Vibration damping actuator, and lens unit and camera equipped therewith

Abstract

The present invention provides a vibration-damping actuator that can reduce the risk of damage to movable parts, etc., when subjected to strong impact forces or the like. [Solution] The present invention provides a vibration-damping actuator (10) comprising a fixed part (12), a movable part (14), a movable part drive mechanism, and a movable part support mechanism (18) that supports the movable part so as to be movable relative to the fixed part, wherein the movable part support mechanism comprises a guide shaft (18c) attached to one of the fixed part or the movable part so as to extend in a plane perpendicular to the optical axis, and a shaft receiving mechanism provided on the other of the fixed part or the movable part so as to engage with the guide shaft, wherein the shaft receiving mechanism comprises a support shaft (18a) provided so as to extend in a plane perpendicular to the optical axis, and a roller (18b) that is rotatable with respect to the support shaft and slidable in the axial direction of the support shaft, and rotates in engagement with the guide shaft.

Description

Technical Field

[0001] The present invention relates to a vibration-proof actuator, and particularly to a vibration-proof actuator for moving an anti-shake lens, a lens unit provided with the same, and a camera.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2021-15187 (Patent Document 1) describes an anti-shake device, a lens device provided with the same, and a camera system. This anti-shake device has a shift lens barrel as a movable member and a base member as a fixed member, and by moving the shift lens barrel with respect to the base member within a plane orthogonal to the optical axis, the anti-shake lens attached to the shift lens barrel is moved to suppress the shake of the image focused on the imaging surface. And three rolling balls are sandwiched between the shift lens barrel and the base member, and the shift lens barrel is supported movably within a plane orthogonal to the optical axis by the rolling of these rolling balls.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the vibration correction device described in Patent Document 1, the movable part (shift lens barrel) is supported by three rolling balls, so the movable part can be moved in any direction with very little force relative to the fixed part (base member). While this ability to move the movable part with little force is advantageous for moving the movable part using the thrust of the movable part drive mechanism, it also presents a problem in that oscillation occurs when moving the movable part by feedback control, leading to unstable control. Furthermore, if the movable part is supported to move with very little force, when a strong impact force is applied to a camera containing a vibration damping actuator (vibration correction device), the movable part may instantaneously move a large amount in any direction due to inertia, posing a risk of damage to the movable part. In addition, since support by rolling balls allows movement of the movable part in any direction, there is also the problem that the movable part is prone to rotational motion that is unnecessary for vibration correction.

[0005] Therefore, the present invention aims to provide a vibration-damping actuator capable of stably performing control of a movable part, and a lens unit and camera equipped therewith. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the present invention provides a vibration-damping actuator for moving a vibration-correcting lens in a plane perpendicular to its optical axis, comprising: a fixed part; a movable part to which a vibration-correcting lens is attached; a movable part drive mechanism for driving the movable part relative to the fixed part; and a movable part support mechanism for supporting the movable part so as to be movable relative to the fixed part, wherein the movable part support mechanism comprises: a guide shaft attached to either the fixed part or the movable part so as to extend in a plane perpendicular to the optical axis; and a shaft receiving mechanism provided on the other of the fixed part or the movable part so as to engage with the guide shaft, wherein the shaft receiving mechanism comprises a support shaft provided so as to extend in a plane perpendicular to the optical axis, and a roller that is rotatable with respect to the support shaft and slidable in the axial direction of the support shaft, and rotates in engagement with the guide shaft.

[0007] According to the present invention configured in this manner, the movable part support mechanism that supports the movable part is composed of a guide shaft and a shaft receiving mechanism, and the shaft receiving mechanism is equipped with a support shaft and a roller that rotates in engagement with the guide shaft, so that a moderate viscous resistance force is generated against the movement of the movable part. As a result, oscillation phenomena when the movable part drive mechanism performs control to drive the movable part are suppressed, and stable drive control of the movable part can be performed. Furthermore, since the movable part support mechanism is composed of a roller that rotates around the support shaft and a guide shaft that engages with the roller, the rotational movement of the movable part relative to the fixed part is suppressed. [Effects of the Invention]

[0008] According to the vibration-damping actuator of the present invention, and the lens unit and camera equipped therewith, control of the movable part can be performed stably. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of a camera according to a first embodiment of the present invention. [Figure 2] This is a side cross-sectional view of a vibration-damping actuator provided in a camera according to the first embodiment of the present invention. [Figure 3] This is a perspective view showing the fixing portion of a vibration-damping actuator provided in a camera according to the first embodiment of the present invention. [Figure 4] This is a perspective view showing the movable part of a vibration-damping actuator provided in a camera according to the first embodiment of the present invention. [Figure 5] This is an enlarged cross-sectional view showing a portion of the movable part support mechanism of a vibration-damping actuator provided in a camera according to the first embodiment of the present invention. [Figure 6] This is an enlarged cross-sectional view showing the movable part support mechanism of a vibration-damping actuator provided in a camera according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0010] (First Embodiment) Next, embodiments of the present invention will be described with reference to the attached drawings. First, a camera according to the first embodiment of the present invention will be described with reference to Figures 1 to 5. Figure 1 is a cross-sectional view of a camera according to the first embodiment of the present invention.

[0011] <Camera Configuration> As shown in Figure 1, the camera 1 of the first embodiment of the present invention comprises a lens unit 2 and a camera body 4. The lens unit 2 comprises a lens barrel 6, a plurality of lenses 8 arranged inside the lens barrel, and an anti-vibration actuator 10 that moves a shake correction lens 16 in a plane perpendicular to its optical axis A. Furthermore, the lens unit 2 comprises a gyro 34, which is a vibration detection means for detecting vibrations of the lens barrel 6, and a controller 36 that controls the anti-vibration actuator 10 based on the detection signal from the gyro 34.

[0012] In the first embodiment of the present invention, the camera 1 detects vibrations using a gyro 34, and based on the detected vibrations, activates an anti-vibration actuator 10 to move the shake-correcting lens 16, thereby stabilizing the image focused on the image sensor surface 4a within the camera body 4. In this embodiment, a piezoelectric vibration gyro is used as the gyro 34. In this embodiment, the shake-correcting lens 16 is composed of a single lens, but the lens for stabilizing the image may be a group of multiple lenses. In this specification, the term "shake-correcting lens" includes a single lens and a group of lenses for stabilizing the image.

[0013] The lens unit 2 is attached to the camera body 4 and is configured to focus the incident light onto the image sensor surface 4a. The generally cylindrical lens barrel 6 holds multiple lenses 8 inside, and focusing is possible by moving some of the lenses 8.

[0014] <Configuration of vibration isolation actuator> Next, a vibration-damping actuator 10 according to a first embodiment of the present invention will be described with reference to Figures 2 to 5. Figure 2 is a side cross-sectional view of the vibration-damping actuator 10. Figure 3 is a perspective view showing the fixed part of the vibration-damping actuator 10. Figure 4 is a perspective view showing the movable part of the vibration-damping actuator 10.

[0015] As shown in Figure 2, the vibration damping actuator 10 includes a fixed plate 12, which is a fixed part fixed inside the lens barrel 6; a movable frame 14, which is a movable part supported movably relative to the fixed plate 12; and a movable part support mechanism 18 that supports the movable frame 14 movably relative to the fixed plate 12. A vibration correction lens 16 is mounted in the center of the movable frame 14, and three movable part support mechanisms 18 (Figures 3 and 4) are arranged around it. As a result, the movable frame 14 is supported parallel to the fixed plate 12 by the movable part support mechanisms 18 on a plane perpendicular to the optical axis A of the vibration correction lens 16, and translational movement of the movable frame 14 in any direction relative to the fixed plate 12 is permitted. The specific configuration of the movable part support mechanism 18 will be described later.

[0016] Next, as shown in Figure 3, the fixing plate 12, which is the fixed part, is a roughly circular, donut-shaped plate fixed inside the lens barrel 6. Two magnet assemblies 22, two magnetic sensors 24 for detecting the position of the movable frame 14 relative to the fixing plate 12, and three coil springs 26 for pulling the movable frame 14, which is supported by the movable part support mechanism 18, towards the fixing plate 12 are attached to this fixing plate 12. In addition, support shafts 18a and rollers 18b, which constitute part of the movable part support mechanism 18, are attached to the fixing plate 12 at three locations.

[0017] The two magnet assemblies 22 are attached to the fixed plate 12 so as to be perpendicular to each other. Each magnet assembly 22 is composed of a yoke 22a made of a metal plate bent in a U shape, and two rectangular plate-shaped driving magnets 22b and 22c attached so as to face the inside of the yoke 22a. A driving coil 20 attached to the moving frame 14 is disposed between the driving magnet 22b and the driving magnet 22c attached so as to face the inside of the yoke 22a (FIG. 2). As will be described later, the combination of the magnet assembly 22 and the driving coil 20 disposed therein functions as a movable part driving mechanism that drives the moving frame 14 with respect to the fixed plate 12, respectively.

[0018] One end of each of the three coil springs 26 is attached to the outer peripheral portion of the fixed plate 12 at intervals of 120 degrees around the optical axis A. The other end of each coil spring 26 is attached to the outer peripheral portion of the moving frame 14, respectively. Thereby, the moving frame 14 is attracted to the fixed plate 12 while being supported in parallel to the fixed plate 12 by the movable part support mechanism 18, and is supported so as to be movable within a plane orthogonal to the optical axis A.

[0019] On the other hand, as shown in FIG. 4, the moving frame 14, which is a movable part, is a substantially circular plate in the shape of a donut supported in parallel to the fixed plate 12. Two driving coils 20 and two position detecting magnets 28 are attached to the moving frame 14. Further, guide shafts 18c that form part of the movable part support mechanism 18 are attached to the moving frame 14 at three locations.

[0020] The two driving coils 20 are fixed to the moving frame 14 so as to be respectively received inside the two magnet assemblies 22 provided on the fixed plate 12. That is, the two driving coils 20 are flat coils wound in an oval shape, and are attached to the moving frame 14 such that the long axes of the ovals are perpendicular to each other.

[0021] In this configuration, when current flows through the drive coil 20, an electromagnetic force acts on the drive coil 20, generating a driving force for the movable frame 14. Therefore, the combination of the magnet assembly 22 and the drive coil 20 located within it functions as a movable part drive mechanism that drives the movable frame 14 relative to the fixed plate 12. Accordingly, in this embodiment, the vibration-damping actuator 10 is equipped with two movable part drive mechanisms. In this embodiment, these movable part drive mechanisms are configured to generate thrust toward the optical axis A in a plane perpendicular to the optical axis A of the vibration-correcting lens 16. That is, the thrusts generated by the two movable part drive mechanisms are perpendicular to each other.

[0022] The two position-detecting magnets 28 are rectangular plate-shaped magnets attached to the movable frame 14, facing each of the two magnetic sensors 24 attached to the fixed plate 12. Each magnetic sensor 24 can detect the position of the movable frame 14 relative to the fixed plate 12 by detecting the magnetism of the opposing position-detecting magnets 28. That is, each magnetic sensor 24 is positioned facing the magnetization boundary line (the boundary line between the south pole and the north pole) of each position-detecting magnet 28, and can measure the distance from the magnetization boundary line. Since the two position-detecting magnets 28 are positioned so that their magnetization boundary lines are perpendicular to each other, each magnetic sensor 24 can detect the movement distance of the movable frame 14 in two directions that are perpendicular to each other. In this embodiment, each magnetic sensor 24 is composed of a Hall element.

[0023] Next, with reference to Figure 5, the configuration of the movable part support mechanism 18 will be explained. Figure 5 is an enlarged cross-sectional view showing a portion of the movable part support mechanism 18 of the vibration-damping actuator 10 of this embodiment.

[0024] As shown in Figure 5, each movable part support mechanism 18 consists of a guide shaft 18c (Figure 4) attached to the movable frame 14 and a shaft receiving mechanism consisting of a support shaft 18a and a roller 18b (Figure 3) attached to the fixed plate 12. Three guide shafts 18c and three shaft receiving mechanisms are provided on both the movable frame 14 and the fixed plate 12, and the three movable part support mechanisms 18 support the movable frame 14 so that it can move relative to the fixed plate 12.

[0025] As shown in Figure 3, the support shaft 18a and roller 18b constituting the shaft support mechanism are mounted on the fixed plate 12 on a circumference centered on the optical axis A, with a central angle of 120 degrees between them. Furthermore, the support shaft 18a is mounted in the tangential direction of the circumference centered on the optical axis A so as to extend in a plane perpendicular to the optical axis A. That is, the fixed plate 12 is provided with three rectangular openings 12a for mounting the support shaft 18a and roller 18b, and both ends of the support shaft 18a are fixed to the edges of each rectangular opening 12a.

[0026] On the other hand, as shown in Figure 5, the roller 18b is a disc-shaped member that is rotatably mounted on the support shaft 18a and received in the opening 12a of the fixed plate 12. Furthermore, the roller 18b is mounted slidably on the support shaft 18a in the axial direction of the support shaft 18a. As a result, the roller 18b can rotate around the support shaft 18a and slide in the axial direction of the support shaft 18a within the opening 12a of the fixed plate 12.

[0027] Furthermore, as shown in Figure 5, a sintered oil-impregnated bearing 30 is attached to the center of the roller 18b. The roller 18b is supported by the sintered oil-impregnated bearing 30 on the support shaft 18a, and the roller 18b is rotatably and slidably attached to the support shaft 18a via the sintered oil-impregnated bearing 30. In this embodiment, the sintered oil-impregnated bearing 30 is a bearing that can be used in a self-lubricating state by compressing and heating metal powder and impregnating the pores formed by powder metallurgy with lubricating oil. As a result, the roller 18b can rotate and slide smoothly on the support shaft 18a.

[0028] Furthermore, as shown in Figure 5, in this embodiment, a rectangular groove is formed on the outer circumferential surface of the roller 18b, and the guide shaft 18c is received between two parallel inner wall surfaces 18d of this groove. Since the guide shaft 18c is received without play between the clamping wall surfaces 18d of the roller 18b, the guide shaft 18c is maintained at approximately a right angle to the support shaft 18a when the movable frame 14 is assembled to the fixed plate 12.

[0029] Next, as shown in Figure 4, the three guide shafts 18c are attached to the movable frame 14 so as to face the three shaft receiving mechanisms (support shafts 18a and rollers 18b) provided on the fixed plate 12. That is, each guide shaft 18c is a shaft with a circular cross-section attached on the circumference of a circle centered on the optical axis A, with a central angle of 120 degrees between each shaft. Furthermore, each guide shaft 18c is fixed so as to extend in the radial direction of a circle centered on the optical axis A in a plane perpendicular to the optical axis A. Thus, in this embodiment, each guide shaft 18c is oriented in different directions (non-parallel) from each other. Note that each guide shaft 18c is mounted floating above the plate surface of the movable frame 14 (closer to the fixed plate 12) so as to be received in the grooves on the outer circumference of the rollers 18b.

[0030] As described above, when the movable frame 14 is assembled to the fixed plate 12, each guide shaft 18c fixed to the movable frame 14 engages with each roller 18b provided on the fixed plate 12. That is, each roller 18b receives each guide shaft 18c in a groove on its outer circumference and rotates in accordance with the movement of the movable frame 14. As each roller 18b rotates while receiving each guide shaft 18c and slides along each support shaft 18a, the movement of the movable frame 14 in a plane perpendicular to the optical axis A is permitted.

[0031] <Camera function> Next, with reference to Figure 1, the operation of the camera 1 according to the first embodiment of the present invention will be described. First, by turning on the camera 1's image stabilization function activation switch (not shown), the vibration damping actuator 10 provided in the lens unit 2 is activated. The gyro 34 attached to the lens unit 2 detects vibrations in a predetermined frequency band moment by moment and outputs them to the controller 36. A lens position command signal is generated based on the angular velocity signal detected by the gyro 34. By moving the image stabilization lens 16 moment by moment to the position commanded by this lens position command signal, the image focused on the image sensor surface 4a of the camera body 4 is stabilized.

[0032] The magnetic flux generated by each position-detecting magnet 28 attached to the movable frame 14 is detected by each magnetic sensor 24 attached to the fixed plate 12, and the position of the vibration-correcting lens 16 attached to the movable frame 14 is determined based on these detection signals. The controller 36 controls the current flowing through each drive coil 20 so that the vibration-correcting lens 16 moves to the position specified by the lens position command signal.

[0033] As a result, the movable frame 14, supported by the movable part support mechanism 18, is moved in a plane perpendicular to the optical axis A by the thrust generated by the movable part drive mechanism (drive coil 20 and magnet assembly 22). Furthermore, since the three guide shafts 18c attached to the movable frame 14 are received in the grooves of each roller 18b attached to the fixed plate 12, the movable frame 14 is less likely to undergo rotational motion around the optical axis A. Therefore, rotational motion of the movable frame 14, which is unnecessary for image stabilization, is suppressed.

[0034] When the image stabilization lens 16 reaches the position specified by the lens position command signal, the current flowing through each drive coil 20 is reduced to zero, and the driving force also becomes zero. Furthermore, if the moving frame 14 deviates from the position specified by the lens position command signal due to disturbances or changes in the lens position command signal, the controller 36 resumes supplying current to each drive coil 20. When current flows through each coil, a driving force is generated between the drive coil 20 and the drive magnets 22b and 22c positioned opposite each drive coil 20, and the moving frame 14 is returned to the position specified by the lens position command signal. As this process is repeated moment by moment, the image stabilization lens 16 attached to the moving frame 14 moves in accordance with the lens position command signal. This stabilizes the image focused on the image sensor surface 4a of the camera body 4.

[0035] Furthermore, if an impactful external force acts on the camera 1, the movable frame 14 will move relative to the fixed plate 12 due to inertia. At this time, the rollers 18b of the movable part support mechanism 18 that supports the movable frame 14 roll against the guide shaft 18c and slide against the support shaft 18a. Viscous resistance acts against the rolling and sliding of these rollers 18b. Therefore, when the movable frame 14 moves due to an impactful external force, the viscous resistance acts, reducing the movement speed of the movable frame 14. This reduces the risk of the movable frame 14 being damaged by a sudden movement due to an external force.

[0036] <Effects of the First Embodiment> According to the vibration-damping actuator 10 of the first embodiment of the present invention, the movable part support mechanism 18 that supports the movable frame 14 is composed of a guide shaft 18c and a shaft receiving mechanism, and the shaft receiving mechanism is equipped with a support shaft 18a and a roller 18b that rotates in engagement with the guide shaft 18c, so that a moderate viscous resistance force is generated against the movement of the movable part. As a result, oscillation phenomena when the movable part drive mechanism performs control to drive the movable part are suppressed, and stable drive control of the movable part can be performed. Furthermore, since the movable part support mechanism 18 is composed of a roller 18b that rotates around the support shaft 18a and a guide shaft 18c that engages with the roller, the rotational movement of the movable frame 14 relative to the fixed plate 12 is suppressed.

[0037] Furthermore, according to the vibration-damping actuator 10 of this embodiment, three movable part support mechanisms 18 are provided, and the guide shafts 18c provided in each movable part support mechanism 18 extend in different directions within a plane perpendicular to the optical axis A. Therefore, the rotational movement of the movable frame 14 can be effectively suppressed by each movable part support mechanism 18. Moreover, since each guide shaft 18c is oriented in different directions, each roller 18b rotates and moves in the axial direction of the support shaft 18a as the movable frame 14 moves. Therefore, a moderate viscous resistance acts on the movement of the movable frame 14, suppressing sudden movements of the movable frame 14.

[0038] Furthermore, according to the vibration-damping actuator 10 of this embodiment, the roller 18b provided in the movable part support mechanism 18 has two parallel clamping wall surfaces 18d that receive the guide shaft 18c between them. As a result, the support shaft 18a that supports the roller 18b and the guide shaft 18c are reliably maintained at a right angle, and the rotational movement of the movable frame 14 can be further suppressed.

[0039] Furthermore, in the vibration-damping actuator 10 of this embodiment, the roller 18b of the movable part support mechanism 18 is supported by a sintered oil-impregnated bearing 30 on the support shaft 18a. As a result, the roller 18b can rotate smoothly around the support shaft 18a and slide in the axial direction of the support shaft 18a. In addition, the lubricating oil impregnated in the sintered oil-impregnated bearing 30 provides viscous resistance to the movement of the movable frame 14.

[0040] (Second Embodiment) Next, a camera according to a second embodiment of the present invention will be described with reference to Figure 6. The camera of this embodiment differs from the first embodiment described above in the configuration of the movable part support mechanism of the vibration-damping actuator provided therein. Therefore, only the differences between this embodiment and the first embodiment will be described here, and similar configurations, operations, and effects will not be explained.

[0041] <Configuration of vibration isolation actuator> Figure 6 is an enlarged cross-sectional view showing the movable part support mechanism of a vibration-damping actuator provided in a camera according to a second embodiment of the present invention. As shown in Figure 6, the movable part support mechanism 50 provided in the vibration-damping actuator of this embodiment includes a support shaft 50a and roller 50b attached to the fixed plate 12, which is the fixed part, and a guide shaft 50c provided on the movable frame 14, which is the movable part. The support shaft 50a and roller 50b attached to the fixed plate 12 constitute a shaft receiving mechanism.

[0042] In this embodiment as well, the movable part support mechanism 50 is provided in three equal-spacing positions on the circumference of a circle centered on the optical axis A. The support shaft 50a is fixed to the fixing plate 12 so as to extend in the tangential direction of the circumference of the circle centered on the optical axis A. The guide shaft 50c is fixed to the moving frame 14 so as to extend in the radial direction of the circle centered on the optical axis A.

[0043] As shown in Figure 6, the roller 50b is rotatably mounted on the support shaft 50a. Also as shown in Figure 6, in this embodiment as well, a sintered oil-impregnated bearing 30 is mounted in the center of the roller 50b. The roller 50b is supported by the sintered oil-impregnated bearing 30 on the support shaft 50a, and the roller 50b is rotatably and slidably mounted on the support shaft 50a via the sintered oil-impregnated bearing 30.

[0044] Furthermore, in this embodiment, a V-shaped outer groove 50d is formed on the outer circumference of the roller 50b. As a result, the guide shaft 50c contacts the inner wall surface at two points where it intersects with the lower end of the outer groove 50d. The roller 50b rotates relative to the support shaft 50a and slides in the axial direction of the support shaft 50a as the movable frame 14 moves relative to the fixed plate 12.

[0045] Thus, in this embodiment, since the guide shaft 50c abuts against the outer circumferential groove 50d of the V-shaped cross-section of the roller 50b, the force holding the guide shaft 50c perpendicular to the support shaft 50a is weaker than in the first embodiment. On the other hand, the positional accuracy required to fix the guide shaft 50c to the movable frame 14 and the positional accuracy required to fix the support shaft 50a to the fixing plate 12 are not as high as those required for the vibration-damping actuator in the first embodiment, and the device can be easily manufactured.

[0046] <Effects of the second embodiment> According to the vibration-damping actuator of the second embodiment of the present invention, the roller 50b of the movable part support mechanism 50 is provided with an outer peripheral groove 50d that receives the guide shaft 50c, and the guide shaft 50c contacts the inner wall surface of the outer peripheral groove 50d at two points. For this reason, the movable part support mechanism 50 of the vibration-damping actuator can be manufactured relatively easily.

[0047] (modified version) Although embodiments of the present invention have been described above, various modifications can be made to the embodiments described above. In particular, in the embodiments described above, the guide shaft was attached to the movable frame and the shaft support mechanism (support shaft and roller) was provided on the fixed plate, but the guide shaft can also be provided on the fixed plate and the shaft support mechanism can be provided on the movable frame.

[0048] Furthermore, in the embodiments described above, each guide shaft was mounted in the radial direction of a circle centered on the optical axis, but some or all of the guide shafts may be mounted in directions other than the radial direction. In addition, in the embodiments described above, the vibration isolation actuator was provided with three movable part support mechanisms, but the number of movable part support mechanisms may be two or fewer, or four or more. If there are two or fewer movable part support mechanisms, rolling balls or the like may be used in combination to support the movable parts.

[0049] Furthermore, in the above-described embodiment, the vibration-damping actuator was provided with two sets of movable part drive mechanisms (magnet assemblies and drive coils), but it is also possible to provide three or more sets of movable part drive mechanisms. For example, if three sets of movable part drive mechanisms are provided, the present invention can be configured such that each movable part drive mechanism generates thrust in the tangential direction of the circumference centered on the optical axis. Moreover, in the above-described embodiment, the magnet assemblies (drive magnets) of the movable part drive mechanisms were provided on a fixed plate and the drive coils were fixed to the movable frame, but it is also possible to provide the drive coils on the fixed plate and the drive magnets on the movable frame.

[0050] (summary) A vibration-damping actuator according to aspect 1 of the present invention is a vibration-damping actuator for moving a vibration-correcting lens in a plane perpendicular to its optical axis, comprising: a fixed part; a movable part to which a vibration-correcting lens is attached; a movable part drive mechanism for driving the movable part relative to the fixed part; and a movable part support mechanism for supporting the movable part so as to be movable relative to the fixed part, wherein the movable part support mechanism comprises: a guide shaft attached to one of the fixed part or the movable part so as to extend in a plane perpendicular to the optical axis; and a shaft receiving mechanism provided on the other of the fixed part or the movable part so as to engage with the guide shaft, wherein the shaft receiving mechanism comprises a support shaft provided so as to extend in a plane perpendicular to the optical axis, and a roller that is rotatable with respect to the support shaft and slidable in the axial direction of the support shaft, and rotates in engagement with the guide shaft.

[0051] In this configuration, the movable part support mechanism, which supports the movable part, consists of a guide shaft and a shaft receiving mechanism. The shaft receiving mechanism is equipped with a support shaft and a roller that rotates in engagement with the guide shaft, so that a moderate viscous resistance force is generated against the movement of the movable part. As a result, oscillation phenomena when the movable part drive mechanism performs control to drive the movable part are suppressed, and stable drive control of the movable part can be performed. Furthermore, since the movable part support mechanism consists of a roller that rotates around the support shaft and a guide shaft that engages with the roller, the rotational movement of the movable part relative to the fixed part is suppressed.

[0052] In the vibration isolation actuator according to embodiment 2 of the present invention, in embodiment 1, two or three movable part support mechanisms are provided, and the guide shafts provided in each movable part support mechanism extend in different directions in a plane perpendicular to the optical axis.

[0053] In this configuration, two or three movable part support mechanisms are provided, and the guide shafts attached to each movable part support mechanism extend in different directions within a plane perpendicular to the optical axis. Therefore, each movable part support mechanism can effectively suppress the rotational movement of the movable frame. Furthermore, since each guide shaft is oriented in a different direction, each roller rotates and moves in the axial direction of the support shaft as the movable frame moves. As a result, a moderate viscous resistance acts on the movement of the movable frame, suppressing sudden movements of the movable frame.

[0054] In the vibration isolation actuator according to embodiment 3 of the present invention, in embodiment 1 or 2, the roller provided in the movable part support mechanism has two parallel clamping wall surfaces that receive the guide shaft between them.

[0055] In this configuration, the roller provided in the movable part support mechanism has two parallel clamping walls that receive the guide shaft between them. As a result, the support shaft supporting the roller and the guide shaft are reliably maintained at a right angle, and the rotational movement of the movable frame can be further suppressed.

[0056] In any one of embodiments 1 to 3, the vibration-damping actuator according to embodiment 4 of the present invention is characterized in that the roller provided in the movable part support mechanism has an outer circumferential groove for receiving a guide shaft, and the guide shaft is in contact with the inner wall surface of the outer circumferential groove at two points.

[0057] In this configuration, the roller of the movable part support mechanism has an outer groove for receiving the guide shaft, and the guide shaft contacts the inner wall surface of the outer groove at two points. Therefore, the movable part support mechanism of the vibration-damping actuator can be manufactured relatively easily.

[0058] In the vibration-damping actuator according to embodiment 5 of the present invention, in any one of embodiments 1 to 4, the roller provided in the movable part support mechanism is supported on the support shaft by a sintered oil-impregnated bearing.

[0059] In this configuration, the rollers of the movable part support mechanism are supported on the support shaft by sintered oil-impregnated bearings. Therefore, the rollers can rotate smoothly around the support shaft and slide in the axial direction of the support shaft. Furthermore, the lubricating oil impregnated in the sintered oil-impregnated bearings provides viscous resistance to the movement of the movable frame.

[0060] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of Symbols]

[0061] 1 Camera 2 Lens Units 4 Camera body 4a Image sensor surface 6 Lens barrel 8 lenses 10 Vibration Isolation Actuator 12 Fixed plate (fixed part) 12a opening 14. Movable frame (movable part) 16 Image stabilization lens 18 Movable part support mechanism 18a Support shaft 18b Roller 18c Guide Shaft 18d Clamping wall surface 20 Drive coils 22 Magnet Assembly 22a York 22b Drive magnet 22c drive magnet 24 Magnetic Sensors 26 Coil springs 28 Magnets for position detection 30 Sintered oil-impregnated bearing 34 Gyro 36 Controllers 50 Movable part support mechanism 50a Support shaft 50b Roller 50c guide shaft 50d outer groove

Claims

1. A vibration-damping actuator for moving a vibration-correcting lens in a plane perpendicular to its optical axis, The fixing part, A movable part to which a lens for image stabilization is attached, A movable part drive mechanism that drives this movable part relative to the fixed part, A movable part support mechanism that supports the above movable part so as to be movable relative to the above fixed part, It has, The above movable part support mechanism is, A guide shaft is attached to either the fixed part or the movable part so as to extend in a plane perpendicular to the optical axis, The other of the fixed part or the movable part is provided with a shaft receiving mechanism that engages with the guide shaft, The above-described shaft support mechanism is characterized by comprising a support shaft provided so as to extend in a plane perpendicular to the optical axis, and a roller that is rotatable with respect to the support shaft and slidable in the axial direction of the support shaft, and that rotates in engagement with the guide shaft.

2. The vibration-damping actuator according to claim 1, wherein two or three of the above-mentioned movable part support mechanisms are provided, and the guide shafts provided in each of the above-mentioned movable part support mechanisms extend in different directions in a plane perpendicular to the optical axis.

3. The vibration-damping actuator according to claim 1, wherein the roller provided in the above-mentioned movable part support mechanism has two parallel clamping wall surfaces that receive the guide shaft between them.

4. The vibration-damping actuator according to claim 1, wherein the roller provided in the movable part support mechanism is provided with an outer circumferential groove for receiving the guide shaft, and the guide shaft is in contact with the inner wall surface of the outer circumferential groove at two points.

5. The vibration-damping actuator according to claim 1, wherein the roller provided in the above-mentioned movable part support mechanism is supported on the support shaft by a sintered oil-impregnated bearing.

Images