JPH0358330A - Objective lens driver - Google Patents

Abstract

PURPOSE:To perform the smooth displacement of a lens bobbin without being pressurized on a supporting shaft in any direction by comprising the connecting part of the lens bobbin of at least a pair of displacement parts provided obliquely to its displacing direction. CONSTITUTION:When the lens bobbin 3 is displaced in a direction of arrow head F i.e. a focusing direction, the displacing arms 17c, 17d and 17a, 17b of a damper member 14 are displaced so as to be extended or compressed, however, an elastic force is off set in the direction of the supporting shaft 5, thereby, no pressurizing force is applied on the shaft 5. Also, even when a driving current based on a tracking error signal flows on a tracking cell 10 and an objective lens 2 is displaced rotatably in a direction of arrow head T around the shaft 5, the connecting part 14c of the member 14 is displaced elastically in a direction in parallel with a pedestal 1, therefore, no contact with pressure of the bobbin 3 to the supporting shaft 5 occurs. Therefore, the bobbin 3 can be displaced smoothly in any direction against the supporting shaft 5, and the read/write of an information signal can be accurately performed.

Description

[Detailed Description of the Invention] A. INDUSTRIAL APPLICATION FIELD The present invention relates to an objective lens drive device used in an optical pick amplifier device and the like, which supports an objective lens and drives the objective lens to be displaced in two axial directions.

B. Summary of the Invention The present invention has a lens bobbin that is pivotally supported by a support shaft so as to be freely displaceable in the axial direction and rotational direction, and the lens bobbin is supported in an objective lens drive device used in an optical pink-up device or the like. A damper member is used, which includes a supporting part, a fixing part, and a connecting part that connects the supporting part and the fixing part and can be elastically displaced in accordance with the displacement of the lens bobbin.
The connecting portion of the damper member is constituted by at least a pair of displacement portions that are inclined with respect to the direction in which the lens bobbin is elastically displaced by displacement, and has a shape that is approximately rotationally symmetrical with respect to a line connecting the fixed portion and the support portion. By doing so, even when the lens bobbin is displaced, the elastic force of the damper member is prevented from acting as a pressing force between the lens bobbin and the support shaft, and the lens bobbin is smoothly displaced to improve the information signal. This allows accurate writing and/or reading.

C. 2. Description of the Related Art Conventionally, an optical pickup device has been used to write and/or read information signals to and from an optical disk, which is an optical recording medium. This optical pickup device uses an objective lens to focus a light beam onto a recording track formed on a signal recording surface of the optical disc.

In this optical pickup device, an objective lens is used to accurately focus the light beam onto the recording track even if so-called surface wobbling or eccentricity occurs due to rotational operation of the optical disc. A drive device is used.

That is, this objective lens driving device is configured to drive the objective lens to follow the surface deflection and eccentricity of the optical disk.

As shown in FIG. 11, this objective lens driving device includes a lens bobbin 1 to which an objective lens 101 is attached.
02, and the lens bobbin 10 set up on the base 103.
A support shaft 1 that pivots 2 in a movable manner in the axial direction and rotational direction.
04 and a magnetic circuit 105 for displacing and driving the lens bobbin 102 has been proposed.

The lens bobbin 102 is formed into a substantially cylindrical shape, and has a support hole 106 formed along its central axis into which the support shaft 104 is inserted. The objective lens 101 is attached to the upper surface of the lens bobbin 102 at a position offset from the central axis of the lens bobbin 102. This lens bobbin 102 has the support shaft 10 in the support hole 106.
4 is pushed through, it is pivotally supported so as to be movable in two directions: the axial direction of the support shaft 104 and the direction of rotation around this support shaft 104.

A focus coil 107 is wound around the circumferential surface of the lens bobbin 102, and a pair of tracking coils 108 wound in a substantially rectangular shape are attached.

The magnetic circuit l05 is constructed on the base 103, with a pair of focus drive magnets 109 facing the focus coil 107, and a pair of tracking drive magnets 110 facing the tracking coil 108. It is being organized. The focus drive magnet 109 is connected to the lens pobin 10.
It is shaped like an arc with a curvature that approximately corresponds to the circumferential surface of 2.

Further, the tracking drive magnet 110 includes a yoke 110a shaped like an arc having a curvature approximately corresponding to the circumferential surface of the lens bobbin 102, and the yoke l10a.
and a pair of magnets 110b attached to the side surface facing the lens bobbin 102.

These focus and tracking drive magnets}1
The magnetic fluxes generated by 09 and 110 are interlinked with the focus coil 107 and the tracking coil 10.

Therefore, by supplying a predetermined focus drive current and a tracking drive current to each of the coils 107 and 108, the lens bobbin 102 is driven to be displaced in the axial direction and rotational direction with respect to the support shaft 104,
The objective lens Lot is displaced and driven in the focusing direction shown by arrow r in FIG. 11 and in the tracking direction shown by arrow t in FIG.

A damper member 111 is used in this objective lens drive device. This damper member 111 is
The fixing part 111a and the supporting part 11lb are made of a material that is flexible and has an appropriate internal loss of vibration, such as silicone rubber or butyl rubber, and is used to connect the fixing part 111a and the supporting part 11lb. Part 11
1C and is formed into a flat plate shape. The above connection part 1
11c is composed of a pair of displacement arm parts 111d and lle that are symmetrical about a line connecting the fixed part 111a and the support part 11lb. The damper member 111 is arranged so as to be substantially parallel to the base 103, with the fixing part 111a attached to the base 103 and the support part 11lb attached to the lens bobbin 102. This damper member 111 holds the lens pobbin 102 at a neutral position when no driving current is supplied to each of the coils 107 and 108. The damper member 111 provides appropriate damping to vibrations of the lens bobbin 102 when a predetermined drive current is supplied to each of the coils 107 and 108 and the lens bobbin 102 is displaced. ,
Abnormal vibrations such as low frequency resonance and partial resonance are prevented.

This objective lens driving device includes each of the above-mentioned coils 107.10.
By supplying a focus drive current based on a focus error signal and a tracking drive current based on a tracking error signal to 8, the objective lens 101 is displaced and driven so as to follow the surface wobbling and eccentricity of the optical disk. The light beam is always focused on the recording track of the optical disk, so that accurate writing and/or reading of information signals can be performed. D.
Problems to be Solved by the Invention By the way, in the objective lens drive device as described above, when the lens bobbin 102 is displaced, the damper member 111 is elastically displaced, and the elastic force of the damper member 111 is applied to the lens bobbin 102. This may act as a pressing force between the inner surface of the support hole 106 and the circumferential surface of the support shaft 104.

When the lens bobbin 102 is displaced so as to rotate around the support shaft 104, as shown in FIG.
Since d and llle are displaced so that one is stretched and the other is compressed, the division of the elastic force of this damper member 111 in the direction toward the support shaft 104 cancels each other out, and the elasticity of this damper member 111 is The generated force does not act as a pressing force on the support shaft 104.

However, the lens bobbin 102 is
When the displacement arm 111d111e is displaced in the axial direction of 4, as shown in FIG. These displacement arm portions 111d. The elastic force of
It acts in 4 directions.

In this way, when the elastic force of the elastically displaced damper member 111 acts in the direction of the support shaft 104, the support hole 10
6 and the circumferential surface of the support shaft 104 are in pressure contact with each other. When the inner surface of the support hole 106 and the circumferential surface of the support shaft 104 are pressed against each other, the frictional force between them increases, and there is a possibility that the lens bobbin 102 may not be smoothly displaced and driven. Accurate writing and/or reading of signals becomes impossible.

Therefore, the present invention is proposed in view of the above-mentioned circumstances, and the lens bobbin, which is pivotally supported by a support shaft so as to be movable in the axial direction and rotational direction of the support shaft, can be displaced in any direction. It is an object of the present invention to provide an objective lens drive device that allows the lens bobbin to be smoothly displaced and driven even when the lens bobbin is in use.

E. Means for Solving the Problems In order to solve the above-mentioned problems and achieve the above-mentioned objects, an objective lens driving device according to the present invention includes a support shaft mounted on a base;
A lens bobbin to which an objective lens is attached and supported by the support shaft so as to be freely displaceable in the axial direction of the support shaft and in a direction around the axis of the support shaft, a fixed part supported by the base, and the lens bobbin. and a connecting portion that connects these fixing portions and the supporting portion and is elastically displaceable in accordance with displacement of the lens bobbin, the connecting portion of the damper member is configured to support the lens bobbin. It consists of at least a pair of displacement parts provided obliquely with respect to the direction of elastic displacement due to the displacement of the displacement part, and is formed in a rotationally symmetrical shape with a line connecting the fixed part and the support part as sleeves. That's what happens.

F. Function In the objective lens driving device according to the present invention, the connecting portion that connects the fixed portion and the supporting portion of the damper member and is elastically displaceable by the displacement of the lens bobbin is elastically displaced in the direction in which the connecting portion is elastically displaced by the displacement of the lens bobbin. The lens bobbin is formed of at least a pair of displacement parts provided at an angle with respect to the lens bobbin, and is rotationally symmetrical with respect to a line connecting the fixed part and the support part. In the state of being displaced both in the axial direction and in the periaxial direction with respect to the support shaft, the elastic forces generated in the pair of displacement parts cancel each other out in the direction toward the support shaft.

G. EXAMPLES Hereinafter, specific examples of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the objective lens driving device according to the present invention has a base l, and a lens bobbin 3 on which an objective lens 2 is attached moves the objective lens 2 in two axial directions. It is pivotably supported so that it can be freely displaced. Further, a magnetic circuit 4 for displacing and driving the lens bobbin 3 is arranged on the base l.

The base 1 is formed into a substantially rectangular flat plate shape using a predetermined material such as a highly permeable material. This base 1 is mounted on an optical block (not shown) of an optical pickup device that writes and/or reads information signals on an optical disc. The base 1 is provided with a light beam through hole 1a through which the light beam emitted from the optical block section and incident on the objective lens 2 passes.

A support shaft 5 for pivotally supporting the lens bobbin 3 is installed approximately at the center of the base 1.

This support shaft 5 is formed into a cylindrical shape from a predetermined material such as metal. This support shaft 5 has a predetermined surface treatment applied to the circumferential surface to reduce friction.

The lens bobbin 3 includes a cylindrical shaft portion 3a and a disk-shaped top portion 3 connected to the upper end of the shaft portion 3a.
b, and an outer circumferential portion 3C formed in a cylindrical shape that is connected so as to hang down from the periphery of the top plate portion 3b and is coaxial with the shaft portion 3a.
It consists of These shaft portion 3a, top plate portion 3b and outer peripheral portion 3
c is integrally formed of a lightweight material such as aluminum or synthetic resin.

A support hole 6 having an inner diameter corresponding to the outer diameter of the support shaft 5 is bored in the shaft portion 3a along the axis of the shaft portion 3a. The support shaft 5 is inserted into the support hole 6, and the lens pobin 3 is supported by the support shaft 5 such that it can be freely displaced in the axial direction of the support shaft 5 and in the direction of rotation around the support shaft 5. That is, the circumferential surface of the support shaft 5 and the inner circumferential surface of the support hole 6 are slidable.

The top plate portion 3b is provided with an objective lens mounting hole 7 and a pair of yoke insertion holes 8a and 8b. The objective lens 2 is fitted into the objective lens attachment hole and attached by bonding using an adhesive or the like. The objective lens 2 is made of a predetermined material such as transparent resin or glass. This objective lens 2 has the above-mentioned support shaft 5.
Objective lens mounting hole 7 of lens bobbin 3 pivotally supported on
By being attached to the support shaft 5, the optical axis is made parallel to the support shaft 5, and it is supported so as to be located above the light beam through hole 1a. The pair of yoke insertion holes 8a,
8b is formed into a substantially fan shape with the shaft portion 3a at the center, and a pair of inner yokes 12a and 12b, which will be described later, are inserted therethrough correspondingly.

A focus coil 9 is provided on the outer circumferential side of the outer circumferential portion 3c of the lens bobbin 3 so as to be wound around the outer circumferential surface of the outer circumferential portion 3c. Furthermore, two pairs of tracking coils 10 are attached to the outside of the focus coil 9, which are wound into a substantially rectangular shape. Each of these tracking coils 10 is connected to each of the above-mentioned yoke insertion holes 8a, 8.
They are attached in pairs corresponding to the positions b.

The magnetic circuit 4 includes a pair of outer yokes ll on the base 1.
a, llb, a pair of inner yokes 12a, 12b, and a pair of magnets 13a, 13b. Each of the outer yokes lla and 11b is made of the same material as the base 1 and is formed into an arc shape. These outer yokes
la and llb are mounted on the base 1 on both sides of the lens bobbin 3, which is pivotally supported on the support shaft 5, so as to face each other along the arc of the outer peripheral surface of the outer peripheral part 3c. Each of the inner yokes 12a and 12b is made of the same material as the base 1 and is formed into an arc shape. These inner yokes 12a, 12b are connected to each of the outer yokes lla. It is mounted on the base 1 between the support shaft 5 and the support shaft 5, and corresponds to the yoke insertion holes 8a and 8b of the lens bobbin 3 supported by the support shaft 5. The pair of magnets l3a and 13b are connected to each outer yoke 11.
It is formed into an arc shape corresponding to the inner circumferential surface of the outer yokes lla and llb, and is attached to the inner circumferential surface of the outer yokes lla and llb, respectively, along the inner circumferential surface. That is, these magnets}13a. 13b, the focus coil 9 is attached to the outer peripheral side of the lens bobbin 3 which is pivotally supported on the support shaft 5.
and is arranged to face the tracking coil 10 with a predetermined gap in between.

The magnetic flux emitted from each of the magnetic nodes l3a and 13b is transmitted to the corresponding outer yoke 11a. 1lb, the base 1 and the corresponding inner yoke 12a. 12b to each magnet}13a
, 13b. That is, the gap between one magnet 13a and one inner yoke 12a, and the gap between the other magnet 13b and the other inner yoke 12b.
The gaps between the two are respectively magnetic gear knobs. Within these magnetic gaps, a portion of the focusing coil 9 and the conducting wires of the respective tracking coils 10 are located perpendicular to the base 1.

That is, in this objective lens drive device, when a predetermined focus drive current is supplied to the focus coil 9, the focus coil 9 receives a drive force from the magnetic flux in each of the magnetic gaps, and the focus coil 9 receives the drive force from the magnetic flux in each of the magnetic gaps, and the focus coil 9 receives a driving force from the magnetic flux in each of the magnetic gaps. As shown by arrow F in FIG. 1, the objective lens 2 is
It is displaced in the axial direction of the support shaft 5, that is, in the focus direction. Further, when a predetermined tracking drive current is supplied to the tracking coil 10, the tracking coil 10 receives a driving force from the magnetic flux in each of the magnetic gaps, and moves the lens bobbin 3 around the support shaft 5. Displace it in the direction of rotation. At this time, the objective lens 2 is displaced in the circumferential direction around the support shaft 5, that is, in the tracking direction, as shown by arrow T in FIG.

By the way, a cable is provided between the base 1 and the lens bobbin 3 to hold the lens bobbin 3 in a neutral position and to prevent resonance etc. of the lens bobbin 3 which is displaced and driven by the magnetic circuit 4. A damper member l4 is attached.

As shown in FIGS. 1 and 2, this damper member 14 has a fixed portion 14a that is attached to and supported by the base 1.
, a support portion l4b that is attached to the lens bobbin 3 and supports the lens bobbin 3, and these fixing portions 14a.
and a connecting part 14c that connects the supporting part 14b,
Because of elastic materials such as so-called silicone rubber and butyl rubber, It is integrally formed by means such as molding.

The fixing portion 14a is formed into a flat plate shape, and is provided with a pair of attachment holes 14d. This fixing part 14a has fixing screws 15b pushed through the pair of attachment holes 14d, and these fixing screws 15b are connected to a pair of support pins planted on the substrate 1 at positions on both sides of the support shaft 5. 1
5a, it is attached to each of the support pins 15a.

The support portion 14b is formed in a substantially annular shape with a mounting hole 14e in the center. This support portion 14b is attached to the top plate portion 3 of the lens bobbin 3 in the attachment hole 14e.
A support bin 16a erected on the lower surface side of the support bin 16a is inserted through the support bin 16a, and a fixed wafer 16b is fitted to the tip of the support bin 16a, thereby being attached to the support bin 16a.

The connecting portion 14c has first to fourth displacement arms 17a17b and 17c, each having approximately the same shape, forming two pairs of displacement portions.
, 17d. This connecting portion 14c is
When the lens bobbin 3 is displaced to displace the objective lens 2 in the focus direction and the tracking direction, each of the displacement arms 17a17b, 17c, and 17d is elastically displaced by the lens bobbin 3, thereby causing the base plate to move. It is elastically displaced in two directions: a direction parallel to the base 1 and a direction perpendicular to the base 1. Each of the displacement arms 17a, 17b, 17c, 17d is shown in FIGS.
As shown in the figure, in the two directions in which the connecting portion 14c is elastically deformed with the displacement of the lens bobbin 3, a fifth
As shown by θ1 and θ2 in the figure, it is formed with an inclination of approximately 45''.In addition, each of these displacement arms L7a
, 17b, 17c, and 17d are a first displacement arm 17a and a third displacement arm 17c, and a second displacement arm 17b and a fourth displacement arm, which face each other via a line connecting the fixed part 14a and the support part 14b. The displacement arms l7d are formed in pairs.

That is, the connecting portion 14c has a shape that is rotationally symmetrical about the line connecting the fixed portion 14a and the supporting portion 14b when the lens bobbin 3 is in a neutral position and the connecting portion 14c is not elastically displaced. ing.

In the objective lens drive device according to the present invention configured as described above, when a focus drive current based on a focus error signal is supplied to the focus coil 9,
The objective lens 2 is displaced and driven to follow the surface play of the optical disc being rotated, and the light beam focused by the objective lens 2 is always focused on the signal recording surface of the optical disc.

In this objective lens drive device, when the objective lens 2 is displaced in the focus direction, the connecting portion 14c of the damper member 14 moves in a direction perpendicular to the base 1, as shown in FIGS. 3 and 6. is elastically displaced.

When the lens bobbin 3 is displaced in a direction away from the base 1 as shown by arrow F in FIG.
the third and fourth displacement arms 17c,
The first and second displacement arms 17a. 17
b is displaced so that it is compressed. At this time, the elastic force of each of these displacement arms 17c, 17d, 17a, and 17b is such that the displacement arms are displaced in a stretched manner and are compressed in the direction toward the support shaft 5. and the displacement arm cancel each other out.

Similarly, when the lens bobbin 3 is displaced in the direction approaching the base 1, each of the displacement arms 17c, 17d
．． The elastic forces of 17a and 17b are canceled out by the displacement arm that is displaced in a stretched manner and the displacement arm that is displaced in a compressed manner in the direction toward the support shaft 5. Therefore, in this objective lens driving device, even if the lens bobbin 3 is displaced in the focus direction, the lens bobbin 3 is not pressed against the support shaft 5.

In this objective lens driving device, as shown in FIG. 6, the lens bobbin 3 is moved within a range until the displacement arms, which are compressed and displaced by the displacement of the lens bobbin 3, become substantially in a straight line with each other. When it is displaced, the elastic force in the direction toward the support shaft 5 is offset as described above.

Further, in this objective lens drive device, when a tracking drive current based on a tracking error signal is supplied to the tracking coil 10, the objective lens 2
is displaced and driven to follow the eccentricity of the optical disk being rotated, and the light beam focused by the objective lens 2 is always focused on a recording track formed on the signal recording surface of the optical disk. .

In this objective lens driving device, when the objective lens 2 is displaced in the tracking direction, as shown in FIGS.
As shown in the figure, the connecting portion 14c of the damper member l4 is elastically displaced in a direction parallel to the base 1.

When the lens bobbin 3 is displaced in one direction as shown by the arrow T in FIG. 4, the objective lens 2 is displaced in one direction from the neutral position shown by the dashed line N in FIG. The first and fourth displacement arms 17a, 1
7d is displaced so as to be stretched, and the second and third displacement arms 17b, 17c on the other side are displaced so as to be compressed. At this time, the elastic force of each of these displacement arms 17c, 17d, 17a, 17b is different from the displacement arm which is displaced in a stretched manner and the displacement arm which is displaced in a compressed manner regarding the precepts in the direction toward the support shaft 5. and cancel each other out.

Similarly, when the lens bobbin 3 is displaced so as to displace the objective lens 2 in the other direction, the elastic force of each displacement arm 17c, 17d, 17a, 17b is controlled in the direction toward the support shaft 5. , the displacement arm displaced in a distraction manner and the displacement arm displaced in a compression manner cancel each other out. Therefore, in this objective lens driving device, even if the lens bobbin 3 is displaced so as to displace the objective lens 2 in the tracking direction, the lens bobbin 3 is not pressed against the support shaft 5.

In this objective lens driving device, as shown in FIG. 7, the lens bobbin 3 is displaced within a range until the displacement arms, which are compressed and displaced by the displacement of the lens bobbin 3, become substantially in a straight line with each other. When the
As described above, the elastic force in the direction toward the support shaft 5 is offset.

Note that in the objective lens driving device according to the present invention, each of the displacement arms 17a. The angle of inclination of the connecting portions 14c of the connecting portions 17b and 17d with respect to the direction in which they are elastically displaced is not limited to approximately 45'';
can be changed as appropriate based on the amount of displacement.

Further, in the objective lens driving device according to the present invention, the damper member 14 is a connecting portion consisting of two pairs of displacement portions, as in the above-mentioned embodiment! 4c, as shown in FIG.
It may also have c. The connecting portion 14c has first and second displacement arms 18a, which are a pair of displacement portions, each of which is inclined with respect to the direction in which the connecting portion 14c is displaced by the lens bobbin 3. Consisting of 18b.

Also in the objective lens drive device configured using the damper member 14 formed in this way, the lens bobbin 3
When is displaced, the elastic force of each of the displacement arms 18a, 18b in the direction toward the support shaft 5 is canceled out, and the lens pobin 3 is not pressed against the support shaft 5.

Furthermore, in the objective lens driving device according to the present invention, the displacement part forming the connection part 14c of the damper member 14 is not limited to the displacement arm as in the above-described embodiment, but as shown in FIGS. 9 and 10. , the fixing part 14a and the support 1
It may be two pairs of displacement plates 19a, 19b 19c 19d or a pair of displacement plates 20a20b that are joined to each other on the line connecting 4b. These displacement plates are arranged such that the displacement plates facing each other via a line connecting the fixed part 14a and the support part 14b form a pair, and the connecting part 1
4c is inclined with respect to the direction in which the lens bobbin 3 is displaced. Even in the objective lens driving device configured using the damper member 14 formed with a temporary displacement as described above, when the lens bobbin 3 is displaced,
The two pairs of displacement plates 19a, 19b. 19c. 19d or a pair of displacement plates 20a. The component of the elastic force of the elastic force 20b in the direction toward the support shaft 5 is canceled out, and the lens bobbin 3 is not pressed against the support shaft 5.

H. Effects of the Invention As described above, in the objective lens driving device according to the present invention, the connecting portion that connects the fixed portion and the supporting portion of the damper member and is elastically displaceable due to the displacement of the lens bobbin can be elastically displaced by the displacement of the lens bobbin. It is comprised of at least a pair of displacement parts provided obliquely with respect to the direction of elastic displacement, and is formed in a shape that is rotationally symmetrical about a line connecting the fixed part and the support part.

Therefore, even when the lens bobbin is displaced both in the axial direction and in the periaxial direction with respect to the support shaft that supports the lens bobbin, the elastic force generated in the pair of displaced parts is directed toward the support shaft. They cancel each other out regarding the precepts of direction. Therefore, in this objective lens driving device, even if the lens bobbin is displaced in any direction, the lens bobbin is not pressed against the support shaft, and the lens bobbin can be smoothly moved against the support shaft. It can be displaced.

That is, in the present invention, even when the lens bobbin, which is pivotally supported by the support shaft so as to be freely displaceable in the axial direction and around the axis, is displaced in any direction, the lens bobbin can be smoothly displaced and driven. Accordingly, it is possible to provide an objective lens driving device that can accurately write and/or read information signals.

4

[Brief explanation of drawings]

FIG. 1 is a partially exploded perspective view showing the structure of the objective lens drive device according to the present invention, and FIG. It is a perspective view which expands and shows the shape of the damper member which was made into a structure. FIG. 3 is an enlarged longitudinal cross-sectional view showing a state in which the lens bobbin of the objective lens drive device is displaced in the axial direction of the support shaft, and FIG. FIG. 3 is an enlarged cross-sectional view showing a state in which the device is displaced in a direction around the axis. FIG. 5 is an enlarged rear view showing the state of the damper member, which is a main part of the objective lens driving device, in a neutral position, and FIG. 6 is a state in which the damper member is displaced in the axial direction of the support shaft. FIG. 7 is an enlarged rear view showing a state in which the damper member is displaced in a direction around the axis of the support shaft. FIG. 8 is an enlarged perspective view showing the shape of a damper member in which the displacement portion is configured as a pair of displacement arms, and FIG. 9 is a perspective view showing the damper member in which the displacement portion is configured as two pairs of displacement plates. FIG. 10 is an enlarged perspective view showing the shape of a damper member whose displacement portion is a pair of displacement plates. FIG. 11 is a partially exploded perspective view showing the structure of the conventional objective lens drive device, and FIG. 12 is a schematic diagram showing the state of displacement of the damper member of the conventional objective lens drive device in the tornoking direction. FIG. 13 is a side view schematically showing the displacement state of the damper member of the conventional objective lens driving device in the focus direction. l・・・・・・・・・・・・・・・ 2・・・・・・・・・・・・・・・ 3・・・・・・・・・・・・・・・・ 6・・・・・・・・・・・・・・・・・ 1 4・・・・・・・・・・・・・・・14a・・・・
・・・・・・・・・ 14b・・・・・・・・・・・・ 14c・・・・・・・・・・・・ 17a・・・・・・・・・・・・・ 17b・・・・・・・・・・・・・・・ 17c・・・・・・・・・・・・ Base objective lens lens bobbin support hole damper member fixing part support part connecting part first displacement arm Second displacement arm Third displacement arm d・・・・・・・・・・・・ a ●●−−●――●●●●●● b・・・・・・・・・・・・・・ a ●●●●−◆−−◆●●●− b・・・・・・・・・・・・・ C Rumor●●Skewer●●◆●Tube−●●−d・・・・・・・・・・・・・・・ a---●●self-◆●Rumor da●● b・・・・・・・・・・・・ Fourth displacement arm First displacement arm Second displacement Arm First displacement plate Second displacement plate Third displacement plate Fourth displacement plate First displacement plate Second displacement plate

Claims (1)

[Scope of Claims] A support shaft is installed on a base, and an objective lens is attached to the support shaft, and the support shaft is pivotally supported by the support shaft so as to be freely displaceable in the axial direction of the support shaft and in the direction around the axis of the support shaft. a lens bobbin supported by the base, a support part that supports the lens bobbin, and a connecting part that connects these fixed parts and the support part and is elastically displaceable in accordance with displacement of the lens bobbin. and a damper member, the connecting portion of the damper member being comprised of at least a pair of displacement portions provided at an angle with respect to the direction in which the lens bobbin is elastically displaced by the displacement of the lens bobbin, An objective lens driving device formed in a rotationally symmetrical shape with respect to a line connecting the part and the support part.