JP2001344777A - Lens drive device and optical pickup using the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of unwanted vibrations of a lens in a lens drive device used in an optical recording/reproducing device. SOLUTION: A lens 2 is attached to a plate shaped damper member 20 made of a base stock having viscoelasticity in omnidirections, for example, a silicone porous substance, and both ends of the damper member 20 are attached to a base 15. Also, two magnets 5, 27 are attached to the peripheral part 3 of the lens by holding the lens 2 between them in order to drive the lens 2, and also driving coils 7, 25 are mounted on positions facing respective magnets 5, 27 of the base 15. The driving coils 7, 25 are provided with two coils for driving the lens 2 in the tracking direction and the focusing direction respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens driving device used for an optical recording / reproducing device for a recording medium such as a compact disk (hereinafter, referred to as "CD") and a DVD, and an optical device provided with such a device. Regarding pickup.

[0002]

2. Description of the Related Art In recent years, optical recording / reproducing apparatuses for compact and large-capacity storage media such as CDs and DVDs have become widespread as means for recording video, audio and other information.
In an optical recording / reproducing apparatus, information is read by irradiating a laser beam while focusing on a recording surface of a recording medium such as an optical disk, and observing the reflected light. The information is recorded along a spiral track on the recording surface.

[0003] Incidentally, there are distortion and deformation of the recording medium, tilting and rubbing motion of a turntable on which the recording medium is mounted, and the distance between the recording surface and the lens fluctuates due to these factors. May not be tied.
Also, due to the eccentricity of the recording medium and turntable,
The track may be displaced in the radial direction of the recording medium and deviate from the optical path of the laser beam.

In order to prevent errors in reading recorded information due to these factors, the lens is moved up and down in the direction of the optical axis (hereinafter, this direction is referred to as the "focus direction") to focus the laser beam on the recording surface, The lens is moved in a radial direction of the recording medium (hereinafter, this direction is referred to as a “tracking direction”) so that the optical path of the laser light is aligned with the track.

[0005] In order to enable such movement of the lens position, the lens is usually mounted on a movable member, and the movable member is driven by driving means to adjust the focal position and optical path of the laser beam. Moreover, in the optical recording / reproducing apparatus, the recording medium rotates at a high speed (for a CD, 200 r.
pm to 500 rpm. For DVD, 1,000 rpm
that's all. ), The lens must be quickly moved to the target position. However, due to the natural vibration of the lens driving device or the optical pickup itself, there has been a problem that the control system becomes unstable.

In order to suppress this vibration, for example, in a lens driving device disclosed in Japanese Patent Laid-Open No. 7-105551, a movable member including a lens is placed in a cantilever state via a linear elastic support member. The elastic support member is filled with a viscoelastic damper member at the base of the elastic support member on the fixed member side. With such a configuration,
The vibration of the elastic support member is damped by the damper member, and as a result, the vibration of the lens is suppressed.

[0007]

However, in the above-described lens driving device, the amplitude of the higher-order vibration of the vibration whose fundamental wave is the length of the support member is smaller than that of the lower-order vibration, There is a problem that the effect of suppressing vibration of the member is hardly effective. Further, in this lens driving device, since the movable member holding the lens is held by the elastic supporting member in a cantilever state on the fixed side member, the size is inevitably increased in the extending direction of the elastic supporting member. Another problem is that it is difficult to reduce the size of the entire apparatus.

The present invention has been made in view of the above problems, and is used for an optical recording / reproducing apparatus.
It is an object of the present invention to provide a small-sized lens driving device and an optical pickup with less vibration.

[0009]

According to another aspect of the present invention, there is provided a lens driving apparatus for driving a lens movably held with respect to a base in a predetermined direction by driving means. The lens is held by the base via a damper member formed of a viscoelastic material. Since a material having viscoelasticity has a resonance suppressing effect due to excellent vibration absorbing properties in all directions, vibration of the lens can be suppressed regardless of the vibration direction.

The material having viscoelasticity in all directions is preferably a gel material. This is because the gel material has substantially uniform viscoelasticity in all directions and is suitable for the damper member. Further, as the gel-like material, one containing silicone as a main material, heat resistance, cold resistance,
It is preferable because it has stable properties with respect to physical properties such as weather resistance and safety.

Further, in the lens driving device according to the present invention,
The base has a damper member accommodating space, and the damper member is formed in a flat plate shape, and both ends in a longitudinal direction thereof are fixed to walls of the damper member accommodating space. I do. With this configuration, the lens can be moved with a smaller driving force in the direction in which the lens is not fixed. As described later, when the lens needs to be driven in the focus direction and the tracking direction, the damper member is formed to have a shape long in a third direction orthogonal to both the focus direction and the tracking direction. By fixing both ends in the third direction to the base, the driving force for driving the lens in the focus direction and the driving force for driving the lens in the tracking direction can be reduced.

Further, it is preferable that the damper member has two protrusions formed at each end in the longitudinal direction, and the protrusions are fixed to the wall of the damper member accommodating space. When driving the lens, the amount of deformation of the damper member increases as it is closer to the portion fixed to the base. On the other hand, if the projection is provided and fixed to the base as in the present invention, the volume of the portion of the damper member where the amount of deformation is large can be reduced. Therefore, the driving force required for driving the lens can be reduced.

Further, the lens driving device according to the present invention has an opening in a main surface of the flat damper member, and the lens has an optical axis in the opening perpendicular to the main surface. It is characterized by being attached. By doing so, it is possible to prevent the damper member from blocking the laser beam that should pass through the lens or attenuating the amount of the laser beam.

Further, in the lens driving device according to the present invention, the driving means includes at least one driving unit including a pair of a driving coil and a magnet, and one of the driving coil and the magnet is a base in one driving unit. And the other is attached to the lens side, and the lens is driven in the predetermined direction by the interaction between the magnetic force generated by energizing the drive coil and the magnetic force of the magnet. Features. Thus, the lens held by the damper member can be driven in a predetermined direction without contact.

Here, it is preferable that a driving coil or a magnet attached to the base in one driving unit is separated from the damper member. If the damper member is in contact with the drive coil or magnet attached to the base side, friction occurs when the damper member deforms as the lens moves, and as a result, the drive for moving the lens Although extra force is required, as in the present invention, if these are separated from each other, the driving force for moving the lens can be reduced, so that the driving device can be further simplified, and Power consumption can also be reduced.

Further, in the lens driving device according to the present invention, the driving means includes first and second driving units whose driving directions are parallel to the optical axis of the lens, and the two driving units are driven by the driving unit. It is characterized in that it is arranged at a different position in a direction orthogonal to the direction. In such a configuration, it is possible to tilt-drive the lens in a predetermined direction by changing the driving force of the first and second driving units.

Further, in the lens driving device according to the present invention, the driving coil may include a first coil wound around a same core in a predetermined direction, and a first coil wound in a direction orthogonal to the winding direction of the first coil. And a wound second coil. Thereby, the installation space for the driving coil can be reduced, which contributes to downsizing of the device. Further, the lens driving device of the present invention has a housing for holding the lens,
The housing is held on the base via the damper member, whereby the lens is held movably with respect to the base.

Further, the optical pickup of the present invention is provided with a semiconductor laser device and a lens drive for driving a laser beam emitted from the semiconductor laser device on a recording surface of an optical storage medium in a predetermined direction. And an optical pickup comprising a light receiving element for receiving reflected light from the optical recording medium, wherein the lens driving device of the present invention is used as the lens driving means.

Further, the optical pickup of the present invention is provided with a semiconductor laser element and a lens drive for driving a laser beam emitted from the semiconductor laser element on a recording surface of an optical storage medium in a predetermined direction. Means, and a light receiving element for receiving light reflected from an optical recording medium, wherein the lens driving device of the present invention is used as the lens driving means, and a housing for holding a lens, The semiconductor laser element and the light receiving element are housed in a state of maintaining a fixed positional relationship with the lens. This makes it possible to obtain an optical pickup that is small and excellent in suppressing resonance.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a lens driving device and an optical pickup according to the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 is an external perspective view showing a configuration of a lens driving device 1 according to a first embodiment of the present invention.

As shown in FIG. 1, the lens driving device 1 holds the lens 2 on a rectangular frame base 15 via a damper member 20. The lens driving device 1 drives the lens 2 in the tracking direction and the focusing direction by using two sets of driving units 29 and 30. The drive unit 29 includes the magnet 5 and the drive coil 7, and the drive unit 30 includes the magnet 27 and the drive coil 25.

FIG. 2 is an assembly view of the lens driving device 1. The lens 2 is a resin molded lens. A pair of cutouts 4 are formed on the periphery 3 of the lens so as to face each other.
28 are provided respectively. A substantially rectangular parallelepiped magnet 5 is fitted into the notch 4. Further, a substantially rectangular parallelepiped magnet 27 is fitted into the notch 28, and the magnet 5 and the magnet 27 are held with their magnetic poles oriented in a predetermined direction.

The damper member 20 is formed in a plate shape from a silicone porous material. Silicone is a generic term for a semi-organic polymer having a siloxane bond as a main chain and an organic group such as a methyl group bonded to a silicon atom. The shape of the main surface of the damper member 20 is substantially H-shaped. An opening 19 having a diameter substantially equal to the diameter of the lens 2 is provided at the center of the main surface. Lens 2
Is arranged so that its optical axis is orthogonal to the main surface of the damper member 20 and passes through the opening 19. The peripheral portion 3 of the lens and the damper member 20 are fixed using an adhesive or the like. Rectangular fitting holes 10 and 21 are provided in the longitudinal direction of the damper member 20 with the opening 19 interposed therebetween. The magnet 5 is fitted into the fitting hole 10, and the magnet 27 is fitted into the fitting hole 21.

The T-shaped legs 9, 11, 22, and 23 formed at both ends in the longitudinal direction of the damper member 20 are respectively provided with grooves 12, 1 and 2 provided in the base 15 respectively.
4, 17, 18 are fitted. Thereby, the damper member 20 is firmly fixed to the base 15. A step 13 is provided between the grooves 12 and 14 on the inner edge of the base 15, and a step 16 is provided between the grooves 17 and 18. The drive coil 7 is installed on the step 13 so as to face the magnet 5, and the drive coil 25 is installed on the step 16 so as to face the magnet 27.

The driving coil 7 is composed of a focus coil 8 and a tracking coil 6 which are wound on a substantially rectangular parallelepiped core in directions orthogonal to each other. Similarly, the driving coil 25 is
And the tracking coil 26 are wound in directions orthogonal to each other. When the focus coils 8 and 24 are excited, magnetic effects are generated between the focus coil 8 and the magnet 5 and between the focus coil 24 and the magnet 27, respectively. By this magnetic action, the lens 2
Is driven in the focus direction. When the tracking coils 6 and 26 are excited, a magnetic effect also occurs, and the lens 2 is driven in the tracking direction.

The damper member 20 is made of a gel material. The gel material is specifically a silicone porous substance formed by filling a mold with a mixture of liquid silicone and a crosslinking agent and heating the mixture. The mixture is preliminarily mixed with a capsule made of an elastic substance having a diameter of 50 μm in which air is sealed therein.
Porosity.

The base 15 is formed by molding an aluminum alloy into a mold. FIG. 3 shows the lens driving device 1
FIG. 1 is a perspective view showing an example of an optical pickup equipped with a.
The optical pickup 31 is a so-called swing arm type optical pickup. The lens driving device 1 is mounted on a surface corresponding to the optical disk 35 at one end of the swing arm 32. At the other end of the swing arm 32,
A counter balance 34 is provided. The swing arm 32 is horizontally supported by a pivot 33. The swing arm 32 is rotated around a pivot 33 in a plane parallel to the optical disk 35 by a rotation drive mechanism (not shown), and traces a track of the optical disk 35.

FIG. 4 is a vertical sectional view of the optical pickup 31 in a plane including the alternate long and short dash line AA in FIG. 3, and particularly shows the configuration of the lens driving device 1 and the optical system members installed immediately below the lens driving device. ing. For the sake of simplicity, FIG. 4 particularly focuses only on the cross section, and the background is not shown. As shown in the figure, a concave portion in which optical elements such as a semiconductor laser device 36, a collimator lens 37, and a mirror 38 are stored is formed at the tip of the swing arm 32. The base 15 of the device 1 is fixed by an adhesive or the like.

The semiconductor laser device 36 is a known semiconductor laser device in which a semiconductor laser device as a light emitting device, a light receiving device as a signal detector, and a hologram optical device as a light branching device for branching incident light are integrated. is there. The optical elements of the semiconductor laser device 36, the collimator lens 37 and the mirror 38 are arranged as follows. That is, after the laser light emitted from the semiconductor laser device 36 is collimated by the collimator lens 37, the optical path is changed by the rising mirror 38, and the laser beam is applied to the lens 2 in a state where the principal ray and the optical axis of the lens 2 are almost coincident. It is arranged to be incident.

The laser light passing through the lens 2 is focused on the recording surface 39 of the optical disk 35. The laser light reflected on the recording surface 39 of the optical disc 35 returns to the semiconductor laser device 36 by traveling backward in the optical path. The reflected light is branched by a light branching element (not shown) in the semiconductor laser device 36 and received by the light receiving element. The light receiving element is
A focus error signal, a tracking error signal, and an information recording signal are generated according to the amount of received light, and output to a control device (not shown).

As described above, since the recording surface 39 is displaced due to surface deviation or eccentricity of the optical disk 35, the recording surface 3 is displaced.
In order to read the information recorded on 9 properly, it is necessary to make the focal point of the laser beam follow this displacement.
For this reason, the control device excites the focus coils 8 and 24 of the drive units 29 and 30 in accordance with the focus error signal generated by the semiconductor laser device 36, displaces the lens 2 by a predetermined amount in the focus direction, and focuses the laser light. Recording surface 3
9 is made to follow the displacement in the optical axis direction.

The controller also follows the track in the tracking direction by displacing the lens 2 in the tracking direction based on the tracking error signal, similarly to the displacement in the tracking direction of the recording surface 39. Let it. Damper member 2 holding lens 2
Since 0 can be elastically deformed in any direction, the displacement of the lens 2 can be performed smoothly. In addition, unnecessary vibration of the lens 2 is suppressed by the resonance suppressing effect due to the excellent vibration absorption of the silicone porous material itself, which is a material of the damper member 20, and the optical reading accuracy of the optical pickup 31 is extremely improved. Can be.

Further, Japanese Patent Application Laid-Open No. 7-1 mentioned as a prior art
In the lens driving device disclosed in Japanese Patent Laid-Open No. 05551, an elongated elastic support member for supporting a lens and a damper member for suppressing vibration of the elastic support member are required.
In the configuration of the present embodiment, since the lens 2 is directly held by the damper member 20, the number of parts of the support member can be reduced, and as a result, the lens driving device 1 can be downsized.

As described above, since the silicone porous material has not only a substantially uniform viscoelasticity in all directions but also excellent weather resistance and durability, another material is used as the damper member. The life of the lens driving device 1 can be extended as compared with the case. Further, since the softness and the like of the silicone porous material can be easily adjusted by the additive, the softness and the like of the damper member 20 are adjusted according to the characteristics of the lens driving device 1 such as the weight of the lens 2 and the magnets 5 and 27. There is also the advantage that you can.

Further, the silicone porous material can have other properties by adding additives. For example, by adding a thermally conductive filler to the silicone porous material to impart thermal conductivity to the damper member 20,
Even when a component of the optical pickup 31, for example, the lens 2 generates heat by the laser beam, the heat can be transmitted to other parts of the lens driving device 1, so that the efficiency of heat radiation and cooling can be improved as a whole.

In the present embodiment, the base 15 is an aluminum die cast formed by molding an aluminum alloy into a mold. However, a magnesium alloy, a resin, or the like may be used. <Second Embodiment> FIG. 5 is an external perspective view of an optical pickup 40 according to a second embodiment of the present invention. The lens 47 is made of resin, and its peripheral edge 46 is fitted and mounted on the steps 53 and 56 in a circular opening (see FIG. 6) provided on the upper surface of the housing 42. The housing 42 is held on a rectangular frame-shaped base 41 via a damper member 43 made of a porous silicone material.

A concave portion is provided at both ends in the longitudinal direction of the housing 42, and the magnets 45 and 48 are fitted into the concave portion. Drive coils 44 and 49 are fixed to the base 41 so as to face the magnets 45 and 48. The magnet 45 and the drive coil 44 constitute a drive unit 50, and the magnet 48
And the drive coil 49 constitute a drive unit 51. The drive coils 44 and 49 are formed by winding a focus coil and a tracking coil around the same core in a direction orthogonal to each other, similarly to the drive coils 7 and 25 in FIG.

FIG. 6 is a vertical sectional view of the optical pickup 40 taken on a plane including the alternate long and short dash line BB in FIG. As shown in the drawing, a light emitting / receiving integrated element 52 and a rising mirror 55 are stored in the housing 42. Integrated light receiving / emitting element 52
Is a device in which one light emitting element and a plurality of light receiving elements are integrated, and has a semiconductor laser element as a light emitting element. The rising mirror 55 has a reflection hologram surface 54.

The laser light emitted from the semiconductor laser element on the light receiving and emitting integrated element 52 is reflected by the reflection hologram surface 54 of the rising mirror 55 and is focused on the recording surface 58 of the optical disk 57 by the lens 47. The laser beam reflected by the recording surface 58 travels backward in the above-described optical path, is branched by the reflection hologram surface 54, and then enters the light receiving element on the integrated light receiving / emitting element 52.

A focus error signal, a tracking error signal, and an information recording signal are output based on the output from each light receiving element. The acquisition of these signals is a known technique, and a description thereof will be omitted. When the focus of the laser beam is displaced in the focus direction with respect to the recording surface 58, a focus error signal is output from the light receiving element. A current corresponding to the focus error signal is supplied to the drive unit 5
By flowing the focus coils 0, 51, the magnet 4
5 and 48 are driven in the focus direction. As a result, the housing 42 and, consequently, the lens 47 are driven in the focus direction, and the focal position of the laser beam can be adjusted. Even when the focal point of the laser light is displaced in the tracking direction with respect to the recording surface 58, the position of the optical path of the laser light can be adjusted in the same manner.

In the present embodiment, unlike the first embodiment, an optical member, that is, a light emitting / receiving integrated element 52,
The rising mirror 55 and the lens 47 are integrated into the housing 4.
2 is driven, so that the main beam of the laser beam and the lens 4
7 can be aligned. Therefore, even when the lens 47 is driven in the tracking direction, the deterioration of the amplitude of the tracking error signal and the offset do not occur, so that stable optical characteristics can be obtained. (Modifications) The present invention has been described based on the embodiments. However, it is needless to say that the present invention is not limited to the above-described embodiments. You can also.

(1) For an actuator utilizing electromagnetic force, an MC type (Moving Coi
l-type and MM type (Moving Magnet) with a magnet on the movable side
Type). In the first or second embodiment, the MM type configuration in which the magnets are all arranged on the movable side is used, but the MC type configuration may be adopted. However, the MC type has an advantage that the magnet is displaced almost in proportion to the amount of current flowing through the driving coil, so that control is easy. However, wiring for applying a current to the coil must be provided on the movable side. There is a disadvantage. Conversely, in the case of the MM type, it is not necessary to provide the wiring on the movable side, but there is a drawback that linearity is lacking.

(2) In order to correctly read the information on the optical disk, it is desirable that the recording surface thereof is orthogonal to the optical axis of the lens. Conventionally, a tilt error signal can be generated by detecting the tilt of the recording surface. In a modified example described below, the tilt of the lens is changed by the tilt error signal (hereinafter, referred to as “tilt drive”). It is a form suitable for the following.

That is, the lens drive unit of this modification has a total of four drive units 60 to 63 as shown in FIG. 7, and two sets of these drive units are arranged with the lens interposed therebetween. Have. In this configuration, the drive unit 6 opposed to the lens with the lens interposed therebetween
When different current amounts are applied to the focus coils by the drive units 0 and 61 and the drive units 62 and 63, torque is generated in a direction for rotating the lens about an axis parallel to the tracking direction, and the lens is tilt-driven in the direction. it can. Similarly, if the drive units 60 and 63 and the drive units 61 and 62 differ in the amount of current applied to the focus coil, the drive unit 60 and the drive unit 61 and the drive unit 61 and the drive unit 61 and the drive unit 61 and the drive unit 61 and the drive unit 61 and the drive unit 61 The lens can be tilt-driven. As described above, in the present modified example, the tilt drive can be performed about two axes orthogonal to each other, so that the tilt drive can be performed in an arbitrary direction. Can be followed. This is effective, for example, when the turntable of the optical disk makes a rubbing motion.

Generally, there are two sets of drive units whose driving directions are parallel to the optical axis of the lens, and if they are located at different positions in a direction orthogonal to the driving direction, it is necessary to change the driving forces of both. Thus, the lens can be tilt-driven in a predetermined direction. If the lens is disposed so as to sandwich the line passing through the center of the lens as described above, the efficiency of the tilt drive can be improved.

(3) In the first or second embodiment, the case where the light emitting element and the light receiving element are integrated is described, but the light emitting element and the light receiving element may be provided separately.
In this case, the optical path of the reflected light from the recording medium may be directed to the light receiving element by using a half mirror or a beam splitter. Further, an integrated element in which another optical element is integrated with the light receiving / emitting element may be used. Even in such a case, the effects of the present invention can be obtained. In the first embodiment, the optical system has an infinite system having a collimator lens in consideration of lens displacement. On the other hand, the second embodiment has a finite system configuration without a collimator lens. However, in any of the embodiments, the effects of the present invention can be obtained regardless of whether the optical system is an infinite system or a finite system.

(4) In the above embodiment, the base is driven by using the swing arm system. However, the base may be driven by using a linear motor system, or coarsely driven by a traverse motor. A traverse feed method may be used. When the lens is a resin molded lens in the first embodiment, the magnet fitted to the peripheral edge of the lens may be insert-molded integrally. Even with the MC type configuration, the drive coil can be insert-molded integrally with the lens.
Also in the second embodiment, the base may be made of resin, and the magnet or the driving coil may be integrally formed by insert molding.

As described above, by integrally molding the movable member, which is a lens or a base, and the drive member, which is a magnet or a drive coil, the apparatus can be manufactured at low cost and the positional accuracy of the drive member can be reduced. Can be secured stably, so that the lens drive characteristics and the like can be stabilized. (5) In the above embodiment, the damper member 20
Is made of a silicone porous material, but the effects of the present invention can be obtained by using a gel-like material containing silicone as a main material. Since the molecular structure of silicone can be adjusted by an additive, it is possible to adjust the vibration damping property and the cushioning property. As additives, there are organic and inorganic additives, and a method of adding an inorganic additive for the purpose of vibration control is known. In the above embodiment, the porous material is used. However, the effect of the present invention can be obtained depending on the additive even if the material is not porous.

Examples of gel-like substances include αGEL
(Geltech). αGEL is a gel material based on silicone and has a penetration (JIS K2530-19)
76-50g load) 50 to 200 material. αGEL
Exhibits extremely high shock absorption, vibration prevention and soundproofing effects in the range of penetration from 50 to 200. αGEL is adjusted to a special cross-linking state and molecular structure, thereby being excellent in self-retaining and restoring properties. The main feature is that the temperature dependency of vibration damping, shock absorption and sound insulation characteristics is small, so that it does not exhibit performance only at room temperature unlike other materials, and can maintain high performance over a wide temperature range . At the same time, it has stable properties such as heat resistance, cold resistance, weather resistance and safety.

In addition to the silicone, as the damper member 20, a vibration-proof rubber (urethane-based high damping rubber,
Polynorbornene rubber, polyisobutyl rubber, natural rubber, EPDM (Ethlen-Propylen-Dien-Monomer) rubber and the like may be used. (6) In the above embodiment, the base is provided with a groove, and the leg of the damper member is fitted into the groove. Alternatively, the base may be fixed by bonding with an adhesive or the like. Good.

[0051]

As described above, according to the lens driving device of the present invention, the lens is held on the base via the damper member having viscoelasticity in all directions, and the vibration of the viscoelastic member is Due to the suppression action, vibration in all directions of the lens can be effectively suppressed. By applying this device to the drive of the objective lens of an optical pickup, it is possible to prevent unnecessary vibration from occurring in the optical system, and to read / write information with high precision from an optical recording medium. realizable.

Further, since the lens is directly held on the base via the damper member, the lens of the apparatus is compared with a conventional case where the lens is held in a cantilever state by a plurality of wire-like elastic supporting members. The size can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a lens driving device according to a first embodiment of the present invention.

FIG. 2 is an assembly diagram of the lens driving device according to the first embodiment of the present invention.

FIG. 3 is a perspective view illustrating a configuration of an optical pickup equipped with the lens driving device according to the first embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a configuration of a main part of an optical pickup equipped with the lens driving device.

FIG. 5 is a perspective view illustrating a configuration of an optical pickup according to a second embodiment of the present invention.

FIG. 6 is a longitudinal sectional view illustrating a configuration of an optical pickup according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a configuration of a modified example of the lens driving device according to the present invention.

[Explanation of symbols]

1, 59 lens drive device 2, 47 lens 5, 27, 45, 48 magnet 6, 26 tracking coil 7, 25, 44, 49 drive coil 8, 24 focus coil 29, 30, 50, 51, 60 to 63 drive Units 20, 43 Damper members 15, 41 Base 31, 40 Optical pickup 32 Swing arm 33 Pivot 34 Counter balance 35, 57 Optical disk 36 Semiconductor laser device 37 Collimator lens 38, 55 Start-up mirror 39, 58 Recording surface 42 Housing 52 Light emitting / receiving integrated device 54 Reflection hologram surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazutoshi Onozawa 1-1, Yukicho, Takatsuki-shi, Osaka Matsushita Electronics Corporation Incorporated (72) Inventor Hideyuki Nakanishi 1-1, Yukicho, Takatsuki-shi, Osaka Matsushita Electronics 5D118 AA01 AA08 AA21 AA23 CD02 CD03 CD04 CG39 DC03 EA02 EA03 EB13 EB15 EC04 ED05 EF02 EF07 FA25 FA34 FB03 FB04 FB19

Claims (13)

[Claims] 1. A lens driving device for driving a lens movably held with respect to a base in a predetermined direction by driving means, wherein the lens is provided via a damper member made of a viscoelastic material. A lens driving device, being held by the base. 2. The lens driving device according to claim 1, wherein the material having viscoelasticity in all directions is a gel material. 3. The lens driving device according to claim 2, wherein the gel material is mainly made of silicone. 4. The base has a damper member accommodating space, and the damper member is formed in a flat plate shape, and is fixed to a wall portion of the damper member accommodating space at both ends in the longitudinal direction. The lens driving device according to any one of claims 1 to 3, wherein: 5. The damper member has two protrusions formed at each end in the longitudinal direction, and is fixed to the wall of the damper member accommodating space at the protrusions. The lens driving device according to claim 4. 6. The flat damper member has an opening in a main surface thereof, and the lens is attached to the opening so that an optical axis thereof is substantially perpendicular to the main surface. The lens driving device according to claim 4, wherein: 7. The drive means includes at least one drive unit comprising a set of a drive coil and a magnet, wherein one of the drive coil and the magnet in one drive unit is attached to the base and the other is provided. Is attached to the lens side, and is configured to drive the lens in the predetermined direction by an interaction between a magnetic force generated by energizing the driving coil and a magnetic force of the magnet. Item 7. A lens driving device according to any one of Items 6. 8. The lens driving device according to claim 7, wherein a driving coil or a magnet attached to the base side in one driving unit is separated from the damper member. 9. The driving unit includes first and second driving units whose driving directions are parallel to an optical axis of the lens,
9. The lens driving device according to claim 7, wherein the two driving units are arranged at different positions in a direction orthogonal to the driving direction. 10. A driving coil comprising: a first coil wound in a predetermined direction on the same core; and a second coil wound in a direction orthogonal to the winding direction of the first coil. The lens driving device according to any one of claims 7 to 9, wherein the lens driving device comprises: 11. A housing for holding a lens, wherein the housing is held on the base via the damper member, whereby the lens is held movably with respect to the base. The lens driving device according to any one of claims 1 to 10, wherein: 12. A semiconductor laser device, lens driving means for converging a laser beam emitted from the semiconductor laser device on a recording surface of an optical storage medium, and driving the lens in a predetermined direction; 12. A light pickup device comprising: a light receiving element that receives reflected light of claim 1; and wherein the lens driving device according to claim 1 is used as the lens driving unit. pick up. 13. A semiconductor laser device, a lens driving means for mounting a lens for condensing laser light emitted from the semiconductor laser device on a recording surface of an optical storage medium and driving the lens in a predetermined direction, and An optical pickup comprising: a light receiving element that receives reflected light of the semiconductor laser device; wherein the lens driving device according to claim 11 is used as the lens driving means, and the semiconductor laser device is provided in a housing according to claim 11. An optical pickup, wherein the light receiving element and the light receiving element are housed in a state of maintaining a fixed positional relationship with the lens.