JP2006260688A - Objective lens driver, optical pickup device and optical disk driver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an objective lens driver having an efficient tilt coil in which driving torque is increased by increasing the effective length and the operating radius of the tilt coil. <P>SOLUTION: The objective lens driver is provided with an objective lens 1, an objective lens holding member 2 which holds the objective lens 1, a movable section which consists of a plurality of driving coils 3A and 3B and driving magnets 6A and 6B which are arranged close to at least a portion of the driving coils 3A and 3B and magnetized so that their magnetic fluxes penetrate the coils. One of the plurality of the driving coils 3A and 3B is a tilt coil that is used to tilt the objective lens 1. The extended line of a portion of the side of the tilt coil that is arranged close to the driving magnets 6A and 6B is constituted so that the extended line goes through an approximate center axis of the magnetized direction of the driving magnets of the movable section. Thus, the effective length and the operating radius of the tilt coil are made large and the driving torque is increased so that an efficient tilt coil is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an objective lens driving device, an optical pickup device using the objective lens driving device, and an optical disk drive device including the optical pickup device.

  In an optical disc drive apparatus, information is obtained by irradiating a disc-shaped optical recording medium (hereinafter referred to as an optical disc) with a light beam from a laser light source of an optical pickup device, and receiving and identifying reflected light from the optical disc with a light receiving element. Reading. The objective lens driving device mounted on the optical pickup device of the optical disk drive device uses the control signal obtained from the reflected light of the optical disk to drive the objective lens in the focusing direction and the tracking direction, A good spot is formed on the recording surface of the optical disk by following the movement such as eccentricity.

  In many cases, the objective lens driving device employs an electromagnetic motor for the driving unit. Electromagnetic motors include a moving coil system in which a coil is disposed on the movable part side and a magnetic circuit is disposed on the fixed part side, and a moving magnet system in which a magnet is disposed on the movable part side and a drive coil is disposed on the fixed part side. In recent years, high-speed recording and reproduction have been desired, and since the rotational speed of the optical disk is high and a large acceleration is required, a moving coil system with high acceleration sensitivity is advantageous. In order to increase sensitivity in an electromagnetic motor, it is effective to increase the magnetic flux penetrating the coil, but in the moving magnet method, if the magnet becomes large in order to increase the magnetic flux, the mass of the moving part will increase, resulting in acceleration sensitivity characteristics. It is difficult to improve.

On the other hand, in the moving coil method, when the magnetic flux is increased by increasing the magnet of the fixed portion, the acceleration sensitivity can be increased in proportion to the increase of the magnetic flux. However, since the drive coil is mounted on the movable part side, current supply to the drive coil is an issue.
Further, in the moving coil system, there are many configurations in which the movable part is elastically supported while supplying current to the drive coil by a plurality of conductive elastic support members. Conventionally, many elastic support members using a wire with a round cross-section have been adopted as a plurality of elastic support members, but recently, a thin plate is punched with high precision by pressing into a rod shape, which is then used as a resin. An integrated molding method in which insert molding is performed in a positioned state has been increasingly adopted.

  Here, in order to increase the density of the optical disk, it is necessary to form a small spot. For this purpose, it is necessary to increase the numerical aperture (NA) of the objective lens or shorten the wavelength of the laser. . However, when the NA is increased or the wavelength of the laser is shortened, coma aberration is likely to occur due to the deviation of the optical axis of the objective lens from the perpendicularity of the optical disc, and the spot quality is deteriorated. This causes a problem that the recording / reproduction quality deteriorates. Therefore, it is necessary to improve the tilt accuracy of the optical disk and the objective lens. In recent years, the accuracy with respect to tilt has become particularly strict, and the tilt (tilt) of the optical disc and the objective lens is triaxially driven to perform tilt drive (tilt operation) in accordance with the tilt of the optical disc at the movable portion of the objective lens driving device including the objective lens Alternatively, a system using a four-axis driving objective lens driving device has also been proposed (Patent Document 1, etc.). In this system, low cost and space saving are possible, and since the movable part is lightweight, it can follow the tilt of the high-speed optical disk.

Here, an example of an objective lens driving device of an optical pickup device used in a conventional optical disk drive device will be described below. FIG. 34 is an overall perspective view of the objective lens driving device, FIG. 35 is a principal perspective view showing only a movable portion of the objective lens driving device, and FIG. 36 is a principal plan view showing only a motor portion of the objective lens driving device.
In FIG. 34, in this objective lens driving device, the objective lens 1 is held by the objective lens holding member 2, and the tangential direction is used as a winding axis on both side surfaces of the objective lens holding member 2 in the tangential direction. Planar drive coils 3A and 3B are attached. Moreover, the relay substrate 7 is attached to the side surfaces on both sides in the tracking direction of the objective lens holding member 2 to constitute a movable portion. A coil terminal is connected to the land portion of the relay substrate 7. A bent portion of the base 4 obtained by bending a magnetic metal plate is a yoke, and drive magnets 6A and 6B are attached to the yoke to constitute a magnetic circuit. The surfaces of the drive magnets 6A and 6B are arranged with a predetermined gap from the drive coils 3A and 3B. Further, a straight wire spring 8 is disposed with the tangential direction as the longitudinal direction, and one end of the wire spring 8 is fixed to the land portion of the relay board 7 on the movable portion, and the other end of the wire spring 8 is the base. The fixing member 5 is fixed to the fixing member 5. The wire spring 8 is electrically conductive, and both ends thereof are also electrically connected. By supplying current from the circuit board or the like on the fixed member 5 side to the drive coils 3A and 3B of the movable part, the movable part is It can be driven in a desired direction.

  Next, the motor unit will be described in detail. As shown in FIGS. 35 and 36, the drive coils 3A and 3B described above are a tracking coil 31, a focusing coil 32, and a tilt coil 33. The focusing coils 32 are disposed on both sides of the tracking coil 31 in the tracking direction. ing. The drive magnets 6A and 6B described above have a magnetization boundary line a in the focusing direction, and are opposite to the portions where current flows in the focusing direction opposite to each tracking coil 31 on both sides of the magnetization boundary line a. Further, the drive magnets 6A and 6B have magnetization boundary lines b and b ′ in the tracking direction, and the focusing coils 32 face each other on both sides of the magnetization boundary lines b and b ′. Magnetization is performed so that magnetic fluxes in opposite directions are applied to portions where current flows in the tracking direction.

  Here, tilt coils 33 having substantially the same shape as the focusing coil 32 are arranged on both sides of the tracking coil 31 in the tracking direction, and the portions where current flows in the tracking direction are connected to the magnetization boundary lines b and b ′ in the tracking direction. It is arranged on both sides across. The tilt coils 33 on both sides of the tracking coil 31 are set in directions of current and magnetic flux so as to generate thrust in opposite directions in the focusing direction, and are driven in the radial tilt direction by supplying current to the tilt coil 33. Can do.

JP-A-10-116431

  Conventionally, it has been possible to realize a tilt-driven objective lens driving device having the above-described configuration. However, with the increase in speed (high speed) of the optical disk drive device, a problem of insufficient thrust has occurred.

The present invention has been made in view of the above circumstances, and an object thereof is to increase the driving torque of a tilt coil in an objective lens driving device.
More specifically, in the present invention,
(1) In the objective lens driving device, by increasing the effective length and working radius of the tilt coil, the driving torque is increased, and an efficient tilt coil is provided.
(2) A configuration in which the effective length and working radius of the tilt coil are maximized to obtain the best configuration;
(3) Improving the efficiency of the tilt coil with a configuration using a planar coil,
(4) Providing a three-axis or four-axis objective lens driving device in combination with a focusing and tracking coil;
(5) To improve the assembly and reduce the cost by configuring the tilt coil with a cylindrical coil capable of direct winding of the movable part;
(6) By reducing the cross action at the time of focusing and tracking offset by making the tilt coil straddle the magnetization boundary line in the focusing direction,
(7) By using the tilt coil as a balancer for the objective lens, it is lightweight and has high-order resonance characteristics, and further reduces cross action.
(8) Increasing the driving torque by increasing the effective length and working radius of the tilt coil in the moving magnet type objective lens driving device;
(9) Providing an optical pickup device capable of maintaining a spot and obtaining a good signal by increasing the efficiency of the tilt coil of the objective lens driving device;
(10) To provide an optical disc drive device that can read and write data satisfactorily by using an optical pickup device that can obtain a good signal.
The purpose is.

In order to achieve the above object, the present invention employs the following technical means.
The first means of the present invention includes an objective lens, an objective lens holding member that holds the objective lens, a movable portion that includes a plurality of drive coils, and is disposed close to at least a part of the drive coils; An objective lens driving device comprising a drive magnet magnetized so that magnetic flux penetrates, wherein one of the plurality of drive coils is a tilt coil for tilting the objective lens, and the drive magnet of the tilt coil An extension line of a part of adjacent sides passes through a substantially central axis in the magnetization direction of the drive magnet of the movable part (claim 1).

According to a second means of the present invention, in the objective lens driving device of the first means, a part of the side of the tilt coil has a center of the movable portion and the drive when viewed from the magnetization direction of the drive magnet. The magnet is substantially parallel to a line connecting the center of the movable portion and the farthest vertex in a region where the tilt coil is close (Claim 2).
According to a third means of the present invention, in the objective lens driving device of the first or second means, the tilt coil has a winding axis in the magnetizing direction of the driving magnet and has a substantially triangular or trapezoidal shape. The drive magnet adjacent to at least a part of the side of the tilt coil applies magnetic fluxes in opposite directions to each of the two hypotenuses forming the triangle or trapezoid ( Claim 3).

  According to a fourth means of the present invention, in the objective lens driving device of the third means, the plurality of drive coils are a planar focusing coil, a tracking coil and the tilt wound around the magnetization direction as a central axis. A focusing coil is disposed on both sides of the tracking coil in the tracking direction, and the drive magnet has a magnetization boundary line a in the focusing direction, and is disposed on both sides of the magnetization boundary line a. In addition, magnetic fluxes in opposite directions are applied to portions where current flows in the opposing focusing direction of each tracking coil, and the drive magnet has magnetization boundary lines b and b ′ in the tracking direction, and the magnetization boundary line b, Magnets in directions opposite to each other in portions where currents flow in the opposing tracking directions of the respective focusing coils arranged on both sides of b ′ And the two hypotenuses of the tilt coil are arranged on substantially both sides of the magnetization boundary line a or the magnetization boundary lines b and b ′, respectively. (Claim 4).

  According to a fifth means of the present invention, in the objective lens driving device according to the third means, the plurality of drive coils are a planar focusing coil, a tracking coil and the tilt wound around the magnetization direction as a central axis. The tracking coil is disposed on both sides in the tracking direction of the focusing coil, and the drive magnet has a magnetization boundary line c in the tracking direction, and is disposed on both sides of the magnetization boundary line c. The focusing coils are magnetized so that magnetic fluxes in opposite directions are applied to the portions where current flows in the tracking direction, and the two hypotenuses of the tilt coil are respectively located substantially on both sides of the magnetization boundary line c. It is arranged (Claim 5).

  According to a sixth means of the present invention, in the objective lens driving device of the third means, the plurality of drive coils are a planar focusing coil, a tracking coil and the tilt wound around the magnetization direction as a central axis. The drive magnet has a magnetization boundary line d in the focusing direction, and magnetic fluxes in opposite directions to portions where current flows in the focusing direction of each tracking coil disposed on both sides of the magnetization boundary line d. Further, the drive magnet has a magnetization boundary line e that intersects the magnetization boundary line d in a substantially cross shape, and current is supplied in the tracking direction of each focusing coil arranged on both sides of the magnetization boundary line e. Magnetization is performed so that magnetic fluxes in opposite directions are applied to the flowing part, and two tilt coils are provided on both sides of the magnetization boundary line d or the magnetization boundary line e. Wherein the hypotenuse of are arranged (claim 6).

  According to a seventh means of the present invention, in the objective lens driving device of the first or second means, the tilt coil has a predetermined angle with the optical axis of the objective lens on a plane including a focusing direction and a tracking direction. A cylindrical coil wound around an axis having a tilting coil, and the drive magnet adjacent to at least a part of the side of the tilt coil is disposed on both sides with respect to a substantially center of the part of the side adjacent to the tilt coil. The magnetic flux in the opposite direction is given by (Claim 7).

According to an eighth means of the present invention, in the objective lens driving device according to any one of the first to fourth, sixth, and seventh means, the magnetization direction of the drive magnet has a magnetization boundary line in a focusing direction, The magnetizing boundary line is opposite in both directions in the tracking direction (claim 8).
According to a ninth means of the present invention, in the objective lens driving device according to any one of the first to fourth, sixth and seventh means, the center of gravity of only the tilt coil is objective with respect to the center of gravity of the entire movable portion. It is arranged on the side opposite to the lens (claim 9).

  The tenth means of the present invention comprises an objective lens, an objective lens holding member for holding the objective lens, a movable part composed of a rectangular drive magnet, and a plurality of drive coils wound around a fixed part. In the objective lens driving device, at least some of the sides of the driving coil are disposed in proximity to the driving magnet so that a current flows substantially perpendicularly to the magnetic flux generated by the driving magnet. One of the drive coils is a tilt coil for tilting the objective lens, and a part of the tilt coil adjacent to the drive magnet is substantially parallel to the diagonal direction of the rectangular drive magnet. It is characterized (claim 10).

According to an eleventh means of the present invention, in an optical pickup device for recording, reproducing or erasing information on an optical recording medium, a light source for emitting light to the optical recording medium, and reflection from the optical recording medium A light receiving optical system for receiving light and an objective lens driving device of any one of the first to tenth means are provided (claim 11).
According to a twelfth aspect of the present invention, there is provided an optical disc drive apparatus comprising: a rotational drive system for rotationally driving a disc-shaped optical recording medium; and an optical pickup device provided so as to be movable in a radial direction of the optical recording medium. The optical pickup device includes an optical pickup device of an eleventh means (claim 12).

In the objective lens driving device of the first means, the extension line of a part of the side close to the drive magnet of the tilt coil passes through the substantially central axis in the magnetization direction of the drive magnet of the movable part, so that the tilt The effective length and working radius of the coil can be increased, and the driving torque can be increased to provide an efficient tilt coil.
Further, in the objective lens driving apparatus of the second means, the best configuration can be obtained with the configuration in which the effective length and the working radius of the tilt coil are maximized.
Furthermore, in the objective lens driving device of the third means, the efficiency of the tilt coil can be improved by the configuration using the planar coil.
Furthermore, in the objective lens driving device according to any one of the fourth to sixth means, a triaxial or four-axis objective lens driving device can be realized in combination with the focusing and tracking coils.

In the objective lens driving device of the seventh means, assembling property can be improved and the cost can be reduced by configuring the tilt coil with a cylindrical coil capable of direct winding of the movable part.
In the objective lens driving device of the eighth means, the cross action at the time of focusing and tracking offset can be reduced by making the tilt coil straddle the magnetization boundary line in the focusing direction.
Further, in the objective lens driving apparatus of the ninth means, the tilt coil is also used as a balancer for the objective lens, so that it is light in weight and high-order resonance characteristics can be increased, and further, the cross action can be reduced. .
In the objective lens driving apparatus of the tenth means, the driving torque can be increased by increasing the effective length and the working radius of the tilt coil in the moving magnet type objective lens driving apparatus.

In the optical pickup device of the eleventh means, by providing the objective lens driving device of any one of the first to tenth means, the efficiency of the tilt coil is increased, a good spot is maintained, and a good signal is obtained. An optical pickup device capable of obtaining the above can be realized.
Further, in the optical disk drive apparatus of the twelfth means, by using the optical pickup device that can obtain the good signal of the eleventh means, an optical disk drive apparatus that can read and write data satisfactorily is realized. Can do.

  Hereinafter, specific configurations, operations, and actions of the present invention will be described in detail based on the illustrated embodiments.

[Example 1 (planar coil: configuration example of symmetrical magnetic circuit vertically and horizontally)]
Example 1-1 (Tilt Coil Arranged Over Focusing Coil)
First, Example 1-1 according to the first to fourth means of the present invention will be described below. An explanatory diagram of the configuration of the present embodiment is shown in FIGS. FIG. 1 is an overall perspective view of the objective lens driving device, FIG. 2 is a main portion perspective view showing only a movable portion of the objective lens driving device, and FIG. 3 is a main portion plan view showing only a motor portion of the objective lens driving device.
As shown in FIGS. 1 and 2, the objective lens 1 is held by the objective lens holding member 2, and the side surfaces on both sides in the tangential direction of the objective lens holding member 2 are planes with the tangential direction as the winding axis. Drive coils 3A and 3B are attached. Moreover, the relay substrate 7 is attached to the side surfaces on both sides in the tracking direction of the objective lens holding member 2 to constitute a movable portion. A coil terminal is connected to the land portion of the relay substrate 7.

A bent portion of the base 4 obtained by bending a magnetic metal plate is a yoke, and drive magnets 6A and 6B are attached to the yoke to constitute a magnetic circuit. The surfaces of the drive magnets 6A and 6B are arranged with a predetermined gap from the drive coils 3A and 3B.
Further, a straight wire spring 8 is arranged with the tangential direction as the longitudinal direction, one end of the wire spring 8 is fixed to the land portion of the relay substrate 7 on the movable portion, and the other end of the wire spring 8 is connected to the base. It is fixed to a fixed fixing member 5. The wire spring 8 is electrically conductive, and both ends thereof are also electrically connected to drive the movable portion in a desired direction by supplying current to the drive coil from a circuit board or the like on the fixed member 5 side. It is possible.

  Next, the motor unit will be described in detail. As shown in FIGS. 2 and 3, the drive coils 3 </ b> A and 3 </ b> B are a tracking coil 31, a focusing coil 32, and a tilt coil 33. The focusing coils 32 are disposed on both sides of the tracking coil 31 in the tracking direction. ing. Further, as shown in FIG. 3, the drive magnets 6A, 6B described above have a magnetization boundary line a in the focusing direction, and on both sides of the magnetization boundary line a, the tracking coils 31 face each other in the facing focusing direction. Magnetic fluxes in opposite directions are given to portions through which current flows, and the drive magnets 6A and 6B have magnetization boundary lines b and b 'in the tracking direction, and on both sides of the magnetization boundary lines b and b', The focusing coils 32 are magnetized so that magnetic fluxes in opposite directions are applied to portions where current flows in the opposing tracking direction. The drive magnets 6A and 6B may be configured such that one magnet is magnetized in multiple poles, or a plurality of magnets may be arranged side by side.

Here, in FIG. 3, triangular tilt coils 33 are arranged on both sides in the tracking direction of the tracking coil 31, and the two hypotenuses are on both sides across the magnetization boundary lines b and b ′ in the tracking direction. Has been placed.
Further, when viewed from the tangential direction, the extension lines of the two hypotenuses substantially coincide with the center of the movable portion. Here, the center of the movable part means both the center of gravity which is the center of mass of the entire movable part and the support center of the wire spring 8.
By providing the triangular tilt coil 33 in this way and providing the hypotenuse with the inclination angle α, as shown in FIG. 5A, the effective length of the tilt coil 33 can be secured long, and the working radius r Is also increased to r ′, so that a larger driving torque (thrust) F ′ can be obtained.
The oblique side of the tilt coil 33 has the highest effect by being substantially parallel to a line connecting the apexes of the drive magnets 6A and 6B and the center of the movable part at the neutral position (= the center of the drive magnet). be able to.

Assuming that the torque of the tilt coil 33 in the present invention is the conventional torque Told, the improvement rate of the drive torque Tnew relative to the conventional configuration (when the effective portion of the tilt coil is in the tracking direction) is
Tnew = (cosα) ^ 2 * Told
When α is taken on the horizontal axis and the torque improvement rate is taken on the vertical axis, the torque improvement rate as shown in FIG. 5B can be estimated geometrically.

  Here, since the hypotenuse of the tilt coil 33 straddles the magnetization boundary lines b and b 'when the movable part moves in the focusing direction, unnecessary force is generated and a cross action is likely to occur. If this becomes a problem, the tilt coil 33 may be trapezoidal as shown in FIG. However, in the case of the trapezoid, the ratio of the invalid length portion of the tilt coil 33 is increased, and the efficiency is lowered.

  In the motor configuration using the planar coil as described above, as shown in FIGS. 6 and 7, a print in which a spiral coil pattern is formed on the printed circuit board as the tracking coil 31, the focusing coil 32 and the tilt coil 33. A plurality of coils 3A ′ and 3B ′ may be used. Although the printed coil as shown in FIG. 7 has a higher component unit cost than the wound coil, it is easy to assemble, so in the case of a complicated coil configuration like this embodiment, the objective lens drive is low in total. An apparatus can be provided.

[Embodiment 1-2 (tilt coil is arranged in tracking coil section)]
Next, Example 1-2 according to the eighth means of the present invention will be described below. Explanatory diagrams of the configuration of this example are shown in FIGS. FIG. 8 is an overall perspective view of the objective lens driving device, FIG. 9 is a main portion perspective view showing only a movable portion of the objective lens driving device, and FIG. 10 is a main portion plan view showing only a motor portion of the objective lens driving device.
In Example 1-1 described above, the oblique sides of the tilt coil 33 are disposed on both sides of the magnetization boundary lines b and b ′ in the tracking direction. However, when the movable part is driven in the focusing direction, the drive coils 3A and 3B are offset from the drive magnets 6A and 6B. Since it is difficult to make the magnetic flux density distribution by the drive magnets 6A and 6B uniform, an unnecessary thrust is generated when offset. Further, since the movable range of the optical disc in the focusing direction is relatively large (about ± 1 mm), there arises a problem that the cross action increases. Therefore, in the embodiment 1-2, the tilt coil 33 is arranged so as to overlap the tracking coil 31, and the oblique side of the tilt coil 33 is not in the tracking direction, but crosses the magnetization boundary line a in the focusing direction, thereby offsetting. I try to reduce the cross action by.

[Example 1-3 (a tilt coil is disposed below the tracking coil)]
Next, Example 1-3 according to the ninth means of the present invention will be described below. Explanatory diagrams of the configuration of this embodiment are shown in FIGS. FIG. 11 is an overall perspective view of the objective lens driving device, FIG. 12 is a main portion perspective view showing only a movable portion of the objective lens driving device, and FIG. 13 is a main portion plan view showing only a motor portion of the objective lens driving device.
In the above-described embodiment 1-2, the tilt coil 33 is disposed so as to overlap the tracking coil 31, but in this embodiment 1-3, the tilt coil 33 is disposed on the opposite side of the objective lens 1 in the focusing direction of the tracking coil 31. This is an example. Here, the center of the movable portion is laid out so as to coincide with the center of thrust of the tracking coil 31. Therefore, when the size of the entire objective lens driving device is the same, the center of the movable part is arranged closer to the optical disc side than in Example 1-2. Therefore, since the distance between the principal point of the objective lens 1 and the center of the movable part can be reduced, the cross action in the tracking direction due to the tilting operation can be reduced. Further, when the principal point of the objective lens 1 is closer to the center of gravity of the movable part, the amplitude of the higher-order resonance due to the elastic deformation of the movable part becomes smaller, so that the servo band can be set higher. Further, since the tilt coil 33 is positioned below the movable part, when a glass lens or the like is used for the objective lens 1, the focusing and tracking acceleration characteristics are deteriorated particularly by an increase in the mass of the tilt coil 33. And good acceleration characteristics can be obtained.

[Example 2 (planar coil: configuration example of upper and lower two-pole magnetized magnetic circuit)]
Next, Example 2 according to the fifth means of the present invention will be described below. Explanatory diagrams of the configuration of this embodiment are shown in FIGS. FIG. 14 is an overall perspective view of the objective lens driving device, FIG. 15 is a principal perspective view showing only a movable portion of the objective lens driving device, and FIG. 16 is a principal plan view showing only a motor portion of the objective lens driving device.
As shown in FIGS. 14 and 15, the objective lens 1 is held by the objective lens holding member 2, and the side surfaces on both sides in the tangential direction of the objective lens holding member 2 are planes with the tangential direction as the winding axis. Drive coils 3A and 3B are attached. Moreover, the relay substrate 7 is attached to the side surfaces on both sides in the tracking direction of the objective lens holding member 2 to constitute a movable portion. A coil terminal is connected to the land portion of the relay substrate 7. A bent portion of the base 4 obtained by bending a magnetic metal plate is a yoke, and drive magnets 6A and 6B are attached to the yoke to constitute a magnetic circuit. The surfaces of the drive magnets 6A and 6B are arranged with a predetermined gap from the drive coils 3A and 3B. Further, a straight wire spring 8 is disposed with the tangential direction as the longitudinal direction, and one end of the wire spring 8 is fixed to the land portion of the relay board 7 on the movable portion, and the other end of the wire spring 8 is the base. The fixing member 5 is fixed to the fixing member 5. The wire spring 8 is electrically conductive, and both ends thereof are also electrically connected. By supplying current to the drive coils 3A and 3B from a circuit board or the like on the fixed member 5 side, the movable portion is moved in a desired direction. It is possible to drive to.

  Next, the motor unit will be described in detail. As shown in FIGS. 15 and 16, the drive coil 3 </ b> A (3 </ b> B) on one side of the movable portion in the tangential direction is composed of one focusing coil 32, four tracking coils 31, and two tilt coils 33. Yes. The drive magnet 6A (6B) described above has a magnetization boundary line c in the tracking direction, and on both sides of the magnetization boundary line c, a magnetic flux in the opposite direction is applied to the portion where current flows in the tracking direction of the focusing coil 32. Yes. The tracking coils 31 are disposed on both sides of the magnetization boundary line c in the focusing direction and on both sides of the focusing coil 32 in the tracking direction. A current flows in each focusing direction, and only a portion adjacent to the focusing coil 32 is driven magnet. It is arranged near the surface of 6A (6B). As the drive magnet 6A (6B), one magnet may be magnetized in multiple poles, or several magnets may be arranged side by side.

Here, a triangular tilt coil 33 is arranged at a position adjacent to both sides of the focusing coil 32 in the tracking direction and overlapping a part of the tracking coil 31. The two hypotenuses of the tilt coil 33 are arranged on both sides across the magnetization boundary line c in the tracking direction.
When viewed from the tangential direction, the extension lines of the two hypotenuses are substantially coincident with the center of the movable part. Here, the center of the movable part means both the center of gravity, which is the center of mass, and the support center of the wire spring 8. By doing so, it is possible to ensure a long effective length of the tilt coil 33 and also to increase the operating radius, so that a large driving torque can be obtained.

[Example 3 (planar coil: configuration example of a quadrupole magnetized magnetic circuit)]
[Embodiment 3-1 (tilt coils arranged in the tracking direction)]
Next, Example 3-1 according to the sixth means of the present invention will be described below. Explanatory diagrams of the configuration of this example are shown in FIGS. FIG. 17 is an overall perspective view of the objective lens driving device, FIG. 18 is a main portion perspective view showing only a movable portion of the objective lens driving device, and FIG. 19 is a main portion plan view showing only a motor portion of the objective lens driving device.
As shown in FIGS. 17 and 18, the objective lens 1 is held by the objective lens holding member 2, and both sides of the objective lens holding member 2 in the tangential direction are planes with the tangential direction as the winding axis. Drive coils 3A and 3B are attached. Moreover, the relay substrate 7 is attached to the side surfaces on both sides in the tracking direction of the objective lens holding member 2 to constitute a movable portion. A coil terminal is connected to the land portion of the relay substrate 7. A bent portion of the base 4 obtained by bending a magnetic metal plate is a yoke, and drive magnets 6A and 6B are attached to the yoke to constitute a magnetic circuit. The surfaces of the drive magnets 6A and 6B are arranged with a predetermined gap from the drive coils 3A and 3B. Further, a straight wire spring 8 is arranged with the tangential direction as the longitudinal direction, and one end of the wire spring 8 is fixed to the land portion of the relay substrate 7 on the movable portion, and the other end of the wire spring 8 is the base. The fixing member 5 is fixed to the fixing member 5. The wire spring 8 is electrically conductive, and both ends thereof are also electrically connected. By supplying current to the drive coils 3A and 3B from the circuit board or the like on the fixed member 5 side, the movable part is moved in a desired direction. It is possible to drive to.

  Next, the motor unit will be described in detail. As shown in FIGS. 18 and 19, the drive coil 3 </ b> A (3 </ b> B) on one side of the movable portion in the tangential direction is composed of two focusing coils 32, two tracking coils 31, and two tilt coils 33. ing. The drive magnet 6A (6B) has a magnetization boundary line d in the tracking direction, and two tracking coils 31 are arranged in the focusing direction, one on each side of the magnetization boundary line d in the focusing direction. Furthermore, the drive magnet 6A (6B) has a magnetization boundary line d and a magnetization boundary line e in the focusing direction in a cross shape, and two focusing coils 32 are provided on both sides in the tracking direction of the magnetization boundary line e. Each one is lined up in the tracking direction. The focusing coil 32 and the tracking coil 31 may be overlapped with each other, or may be arranged side by side on the same surface (in the figure, an example of overlapping is shown).

Here, the triangular tilt coils 33 are arranged on both sides in the tracking direction of the magnetization boundary line e in the focusing direction. The two hypotenuses of the tilt coil 33 are arranged on both sides across the magnetization boundary line d in the tracking direction.
When viewed from the tangential direction, the extension lines of the two hypotenuses are substantially coincident with the center of the movable part. Here, the center of the movable part means both the center of gravity, which is the center of mass, and the support center of the wire spring 8. By doing so, it is possible to ensure a long effective length of the tilt coil 33 and also to increase the operating radius, so that a large driving torque can be obtained.

[Example 3-2 (Tilt coils are arranged in the tracking direction and focusing direction)]
Next, another embodiment 3-2 according to the sixth means of the present invention will be described below. An explanatory diagram of the configuration of this embodiment is shown in FIGS. FIG. 20 is an overall perspective view of the objective lens driving device, FIG. 21 is a main portion perspective view showing only a movable portion of the objective lens driving device, and FIG. 22 is a main portion plan view showing only a motor portion of the objective lens driving device.
If the thrust in the tilt direction is insufficient in Example 3-1 described above, the tilt coil 33 may be quadruple as shown in FIGS. In this case, in addition to the configuration of the embodiment 3-1, a triangular tilt coil 33 is added on both sides in the focusing direction of the magnetization boundary line d in the tracking direction, and the two hypotenuses of these tilt coils 33 are focused. It arrange | positions on both sides across the magnetization boundary line e of a direction.
In this configuration, since the volume occupied by the tilt coil 33 is doubled as compared with the embodiment 3-1, it is possible to increase the tilt thrust.

[Example 3-3 (tilt coil is disposed below the tracking coil)]
Next, Example 3-3 according to the sixth and ninth means of the present invention will be described below. An explanatory diagram of the configuration of the present embodiment is shown in FIGS. FIG. 23 is an overall perspective view of the objective lens driving device, FIG. 24 is a principal perspective view showing only a movable portion of the objective lens driving device, and FIG. 25 is a principal plan view showing only a motor portion of the objective lens driving device.
In Example 3-3, as shown in FIGS. 23 to 25, a tilt coil 33 is disposed on the same surface as the tracking coil 31 and on the side opposite to the objective lens 1 in the focusing direction. That is, the drive coil 3A (3B) on one side of the movable portion in the tangential direction is composed of two focusing coils 32, one tracking coil 31, and one tilt coil 33. The drive magnet 6A (6B) has a magnetization boundary line d in the tracking direction, and a tracking coil 31 is disposed on the objective lens 1 side (optical disc side) in the focusing direction of the magnetization boundary line d. Furthermore, the drive magnet 6A (6B) has a magnetization boundary line d and a magnetization boundary line e in the focusing direction in a cross shape, and two focusing coils 32 are provided on both sides in the tracking direction of the magnetization boundary line e. Each one is lined up in the tracking direction.
Here, a triangular tilt coil 33 is disposed on the same plane as the tracking coil 31 on the opposite side of the objective lens 1 in the focusing direction of the magnetization boundary line d in the tracking direction. The two hypotenuses of the tilt coil 33 are arranged on both sides across the magnetization boundary line e in the focusing direction.

  Here, the center of the movable portion is laid out so as to coincide with the center of thrust of the tracking coil 31. Therefore, when the size of the entire objective lens driving device is the same, the center of the movable part is arranged closer to the optical disc side than in the case of Example 3-1 or Example 3-2. As a result, the distance between the principal point of the objective lens 1 and the center of the movable part can be reduced, so that the cross action in the tracking direction due to the tilting operation can be reduced. Further, when the principal point of the objective lens 1 is closer to the center of gravity of the movable part, the amplitude of the higher-order resonance due to the elastic deformation of the movable part becomes smaller, so that the servo band can be set higher. Further, since the tilt coil 33 is positioned below the movable part, when a glass lens or the like is used for the objective lens 1, the focusing and tracking acceleration characteristics are deteriorated particularly by an increase in the mass of the tilt coil 33. And good acceleration characteristics can be obtained.

[Example 4 (configuration example in which a tilt coil is wound around an objective lens holding member)]
Next, a fourth embodiment according to the seventh means of the present invention will be described below. An explanatory diagram of the configuration of this embodiment is shown in FIGS. FIG. 26 is an overall perspective view of the objective lens driving device, FIG. 27 is a perspective view of relevant parts showing only a movable portion of the objective lens driving device, and FIG. 28 is a diagram showing only a tilt coil and a driving magnet of a motor part of the objective lens driving device. FIG.
As shown in FIGS. 26 and 27, the objective lens 1 is held by the objective lens holding member 2, and the side surfaces on both sides in the tangential direction of the objective lens holding member 2 are planes with the tangential direction as the winding axis. The drive coils 3A and 3B (here, the focusing coil 32 and the tracking coil 31) and the cylindrical tilt coil 33 are attached. Moreover, the relay substrate 7 is attached to the side surfaces on both sides in the tracking direction of the objective lens holding member 2 to constitute a movable portion. A coil terminal is connected to the land portion of the relay substrate 7. A bent portion of the base 4 obtained by bending a magnetic metal plate is a yoke, and drive magnets 6A and 6B are attached to the yoke to constitute a magnetic circuit. The surfaces of the drive magnets 6A and 6B are arranged with a predetermined gap from the drive coils 3A and 3B. Further, a straight wire spring 8 is disposed with the tangential direction as the longitudinal direction, and one end of the wire spring 8 is fixed to the land portion of the relay board 7 on the movable portion, and the other end of the wire spring 8 is the base. The fixing member 5 is fixed to the fixing member 5. The wire spring 8 is electrically conductive, and both ends thereof are also electrically connected. By supplying current to the drive coils 3A and 3B from a circuit board or the like on the fixed member 5 side, the movable portion is moved in a desired direction. It is possible to drive to.

  Next, the motor unit will be described in detail. As shown in FIGS. 27 and 28, the drive coil 3A (3B) on the side surface in the tangential direction of the movable portion is composed of one planar focusing coil 32 and four planar tracking coils 31, and 2 A continuous cylindrical tilt coil 33 is provided. The drive magnets 6A and 6B described above have a magnetization boundary line f in the tracking direction, and on both sides of the magnetization boundary line f, a magnetic flux in the opposite direction is applied to a portion where current flows in the tracking direction of the focusing coil 32. . The tracking coils 31 are arranged on both sides of the magnetization boundary line f in the focusing direction and on both sides of the focusing coil 32 in the tracking direction, and a current flows in each focusing direction, and only the portion adjacent to the focusing coil 32 is driven magnet. It is arranged near the surface of 6A (6B). As the drive magnet 6A (6B), one magnet may be magnetized in multiple poles, or several magnets may be arranged side by side.

Here, the tilt coil 33 is directly wound around the objective lens holding member 2 in a cylindrical shape around an axis that forms a predetermined angle ± α with the optical axis of the objective lens 1. The oblique sides on both side surfaces in the tangential direction of the objective lens holding member 2 of the tilt coil 33 are arranged in the vicinity of the surfaces of the drive magnets 6A and 6B.
When viewed from the tangential direction, the extension lines of the two hypotenuses are substantially coincident with the center of the movable part. Here, the center of the movable part means both the center of gravity, which is the center of mass, and the support center of the wire spring 8. By doing so, it is possible to ensure a long effective length of the tilt coil 33 and also to increase the operating radius, so that a large driving torque can be obtained.

  The configuration in which the coil is directly wound around the objective lens holding member 2 as in the tilt coil 33 of this configuration can be realized at low cost because it is easy to assemble, and an assembling error with respect to the objective lens holding member 2 is also possible. Is small. Further, if the focusing coil 32 and the tracking coil 31 are formed of a print coil or the like, it is possible to relatively easily realize a three-axis / four-axis drive objective lens driving device.

[Example 5 (Configuration Example of Moving Magnet Method)]
A fifth embodiment according to the tenth means of the present invention will be described below. Explanatory diagrams of the configuration of this example are shown in FIGS. FIG. 29 is an overall perspective view of the objective lens driving device, FIG. 30 is a main portion perspective view showing only a movable portion of the objective lens driving device, and FIG. 31 is a main portion plan view showing only a motor portion of the objective lens driving device.
As shown in FIGS. 29 and 30, the objective lens 1 is held by the objective lens holding member 2, and there are magnetizing boundary lines g in the focusing direction on both side surfaces in the tangential direction of the objective lens holding member 2. The drive magnets 6A and 6B magnetized to two poles in the tangential direction are attached to form a movable part. On the base 4 side, driving coils 3A and 3B including a focusing coil 32, a tracking coil 31, and a tilt coil 33 are attached. The surfaces of the drive coils 3A and 3B are arranged with a predetermined gap from the drive magnets 6A and 6B. Further, a straight wire spring 8 is arranged with the tangential direction as the longitudinal direction, one end of the wire spring 8 is fixed to the side of the movable portion, and the other end of the wire spring 8 is fixed to the base 4. 5 is fixed. The drive coils 3A and 3B are connected to a circuit board or the like of the fixed member 5 via a wiring (not shown), and it is possible to drive the movable part in a desired direction by supplying current to the drive coils 3A and 3B. Yes.

  Next, the motor unit will be described in detail. As shown in FIGS. 29 to 31, the drive coil 3 </ b> A (3 </ b> B) on one side in the tangential direction facing the movable portion is composed of two focusing coils 32, two tracking coils 31, and one tilt coil 33. Has been. As the objective lens driving device, since these driving coils 3A (3B) are arranged on both sides of the tangential direction with the movable part interposed therebetween, they are connected in series. The drive magnets 6A and 6B provided on the movable part side have a magnetization boundary line g in the focusing direction, and magnetic fluxes in opposite directions are generated on both sides of the magnetization boundary line g. On both sides in the tracking direction of the magnetization boundary line g, the focusing coil 32 wound in the opposite direction to the tracking direction and the focusing coil 32 wound in the opposite direction and wound in the opposite direction to each other in the focusing direction A tracking coil 31 is disposed. The tilt coil 33 is wound so as to be parallel to the diagonal direction of the rectangular drive magnet 6A (6B). And it is possible to drive a movable part to each axial direction by sending an electric current through each drive coil.

  Further, when viewed from the tangential direction, the magnetization boundary line g of the drive magnet 6A (6B) is substantially coincident with the center of the movable portion. Here, the center of the movable part means both the center of gravity, which is the center of mass, and the support center of the wire spring 8. By doing so, the efficiency of the tilt coil 33 is improved, and a large driving torque can be obtained.

[Embodiment 6 (an embodiment of an optical pickup device equipped with any one of the objective lens driving devices of Embodiments 1 to 5)]
Next, the configuration of Embodiment 6 according to the eleventh means of the present invention will be described with reference to FIG. FIG. 32 is a schematic configuration diagram illustrating a configuration example of the optical pickup device. Diffused light emitted from a light source (for example, a semiconductor laser (LD)) 43 mounted on the optical pickup device 42 is converted into substantially parallel light by a collimator lens 44. Thereafter, the light passes through the beam splitter 45, and the optical path is bent by the rising mirror 46. The parallel light whose optical path is bent by the rising mirror 46 is incident on the objective lens 1 of the objective lens driving device 41 mounted on the optical pickup device 42 to form a minute spot on the optical disc 16 which is an optical recording medium. The reflected light from the optical disk 16 due to the spot is changed by 90 degrees in the direction and direction of incidence by the beam splitter 45, passes through the condenser lens 47 and the cylindrical lens 48 of the light receiving optical system 50, and then enters the light receiving element 49. It should be noted that the reflected light of the spot on the optical disk 16 is arranged so as to enter the light receiving element 49, and the objective lens driving device is based on the signals (focusing error signal, tracking error signal, etc.) obtained by the light receiving element 49. By driving the focusing coil 32 and the tracking coil 31 of 41, the optical disk 16 can follow the objective lens 1 to obtain information on the optical disk.

  Here, as the objective lens driving device 41 mounted on the optical pickup device 42, the objective lens driving device 41 having a small tilt variation due to the focusing operation and the tracking operation described in the first to fifth embodiments is mounted. Therefore, an optical pickup device that can obtain a good signal can be realized.

[Embodiment 7 (Embodiment of an optical disk drive device on which the optical pickup device of Embodiment 6 is mounted)]
Next, the configuration of Embodiment 7 according to the twelfth means of the present invention will be described with reference to FIG. FIG. 33 is a diagram showing a configuration example of the optical disk drive device, where (a) is a schematic plan view of the optical disk drive device, and (b) is a schematic side view of the optical disk drive device.
A pickup module base 53 is installed in a housing 51 of the optical disk drive device via a vibration isolating rubber 52. A spindle motor 54 that rotates the optical disk 16 is fixed to the pickup module base 53. An optical pickup device 42 having the configuration shown in FIG. 32 is mounted on the seek rail 55 attached to the pickup module base 53. The optical pickup device 42 can move on the seek rail 55 in the radial direction of the optical disk 16.
Here, the optical pickup device 42 mounted on the optical disk drive device of the present embodiment is an optical pickup device capable of maintaining a good spot as described in the sixth embodiment and obtaining a good signal. It is possible to provide an optical disk drive device having excellent recording / reproducing performance.

1 is an overall perspective view of an objective lens driving device showing an embodiment of the present invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a principal part top view which shows another structure of the motor part of the objective lens drive device shown in FIG. It is explanatory drawing of the effect at the time of making a tilt coil into a triangle shape, (a) is a figure which shows the change of a coil effective length, and a change of an action radius and a thrust at the time of providing the inclination coil of the angle (alpha) in a tilt coil, (B) is a figure which shows the torque improvement rate with respect to angle (alpha) of the inclination side of a tilt coil. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a top view of the printed coil which shows the example at the time of forming the drive coil of the objective lens drive device shown in FIG. 6 on the printed circuit board. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a whole perspective view of the objective lens drive device which shows another Example of this invention. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG. It is a schematic block diagram of the optical pick-up apparatus which shows another Example of this invention. FIG. 6 is an explanatory diagram of a configuration of an optical disc drive apparatus showing still another embodiment of the present invention. It is a whole perspective view of the objective lens drive device which shows an example of a prior art. It is a principal part perspective view which shows only the movable part of the objective lens drive device shown in FIG. It is a principal part top view which shows only the motor part of the objective lens drive device shown in FIG.

Explanation of symbols

1: Objective lens 2: Objective lens holding member 3A, 3B: Drive coil 4: Base 5: Fixed member 6A, 6B: Drive magnet 7: Relay substrate 8: Wire spring 16: Optical disc (optical recording medium)
31: Tracking coil 32: Focusing coil 33: Tilt coil 41: Objective lens driving device 42: Optical pickup device 43: Light source 44: Collimating lens 45: Beam splitter 46: Raising mirror 47: Condensing lens 48: Cylindrical lens 49: Light receiving element 50: Light receiving optical system 51: Housing 52: Anti-vibration rubber 53: Pickup module base 54: Spindle motor 55: Seek rail

Claims (12)

An objective lens, an objective lens holding member that holds the objective lens, a movable part that includes a plurality of drive coils, and a magnet that is disposed in the vicinity of at least a part of the drive coils and penetrates the magnetic flux. In an objective lens driving device comprising a driving magnet,
One of the plurality of drive coils is a tilt coil that tilts the objective lens, and an extension line of a part of the tilt coil adjacent to the drive magnet is magnetized by the drive magnet of the movable portion. An objective lens driving device characterized by passing through a substantially central axis of direction. The objective lens driving device according to claim 1,
A part of the side of the tilt coil includes a center of the movable part and a vertex farthest from the center of the movable part in a region where the tilt coil of the drive magnet is close as viewed from the magnetization direction of the drive magnet. An objective lens driving device characterized by being substantially parallel to a line connecting the two. The objective lens driving device according to claim 1 or 2,
The tilt coil has a winding axis in the magnetizing direction of the drive magnet and has a substantially triangular or substantially trapezoidal shape, and the drive magnet adjacent to at least a part of the side of the tilt coil has the triangular or trapezoidal shape. An objective lens driving device, wherein magnetic fluxes in opposite directions are applied to each of the two hypotenuses forming the lens. The objective lens driving device according to claim 3, wherein
The plurality of drive coils are a planar focusing coil, a tracking coil, and a tilt coil wound around the magnetization direction as a central axis, and focusing coils are disposed on both sides of the tracking coil in the tracking direction. And the drive magnet has a magnetization boundary line a in the focusing direction, and magnetic fluxes in opposite directions to portions where current flows in the opposing focusing direction of each tracking coil arranged on both sides of the magnetization boundary line a. Further, the drive magnet has magnetization boundary lines b and b 'in the tracking direction, and current flows in the tracking direction facing each focusing coil arranged on both sides of the magnetization boundary lines b and b'. Magnetized so as to give magnetic fluxes in opposite directions to the part, the magnetization boundary line a or the magnetization boundary Line b, the objective lens driving device, characterized in that the two oblique sides of the tilt coil in a substantially opposite sides of the b 'are arranged, respectively. The objective lens driving device according to claim 3, wherein
The plurality of drive coils are a planar focusing coil, a tracking coil, and a tilt coil wound around the magnetization direction as a central axis, and tracking coils are disposed on both sides in the tracking direction of the focusing coil. The driving magnet has a magnetization boundary line c in the tracking direction, and magnetic fluxes in opposite directions are applied to portions where current flows in the tracking direction of each focusing coil arranged on both sides of the magnetization boundary line c. An objective lens driving device characterized in that the two oblique sides of the tilt coil are respectively arranged on substantially both sides of the magnetization boundary line c. The objective lens driving device according to claim 3, wherein
The plurality of drive coils are a planar focusing coil, a tracking coil, and the tilt coil wound around the magnetization direction as a central axis, and the drive magnet has a magnetization boundary line d in the focusing direction. In addition, magnetic fluxes in opposite directions are applied to portions where current flows in the focusing direction of each tracking coil disposed on both sides of the magnetization boundary line d, and the drive magnet intersects the magnetization boundary line d in a substantially cross shape. The magnetizing boundary line e is magnetized so as to give magnetic fluxes in opposite directions to portions where current flows in the tracking direction of each focusing coil arranged on both sides of the magnetizing boundary line e. The objective lens drive characterized in that two oblique sides of the tilt coil are respectively arranged on both sides of the magnetic boundary line d or the magnetization boundary line e. Location. The objective lens driving device according to claim 1 or 2,
The tilt coil is a cylindrical coil wound around a plane having a predetermined angle with the optical axis of the objective lens on a plane including a focusing direction and a tracking direction, and at least a part of the tilt coil An objective lens driving device according to claim 1, wherein the driving magnets close to the sides of the tilting magnets provide magnetic fluxes in opposite directions on both sides with respect to the approximate center of a part of the sides close to the tilt coil. In the objective lens drive device according to any one of claims 1 to 4, 6, and 7,
2. The objective lens driving device according to claim 1, wherein the magnetization direction of the drive magnet has a magnetization boundary line in a focusing direction, and is opposite to both sides in the tracking direction with respect to the magnetization boundary line. In the objective lens drive device according to any one of claims 1 to 4, 6, and 7,
2. An objective lens driving device according to claim 1, wherein the center of gravity of only the tilt coil is disposed on the side opposite to the objective lens with respect to the center of gravity of the entire movable portion. An objective lens, an objective lens holding member that holds the objective lens, a movable portion including a rectangular drive magnet, and a plurality of drive coils wound around a fixed portion, and at least a part of the drive coil In the objective lens driving device, the side is arranged close to the driving magnet so that a current flows substantially perpendicular to the magnetic flux generated by the driving magnet.
One of the plurality of drive coils is a tilt coil that tilts the objective lens, and a part of the tilt coil adjacent to the drive magnet is substantially parallel to a substantially diagonal direction of the rectangular drive magnet. An objective lens driving device comprising: In an optical pickup device for recording, reproducing or erasing information on an optical recording medium,
A light source that emits irradiation light to the optical recording medium, a light receiving optical system that receives reflected light from the optical recording medium, and the objective lens driving device according to claim 1. An optical pickup device characterized by the above. In an optical disk drive device comprising: a rotational drive system that rotationally drives a disk-shaped optical recording medium; and an optical pickup device that is movably provided in a radial direction of the optical recording medium.
An optical disc drive apparatus comprising the optical pickup apparatus according to claim 11 as the optical pickup apparatus.

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