JP2002074705A - Objective lens driving device, method of assembling the same, and optical disk device - Google Patents

Abstract

(57) [Summary] [Problem] Even if parts accuracy and assembly accuracy are not strict,
Provided is an objective lens driving device capable of absorbing an assembly error and a component error by performing adjustment after assembling and reducing a tilt at the time of moving a movable portion. SOLUTION: When the objective lens 5 is tilted to the left,
The rigidity ratio of the left and right wire springs 8 is adjusted by injecting and constraining the high-viscosity material 22 to the ends of the right two wire springs 8 on the fixing member 13 side, and the two right wire springs 8 are fixed. 8 to increase the supporting force. Thereby, the position of the support center is made to coincide with the center of the driving force, and the adjustment is made so that the inclination of the objective lens 5 is minimized. In particular, since the high-viscosity material 22 is used, the adjustment amount can be determined as it is by performing additional injection while checking the inclination of the objective lens 5, and the workability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an objective lens driving device for an optical disk drive or a magneto-optical disk drive,
The present invention relates to an assembling method and an optical disk device.

[0002]

2. Description of the Related Art There are several types of this type of objective lens driving device, and a four-wire type (4WS type) is a low cost and advantageous method for reducing the weight of a movable part.

A conventional example of this 4WS type objective lens driving device (example shown in Japanese Patent Application Laid-Open No. Hei 8-22626: first)
12 is shown in FIG.

An objective lens holding member 102 for holding an objective lens 101 is elastically supported by four wire springs 103. A focus coil 104 is wound in a cylindrical shape on the objective lens holding member 102, and a track coil 105 wound in a planar shape is attached to a side surface thereof. The magnet 107 provided on the base 106 is provided with a gap so that a magnetic flux penetrates a driving portion of the focus coil 104 and the track coil 105 so that a yoke 108 is provided.
It is fixed to. In such a configuration, the objective lens 101 can be moved in the focus direction (Y direction) and the track direction (X direction) by passing a current through the focus coil 104 and the track coil 105. Reference numeral 109 denotes a fixing member provided on the base 106 to support the four wire springs 103, and 110 denotes a wire spring 1
03 is a holding member that holds both ends of the hinge 03 in a hinge structure that is movable in the axial direction.

[0005]

However, in the case of an objective lens driving device provided with a motor for driving by a magnetic circuit and a coil as shown in FIG. 12, the tilt when the objective lens 101 is operated for focusing and tracking. Is a big problem.

FIGS. 13 and 14 show the principle of generation of this tilt.
It will be described based on. FIG. 13 is a schematic plan view showing a drive motor portion extracted therefrom, and FIG. 14 is a schematic front view thereof. FIG. 13A shows a case where the assembling and component accuracy are ideal, and the driving center of the driving force generating portion coincides with the center of the four wire springs 103 (the movable portion supporting center). No moment is generated. However, the center of the driving force generating portion and the center of the movable portion support (or the center of gravity) may not coincide with each other as shown in FIG. Now, when the focus movement is performed when the center of the focusing driving force and the center of the movable portion support in the tracking direction of the movable portion are shifted as shown in FIG. As shown in FIG. 14, a moment is generated, and the movable part (the objective lens 101) is tilted.

[0007] In recent years, in optical discs, the need for high-density recording has increased the need for tilt as the numerical aperture NA of the objective lens increases in order to reduce the spot size, as shown in FIG. In the case of an objective lens driving device provided with a suitable driving motor, the tilt when the objective lens 101 is operated for focusing and tracking becomes a serious problem.

That is, for a conventional optical disc such as a CD, the laser wavelength used in the optical pickup is 780 nm.
Before and after, the track pitch is about 1.6 μm,
Since the recording density on the optical disk is relatively low, the tolerance of the optical pickup, particularly the optical tilt (tilt) of the objective lens with respect to the optical disk surface, is large. The product will be of a level where the tilt of the optical pickup will not be a problem as the overall accuracy later. However, in recent years, the D
An optical disk for high-density recording such as VD is in the stage of practical use, and the laser wavelength used in the optical pickup is shortened to about 650 nm, and the track pitch is reduced to about 0.74 μm in response to the increase in density. Strict standard conditions are required. Correspondingly, severe conditions such as the fact that the tilt of the optical pickup, particularly the objective lens, must be suppressed to about half that of the conventional CD have been imposed.

In order to deal with such a problem, for example,
Japanese Patent Application Laid-Open No. H11-134679 proposes that a stem (fixing member) can be moved and adjusted with respect to a magnetic circuit (second conventional example). An example of the configuration is shown in FIG. 15 (note that parts corresponding to those in FIG. 9 are denoted by the same reference numerals ... the same applies to FIGS. 16 to 19).

[0010] Projections 106a and 106b are provided on the mounting surface of the support holder 109 of the base 106 integrated with the yoke 108. The projections 106a and 106b are provided on the support holder 109.
Two long holes 109a long in the movement direction so as to fit
When the screw 111 is rotated, the support holder 109 performs tracking with respect to a magnetic circuit including the first yoke 108a, the second yoke 108b, the first magnet 107a, and the second magnet 107b. In the direction (radial direction of the optical disk).

According to this, by adjusting the movement of the support holder 109 in the tracking direction with respect to the magnetic circuit, the occurrence of a moment can be prevented by eliminating the displacement that has occurred in the first conventional example. Can be reduced.

However, in the case of the second conventional example,
With the movement adjustment of the support holder 109, the objective lens 101
Also move in the radial direction, causing an optical axis shift (a shift between the optical axis of the laser and the optical axis of the objective lens 101). Another problem is that the radial gap between the magnetic circuit and the movable part must be increased by the amount of adjustment.

On the other hand, contrary to the case of Japanese Patent Application Laid-Open No. H11-134679, there is a proposal that a magnet can be freely adjusted with respect to a stem (fixed member) (third conventional example). FIG. 16 shows an example of the configuration. That is, in this objective lens driving device, the problem of the optical axis shift in the second conventional example is solved by fixing the fixing member 109 and moving and adjusting the magnet 107a in the radial direction. In the figure, 112 is a substrate, 113 is an optical disk, 114 is a rising prism,
Reference numeral 115 denotes solder for fixing the wire spring 103.

However, also in the case of the third conventional example, it is the same as the second conventional example in that the radial gap between the magnetic circuit and the movable portion must be increased by an amount corresponding to the adjustment. Further, there is a danger that the wire spring 103 supporting the movable portion may be damaged because a jig is inserted into a small gap between the magnetic circuit and the movable portion to move and adjust the magnet 107a.

Further, there is a proposal in which a viscoelastic material is used to change the rigidity ratio of the wire spring on both sides of the central axis in the moving direction in the moving direction (fourth conventional example). Examples of the configuration are shown in FIGS. Schematically, by changing the amount of the viscoelastic material 116 for fixing the wire spring 103 and changing the rigidity ratio so that the drive center and the support center coincide with each other, the occurrence of tilt during movement is suppressed. It was made. Four wire springs 10
The fixed side of 3 is inserted into truncated conical holes 117R and 117L formed in the fixing member 109, and is fixed and supported by the viscoelastic material 116. Here, a hole 117 for injecting the viscoelastic material 116 is formed larger than usual, so that the viscoelastic material 117 can be added.

For example, when the movable part is driven in the focusing direction before the adjustment, as shown in FIG.
When 1 is tilted to the left (in the direction indicated by the arrow θ in FIG. 18), there is a deviation between the center of the focus driving force and the center of support in the track direction, and the movable portion (the objective lens 101 and the objective lens holding With respect to the center of the member 102), the right thrust is strong or the right support force is weak. Therefore, as shown in FIG. 19B, by adding a small amount of the viscoelastic material 116 to the hole 117R on the right side and increasing the supporting force of the wire spring 103 on the right side, the center of the focus driving force is reduced. By matching the support center, the inclination of the objective lens 5 during the focus movement can be reduced.

However, in the case of the fourth conventional example described above, even if the stiffness of the wire spring 103 is adjusted by adding the viscoelastic material 116, the viscoelastic material 116 is thereafter cured (ultraviolet curing, heat curing, etc.). ), The rigidity changes. Further, it is difficult to change the length of the wire spring 103 in proportion to the amount of the viscoelastic material 116 added. After all, adjustment is difficult and workability is poor.

Therefore, the present invention has a configuration that does not cause optical axis shift and does not require a large gap between the magnetic circuit and the movable part. It is an object of the present invention to provide an objective lens driving device that absorbs assembly errors and component errors by performing adjustment after assembling and has a small tilt at the time of moving the movable portion, an assembling method thereof, and an optical disk device.

[0019]

According to the first aspect of the present invention,
An objective lens for forming a light spot, an objective lens holding member for holding the objective lens, and several rod-like elastic members for supporting the objective lens holding member so as to be movable in one axis direction or two axis directions with respect to the base. In an objective lens driving device including a support member and a fixing member supporting the rod-shaped elastic support member, one end of at least one rod-shaped elastic support member in the rod-shaped elastic support member is restrained by a high-viscosity material. Thus, the rigidity ratio with respect to the other rod-shaped elastic support member is changed.

Therefore, as a configuration in which the optical axis does not shift and the gap between the magnetic circuit and the movable portion does not need to be increased, the target rod-shaped elastic member is maintained while maintaining the positional relationship between the movable portion and the magnetic circuit. By adjusting one end of the support member with a high-viscosity material to change the rigidity ratio of the rod-shaped elastic support member, the assembly error and the component error are absorbed, and the center of the driving force and the center of the support are matched. When the movable part moves, the objective lens can be hardly inclined with respect to the optical disc. In particular, since a high-viscosity material is used, the amount of adjustment can be determined as it is by performing additional injection while checking the inclination of the objective lens, and the rigidity does not change after adjustment, and workability is improved. Good.

According to a second aspect of the present invention, in the objective lens driving device according to the first aspect, an end of the rod-like elastic support member to be constrained on the fixing member side is constrained by the high-viscosity material. .

Therefore, in realizing the first aspect of the present invention, since the high-viscosity material is used for the fixed member, the weight of the movable portion increases, and the balance of the movable portion is lost. Nothing.

According to a third aspect of the present invention, in the objective lens driving device according to the first aspect, the end of the rod-shaped elastic support member to be restrained on the objective lens holding member side is restrained by the high-viscosity material. I made it.

Therefore, in realizing the first aspect of the present invention, since a high-viscosity material is used for the objective lens holding member side, a viscoelasticity for fixing the rod-shaped elastic support member to the objective lens holding member is provided. The high-viscosity material can be injected without disturbing the material, and the high-viscosity material can absorb a quantitative error and a curing error of the viscoelastic material.

According to a fourth aspect of the present invention, in the objective lens driving device according to the first or second aspect, the fixing member is configured to inject the high-viscosity material into an end of the rod-shaped elastic supporting member. Has a passage.

Therefore, the use of the passage makes it possible to easily perform the operation of injecting the high-viscosity material at the end of the process such as the injection and curing of the viscoelastic material, thereby reducing the quantitative error and the curing error of the viscoelastic material. In addition to being able to be absorbed by the high-viscosity material, it is also possible to avoid an increase in the weight of the movable section.

[0027] The invention according to claim 5 is the invention according to claims 1 to 4.
In the objective lens driving device according to any one of the above, the positions of the support center and the thrust center when the objective lens driving device is assembled at the design center are shifted in a certain direction.

Therefore, when the objective lens driving device is assembled at the center of design, the center of support and the center of thrust are always deviated in a certain direction. Only the operation of matching the center of support and the center of thrust by injecting a high-viscosity material may be performed, and the target of the adjustment operation can be specified, and the workability is improved.

According to a sixth aspect of the present invention, in the objective lens driving device according to the fifth aspect, the rod-like elastic support member to be constrained, which restricts the rod-like elastic support member closer to the center of thrust by the high-viscosity material, did.

Therefore, when the objective lens driving device is assembled at the center of design, the center of support and the center of thrust are always deviated in a certain direction. Only the operation of matching the center of support and the center of thrust by injecting a high-viscosity material may be performed, and the target of the adjustment operation can be specified, and the workability is improved.

According to a seventh aspect of the present invention, there is provided an objective lens for forming a light spot, an objective lens holding member for holding the objective lens, and the objective lens holding member being uniaxial or biaxial with respect to the base. A plurality of rod-shaped elastic supporting members movably supported on the object lens; a driving coil provided on the objective lens holding member for displacing the objective lens in the one-axis direction or the two-axis direction; A method of assembling an objective lens driving device including a fixed member that supports a member, wherein a current is supplied to the driving coil to displace a movable portion formed by the objective lens, the objective lens holding member, and the driving coil. An adjustment is made by injecting a high-viscosity material into one end of one of the rod-shaped elastic support members so that the inclination of the objective lens generated when the object is made is small.

Therefore, by adjusting the rigidity ratio of the rod-shaped elastic support member using a high-viscosity material so that the inclination of the objective lens generated when the movable part moves is reduced, the inclination of the objective lens can be confirmed. By performing the additional injection, the adjustment amount can be fixed as it is, and the rigidity does not change after the adjustment, and the workability of the adjustment in the assembling work is good.

According to an eighth aspect of the present invention, there is provided an objective lens for forming a light spot, an objective lens holding member for holding the objective lens, and the objective lens holding member in a uniaxial or biaxial direction with respect to a base. A method for assembling an objective lens driving device comprising: several rod-like elastic support members movably supporting the object; and a fixing member supporting the rod-like elastic support member, wherein a moment causing the inclination of the objective lens is reduced. A shift between the generated support center and the thrust center is calculated, and a high-viscosity material is injected into one end of one of the rod-shaped elastic support members so that the support center moves by the amount of the shift. Was adjusted by changing.

Accordingly, by adjusting the rigidity ratio of the rod-shaped elastic support member using a high-viscosity material so as to reduce the inclination of the objective lens generated when the movable part moves, the inclination of the objective lens can be confirmed while checking the inclination of the objective lens. By performing the additional injection, the adjustment amount can be fixed as it is, and the rigidity does not change after the adjustment, and the workability of the adjustment in the assembling work is good. In particular, it is only necessary to add a high-viscosity material in an amount corresponding to the inclination of the objective lens, and the adjustment can be performed efficiently.

The optical disk apparatus according to the ninth aspect of the present invention
7. The objective lens driving device according to claim 1, wherein the motor drives the optical disc to rotate, the objective lens irradiates a light spot to the optical disc driven to rotate by the motor, and the objective lens driving apparatus drives the objective lens. And an optical pickup device including:

Therefore, the objective lens driving device according to any one of claims 1 to 6 has a small inclination of the objective lens when the movable portion is moved, so that a stable recording or reproducing operation can be performed. .

[0037]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. FIG. 1 shows a schematic configuration of an optical disk device using the objective lens driving device 1 of the present embodiment. The objective lens driving device 1 is disposed opposite an optical disk (including a magneto-optical disk) 3 driven to rotate by a motor 2 such as a spindle motor or the like, and is included in an optical pickup device 4 for performing a recording or reproducing operation. The lens 5 (see FIG. 2) is driven and controlled in the focus direction or the track direction, and is provided so as to be movable in the radial direction of the medium by a seek mechanism such as a seek motor 6 or the like.

FIG. 2 shows a configuration example of the objective lens driving device 1 for the objective lens 5 in the optical pickup device 4.
Shown in First, an objective lens holding member 7 for holding the objective lens 5 facing the optical disc 3 is provided. The objective lens holding member 7 is elastically supported by four wire springs 8 which are rod-shaped elastic support members, and a movable portion formed by the objective lens 5, the objective lens holding member 7 and a driving coil described later. Reference numeral 9 denotes a base 10 which can be displaced and moved in two axial directions: a focus direction along the optical axis direction of the objective lens 5 and a track direction orthogonal to the focus direction. Here, the movable side end of the wire spring 8 is fixed on the coil terminal plate 12 by solder 11 on both sides of the objective lens holding member 7, and the fixed side end is supported by a fixing member 13 provided on the base 10. ing. More specifically,
The fixed sides of the four wire springs 8 are inserted into truncated conical holes 14R and 14L formed in the fixed member 13, and the resonance is attenuated by the viscoelastic material 15; Are attached, and the wire spring 8 is electrically connected and fixedly supported by soldering.

A focus coil 17 as a driving coil is wound on the objective lens holding member 7 in a cylindrical shape, and two track coils as a driving coil wound on the side surface in a planar shape. 18 are attached. These coils 17 and 18 constitute a driving coil, and the coils 17 and 18 can be energized via the wire spring 8 and the coil terminal plate 12 described above. The magnets 19a and 19b are fixed to the yokes 20a and 20b with a gap provided so that a magnetic flux penetrates the driving portions of the focus coil 17 and the track coil 18. These yokes 20a and 20b are integrated on the base 10. Reference numeral 21 denotes a rising prism.

With such a basic configuration, it is possible to move the objective lens 5 in the focus direction and the track direction by supplying a current to the focus coil 17 and the track coil 18.

In this embodiment of the objective lens driving device 1, in this embodiment, a high-viscosity material is inserted into a hole 14R with respect to a part of the wire spring 8, for example, two wire springs 8 on the right side on the fixing member 13 side. By injecting 22 and restraining the wire spring 8 to adjust its movable length, the rigidity ratio with the two left wire springs 8 can be changed.

This point will be described in detail including the process of assembling the objective lens driving device 1. First, an assembly of the movable section 9 including the objective lens 5, the objective lens holding member 7, the focus coil 17, the track coil 18, and the coil terminal board 12 is assembled. Next, the assembly of the movable portion 9 is attached to the substrate 16 by soldering via the wire spring 8. Then, the magnets 19a and 19b and the yoke 20
The fixing member 13 is installed on the base 10 having the components a and 20b.

At this stage, when a current is applied to the focus coil 17 or the track coil 18 to move the movable portion 9, the thrust center generated based on the driving force and the support center formed by the four wire springs 8 are moved. Are shifted due to component errors and assembly errors. Due to this displacement, the movable portion 9 including the objective lens 5 is inclined with respect to the optical disc 3 as described above.

Therefore, the tilt of the objective lens 5 generated when the movable portion 9 is moved is adjusted so as to be small. Here, the adjustment method is described here when the lens is driven in the focus direction. The case where the inclination is reduced will be described as an example.

First, the inclination of the objective lens 5 is measured by an autocollimator or the like. Here, the focus coil 1
The movable part 9 of the objective lens driving device 1 is moved up and down by passing an electric current through the movable member 7. At this time, if the adjustment is not performed, the center of thrust in the focus direction generated by the focus coil 17 and the center of support of the four wire springs 8 in the focus direction usually have an assembly error. The moment is generated because it is not done.

For example, if the objective lens 5 tilts to the left as shown in FIG. 3 when the movable section 9 is moved to the plus side in the focus direction, the support center is located to the left of the thrust center, and the two wire springs 8 are located on the right. Is smaller than the rigidity of the two wire springs 8 on the left side. Therefore, as shown in FIG. 2, by injecting the high-viscosity material 22 into the ends of the two right-side wire springs 8 on the fixing member 13 side, the ends of the wire springs 8 are restrained to reduce the movable length. The support center is moved radially to the right by shortening the length and increasing the rigidity of the right wire spring 8. At this time, in this embodiment, since the fluid high-viscosity material 22 is used, the high-viscosity material 22 can be additionally injected while observing the inclination of the objective lens 5. By making the support center coincide with the thrust center in this way, it is possible to eliminate the inclination of the objective lens 5 that occurs when the movable section 9 is moved in focus.

However, since the moving amount ΔS1 of the supporting center with respect to the length change ΔL of the wire spring 8 can be calculated in advance, the supporting center can be calculated from the inclination amount θ of the objective lens 5 measured by the collimator and the focus moving amount Δy. And the displacement amount ΔS2 of the thrust center is obtained, and the support center is moved by the displacement amount ΔS2, that is, the high-viscosity material 22 is injected into one end of the wire spring 8 so that ΔS1 = ΔS2. Adjustment may be made to change the movable length of the wire spring 8.

In any case, as described above, the high-viscosity material 2
After adjusting the tilt of the objective lens 5 during the movement of the movable part 9 using the injection of 2, the ultraviolet-curable viscoelastic material 15 is fixed around the end of the wire spring 8 on the fixing member 13 side. By assembling into holes 14R and 14L formed in 13, assembly is completed. By fixing the wire spring 5 by such injection of the viscoelastic material 15, the resonance of the movable portion 9 is attenuated.

Therefore, according to the present embodiment, the movable portion 9
(Objective lens 5, objective lens holding member 7, coil 1
7, 18) and magnetic circuit (magnets 19a, 19b and yoke 2)
0a, 20b) (that is, a configuration in which the optical axis does not shift and the gap between the movable part and the magnetic circuit does not need to be increased). By constraining one end of the spring 8 (for example, the right wire spring) with the high-viscosity material 22, the wire spring 8
The adjustment for changing the overall rigidity ratio can absorb the assembly error and the component error and make the center of the driving force coincide with the center of the support. When the movable part 9 moves, the objective lens 9 Can be hardly inclined. In particular, since the high-viscosity material 22 is used, the amount of adjustment can be determined as it is by performing additional injection while checking the inclination of the objective lens 5, and the rigidity does not change after the adjustment, and Good nature. In addition, since the high-viscosity material 22 is injected into the fixed member 13, the weight of the movable section 9 does not increase, and the balance of the movable section 9 is not lost.

FIGS. 4 and 5 show a second embodiment of the present invention.
It will be described based on. The same parts as those used in the first embodiment are denoted by the same reference numerals, and description thereof is omitted (the same applies to the following embodiments). In the present embodiment, the high-viscosity material 22 is injected into the end of the wire spring 8 on the movable portion 9 side (the objective lens holding member 7 side).

That is, in the first embodiment, the fixing member 1
Since the high-viscosity material 22 is injected into the end of the wire spring 8 on the third side, the inclination of the objective lens 5 during movement must be adjusted before the viscoelastic material 15 for damping the resonance of the movable portion 9 is injected. If the viscoelastic material 15 is subsequently injected and hardened, the injection amount and the degree of hardening vary among the four wire springs 8, and the support center may move again.

In this regard, in the present embodiment, at the end of the assembling process of the objective lens driving device 1 (after the wire tension, the injection of the viscoelastic material 15 and the hardening of the viscoelastic material 15), the target wire is The movable length (that is, rigidity) of the wire spring 8 is changed by injecting and attaching a high-viscosity material 22 so as to restrain the end of the spring 8 on the movable portion 9 side.
FIG. 5 is an enlarged view showing the vicinity of the movable section 9 to which the high-viscosity material 22 is injected and adhered. By performing this for only the wire spring 8 on one side with respect to the center axis of the moving part 9 in the moving direction, the support center in the moving direction can be moved.

Therefore, according to the present embodiment, the same basic effects as those of the first embodiment can be obtained, and the adjustment using the high-viscosity material 22 is performed on the movable section 9 side. Therefore, component dimensional error and assembly error, viscoelastic material 1
5 can be corrected so as to absorb all deviations between the support center and the thrust center caused by the injection amount error 5 and the curing error thereof.

FIGS. 6 and 7 show a third embodiment of the present invention.
It will be described based on. First, in the above-described second embodiment, the high-viscosity material 22 is adhered to the movable portion 9 side, so that the merit of being able to process the high-viscosity material 22 at the end of the assembling process is obtained. When the high-viscosity material 22 is added to the side of the movable unit 9, the weight of the movable unit 9 increases, so that the acceleration characteristic of the objective lens driving device 1 deteriorates.
High-viscosity material 2 only on the wire spring 8 on one side with respect to the center of gravity
Since 2 is added, a problem may occur that the balance of the movable portion 9 is lost and resonance in the rotating rigid body mode is increased.

In consideration of such points, this embodiment is
For example, as shown in FIG. 2 and the like, in the first embodiment in which the high-viscosity material 22 is injected on the fixing member 13 side, the inner side of the holes 14R and 14L (the smaller diameter side)
Are formed so as to be exposed at the upper and lower ends, respectively. This passage 23 is for injecting the high-viscosity material 22 at the end of the assembly process.

More specifically, the viscoelastic material 15 is
The high-viscosity material 13 is injected into the fixed member 13 side after being injected into the R and cured, so that the weight of the movable portion 9 does not increase. For this reason, a passage 23 for injecting the high-viscosity material 22 is formed in the fixing member 13 as shown in FIGS. 6 and 7 (only the right side in the drawing is formed, but the left side hole 14L is formed). Is similarly formed).

In such a configuration, at the end of the assembling process of the objective lens driving device 1 (wire tension, viscoelastic material 1)
After the injection 5 and the curing of the viscoelastic material 15), the high-viscosity material 22 is injected by a dispenser from the injection port 23a of the passage 23 formed in the fixing member 13. The injected high-viscosity material 22 passes through the passage 23 and enters the root portion of the wire spring 8 from the fixing member 13 side of the wire spring 8. Thereby, the movable length (that is, rigidity) of the wire spring 8 can be changed by restraining the end of the wire spring 8. By performing this only for the wire spring 8 on one side (for example, the right side) with respect to the central axis in the moving direction of the movable portion 9, the support center in the moving direction can be moved.

Therefore, according to the present embodiment, the effects of the first and second embodiments are combined. That is, since the high-viscosity material 22 only needs to be handled last, a deviation between the support center and the thrust center caused by a component dimensional error, an assembly error, an injection amount error of the viscoelastic material 15, and a hardening error thereof is corrected. Since the high-viscosity material 22 is handled on the fixed member 13 side, the weight of the movable portion 9 does not increase.

A fourth embodiment of the present invention will be described with reference to FIG. As described above, the thrust center and the support center are normally displaced in either direction. However, in the present embodiment, the thrust center and the support center are intentionally set in a certain direction from the beginning in the design center. It is intended to be staggered.

That is, in the present embodiment, the end of the wire spring 8 on the movable section 9 side is fixed to the coil terminal board 12 mounted on the objective lens holding member 7 by the solder 11. The position 12 is shifted in the axial direction of the wire spring 8 on the left and right by a shift amount ΔL ′. When the objective lens driving device 1 is assembled at the design center, the shift amount ΔL ′ is equivalent to the maximum expected amount of a shift ΔS1 between the support center and the thrust center caused by an assembly error and a component error.
It is set as a value larger than L.

In the present embodiment, as shown in FIG. 8, the left coil terminal board 12 is set so as to be close to the fixing member 13 side. The wire spring 8 is shorter on the left side and longer on the right side. Therefore, at the final stage of the assembly, the right wire spring 8 is specified from the beginning as the object to be restrained.
The adjustment can be performed by injecting the high-viscosity material 22 only into the end of the wire spring 8 on the right side of the fixing member 13. Also, when the passage 23 is formed in the fixing member 13 as in the third embodiment, the passage 23 may be formed only in the hole 14R on the right side as shown in FIG.

Therefore, according to the present embodiment, when the objective lens driving device 1 is assembled at the design center, the center of support and the center of thrust are always deviated in a certain direction. By injecting the high-viscosity material 22 only into the wire spring 8 on the side, the work of matching the support center and the thrust center may be performed, and the target of the adjustment work can be specified, and the workability is improved.

As means for intentionally shifting the center of support and the center of thrust in a certain direction from the beginning, other means such as shifting the position of the coil 17 or 8 or changing the wire diameter of the wire spring 8 between the left and right. It may be performed by means such as changing the intensity or changing the strength of the magnetic field.

In each of the embodiments described above, an example of application to a configuration in which a cylindrical focus coil 17 and a planar track coil 18 are combined with a driving motor portion has been described. However, the present invention is not limited to this. For example, FIGS. 9 and 10
As shown in the figure, the focus coil 31 and the track coil 3
Both can be similarly applied to the case of a driving motor configuration using a planar motor.

FIG. 9 is an exploded perspective view showing a driving motor, FIG. 10 is an explanatory view thereof, (a) is a horizontal sectional view of a coil viewed from a focusing direction, and (b) is a magnetic field distribution in a tracking direction. (C) is a front view showing the positional relationship between the coil and the driving magnet, (d) is a characteristic diagram showing the magnetic field distribution in the focusing direction, and (e) is a longitudinal side view of the coil viewed from the tracking direction. FIG.

Focus coil 31 and track coil 3
2 is located at a position sandwiched between two magnets 34 bonded to the yoke 33. As shown in FIG. 9, the magnet 34 is magnetized by being divided into four parts at the boundary of the crossed magnetized boundary lines a and b. The magnetized directions are a focusing direction [Y-axis direction] and a tracking direction [X-axis]. Direction [Z]
[Axial direction] and in a direction opposite to an adjacent region. The focus coil 31 is formed of a coil having a planar shape, and is provided at two positions on both sides of a magnetized boundary line a in the focus direction, and at a position straddling the magnetized boundary line b in the tracking direction, respectively. )). On the other hand, two track coils 32 are provided on both sides of the magnetized boundary line b in the track direction, and are each held by the objective lens holding member across the magnetized boundary line a in the focus direction. Further, the magnet 34 is arranged such that the portions facing each other with the focus coil 31 and the track coil 32 interposed therebetween have the same magnetization direction. By configuring the motor in this manner, the movable section can be driven in two axial directions of the focus direction and the track direction. The configuration of each of the other parts can be formed in the same manner as in the above-described embodiments.

In the case of the objective lens driving device having such a motor configuration, the coils 31, 32 are moved when the movable portion is moved.
Is less affected by the distribution of the magnetic field, so the tilt of the objective lens when moving the movable part due to the magnetic field distribution is small, but on the other hand, if the support center and the thrust center shift due to assembly, Although it is difficult to adjust the tilt of the objective lens during movement by the method of the second conventional example or the third conventional example of adjusting the positional relationship between the magnetic circuit and the coil, the method of each embodiment described above is difficult. As in the case, by using the method of changing the rigidity of the elastic support member, it is possible to effectively adjust the inclination of the objective lens when the movable portion moves.

That is, in the driving motor as shown in FIGS. 9 and 10, when the movable portion moves in both the focus and track directions, the focus coil 31 and the track coil 3 move.
In order to cancel the moment of 2, the tilt at the time of moving the objective lens is as shown in FIG.
Small around ± 1mm). However, when the support center is mounted to be shifted in the radial direction with respect to the thrust center, a tilt occurs even when focusing is performed with tracking (Tr) = 0, resulting in the state shown in FIG. 11B. I will.

In the driving motor shown in FIGS. 9 and 10, since the coils 31 and 32 are arranged inside the magnetic circuit, the focus coil 17 as in the above-described embodiment surrounds the magnetic circuit. Radial direction (X direction) with respect to the magnetic circuit of the movable part rather than the driving motor
Since the influence of the position shift on the tilt is small, it is possible to reduce the tilt by relatively moving and adjusting the magnetic circuit and the movable part as described in the second and third conventional examples. difficult. In this respect, according to the above-described embodiment, the tilt can be reduced by changing the rigidity of the elastic support member to move the support center and to match the thrust center. That is, after adjustment, FIG.
Characteristics such as 1 (a) can be secured.

[0070]

According to the first aspect of the present invention, one end of at least one rod-shaped elastic support member in the rod-shaped elastic support member is restrained by a high-viscosity material and rigidity with another rod-shaped elastic support member. Since the ratio is changed, there is no need to increase the gap between the magnetic circuit and the movable part without causing optical axis deviation, and the target is maintained while maintaining the positional relationship between the movable part and the magnetic circuit. By adjusting the rigidity ratio of the rod-shaped elastic support member by changing one end of the rod-shaped elastic support member to be high-viscosity material, the assembly error and the component error can be absorbed, and the driving force center and the support center can be adjusted. When the movable part moves, the objective lens can be made hard to tilt with respect to the optical disk. In particular, since a high-viscosity material is used, additional injection is performed while checking the tilt of the objective lens. The adjustment amount as it can be determined, without such rigidity is changed after the adjustment, it is possible to improve the workability and.

According to the second aspect of the present invention, in order to realize the first aspect of the present invention, a high-viscosity material is used for the fixed member side. Adjustment that does not cause the balance of the unit to be lost can be performed.

According to the third aspect of the present invention, there is provided the first aspect.
In realizing the described invention, a high-viscosity material is used for the objective lens holding member side, so that the viscoelastic material for fixing the rod-shaped elastic support member to the objective lens holding member does not interfere with the high viscosity material. In addition to being able to inject the material, the quantitative and hardening errors of the viscoelastic material can be absorbed by the high viscosity material.

According to a fourth aspect of the present invention, in the objective lens driving device according to the first or second aspect, the passage for injecting the high-viscosity material into the fixed member into the end of the rod-shaped elastic support member is provided. Since the viscoelastic material is formed, the injection of high-viscosity material can be easily performed at the end of the process such as injection and curing of the viscoelastic material by using the passage. In addition to being able to be absorbed by the viscous material, it is also possible to avoid an increase in the weight of the movable section.

According to the fifth aspect of the present invention, in the objective lens driving device according to any one of the first to fourth aspects, when the objective lens driving device is assembled around a design center, the support center is intentionally supported. The thrust center and the thrust center are always deviated in a certain direction, so the work of matching the support center with the thrust center is performed by injecting high-viscosity material only into the rod-shaped elastic support member on the thrust center side. For example, the target of the adjustment work can be specified, and the workability can be improved.

According to the sixth aspect of the present invention, when the objective lens driving device is assembled at the design center, the center of support and the center of thrust are intentionally deviated in a certain direction. By injecting a high-viscosity material only into the rod-shaped elastic support member on the thrust center side, the work of matching the support center with the thrust center can be performed, and the target of the adjustment work can be specified, and the workability can be improved. it can.

According to the seventh aspect of the present invention, the rigidity ratio of the rod-shaped elastic support member is adjusted using a high-viscosity material so that the inclination of the objective lens generated when the movable portion moves is reduced. By performing additional injection while checking the tilt of the objective lens, the adjustment amount can be determined as it is, and the rigidity does not change after adjustment,
The workability of the adjustment in the assembling work is improved.

According to the eighth aspect of the invention, the rigidity ratio of the rod-shaped elastic support member is adjusted by using a high-viscosity material so that the inclination of the objective lens generated when the movable portion moves is reduced. By performing additional injection while checking the tilt of the objective lens, the adjustment amount can be determined as it is, and the rigidity does not change after adjustment,
The workability of the adjustment in the assembling work is good. In particular, it is sufficient to add a high-viscosity material in an amount corresponding to the inclination of the objective lens, and the adjustment can be performed efficiently.

According to the ninth aspect of the present invention, the objective lens driving device according to any one of the first to sixth aspects is provided with a small inclination of the objective lens when the movable portion moves. The recorded or reproduced operation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an optical disk device using an objective lens driving device of the present invention.

FIG. 2 shows an objective lens driving device, (a) is a plan view,
(B) is a side view thereof.

FIG. 3 is a front view showing an objective lens driving device before adjustment.

4A and 4B show an objective lens driving device according to a second embodiment of the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a side view thereof.

FIG. 5 is a partially enlarged view showing (a) a plan view;
(B) is a side view thereof.

6A and 6B show an objective lens driving device according to a third embodiment of the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a side view thereof.

FIG. 7 is a front view showing the objective lens driving device before adjustment.

FIG. 8 is a plan view showing an objective lens driving device according to a fourth embodiment of the present invention.

FIG. 9 is an exploded perspective view showing a driving motor according to a modification.

FIGS. 10A and 10B are explanatory diagrams thereof, in which FIG. 10A is a horizontal cross-sectional view of a coil viewed from a focusing direction, FIG. 10B is a characteristic diagram showing a magnetic field distribution in a tracking direction, and FIG. FIG. 3D is a front view showing an arrangement relationship, FIG. 4D is a characteristic diagram showing a magnetic field distribution in a focusing direction, and FIG. 4E is a longitudinal side view of a coil viewed from a tracking direction.

FIG. 11 is a graph showing a relationship between a focus movement amount and a tilt amount.

FIG. 12 is a perspective view showing a first conventional example of an objective lens driving device.

FIGS. 13A and 13B schematically show the occurrence of tilt, wherein FIG. 13A is a plan view of an ideal case where no tilt occurs, and FIG. 13B is a plan view of a case where tilt occurs.

FIG. 14 is a schematic front view when a tilt occurs.

FIG. 15 is a plan view showing a second conventional objective lens driving device.

FIG. 16 shows a third prior art objective lens driving device;
(A) is a plan view and (b) is a side view thereof.

FIG. 17 shows a fourth conventional objective lens driving device;
(A) is a plan view and (b) is a side view thereof.

FIG. 18 is a front view showing an objective lens driving device before adjustment.

FIG. 19 is an enlarged view showing a part of the objective lens driving device;
(A) is a horizontal sectional view before adjustment, (b) is a horizontal sectional view after adjustment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens drive device 2 Motor 3 Optical disk 4 Optical pickup device 5 Objective lens 7 Objective lens holding member 8 Rod-like elastic support member 9 Movable part 13 Fixed member 17, 18 Driving coil 22 High viscosity material

Claims (9)

[Claims] 1. An objective lens for forming a light spot, an objective lens holding member for holding the objective lens, and the objective lens holding member movably supported in a one-axis direction or a two-axis direction with respect to a base. In an objective lens driving device including several rod-shaped elastic support members and a fixing member that supports the rod-shaped elastic support members, one end of at least one of the rod-shaped elastic support members in the rod-shaped elastic support members is raised. An objective lens driving device characterized by changing a rigidity ratio with respect to the other rod-shaped elastic support member by being constrained by a viscous material. 2. The objective lens driving device according to claim 1, wherein an end of the rod-shaped elastic support member to be restricted on the fixing member side is restricted by the high-viscosity material. 3. The objective lens driving device according to claim 1, wherein an end of the rod-shaped elastic support member to be restrained on the objective lens holding member side is restrained by the high-viscosity material. 4. The objective lens driving device according to claim 1, wherein the fixing member has a passage for injecting the high-viscosity material into an end of the rod-shaped elastic support member. 5. The method according to claim 1, wherein the position of the center of support and the center of thrust when the objective lens driving device is assembled at the design center are shifted in a certain direction. The objective lens driving device as described in the above. 6. The objective lens driving device according to claim 5, wherein the rod-like elastic support member closer to the thrust center is a rod-like elastic support member to be constrained by the high-viscosity material. 7. An objective lens for forming a light spot, an objective lens holding member for holding the objective lens, and the objective lens holding member movably supported in a uniaxial or biaxial direction with respect to a base. Several rod-shaped elastic support members, a driving coil provided on the objective lens holding member for displacing the objective lens in the one-axis direction or two-axis direction, and a fixing member for supporting the rod-shaped elastic support members The method for assembling an objective lens driving device comprising: energizing the driving coil, and displacing a movable portion formed by the objective lens, the objective lens holding member, and the driving coil. The objective lens drive is characterized in that a high-viscosity material is injected into one end of one of the rod-shaped elastic support members so as to reduce the inclination of the objective lens. Method of assembling the apparatus. 8. An objective lens for forming a light spot, an objective lens holding member for holding the objective lens, and the objective lens holding member movably supported in a uniaxial or biaxial direction with respect to a base. An assembling method of an objective lens driving device comprising: a plurality of rod-shaped elastic support members; and a fixing member that supports the rod-shaped elastic support members, wherein a support center that generates a moment that causes the objective lens to tilt and a thrust force Calculate the deviation from the center and adjust it by injecting a high-viscosity material into one end of one of the rod-shaped elastic support members and changing the length so that the support center moves by this deviation. A method of assembling the objective lens driving device. 9. A motor for rotating an optical disk, an objective lens for irradiating a light spot on the optical disk rotationally driven by the motor, and an objective lens for driving the objective lens. An optical pickup device, comprising: an optical pickup device including the objective lens driving device.