JP2001216666A - Head moving device and disk device having it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably perform tracking control excellent in seek operation and high speed followup ability in a disk device while restraining the increase of manufacturing costs for a head moving device. SOLUTION: A carriage 7 of the head moving device is divided into a first movable member 7a which supports a head 2 and has the coil part 80 of a voice coil motor VCM and a second movable member 7b which is moved and guided in a fixed direction by a guide member 85. The first movable member 7a is relatively and movably supported by the second movable member 7b so as to reciprocate in the fixed direction independently of the second movable member 7b. The second movable member 7b is pushed and moved by the first member 7a when the first movable member 7a is moved in the fixed direction beyond a fixed dimension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head moving device used for reciprocating a desired head such as an optical head or a magnetic head of a disk device along a predetermined path, and a disk device provided with the head moving device. About.

However, in this specification, the term "disk" simply means various disks as data storage media such as a magnetic disk, an optical disk, and a magneto-optical disk. Further, in this specification, when simply referred to as "disk device", a device for recording, reproducing, and erasing data on a predetermined disk such as a magnetic disk, an optical disk, or a magneto-optical disk, or at least one of them. It means an apparatus for performing one process.

[0003]

2. Description of the Related Art As is well known, in a magneto-optical disk device, for example, in order to perform data recording / reproducing processing, it is necessary to perform an operation of detecting a target track of a magneto-optical disk by an optical head, that is, a seek operation. .
Therefore, conventionally, there is a head moving device using a voice coil motor. This head moving device is of the so-called direct-acting type, and specifically has a structure as shown in FIG.

In this conventional head moving device, a carriage 9 for supporting an optical head 9 via a suspension 95 is provided.
0 and a pair of voice coil motors VCM. When the optical head 9 receives a laser beam traveling in a horizontal direction from a light source device (not shown),
For example, the laser beam is reflected upward by the mirror 9a and then focused by the objective lens 9b, thereby forming a beam spot on the recording layer of the magneto-optical disk D. The coil unit 93 of each voice coil motor VCM is provided on the carriage 90. Each voice coil motor VCM includes a magnetic field generated by energizing the coil unit 93, a magnet 91 and a yoke 92.
The carriage 90 can be moved in the tracking direction indicated by the arrow Tg by the interaction with the magnetic flux. The carriage 90 is provided such that its movement is guided by a pair of guide members 94 extending in the tracking direction.

According to the head moving device having such a configuration, the carriage 90 and the optical head 9 can be moved by a predetermined amount in the tracking direction by driving the voice coil motor VCM. Therefore, the above-described seek operation is possible.

[0006]

However, the conventional head moving device has the following disadvantages.

That is, in order to accurately perform data recording / reproducing processing on the magneto-optical disk D, control (tracking control) for causing the optical head 9 to follow a target track of the magneto-optical disk D after the seek operation is performed. There is a need to do. However, when such tracking control is performed using the above-described conventional head moving device, the entire carriage 90 is moved in the tracking direction as in the case of the seek operation. On the other hand, the carriage 90 needs to be formed in a size that can appropriately support the optical head 9 and also needs to be formed in a form that is stably supported by the pair of guide members 94.
The overall size and weight of the carriage 90 will increase to some extent.

Therefore, when tracking control is performed by the conventional head moving device, the weight of the movable portion (inertia mass) at that time is relatively large, so that the carriage 90 and the carriage 90 for driving the voice coil motor VCM are driven. The responsiveness of the moving operation of the optical head 9 has deteriorated. In this case, when speeding up the data recording / reproducing process on the magneto-optical disk D, it is difficult to perform quick and accurate tracking control corresponding to the speeding up.

Means for solving the above-mentioned problems include:
For example, a means may be conceived in which a fine movement actuator (not shown) capable of operating in a minute stroke is mounted on the carriage 90, and the optical head 9 is movable in the tracking direction by using the fine movement actuator. However,
In such a means, since an expensive fine movement actuator must be provided separately from the voice coil motor VCM, there arises a problem that the cost of the entire head moving device becomes expensive.

The present invention has been conceived under such circumstances, and appropriately performs seek control and tracking control excellent in high-speed followability in a disk drive while suppressing an increase in manufacturing cost. It is an object of the present invention to provide a head moving device capable of performing such operations. Also,
Another object of the present invention is to provide a disk device having such a head moving device.

[0011]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

A head moving device provided by a first aspect of the present invention has a carriage on which a head is mounted, and a voice coil motor for generating a driving force for reciprocating the carriage in a predetermined direction. Wherein the carriage supports the head, and has a first movable member having a coil portion of the voice coil motor, and a guide for moving in the fixed direction by a guide member. And the first movable member is separated into a second movable member and the second movable member so that the first movable member can reciprocate in the fixed direction independently of the second movable member. The second movable member is supported so as to be relatively movable, and can be pushed by the first movable member when the first movable member moves in the predetermined direction beyond a predetermined dimension. It is characterized in that it is.

In the head moving device having such a configuration, when the head is to be moved by a short stroke equal to or less than the predetermined dimension, the first movable member of the carriage is made independent of the second movable member. Can be moved alone. With this configuration, the weight of the entire movable portion of the carriage can be reduced by the amount that the second movable member is not moved, and the first movable member and the head can be used for driving the voice coil motor. This makes it possible to move quickly with good responsiveness.
On the other hand, when the head is moved with a long stroke exceeding the certain dimension, the first movable member is pushed by the first movable member, so that the first and second movable members are moved together. Can be moved. With this configuration, the second movable member can be moved in a stable state over a long stroke by the guide action of the guide member, so that the first movable member and the head are also moved accordingly. Thus, it is possible to move in a stable state over a long stroke.

As described above, in the head moving device according to the present invention, there are two types of operations, namely, a stable moving operation of the head in a long stroke exceeding a certain dimension and a rapid moving operation of the head in a short stroke of a certain dimension or less. The movement operation can be compatible. For this reason, if the head of the disk device is moved in the tracking direction by the head moving device according to the present invention, an appropriate seek operation and tracking control excellent in high-speed following performance can be performed. Further, in the present invention, the two types of movements of the head described above are both performed using the driving force of the voice coil motor. Therefore, the cost of the head moving device can be reduced as compared with a means for finely moving the head using a fine movement actuator different from the voice coil motor.

In a preferred embodiment of the present invention, the second movable member sandwiches the first movable member in the fixed direction so as to form a gap between the second movable member and the first movable member. It has a pair of pressed parts.

According to such a configuration, when the first movable member is moved within the range of the gap,
The first movable member can be moved independently of the second movable member. On the other hand, when the first movable member contacts or approaches one of the pair of pressed portions, the pressed portion can be pressed by the first movable member. Can be moved together with the second movable member. The first movable member can be moved together with the second movable member. Therefore, according to the above configuration,
When selecting one of the operation of independently moving the first movable member and the operation of moving the first movable member together with the second movable member, it is not necessary to separately provide a special switching means for performing the selection. Therefore, the structure of the carriage can be simplified.

In another preferred embodiment of the present invention, the second movable member has a front wall portion and a rear wall portion facing each other at an interval so as to form a space for accommodating the first movable member. It has a wall, and a part of each of the front wall and the rear wall is the pair of pressed parts.

According to this structure, since the first movable member is housed in the space of the second movable member, the entire carriage including the first and second movable members is combined. This is advantageous in reducing the size of the.

In another preferred embodiment of the present invention, the first movable member is connected to the second movable member via at least one spring member capable of elastically deforming in the predetermined direction.
Is supported by a movable member.

According to such a configuration, the first movable member can be appropriately supported so as to be relatively movable with respect to the second movable member using the spring member.

A disk device provided by the second aspect of the present invention is a disk device including a head moving device for moving a head in a radial direction of a disk. The head moving device provided by the first aspect of the present invention is used. The head may be an optical head or a magnetic head.

According to the disk drive having such a configuration, the same effects as described in the head moving device provided by the first aspect of the present invention can be expected.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIGS. 1 to 6 show an example of a head moving device and a disk device according to the present invention. The disk device A of the present embodiment is a magneto-optical disk device capable of recording and reproducing data on and from a magneto-optical disk D.
2 and FIG. 2, the magneto-optical disk D
And a head moving device B for moving the optical head 2 in a tracking direction indicated by an arrow Tg, and a light source / detection unit 60. The disk device A also includes a magnetic head or a coil (both not shown) for forming a magnetic field required for recording / reproducing data on / from the magneto-optical disk D, as described later.

The optical head 2 plays a role of irradiating the recording layer of the magneto-optical disk D with a laser beam, and for example, a slider 21 for holding the objective lens 20.
And the mirror 22. The optical head 2 is supported by a distal end of a suspension 3 made of a leaf spring member extending in the tracking direction.
It is arranged below the magneto-optical disk D. When the magneto-optical disk D rotates at a high speed, the slider 21 opposes the downward surface of the magneto-optical disk D at a small interval by the action of air flowing between the slider 21 and the magneto-optical disk D ( (Floating), and follows the surface deflection (fluctuation in the focus direction indicated by the arrow Fs) of the magneto-optical disk D so that the interval is always constant. The slider 21 can be tilted in various directions relative to the tip of the suspension 3. When the surface of the magneto-optical disk D is tilted, the slider 21 is tilted following the tilted surface, thereby maintaining a constant relationship with the surface. Is to be maintained.

The mirror 22 serves as a so-called rising mirror that reflects the laser light traveling in the horizontal direction from the light source / detection unit 60 via the mirror 61 so as to be incident on the objective lens 20. As the mirror 22, for example, a mirror using a triangular prism can be used. The objective lens 20 includes a mirror 22
The beam spot is formed on the recording layer of the magneto-optical disk D by converging the laser light traveling from the optical disk. The objective lens 20 may be constituted by one lens, but may be constituted by combining a plurality of lenses. From the viewpoint of minimizing the beam spot and increasing the recording density of the magneto-optical disk D, it is preferable to increase the numerical aperture of the objective lens 20 by combining a plurality of lenses including a solid immersion lens and the like. If the distance between the slider 21 and the surface of the magneto-optical disk D and the distance from the objective lens 20 to the position where the beam spot is formed are made very small, only the operation of the slider 21 following the surface deflection of the magneto-optical disk D The beam spot is always set to the magneto-optical disk D
Can be appropriately formed on the recording layer. Therefore, in such a case, the need for focus control can be eliminated.

The light source / detection section 60 receives a laser beam reflected from the recording layer when a beam spot is formed on the recording layer of the magneto-optical disk D, in addition to a role as a light source for emitting a laser beam. Thus, it is configured to also function as a detection unit that performs detection processing of recording data and detection processing of a tracking error signal, for example. However, it is also possible to adopt a configuration in which the light source and the detection unit are separated. When writing or reading data on the magneto-optical disk D by, for example, a magnetic field modulation method, as a means for forming a necessary magnetic field at a beam spot forming position, for example, a coil for generating a magnetic field is mounted on the optical head 2. Means can be employed. According to such means, it is not necessary to provide a magnetic head separately from the optical head, and the structure of the disk device can be simplified. The optical head according to the invention of the present application is a concept including an optical head that also has such a coil for generating a magnetic field. Of course, in the present invention, it is also possible to provide a magnetic head different from the optical head 2 above the magneto-optical disk D, and to adopt means for bringing this magnetic head closer to the spot where the beam spot is formed.

As best seen in FIGS. 3 and 4,
The head moving device B includes a carriage 7 and a pair of voice coil motors VCM for reciprocating the carriage 7 in the tracking direction. The configuration of each voice coil motor VCM itself is the same as the conventional one, and includes a coil section 80, a yoke 81 and a magnet 82. The yoke 81 and the magnet 82 constitute a magnetic circuit in a broad sense. The yoke 81 is made of a ferromagnetic material, and is formed, for example, in a rectangular frame shape. The coil part 80 is provided with the yoke 8
1 is loosely fitted to a straight portion extending in the tracking direction.

The carriage 7 is divided into a first movable member 7a and a second movable member 7b.
The configuration of the carriage 7 has the greatest feature. The first movable member 7a has, for example, a substantially rectangular parallelepiped shape, and a support plate 70a provided on an upper surface portion of the first movable member 7a.
The base end of the suspension 3 is joined to the suspension. A pair of coil portions 80 are provided at both ends in the width direction of the first movable member 7a.
Is provided. Therefore, the voice coil motor V
The driving force of the CM acts directly on the first movable member 7a, and by energizing and stopping the pair of coil units 80 and switching the energizing direction, the first movable member 7a is activated. It is possible to move forward or backward by a desired amount in the tracking direction. In the present invention, a bobbin in which the coil conductor of the coil unit 80 is partially wound can be used as the first movable member 7a.

As best seen in FIGS. 4 and 5,
The front end and the rear end of the first movable member 7a in the tracking direction are attached to the respective upper ends of two leaf springs 74a and 74b rising upward from the bottom 71 of the second movable member 7b. These two leaf springs 74a, 74b
Can be flexed and deformed in the tracking direction with an appropriate elastic restoring force, and their lower ends are fixed to a bottom plate 71 of the second movable member 7b, for example.
Supported by In the present embodiment, the first movable member 7a is supported by using two leaf springs 74a and 74b. However, the present invention is not limited to this. For example, one spring member or three or more spring members may be used. A structure in which the first movable member 7a is supported by a spring member may be employed. From the viewpoint of stabilizing the support of the first movable member 7a, it is desirable to use a plurality of spring members as in the present embodiment.

The second movable member 7b includes a front wall portion 72 rising upward from each of a front end and a rear end of the bottom portion 71.
And a rear wall portion 73, and the overall shape is a box shape or an almost box shape with an open top. A space is formed between the front wall 72 and the rear wall 73, and the first movable member 7a and the pair of leaf springs 74a and 74b are accommodated and arranged in the space. With such a configuration, the first movable member 7a and the pair of leaf springs 74a and 74b can be prevented from protruding significantly outside the second movable member 7b. Is preferable for reducing the value of.

However, the front wall portion 72 and the rear wall portion 73
An appropriate gap s1, s2 is provided between these and the upper ends of the pair of leaf springs 74a, 74b. The total size of the gaps s1 and s2 is, for example, 1
mm or about several tenths of a millimeter. Sign n
The upper portion of each of the front wall portion 72 and the rear wall portion 73 indicated by 1 and n2 is a portion corresponding to an example of a pair of pressed portions in the present invention, and the first movable member 7a moves forward or backward in the tracking direction. When retracted, either one of the pair of pressed portions can be pressed by the first movable member 7a. A pair of rod-shaped guide members 8 extending in the tracking direction are provided on the front wall portion 72 and the rear wall portion 73.
5 penetrates. In the present embodiment, the second movable member 7
b is slidable with respect to each guide member 85 so that each guide member 85 guides movement in the longitudinal direction. In addition, a bearing may be attached to the second movable member 7b, and the bearing may roll on the guide member 85 so that the entire second movable member 7b can be moved in the longitudinal direction of the guide member 85.

Next, the operation of the head moving device B and the disk device A having the above configurations will be described.

First, in the head moving device B, the following two modes can be obtained as modes of the moving operation of the carriage 7. That is, in the first mode, the first movable member 7a is driven by the driving force of the voice coil motor VCM.
Is finely moved within the range of the gaps s1 and s2 shown in FIG. More specifically, in the first embodiment, while causing the two leaf springs 74a and 74b to bend and deform, for example, as shown in FIG.
4b is the front wall 7 of the second movable member 7b.
2 or within the range until it comes into contact with the rear wall 73,
This is a mode in which the first movable member 7a is moved in the tracking direction. In this case, regarding the second movable member 7b,
Since it is not pressed by the first movable member 7a,
Can be kept stationary. Therefore, the weight of the movable portion in the first embodiment can be reduced by the amount that the second movable member 7b is not moved, and the responsiveness of the movement operation of the first movable member 7a to the driving of the voice coil motor VCM is reduced. Can be improved.

The second mode of the moving operation of the carriage 7 is as follows.
In this embodiment, the first movable member 7a is moved with a large stroke together with the second movable member 7b. More specifically, in the second aspect, as shown in FIG. 6, for example, in a state where the upper end of the leaf spring 74a is in contact with the front wall 72, the first movable member 7a is still moved. Move forward in the direction indicated by arrow N1. By doing so, the front wall 72
Can be pressed by the first movable member 7a.
And the second movable members 7a and 7b can be advanced together. Of course, the upper end of the leaf spring 74b is
If the first movable member 7a is retracted in a state where the first movable member 7a contacts the third movable member 3, both the first and second movable members 7a and 7b can be retracted. In such a second aspect, the movement of the second movable member 7b can be stabilized over a long stroke by the guide action of the pair of guide members 85. On the other hand, the first movable member 7a
It is supported by the second movable member 7b.
When the movable member 7b is pushed, it is possible to prevent the relative positional relationship with the second movable member 7b from being shifted. Therefore, the first movable member 7a can be stably moved over a long stroke, similarly to the second movable member 7b.

In the disk device A, when data recording / reproducing processing is performed on the magneto-optical disk D, the first movable member 7a is moved in the above-described second mode so that the optical head 2 is elongated in the tracking direction. It can be moved stably with a stroke. Therefore, the seek operation can be appropriately performed. Also,
Thereafter, based on the tracking error signal obtained by the light source / detection unit 60, the first movable member 7a
By moving the optical head 2 in the mode described above, the optical head 2 can be finely moved in the tracking direction, and tracking control can be performed. As described above, the movement operation of the first movable member 7a according to the first aspect has good responsiveness to the driving of the voice coil motor VCM, so that tracking control excellent in high-speed following performance can be performed.

In the disk device A of the present embodiment,
The first and second above described first movable member 7a
In any of the movement operations of the above-described modes, the driving force of the pair of voice coil motors VCM is used. Therefore, for example, as compared with a case where the first movable member 7a is finely moved in the tracking direction using a drive source separate from each voice coil motor VCM, the structure of the disk device is rational and the structure is simplified. Becomes possible.

The specific configuration of each part of the head moving device and the disk device according to the present invention can be variously modified in addition to the above-described embodiment.

For example, the head moving device according to the present invention may be configured as a device for moving a magnetic head instead of the optical head. In both cases of the optical head and the magnetic head, there are a type in which the head floats above the disk by using a slider and a type in which the head does not float, and the present invention is applied to both types. Can be. The optical head and the magnetic head may be supported by a focus control actuator mounted on the carriage. The optical head according to the present invention refers to a head including at least an objective lens for forming a beam spot. The magnetic head according to the present invention refers to a head provided with at least a coil for generating a magnetic field.

In addition, the disk device according to the present invention is:
It is needless to say that the present invention is not limited to the magneto-optical disk device, and may be configured as a disk device for writing or reading data by driving a disk (magnetic disk, optical disk, or the like) different from the magneto-optical disk.

[0042]

As described above, according to the present invention, it is possible to appropriately perform a seek operation and a tracking control that is excellent in high-speed tracking performance in a disk drive.
Further, since it is not necessary to increase the number of driving sources for moving the head, it is possible to suppress an increase in manufacturing costs of the head moving device and the disk device.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an example of a head moving device and a disk device according to the present invention.

FIG. 2 is a schematic side view of FIG.

FIG. 3 is a perspective view of a main part of FIG. 1;

FIG. 4 is a partial cross-sectional perspective view of FIG. 3;

FIG. 5 is a side sectional view of a main part of FIG. 3;

FIG. 6 is an operation explanatory diagram of the structure shown in FIG. 5;

FIG. 7 is a perspective view of a main part showing a conventional technique.

[Explanation of symbols]

 A Magneto-optical disk device (disk device) B Head moving device D Magneto-optical disk (disk) VCM Voice coil motor n1, n2 Pressed portion 2 Optical head (head) 7 Carriage 7a First movable member 7b Second movable member 72 front wall portion 73 rear wall portion 74a, 74b leaf spring (spring member) 80 coil portion 85 guide member

Claims (5)

[Claims] 1. A head moving device comprising: a carriage on which a head is mounted; and a voice coil motor for generating a driving force for reciprocating the carriage in a fixed direction, wherein the carriage has: It is divided into a first movable member that supports the head and has a coil portion of the voice coil motor, and a second movable member that can be guided by the guide member in the predetermined direction. In addition, the first movable member is supported by the second movable member so as to be able to reciprocate in the fixed direction independently of the second movable member, and is relatively movable. The head moving device, wherein the second movable member is capable of being pushed by the first movable member when the first movable member moves in the predetermined direction beyond a predetermined dimension. 2. The second movable member has a pair of pressed parts sandwiching the first movable member in the fixed direction so as to form a gap between the second movable member and the first movable member. The head moving device according to claim 1, wherein: 3. The second movable member has a front wall portion and a rear wall portion which are opposed to each other at an interval so as to form a space for accommodating the first movable member, and these The head moving device according to claim 2, wherein a part of each of the front wall portion and the rear wall portion is the pair of pressed portions. 4. The apparatus according to claim 1, wherein the first movable member is supported by the second movable member via at least one spring member capable of elastically deforming in the predetermined direction. A head moving device according to any one of the above. 5. A disk drive comprising a head moving device for moving a head in a radial direction of a disk, wherein the head moving device according to claim 1 is used as the head moving device. A disk device, wherein the device is used.