JP2000242945A - Objective lens driving device for optical disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make thin the driving motor part of an objective lens driving device. SOLUTION: This device is provided with a first focusing driving magnet 34 magnetized vertically to a face including a Y direction and a Z direction, a second focusing driving magnet 35 magnetized in a parallel and opposite direction to this magnet 34 and arranged to the Y direction so as to be made adjacent to the magnet 34, a focusing driving coil 38 fixed so that a first side 38a in which currents are allowed to flow in to the Z direction can be positioned near the surface of the driving magnet 34, and a second side 38b in which currents are allowed to flow in a parallel and opposite direction to the first side 38a can be positioned near the surface of the driving magnet 35, tracking driving magnets 36 and 37 magnetized vertically to the face including the X direction and the Z direction and arranged to the Z direction so as to be made adjacent to the driving magnets 34 and 35, and tracking driving coils 39 and 40 fixed so that only first sides 39a and 40a in which currents are allowed to flow in the Y direction can be positioned near the surfaces of the driving magnets 36 and 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device for an optical disk drive having a driving motor for moving an objective lens in a focusing direction and a tracking direction.

[0002]

2. Description of the Related Art A first conventional example of an objective lens driving apparatus for an optical disk drive, that is, a conventional actuator will be described with reference to FIG. First, an objective lens holding member 2 for holding an objective lens 1 is elastically supported by four wire springs 4 pulled out from a fixing member 3. A focusing coil 5 and a tracking coil 6 are wound around the objective lens holding member 2 in directions orthogonal to each other. The wire spring 4 is pulled out from the substrate 7 and electrically connected to the focusing coil 5 and the tracking coil 6 by soldering portions 8 at the distal and proximal ends, respectively, and has a function as a conducting wire. And
Magnets 10 supported by a yoke 9 with the objective lens holding member 2 interposed therebetween are arranged with their magnetic poles facing each other.
Reference numeral 11 denotes a rising prism, and reference numeral 12 denotes an optical axis.

In such a configuration, by supplying a control current to the focusing coil 5 and the tracking coil 6, the objective lens holding member 2 moves to move the objective lens 1 in the focusing direction (Y direction) and the tracking direction (Z direction). ) Can be moved.

Next, an example of a second conventional actuator will be described with reference to FIG. The same parts as those described with reference to FIG. 6 are denoted by the same reference numerals, and the description thereof will be omitted.
Two sets of magnets 10 fixed to the yoke 9 are disposed outside the objective lens holding member 2, and a yoke 9 facing each magnet 10 is further disposed inside so as to sandwich the focusing coil 5 and the tracking coil 6. Thus, a magnetic circuit of a closed magnetic circuit is formed. Also in this case, by supplying a control current to the focusing coil 5 and the tracking coil 6, the objective lens holding member 2 moves to move the objective lens 1 in the focusing direction (Y direction) and the tracking direction (Z direction). be able to.

Further, as a third conventional example, although not particularly shown, there is one disclosed in Japanese Patent Application Laid-Open No. 9-180207. This is such that an objective lens holding member for holding an objective lens is provided with a deflecting mirror that is movable integrally with the objective lens, thereby preventing the optical axis of the light beam from being shifted when the tracking movement is performed. Things.

[0006]

Problems to be Solved by the Invention
In order to adopt an objective lens driving device configuration having no optical axis deviation as disclosed in Japanese Patent Publication No. 7 (third conventional example), it is necessary to make a light beam incident from the tracking direction. In the case of the first conventional example, focusing is performed. Since the light beam is blocked by the coil 5, the above configuration cannot be adopted. As a result, FIG.
As shown in (1), the rising prism 11 must be located below the objective lens holding member 2, and there is a problem that the whole cannot be formed thin.

Further, a structure in which a deflecting mirror movable integrally with an objective lens is attached to an objective lens holding member described in Japanese Patent Application Laid-Open No. 9-180207 (third conventional example) is similar to the second conventional example. Although it is conceivable to adopt a structure shown in FIG. 8 by applying a drive motor of a type that forms a closed magnetic circuit, in this case, since the focusing coil 5 takes a configuration surrounding the magnet 10, FIG. As shown in (1), there is a problem that the tilt caused by the torque generated from the difference between the center of the driving force of the focusing coil 5 and the center of gravity of the movable portion is large.

Further, in one embodiment disclosed in Japanese Patent Application Laid-Open No. 9-180207 (third conventional example),
The tracking drive motor is constituted by a magnetic circuit different from the focusing drive motor, which is problematic in terms of assembly and cost.

Therefore, according to the present invention, a focusing operation and a tracking operation can be performed by substantially one magnet, and a driving motor portion can be formed in a flat shape.
In addition, the focusing drive coil does not adopt a configuration surrounding the magnet, and can input a light beam from the tracking direction. In addition, the center of the driving force of the focusing drive coil when the movable part moves and the center of gravity of the movable part are moved. It is an object of the present invention to provide an objective lens driving device for an optical disk drive in which the displacement is small and the tilt is difficult.

Further, the present invention provides an optical disk drive in which the magnetic circuit is formed as a closed magnetic circuit so that the magnetic flux density can be increased to increase the thrust of the motor and the magnetic flux density can be made more uniform to reduce the tilt. It is an object of the present invention to provide an objective lens driving device.

Another object of the present invention is to provide an objective lens driving device of an optical disk drive that can correct the inclination of the optical axis of the objective lens with respect to the disk recording surface.

Another object of the present invention is to provide an objective lens driving device of an optical disk drive in which a magnet can be assembled accurately and easily.

[0013] Similarly, an object of the present invention is to provide an objective lens driving device of an optical disk drive in which a coil can be assembled accurately and easily.

[0014]

According to the first aspect of the present invention,
A first focusing drive magnet magnetized perpendicularly to a plane including a focusing direction and a tracking direction; and a first focusing magnet which is magnetized in a direction parallel to and opposite to the first focusing drive magnet. A second focusing driving magnet disposed adjacent to the driving magnet in the focusing direction; and a first side wound in a substantially quadrangular shape and having a current flowing in the tracking direction. Located near the surface of the driving magnet,
A focusing drive coil fixed to the objective lens holding member such that a second side in which a current flows in a direction parallel to and opposite to the first side is located near a surface of the second focusing drive magnet; A tracking drive magnet that is magnetized perpendicularly to a plane including the direction and the tracking direction and is disposed adjacent to the focusing drive magnet in the tracking direction, and is wound in a substantially quadrangular shape to perform focusing. Current flows in the first direction
Is located near the surface of the tracking drive magnet, and the second side in which current flows in a direction parallel to and opposite to the first side is located away from the surface of the tracking drive magnet. A tracking drive coil fixed to the objective lens holding member.

Therefore, a combination of substantially one magnet, a focusing drive coil and a tracking drive coil located on the same plane can be formed to be thin, whereby the drive motor has a flat shape. be able to. Moreover, since the focusing drive coil does not surround the magnet, the light beam can be incident from the tracking direction, and the movable deflecting mirror and the rising prism can be arranged within the thickness of the objective lens holding member. ,
A configuration without optical axis deviation can be adopted. At this time, since the focusing driving coil and the tracking driving coil are not disposed so as to overlap with each other, the thickness of the coil can be reduced,
A portion having a high magnetic flux density can be used. Furthermore, since the focusing drive coil does not need to have a structure surrounding the magnet, the displacement between the center of the driving force of the focusing drive coil and the center of gravity of the movable part when the movable part moves can be reduced. , It is difficult to tilt.

According to a second aspect of the present invention, in the objective lens driving device for an optical disk drive according to the first aspect, a pair of the first focusing drive is provided with the focusing drive coil and the tracking drive coil interposed therebetween. The magnet for driving, the second focusing driving magnet and the tracking driving magnet are arranged in close proximity to each other and the magnetizing directions of the opposing magnets are arranged in the same direction to form a closed magnetic circuit.

Therefore, in addition to the first aspect of the present invention, since the magnetic circuit has a closed magnetic circuit configuration, the magnetic flux density can be increased to increase the thrust of the motor, and the magnetic flux density distribution can be made more uniform. can do.

According to a third aspect of the present invention, there is provided a first focusing driving magnet magnetized perpendicular to a plane including a focusing direction and a tracking direction, and a first focusing driving magnet parallel and opposite to the first focusing driving magnet. A second focusing drive magnet that is magnetized in the direction and is disposed adjacent to the first focusing drive magnet in the focusing direction; and a focusing direction and tracking with respect to the first focusing drive magnet. A third focusing driving magnet which is disposed oppositely at a predetermined interval in a direction perpendicular to the first direction and is magnetized in the same direction as the first focusing driving magnet.
Focusing driving magnet, and facing the second focusing driving magnet at a predetermined interval in a direction perpendicular to the focusing direction and the tracking direction, and adjacent to the third focusing driving magnet. A fourth focusing drive magnet disposed and magnetized in the same direction as the second focusing drive magnet;
A first side wound in a substantially quadrangular shape and through which a current flows in the tracking direction is located at a portion sandwiched between the first and third focusing drive magnets, and is parallel to and opposite to the first side. The second side through which current flows in the direction is the second and fourth sides.
A focusing drive coil fixed to the objective lens holding member so as to be positioned between the focusing drive magnets, and a magnetizing device which is magnetized perpendicularly to a plane including a focusing direction and a tracking direction, and A first tracking drive magnet disposed adjacent to the magnet in the tracking direction; and a first tracking drive magnet disposed opposite to the first tracking drive magnet at a predetermined interval in the focusing direction and the tracking direction. A second tracking driving magnet magnetized in the same direction as the first tracking driving magnet, and a first side wound in a substantially quadrangular shape and having a current flowing in the focusing direction, having only the first and second sides; A second current flowing in a direction parallel to and opposite to the first side and located at a portion sandwiched between the second tracking drive magnets; Sides and a tracking drive coil secured to said objective lens holding member so as to be positioned away from the portion sandwiched between the first and second tracking driving magnets.

Accordingly, since the magnetic circuit has a closed magnetic circuit configuration, the magnetic flux density can be increased to increase the thrust of the motor, and the magnetic flux density distribution can be made more uniform.

According to a fourth aspect of the present invention, in the objective lens driving device for an optical disk drive according to the first, second or third aspect, the tracking drive magnet is disposed adjacent to both sides of the focusing drive magnet. The tracking drive coil is disposed adjacent to both sides of the focusing drive coil.

Therefore, the arrangement of the tracking driving coil can be balanced and the operation can be stabilized.

According to a fifth aspect of the present invention, in the objective lens driving device for an optical disk drive according to the fourth aspect, the two tracking driving coils are independently supplied with power.

Therefore, by tilting the objective lens with respect to the disk recording surface, the amount of tilt of the light spot with respect to the disk recording surface can be adjusted, and the inclination of the optical axis of the objective lens with respect to the disk recording surface can be easily corrected. Can be done.

The invention according to claim 6 is based on claims 1, 2, and
The objective lens driving device for an optical disc drive according to 3, 4, or 5, wherein the focusing drive magnet and the tracking drive magnet on the same surface in a direction perpendicular to the focusing direction and the tracking direction are at least one magnet. It is formed integrally by multi-pole magnetization.

Therefore, the magnets located on the same plane can be mounted more accurately and more easily.

The invention according to claim 7 is based on claims 1, 2, and
7. The objective lens driving device for an optical disk drive according to 3, 4, 5, or 6, wherein the focusing drive coil and the tracking drive coil are formed on the same substrate.

Therefore, the coils located on the same plane can be mounted more accurately and more easily.

[0028]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. The objective lens driving device of the optical disk drive according to the present embodiment is described in
It is applied to an optical system having a movable deflection mirror and eliminating optical axis deviation, as in the example of JP-180207A. FIG.
(A) is a plan view seen from a Y direction showing a focusing direction, FIG. 1 (b) is a vertical side view seen from a Z direction showing a tracking direction, and FIG. 1 (c) is a front view of a motor part seen from an X direction. FIG. 2 is an exploded perspective view of the motor part.

First, a rectangular objective lens holding member 22 for holding the objective lens 21 is elastically moved in the focusing direction and the tracking direction by wire springs 24 as four elastic support members pulled out from the stem 23. Supported. The inside of the objective lens holding member 22 is formed as a space 25 having one open side.
An opening 27 is formed in one of the support walls 26, and the objective lens 21 is fixed to the opening 27. Further, on both sides of the space 25 of the objective lens holding member 22 in the X direction, side walls 28 serving as substrates are formed. Drive coil assemblies 29 are provided on the outer surfaces of these side walls 28, respectively.
Has been fixed. The detailed structure of these drive coil assemblies 29 will be described later.

A notch (not shown) for passing the optical axis 20 is formed on one side surface of the space 25 of the objective lens holding member 22, and the space 2 is opposed to the notch.
5 is provided with a movable deflection mirror 30. Then, as disclosed in Japanese Patent Application Laid-Open No. 8-221776, the wire spring 24 offsets the object farther from the objective lens 21 on the light incident side in the tangential direction so as not to block the light beam. Considered. Further, a rising prism 31 that guides the optical axis 20 reflected by the movable deflecting mirror 30 to the objective lens 21 and located in the space 25 is provided.

Then, a yoke 32 and a driving magnet 33 are provided on both sides in the axial direction (X direction) of the wire spring 24 of the objective lens holding member 22 so as to face each of the drive coil assemblies 29 with an appropriate space therebetween. Is provided. As shown in FIG. 2, these driving magnets 33 are magnetized by being divided into four parts by H-shaped magnetizing boundary lines a, b, and c, and the magnetizing direction is the focusing direction ( (Ie, X direction) and a tracking direction (Z direction).
Direction). Here, portions adjacent to each other in the focusing direction with the magnetization boundary line a interposed therebetween are a first focusing drive magnet 34 and a second focusing drive magnet 35, and as shown in FIG. Is the opposite direction. The portions adjacent to the focusing drive magnets 34 and 35 in the tracking direction with the magnetization boundary lines b and c interposed therebetween are both tracking drive magnets 36 and 37.
It has been. That is, the focusing driving magnets 34,
35 and the tracking drive magnets 36 and 37 are integrally formed by multipolar magnetization of one drive magnet 33.

The drive coil assembly 29 includes one focusing drive coil 38 and two tracking drive coils 39 and 40. The focusing drive coil 38 is wound in a substantially quadrangular shape (track shape) and has four sides of upper, lower, left and right, and the focusing drive magnets 34, 35 straddling the magnetizing boundary line a in the focusing direction.
Is provided so as to face the vicinity of the surface. Therefore,
The focusing drive coil 38 has a first side 38 a located near the surface of the first focusing drive magnet 34 due to a current flowing in the tracking direction, and the first side 38 a.
A current flows in a direction parallel to and opposite to the direction a, and the second side 3 located near the surface of the second focusing drive magnet 35
8b. The tracking drive coil 3
Currents 9 and 40 flow in the focusing direction, and the first sides 39a and 40a located near the surfaces of the tracking driving magnets 36 and 37, and the currents are parallel to and opposite to the first sides 39a and 40a. The second side 39 flowing away and located away from the surfaces of the tracking driving magnets 36 and 37
b, 40b. Thus, the focusing driving coil 38, the tracking driving coil 39,
A drive motor 41 is formed by the drive magnet 40 and the drive magnet 33. Note that reference numeral 42 is a medium.

In such a configuration, the driving force in the focusing direction is generated at the first and second sides 38a and 38b where current flows in the tracking direction when the focusing drive coil 38 is energized. Here, in the first and second sides 38a and 38b, current flows in opposite directions, but the corresponding first and second focusing driving magnets 3
Since the magnetization directions of the 4,35 portions are opposite,
The driving force in the focusing direction acts in the same direction, and the direction is switched according to the direction of the current. At this time, a driving force in the tracking direction is generated at both left and right portions where the current flows in the focusing direction of the focusing driving coil 38, but a driving force of substantially the same magnitude is generated in the opposite direction on both the left and right sides.

On the other hand, when the driving force in the tracking direction is applied to the tracking drive coils 39 and 40 in the reverse direction, the first side 39a, where the current flows in the focusing direction, is used.
This occurs between the portion 40a and the tracking driving magnets 36 and 37. At this time, a current also flows in the focusing direction in the portions on the second sides 39b and 40b, but since they are arranged outside the magnetic field generated by the tracking driving magnets 36 and 37, no driving force is generated by these portions. Further, a driving force in the focusing direction is generated in the upper and lower portions where the current flows in the tracking direction of the tracking drive coils 39 and 40, but a driving force of substantially the same magnitude is generated in opposite directions in the upper and lower directions, and thus cancels out.

Therefore, the focusing driving coil 38
By appropriately controlling the magnitude and direction of the current flowing through the tracking drive coils 39 and 40, the objective lens 21 can be moved in the focusing direction and the tracking direction. In particular, according to the configuration of the present embodiment, the driving coils 38, 39, and 40 disposed on both sides of the objective lens 21 in the X-axis direction are driven in both the focusing direction and the tracking direction. 38, 39, and 40 are thin and arranged on both sides and are not wound around the entire circumference, so that a light beam can be incident from the tracking direction therebetween, and the movable deflection mirror 30 and the rising prism 31 can be disposed within the thickness of the objective lens holding member 22, and a configuration without optical axis shift can be adopted. In addition, since the focusing driving coil 38 and the tracking driving coils 39 and 40 are not disposed so as to overlap each other, the thickness of the coil can be reduced, and a portion having a high magnetic flux density can be used. Further, since the focusing drive coil 38 does not need to have a structure surrounding the magnet, the focusing drive coil 38
Of the center of the driving force and the center of gravity of the movable portion can be reduced, and tilting can be suppressed.

In this embodiment, the tracking drive coils 3 are provided on both sides of the focusing drive coil 38.
Since the tracking drive coils 39 and 40 are independently supplied with power, the objective lens 21 is tilted with respect to the disk recording surface of the medium 30 and the light with respect to the disk recording surface is provided. The tilt amount of the spot can be adjusted. In this case,
A larger number of conductive wires to the tracking drive coils 39 and 40 are required. However, the wire spring 24 may have a plurality of cores, or the number of wire springs 24 (for example, six) may be added. Then, the electrical connection may be made.

In configuring the objective lens driving device of the present embodiment, a sheet coil in which the focusing driving coil 38 and the tracking driving coils 39 and 40 are laminated on the same substrate is used. You may.
The sheet coil is usually formed with 2 to 6 layers. Accordingly, the positional relationship between the focusing driving coil 38 and the tracking driving coils 39 and 40 can be accurately maintained, and the assembly with the objective lens holding member 22 can be easily performed. 22 can be assembled by integral molding.

FIGS. 3 and 4 show a second embodiment of the present invention.
It will be described based on. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, the drive motor 51 has a magnetic circuit configuration of a closed magnetic circuit. That is, in comparison with the first embodiment,
A pair of drive magnets are provided so as to sandwich the drive coil assembly 29.

More specifically, in addition to the yoke 32 and the driving magnet 33 located outside the drive coil assembly 29, the yoke 52 and the yoke 52 A driving magnet 53 supported by the yoke 52 is provided. The driving magnet 53 has the same configuration as the driving magnet 33, which is completely symmetric. That is, as shown in FIG. 4, H-shaped magnetization boundary lines a, b, c
Is divided into four parts and magnetized, and the magnetization direction is
Focusing direction (Y direction) and tracking direction (Z
Direction (ie, the X direction). Here, portions adjacent to each other in the focusing direction with the magnetization boundary line a interposed therebetween are a third focusing drive magnet 54 and a fourth focusing drive magnet 55,
As shown in FIG. 4, the magnetization direction is the opposite direction. The third focusing drive magnet 54 corresponds to the first focusing drive coil 34, and the fourth focusing drive coil 55 corresponds to the second focusing drive magnet 35. The portions adjacent to the focusing drive magnets 54 and 55 in the tracking direction with the magnetization boundary lines b and c interposed therebetween are both tracking drive magnets (second
Tracking driving magnets) 56 and 57.
That is, the focusing driving magnets 54 and 55 and the tracking driving magnets 56 and 57 are integrally formed by multi-polar magnetization of one driving magnet 53.

In such a configuration, the operation is the same as that of the first embodiment, but in particular, the yoke 32
Further, since the drive motor 51 is constituted by a magnetic circuit of a closed magnetic circuit by the drive magnet 33, the yoke 52, and the drive magnet 53, the magnetic flux density can be increased, and the distribution of the magnetic flux density can be more uniform Can be

A third embodiment of the present invention will be described with reference to FIG. The present embodiment is designed to cope with high acceleration by reducing the weight without providing the movable deflecting mirror 30. In contrast to the structure of the above-described second embodiment, the driving motor 51 is provided only on one side. Is provided. That is,
The drive motor 51 on the movable free end side is omitted, and the tip of the objective lens holding member 22 is cut from the holding portion of the objective lens 21. Therefore, since the distal end portion of the objective lens holding member 22 is in an open state, the optical axis 20 to the objective lens 21 is provided directly from the distal end via the rising prism 31. Further, the wire spring 24 does not need to be offset in the tangential direction as in the first embodiment, and can be supported and coupled at the same position.

[0042]

According to the first aspect of the invention, it is possible to form a thin combination of substantially one magnet, focusing driving coil and tracking driving coil located on the same plane. As a result, the drive motor can be made flat, and since the focusing drive coil does not surround the magnet, the light beam can be incident from the tracking direction. It is also possible to dispose within the thickness of the lens holding member, and it is possible to adopt a configuration without optical axis deviation. In this case, since the focusing drive coil and the tracking drive coil are not arranged overlapping, the coil thickness is reduced. Can use the part with high magnetic flux density,
Furthermore, since the focusing drive coil does not need to have a structure surrounding the magnet, the displacement between the center of the driving force of the focusing drive coil and the center of gravity of the movable part when the movable part moves can be reduced. , It is difficult to tilt.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, since the magnetic circuit has a closed magnetic circuit configuration, the magnetic flux density can be increased to increase the thrust of the motor. In addition, the magnetic flux density distribution can be made more uniform.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention, since the magnetic circuit has a closed magnetic circuit structure, the magnetic flux density can be increased to increase the thrust as a motor. In addition, the magnetic flux density distribution can be made more uniform.

According to the fourth aspect of the present invention,
In addition to the invention of the objective lens driving device for an optical disk drive described in the item 2 or 3, the arrangement of the tracking drive coil can be balanced and the operation can be stabilized.

According to the fifth aspect of the present invention, in addition to the objective lens driving device of the optical disk drive according to the fourth aspect, by tilting the objective lens with respect to the disk recording surface, the light spot on the disk recording surface can be adjusted. The tilt amount can be adjusted, and the tilt of the optical axis of the objective lens with respect to the disk recording surface can be easily corrected.

According to the invention of claim 6, according to claim 1,
In addition to the objective lens driving device of the optical disk drive described in 2, 3, 4 or 5, a magnet located on the same plane can be mounted with high accuracy and more easily.

According to the invention of claim 7, according to claim 1,
In addition to the objective lens driving device of the optical disk drive described in 2, 3, 4, 5 or 6, a coil located on the same plane can be mounted with high accuracy and more easily.

[Brief description of the drawings]

1 shows a first embodiment of the present invention, wherein (a) is a plan view, (b) is a longitudinal side view, and (c) is a front view.

FIG. 2 is an exploded perspective view of the driving motor portion.

3A and 3B show a second embodiment of the present invention, wherein FIG. 3A is a plan view and FIG. 3B is a longitudinal side view.

FIG. 4 is an exploded perspective view of the driving motor portion.

FIG. 5 shows a third embodiment of the present invention, wherein (a) is a plan view and (b) is a longitudinal side view.

6A and 6B show a first conventional example, in which FIG. 6A is a plan view and FIG.
Is a longitudinal side view.

FIG. 7 is a perspective view showing a second conventional example.

FIG. 8 is a plan view showing a state where the second conventional example is applied.

FIG. 9 is a front view showing a cause of tilt based on a deviation between the center of the focusing drive coil and the center of the movable part.

[Explanation of symbols]

 22 Objective lens holding member 34 First focusing drive magnet 35 Second focusing drive magnet 36, 37 Tracking drive magnet 38 Focusing drive coil 38a First side 38b Second side 39, 40 Tracking drive coil 39a, 40a First side 39b, 40b Second side 54 Third focusing drive magnet 55 Fourth focusing drive magnet 56, 57 Second tracking drive magnet

Claims (7)

[Claims] A first focusing drive magnet magnetized perpendicular to a plane including a focusing direction and a tracking direction; and a first focusing drive magnet parallel and opposite to the first focusing drive magnet. A second focusing drive magnet disposed adjacent to the first focusing drive magnet in the focusing direction; and a first side wound in a substantially quadrangular shape and through which current flows in the tracking direction. The second side is located near the surface of the first focusing driving magnet, and the second side through which current flows in a direction parallel to and opposite to the first side is located near the surface of the second focusing driving magnet. A focusing drive coil fixed to an objective lens holding member; and a focusing coil that is magnetized perpendicularly to a plane including a focusing direction and a tracking direction. A tracking driving magnet disposed adjacent to the tracking driving magnet in the tracking direction; and a first side wound substantially in a quadrangular shape and having a first current flowing in the focusing direction. A tracking drive fixed to the objective lens holding member such that a second side near the surface and through which current flows in a direction parallel to and opposite to the first side is located away from the surface of the tracking drive magnet; Objective lens driving device for an optical disk drive, comprising: 2. A pair of the first focusing driving magnet, the second focusing driving magnet, and the tracking driving magnet are symmetrically arranged in proximity to each other with the focusing driving coil and the tracking driving coil interposed therebetween. 2. The objective lens driving device for an optical disk drive according to claim 1, wherein the magnetizing directions of the opposing magnets are arranged in the same direction to form a magnetic circuit of a closed magnetic circuit. 3. A first focusing driving magnet magnetized perpendicularly to a plane including a focusing direction and a tracking direction, and a first magnetizing driving magnet parallel to and opposite to the first focusing driving magnet. A second focusing drive magnet disposed adjacent to the first focusing drive magnet in the focusing direction; and a direction perpendicular to the focusing direction and the tracking direction with respect to the first focusing drive magnet. A third focusing drive magnet arranged opposite to the first focusing drive magnet at a predetermined interval and magnetized in the same direction as the first focusing drive magnet; and a focusing direction and tracking with respect to the second focusing drive magnet. The third focusing drive at a predetermined interval in the direction perpendicular to the A fourth focusing drive magnet disposed adjacent to the second focusing drive magnet and magnetized in the same direction as the second focusing drive magnet; and a fourth focusing drive magnet wound in a substantially quadrangular shape and having a current flowing in the tracking direction. One side is located at a portion sandwiched between the first and third focusing drive magnets, and a second side in which current flows in a direction parallel to and opposite to the first side is the second and fourth sides.
A focusing drive coil fixed to the objective lens holding member so as to be positioned between the focusing drive magnets; and a magnetizing device that is magnetized perpendicularly to a plane including a focusing direction and a tracking direction. A first tracking driving magnet disposed adjacent to the magnet in the tracking direction; and a first tracking driving magnet disposed opposite to the first tracking driving magnet at a predetermined interval in the focusing direction and the tracking direction. A second tracking drive magnet magnetized in the same direction as the first tracking drive magnet; and a first side wound in a substantially quadrangular shape and having only a first side through which current flows in the focusing direction. A current is located at a portion sandwiched between the second tracking drive magnets, and a current flows in a direction parallel to and opposite to the first side. And a tracking drive coil fixed to the objective lens holding member such that a side of the tracking drive magnet is positioned away from a portion sandwiched between the first and second tracking drive magnets. . 4. The tracking drive magnet is disposed adjacent to both sides of the focusing drive magnet, and the tracking drive coil is disposed adjacent to both sides of the focusing drive coil. 4. The objective lens driving device for an optical disk drive according to claim 1, wherein 5. The objective lens driving device for an optical disk drive according to claim 4, wherein the two tracking driving coils are independently supplied with power. 6. The focusing drive magnet and the tracking drive magnet on the same plane in a direction perpendicular to the focusing direction and the tracking direction are integrally formed by multipolar magnetization of at least one magnet. An objective lens driving device for an optical disk drive according to claim 1, 2, 3, 4, or 5. 7. The objective lens driving device for an optical disk drive according to claim 1, wherein said focusing driving coil and said tracking driving coil are laminated on the same substrate. .