the detecting means includes three or more electrodes provided on the slider so as to be spaced apart from each other in two axial directions perpendicular to each other in a plane substantially parallel to the disk. And measuring the capacitance between each of the three or more electrodes and the conductor layer of the disk, so that the direction and magnitude of the inclination of the slider can be detected. Yes.
[0016]
According to such a configuration, in order to detect the tilt of the slider based on the capacitance between at least three electrodes spaced apart in a predetermined direction and the conductor layer of the disk, the tilt of the slider The direction and the size of the can be accurately detected. In addition, a predetermined number of electrodes are provided on the slider, but since these electrodes can be formed in a thin and lightweight form, the size and weight increase of the entire movable part including the slider can be suppressed. Further, it is possible to prevent the high-speed operability of the slider from being greatly impaired.
[0019]
Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to the drawings.
[0021]
1 and 2 show an embodiment of a disk device according to the present invention. The disk apparatus A according to the present embodiment is configured as a magneto-optical disk apparatus capable of recording and reproducing data on the magneto-optical disk D.
[0022]
As clearly shown in FIG. 1, the disk apparatus A includes a spindle 10 for supporting a magneto-optical disk D and rotating it around its central axis, a magneto-optical head H, a controller 3, and the magneto-optical disk. A fixed optical unit 4 that advances laser light toward the head H is provided. The magneto-optical disk D is such that the downward surface layer portion is a recording layer 99. In this embodiment, the slider 22 of the magneto-optical head H is disposed below the magneto-optical disk D to form the recording layer 99. A so-called front illumination system is used to face each other. This front illumination method is suitable for suppressing coma aberration caused by the substrate thickness of the magneto-optical disk D when forming a laser spot on the recording layer 99 and spherical aberration caused by uneven thickness of the substrate.
[0023]
The fixed optical unit 4 collimates a laser beam emitted from a light source 40 such as a laser diode by using a collimator lens 41, and the laser beam is passed through a beam splitter 42, a beam expander 43, and a galvano mirror 44 in a predetermined manner. It is configured to be guided to the magneto-optical head H by advancing along this path. The magneto-optical head H is provided with a mirror 29 and an objective lens 28, and light that travels in a substantially horizontal direction from the galvano mirror 44 toward the magneto-optical head H is reflected upward by the mirror 29. The light enters the objective lens 28. The objective lens 28 forms a laser spot on the recording layer 99 of the magneto-optical disk D by converging the incident light. The objective lens 28 can be configured to use a plurality of lenses in order to increase the NA. The laser light applied to the magneto-optical disk D is then reflected by the recording layer 99 and travels in an optical path opposite to the optical path described above. It is detected by the detection circuit 45.
[0024]
The beam expander 43 has, for example, two lenses 43a and 43b, and when the laser beam passes through the beam expander 43, the effective diameter of the laser beam is reduced. When the effective diameter of the laser beam is reduced in this way, the diameter of the objective lens 28 can be reduced. Therefore, the total weight of the mounted components of the slider 22 that supports the objective lens 28 is reduced, thereby preventing deterioration of the operation performance. This is preferable. Further, until the laser beam reaches the beam expander 43, the effective diameter of the laser beam may remain relatively large. Therefore, the light source 40 and the collimating lens 41 can be easily used with existing sizes. Can also be obtained. Focus control when forming a laser spot on the surface of the magneto-optical disk D can be performed by moving one of the two lenses 43a and 43b of the beam expander 43 in the optical axis direction. The galvanometer mirror 44 is rotatable about an axis 44a, and by this rotation operation, the light reflection direction can be finely adjusted and tracking control can be performed.
[0025]
The magneto-optical head H has a configuration in which the base end portion of the suspension 21 that supports the slider 22 at the tip end portion is attached to the carriage 20 via the actuator 5. The carriage 20 is mounted with the above-described mirror 29 and can reciprocate in the tracking direction (radial direction of the magneto-optical disk D) indicated by the arrow Tg below the magneto-optical disk D. The carriage 20 is preferably movable up and down in the direction of arrow Z with a relatively large stroke by a lifting device (not shown). In this way, the magneto-optical head H can be disposed in the vicinity of the magneto-optical disk D in the normal state, while the magneto-optical head H is moved to the magneto-optical disk when the magneto-optical disk D is attached to and detached from the spindle 10. It can be kept far away from the setting position of the disk D so that they do not touch each other. In the present invention, in place of the means using the carriage 20 that is movable in the tracking direction as in the present embodiment, a swing arm that can swing in the radial direction of the magneto-optical disk D is used. A configuration in which the suspension 21 and the slider 22 are supported on a swing arm may be employed.
[0026]
The slider 22 has a substantially block shape as a whole, and is mainly composed of ceramic, for example. In the present embodiment, a magnetic field modulation method is employed in order to realize high data recording density and high-speed data transfer, and the slider 22 has an objective lens as shown in FIG. A coil 27 for generating a magnetic field that surrounds 28 is also provided. Although not shown in the drawings, the slider 22 is supported by the tip of the suspension 21 so as to be swingable in various directions via a gimbal spring, for example, as in the existing one. As will be described later, this slider 22 is always parallel to the downward surface of the magneto-optical disk D when the slider 22 floats over the magneto-optical disk D through an air layer. This is to make it follow.
[0027]
On the upward surface of the slider 22, four electrodes 30 a to 30 d as conductors are provided so as to surround the objective lens 28. These electrodes 30a to 30d are for detecting the inclination of the slider 22, and are distributed and arranged so as to be spaced apart from each other in the tracking direction Tg and the track direction Tc of the magneto-optical disk D perpendicular thereto. Yes. Since the recording layer 99 of the magneto-optical disk D is a conductor layer, by utilizing the electrodes 30a to 30d, electrostatic capacitance between each of the electrodes 30a to 30d and the recording layer 99 of the magneto-optical disk D can be obtained. Capacitance can be measured. The capacitance measurement itself is also performed in the above-described prior art, and since the method is known, the description thereof is omitted. Since the measured capacitance corresponds to the distance between each of the electrodes 30a to 30d and the recording layer 99, the presence or absence of the inclination of the slider 22 with respect to the recording layer 99 based on the data of the plurality of capacitances, It is also possible to determine the direction and magnitude of the inclination when there is an inclination. The shorter the distance between the electrodes 30a to 30d and the recording layer 99, the larger the capacitance.
[0028]
  The suspension 21 can be bent and deformed in a vertical direction indicated by an arrow Z, and a base end portion thereof is supported by the actuator 5. The actuator 5 is capable of rotating the suspension 21 in the direction of arrow N1 around the first axis C1 extending in the tracking direction Tg and in the direction of arrow N2 around the second axis C2 extending in the track direction Tc perpendicular thereto. The suspension 21 can be moved up and down in the vertical direction indicated by the arrow N3. As this actuator 5,BookThe embodiment is,NextIt has the structure as follows.
[0029]
  In the actuator 5, an upper plate portion 50 a that supports the base end portion of the suspension 21 is supported on the lower plate portion 50 b via a plurality of support columns 51 having spring properties. Four magnets 52 and corresponding electromagnets 53 (53a to 53d) are provided on the outer peripheral edges of the upper plate portion 50a and the lower plate portion 50b. For example, when the electromagnet 53 (53a) is driven to generate a repulsive force between the electromagnet 53 and the corresponding magnet 52 (52a), the upper plate portion 50a and the suspension 21 are in the direction of the arrow N4 around the axis C1. Rotate to. With this principle, the actuator 5 can rotate the suspension 21 in a desired direction around the axes C1 and C2. Further, if a repulsive force is evenly generated between all of the four electromagnets 53 and the four magnets 52, the upper plate portion 50a and the suspension 21 will rise without rotation, and this principle Thus, it is possible to move up and down by a desired dimension in the direction of the arrow N3. Of course, it is also possible to combine the rotation operation of the suspension 21 around the axes C1 and C2 and the lifting operation..
[0030]
The control unit 3 includes, for example, a CPU and a memory attached to the CPU. As will be described later, these electrodes 30a to 30d are utilized at four times using four electrodes 30a to 30d of the slider 22. The inclination is detected by measuring the capacitances at four locations between 30d and the recording layer 99 of the magneto-optical disk D, and the actuator 5 is controlled based on the detected data.
[0031]
Next, the operation of the disk device A will be described.
[0032]
First, the disk apparatus A employs a so-called ramp load system, and when the apparatus is not activated, the slider 22 is fixed from the recording layer 99 of the magneto-optical disk D below the magneto-optical disk D. Wait at a predetermined release position that is more than a distance away. Next, after the disk device A is activated and the magneto-optical disk D starts to rotate, the actuator 5 is driven under the control of the control unit 3, thereby raising the suspension 21 and the slider 22. At the time of these ascents, the control of the control unit 3 performs the tilt detection process of the slider 22 using the four electrodes 30a to 30d, and when the slider 22 is detected, the actuator 5 moves so as to eliminate the tilt of the slider 22. To be controlled.
[0033]
As a specific example, for example, in FIG. 2, when the slider 22 is inclined so that the electrodes 30a and 30b are higher than the electrodes 30c and 30d, the recording of the electrodes 30a and 30b and the magneto-optical disk D is performed. The electrostatic capacity between the layers 99 is larger than the electrostatic capacity between the electrodes 30 c and 30 d and the recording layer 99. Based on the difference between these capacitance values, the controller 3 determines the direction of inclination of the slider 22 and its angle, and causes the actuator to rotate the suspension 21 by a predetermined angle in the direction of arrow N4 around the axis C1. 5 is driven. Then, since the slider 22 is supported by the suspension 21, the slider 22 rotates in the direction of the arrow N4 like the suspension 21, and the upward surface of the slider 22 becomes horizontal.
[0034]
Of course, in the disk apparatus A, a control method different from the above method can be used. For example, capacitance data between the electrodes 30a to 30d and the recording layer of the magneto-optical disk D when the slider 22 floats with respect to the magneto-optical disk D via the air layer 80 is obtained in advance by experiments or the like. This data is stored in the memory of the control unit 3. When the slider 22 is actually raised, the actuator 5 is moved so that the measured value of the capacitance is compared with the data stored in the memory by comparing the measured value with the data stored in the memory. Control. The slider 22 can be leveled also by such a method.
[0035]
Since the four electrodes 30a to 30d are dispersed so as to be spaced apart from each other in the tracking direction Tg and the track direction Tc perpendicular to each other on the magneto-optical disk D, the upward surface of the slider 22 is relative to the magneto-optical disk D. Regardless of the direction of inclination, the direction of inclination and the angle of inclination can be determined. Further, the actuator 5 can raise the suspension 21 and rotate the suspension 21 around the two axes C1 and C2 extending in the tracking direction Tg and the track direction Tc. It is possible to appropriately correct the tilted state regardless of which direction is tilted. The control unit 3 repeatedly executes the tilt detection process of the slider 22 and the correction thereof a plurality of times by feedback control. By performing such feedback control, the slider 22 can be placed in a horizontal posture without tilting with respect to the magneto-optical disk D with higher accuracy.
[0036]
As described above, the controller 3 raises the slider 22 to the set position where the slider 22 can float through the air layer 80 directly below the magneto-optical disk D while correcting the slider 22 to the horizontal posture. Then, the slider 22 floats through the air layer 80 directly below the magneto-optical disk D without colliding with the magneto-optical disk D. Since the dimension of the gap between the slider 22 and the magneto-optical disk D is, for example, on the order of μm, a part of the slider 22 comes into contact with the magneto-optical disk D when the slider 22 approaches the magneto-optical disk D while being tilted. However, in this embodiment, such a fear can be eliminated. After the slider 22 floats through the air layer 80, the slider 22 follows so as to be in a posture parallel to the downward surface of the magneto-optical disk D, and thereafter, the driving of the actuator 5 may be stopped. .
[0037]
Next, when the drive of the disk device A is terminated, the control unit 3 performs control to lower the slider 22 from the set position to the original release position and return. At that time, the control unit 3 starts control for lowering the suspension 21 and the slider 22 by the actuator 5, and at the same time, executes control for bringing the slider 22 into a horizontal posture. This posture control can be performed on the same principle as when the slider 22 is moved up and down from the release position to the set position. If such control is performed, the slider 22 will not collide with the magneto-optical disk D even when the slider 22 is inclined due to a dimensional error or an assembly error of each part of the magneto-optical head H. Thus, it is possible to properly return to the original release position.
[0038]
As described above, in the disk device A, the slider 22 can be prevented from colliding with the magneto-optical disk D both at the time of starting and at the end of driving. Therefore, the slider 22 and the magneto-optical disk D can be protected. With respect to the magneto-optical disk D, there is no possibility that a portion that collides with the slider 22 cannot be used as a data storage area, so that the storage capacity can be increased.
[0039]
The contents of the present invention are not limited to the contents of the above-described embodiment. The specific configuration of each part of the disk device according to the present invention can be varied in design in various ways.
[0040]
  As a means for detecting the inclination of the slider, for example, as shown in FIG. 3, a configuration in which only three electrodes 30 in total are provided on the slider 22 may be employed. Even if the total number of the electrodes 30 is three, if the electrodes 30 are distributed in two orthogonal directions, the direction of the inclination of the slider 22 with respect to the disk and the size thereof should be determined appropriately. Is possible. The directions of the two axes are not necessarily limited to the track direction or tracking direction of the magneto-optical disk. However, in the present invention, as a detecting means for detecting the tilt of the slider, a means for detecting the tilt according to other principles can be adopted instead of measuring the capacitance..
[0041]
The present invention can be applied not only to a magneto-optical disk apparatus but also to an optical disk apparatus and a magnetic disk apparatus.
[0042]
【The invention's effect】
As described above, according to the present invention, contact between the slider and the disk at the start of the apparatus and at the end of driving can be avoided, so that the slider and the disk can be protected and the disk can be protected. The storage capacity can be made larger than before.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an embodiment of a disk device according to the present invention.
FIG. 2 is a perspective view of the main part of FIG.
FIG. 3 is a perspective view showing a main part of another embodiment of the present invention.
FIG. 4 is an explanatory diagram showing an example of a conventional technique.
FIGS. 5A and 5B are operation explanatory diagrams of the prior art.
[Explanation of symbols]
A disk unit
D magneto-optical disk
H magneto-optical head
3 Control unit
4 Fixed optics
5 Actuator
20 Carriage
21 Suspension
22 Slider
30a-30d electrode
99 Recording layer (for magneto-optical disk)

Claims (3)

Arranged at a position opposed to the disc, and a flying slider in through an air layer with respect to the disk when the disk rotates, supports a this slider, and the and the slider and the disk-facing and comprising a suspension which is movable in a direction, and detectable detection means the inclination of the slider with respect to the upper SL disk, a freely actuator changes the inclination of the upper Symbol modifiable to the suspension the inclination of the slider, the to A disk device,
The actuator includes an upper plate portion that supports the base end portion of the suspension and is supported on the lower plate portion via a plurality of support columns having spring properties, and four actuators attached to the outer peripheral edge of the upper plate portion. A magnet, and four electromagnets attached to the outer peripheral edge of the lower plate portion and arranged corresponding to the four magnets, and selectively driving the electromagnet to the disc. a function to rotate the slider about two axes perpendicular to each other in substantially plane parallel, an der Rukoto that the said slider and said disk to realize a function for reciprocating the suspension in opposite directions A disk device characterized. Based on the data of the tilt of the slider detected by the detecting means, the control means is provided that can control the actuator so as to reduce the tilt, and
The control means is configured such that when the slider approaches a set position where the slider floats through the air layer from a release position separated from the disk by a certain distance or more, and the slider moves from the set position to the disk. The disk device according to claim 1, wherein the disk device is configured to perform control for correcting the inclination of the slider when moving to a release position.   The detection means includes three or more electrodes provided on the slider so as to be spaced apart from each other in two axial directions orthogonal to each other in a plane substantially parallel to the disk, and the three or more electrodes. 3. The disk device according to claim 1, wherein a direction and a magnitude of the inclination of the slider can be detected by measuring an electrostatic capacity between each of the disk and a conductor layer of the disk. .

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