Vibration actuators, optical instruments, and drive devices

Abstract

To provide a vibration type actuator capable of appropriately transmitting applied pressure to a vibrator, that reduces occurrence of abnormal noise.SOLUTION: A vibration type actuator 1 comprises a vibrator 2; a friction member 10 coming into contact with the vibrator 2; a vibrator holding member 3 for holding the vibrator 2; a pressurizing member 15 for bringing the vibrator 2 into pressure contact with the friction member 10; a first pressurizing transmission member 13 positioned with respect to the vibrator holding member 3, that is arranged between the pressurizing member 15 and the vibrator 2; and a second pressurizing transmission member 14 positioned with respect to the first pressurizing transmission member 13, that is arranged between the pressurizing member 15 and the vibrator 2. It is so constituted that the second pressurizing transmission member 14 comes into no contact with the vibrator holding member 3.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a vibration actuator, an optical device provided with the vibration actuator, and a driving device.

Background Art

[0002] A vibration actuator can obtain a large output even if it is small and has the feature of being excellent in quietness during driving. Therefore, for example, it is used for driving an optical lens in an imaging device such as a digital camera. Vibration actuators with various structures are known. One of them is a type that vibrates a vibrating body provided with a plurality of protrusions to generate an elliptical motion at the tip of the protrusion, and gives a frictional driving force to a driven body in contact with the protrusion to relatively move the vibrating body and the driven body.

[0003] This type of vibration actuator requires a pressing member and a pressure transmission member in order to press the vibrating body against the driven body. For example, Patent Document 1 describes a configuration in which the pressing force of a coil spring as a pressing member is transmitted to a vibrating body via two pressure transmission members (a first pressure transmission member and a second pressure transmission member) arranged in the pressing direction. The first pressure transmission member directly contacting the coil spring transmits the pressing force of the coil spring to the vibrating body via the second pressure transmission member having spherical protrusions. At this time, in Patent Document 1, it is devised so that an unnecessary moment does not act on the vibrating body by applying a pressing force to a substantially central position of the flat vibrating body by transmitting the pressing force with the spherical protrusions.

[0004] Also, in Patent Document 1, a buffer member is arranged between the vibrating body and the second pressure transmission member closer to the vibrating body so that a pressing force acts uniformly on the pressure receiving surface of the vibrating body. For the buffer member, a material such as felt that is unlikely to inhibit the vibration of the vibrating body even when it abuts on the vibrating body is used. Thus, in Patent Document 1, the pressing force of the coil spring is transmitted to the vibrating body in the order of the first pressure transmission member, the second pressure transmission member having spherical protrusions, and the buffer member from the coil spring.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-5374 [Overview of the project] [Problems that the invention aims to solve]

[0006] In the vibration actuator described in Patent Document 1 above, the vibrating body is directly held by the vibrating body holding member. The first pressure transmission member and the vibrating body holding member are in contact for mutual positioning, and the second pressure transmission member is also in contact with the vibrating body holding member for mutual positioning. Therefore, when the vibrating body is excited at a predetermined frequency, the high-frequency vibration of the vibrating body holding member that occurs in conjunction with the vibration of the vibrating plate causes high-frequency collisions at the contact points between the vibrating body holding member and the first pressure transmission member, and between the vibrating body holding member and the second pressure transmission member, resulting in the generation of abnormal noise.

[0007] The present invention aims to provide a vibration-type actuator that can appropriately transmit pressurizing force to a vibrating body while reducing the generation of abnormal noise. [Means for solving the problem]

[0008] The vibration-type actuator according to the present invention comprises a vibrating body, a driven body in contact with the vibrating body, a holding member for holding the vibrating body, and a pressurizing member for pressurizing contact between the vibrating body and the driven body, wherein the actuator comprises a first pressurizing member positioned relative to the holding member and a second pressurizing member positioned relative to the first pressurizing member, the first pressurizing member being positioned between the vibrating body and the second pressurizing member, and the second pressurizing member in contact with the holding member. The first pressure transmission member has a third positioning portion that contacts the holding member and determines the position of the first pressure transmission member relative to the holding member in a plane substantially perpendicular to the direction of pressure applied by the pressure member, the holding member has a contact surface surrounded by an inner wall that contacts the third positioning portion and has a housing space for housing the first pressure transmission member, and the inner wall is substantially parallel to the direction of pressure. It is characterized by the following: [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a vibration-type actuator that can appropriately transmit pressurizing force to a vibrating body while reducing the generation of abnormal noise. [Brief explanation of the drawing]

[0010] [Figure 1] This is an exploded perspective view of a vibratory actuator according to an embodiment. [Figure 2] This is a perspective view of the external appearance of a vibrating actuator. [Figure 3] This is a diagram illustrating the shape of the first pressure transmission member. [Figure 4] This figure shows the state in which the first pressure transmission member and the vibrator holding member are positioned. [Figure 5] This diagram illustrates the shape of the second pressure transmission member. [Figure 6] This figure shows the first and second pressure transmission members in their positioned positions. [Figure 7] This diagram shows the state in which the vibrating body holding member, the first pressure transmission member, and the second pressure transmission member are positioned. [Figure 8] This is a magnified section of Figure 7(b). [Figure 9] This is a cross-sectional view showing the second pressure transmission member tilted relative to the first pressure transmission member. [Figure 10] This is a cross-sectional view showing the schematic configuration of the imaging device. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0012] Figure 1 is an exploded perspective view of the vibrating actuator 1 according to an embodiment, and the viewing direction of the vibrating actuator 1 differs between Figure 1(a) and Figure 1(b), as indicated by the orthogonal coordinate axes in the figure. Figure 2 is an external perspective view of the vibrating actuator 1, and the viewing direction of the vibrating actuator 1 differs between Figure 2(a) and Figure 2(b), as indicated by the orthogonal coordinate axes in the figure. In the orthogonal coordinate axes shown in Figures 1 and 2, the X direction is the direction in which the vibrating body 2, described later, moves relative to the friction member 10, described later (driving direction). The Z direction is the direction in which the vibrating body 2 is pressed against the friction member 10 (pressure direction), and the Y direction is perpendicular to both the X and Z directions.

[0013] The vibrating actuator 1 comprises a vibrating body 2, a vibrating body holding member 3, a connecting member 4, a movable frame 5, a movable guide member 6, rolling balls 8, a fixed guide member 9, a friction member 10, a housing 11, a cushioning member 12, a first pressure transmission member 13, a second pressure transmission member 14, and a pressure member 15.

[0014] The vibrating body 2 has a rectangular flat elastic member 2c having two protrusions 2b, and a rectangular flat piezoelectric element 2a joined to the surface of the elastic member 2c opposite to the surface on which the protrusions 2b are provided, using an adhesive or the like. For example, the piezoelectric element 2a is a piezoelectric ceramic such as PZT (lead zirconate titanate), and the elastic member 2c is a metal plate such as stainless steel. A flexible substrate (not shown), which is a power supply member, is attached to the piezoelectric element 2a, and it is possible to apply an AC voltage to the piezoelectric element 2a via the flexible substrate. When a predetermined AC voltage is applied to the piezoelectric element 2a, elliptical motion can be generated at the tips of the protrusions 2b. Note that the method for generating elliptical motion at the tips of the protrusions 2b is well known, so a detailed explanation is omitted. Also, the number of protrusions provided on the vibrating body 2 is not limited to two, and may be one.

[0015] The vibrating body holding member 3 is a resin-made frame that holds the vibrating body 2 by directly adhering the vibrating body 2 thereto. The friction member 10 is a driven body that receives a frictional driving force (thrust) from the projection 2b of the vibrating body 2. Here, it is a metal plate having a sliding surface 10a that comes into frictional contact with the projection 2b of the vibrating body 2 and is fixed to the housing 11. The housing 11 is a member that serves as the base of the vibration type actuator 1 and is a member that is fixed to the frame of the device or the like when the vibration type actuator 1 is mounted on an electronic device or the like. In this embodiment, by generating an elliptical motion at the tip of the projection 2b, the vibrating body 2 moves relative to the friction member 10. However, the configuration is not limited to this, and a configuration in which the friction member 10 moves relative to the vibrating body 2 by exciting vibration in the vibrating body 2 may be employed.

[0016] The first pressure transmission member 13 is a resin molded product, and the second pressure transmission member 14 is a metal plate. The first pressure transmission member 13 is disposed between the vibrating body 2 and the second pressure transmission member 14 in the pressing direction (-Z direction). A plurality of pressing members 15 are attached to the second pressure transmission member 14. Specifically, four tension springs are used as the pressing members 15.

[0017] Spring hanging portions 14a are provided at the four corners of the second pressure transmission member 14, and one end of each tension spring is hooked to each spring hanging portion 14a. The other end of each of the four tension springs is hooked to spring hanging portions 6b provided at four locations on the movable guide member 6. Thus, the pressing members 15 are disposed around (at the four corners) of the movable frame 5, and the vibrating body 2 is pressed in the pressing direction (-Z direction) by the resultant force of the tensile forces generated in each of the four pressing members 15, and the vibrating body 2 comes into pressure contact with the friction member 10. Further, the second pressure transmission member 14 and the movable guide member 6 are connected via the pressing members 15.

[0018] The buffer member 12 is attached to the first pressure transmission member 13. The buffer member 12 is made of a material that is difficult to inhibit the vibration of the vibrating body 2 even when it contacts the vibrating body 2. In this embodiment, felt is used, but it is not limited thereto. The first pressure transmission member 13 is provided with a kamaboko-shaped portion 13c (see FIG. 8). The kamaboko-shaped portion 13c has a substantially elliptical shape in a cross section orthogonal to the Y direction and extends in the Y direction. The second pressure transmission member 14 contacts the first pressure transmission member 13 at the ridge line of the kamaboko-shaped portion 13c or in its vicinity. Thereby, the second pressure transmission member 14 is held so as to be relatively rotatable around the kamaboko-shaped portion 13c with respect to the first pressure transmission member 13. The second pressure transmission member 14 transmits the pressure (the resultant force of tensile forces) generated by the four pressure members 15 to the first pressure transmission member 13, and the first pressure transmission member 13 transmits the pressure to the vibrating body 2 via the buffer member 12.

[0019] The movable frame 5 is a resin frame body arranged to surround the vibrating body holding member 3. The movable frame 5 and the vibrating body holding member 3 are each connected to a substantially thin plate-shaped connecting member 4. The connecting member 4 determines the relative positions of the movable frame 5 and the vibrating body holding member 3 in the XY plane, and play (rattling) between the movable frame 5 and the vibrating body holding member 3 in the driving direction (X direction) of the vibrating body 2 is suppressed. In the vibration type actuator 1, the connecting portion of the connecting member 4 with the movable frame 5 and the connecting portion with the vibrating body holding member 3 are provided at substantially the same height in the Z direction. Thereby, it is suppressed that elastic force is generated in the connecting member 4 due to the difference in the height in the Z direction of each connecting portion of the movable frame 5 and the vibrating body holding member 3 with respect to the connecting member 4, and the transmission of the elastic force generated in the connecting member 4 to the vibrating body 2 via the vibrating body holding member 3 is suppressed. Thus, by configuring the connecting member 4 not to generate elastic force with respect to the vibrating body 2, it becomes possible to stabilize the pressure of the pressure member 15.

[0020] The movable guide member 6 and the fixed guide member 9 are metal plates. The movable guide member 6 has a guide groove 6a that extends in the direction of movement of the vibrating body 2. The movable guide member 6 and the movable frame 5 are connected by screws 7. The movable guide member 6 is also provided with a connecting portion 6c used for connecting to an object to be driven (not shown).

[0021] The fixed guide member 9 has a guide groove 9a positioned opposite the guide groove 6a in the pressurizing direction (Z direction). The rolling balls 8 are held between the guide grooves 6a and 9a in the Z direction so as to be able to roll in the X direction, using the reaction force of the pressurizing member 15 pressing the vibrating body 2 against the friction member 10, thereby enabling the vibrating body 2 (movable guide member 6) to move in the X direction. The fixed guide member 9 is fixed to the housing 11.

[0022] In the vibrating actuator 1, the pressurizing member 15, the first pressurizing transmission member 13, the second pressurizing transmission member 14, and the cushioning member 12 function as a pressurizing mechanism that generates and transmits a pressurizing force to the vibrating body 2, pressing it against the friction member 10. In addition, the connecting member 4, the movable frame 5, the movable guide member 6, the fixed guide member 9, and the rolling ball 8 function as a holding mechanism that guides the vibrating body 2 so that it can move relative to the friction member 10.

[0023] Next, the positioning method for the components constituting the pressurizing mechanism of the vibration-type actuator 1 will be described. Figure 3 illustrates the shape of the first pressurizing transmission member 13, with Figure 3(a) being a top view (viewed from the +Z side) and Figure 3(b) being a front view (viewed from the -Y side).

[0024] As shown in Figure 3, the first pressure transmission member 13 has contact portions 13a1 protruding from both the +X and -X sides in the X direction. The first pressure transmission member 13 also has contact portions 13a2 protruding from both the +Y and -Y sides in the Y direction. Furthermore, the first pressure transmission member 13 has a positioning portion 13b1 formed as a projection in the Z direction and two positioning portions 13b2 formed in the Z direction. The contact portions 13a1 and 13a2 are used to position the first pressure transmission member 13 relative to the vibrating body holding member 3. The positioning portions 13b1 and 13b2 are used to position the second pressure transmission member 14 relative to the first pressure transmission member 13.

[0025] Figure 4 shows the positioning of the first pressure transmission member 13 and the vibrating body holding member 3, with Figure 4(a) being a top view and Figure 4(b) being a front view. The vibrating body holding member 3 has a roughly rectangular housing space for accommodating the first pressure transmission member 13, surrounded by inner walls 3a1 and 3a2 that are roughly parallel to the pressurizing direction (Z direction) by the pressurizing member 15. The first pressure transmission member 13 is inserted into the housing space of the vibrating body holding member 3. Then, the contact portion 13a1 protruding in the X direction of the first pressure transmission member 13 comes into contact with the inner wall 3a1 of the vibrating body holding member 3, thereby determining the relative position of the first pressure transmission member 13 and the vibrating body holding member 3 in the X direction. Also, the contact portion 13a2 protruding in the Y direction comes into contact with the inner wall 3a2 of the vibrating body holding member 3, thereby determining the relative position of the first pressure transmission member 13 and the vibrating body holding member 3 in the Y direction. In other words, the contact portions 13a1 and 13a2 of the first pressure transmission member 13 come into contact with the inner walls 3a1 and 3a2 of the vibrating body holding member 3, respectively, thereby determining the position of the first pressure transmission member 13 relative to the vibrating body holding member 3 in a plane (XY plane) that is substantially perpendicular to the direction of pressure applied by the pressure member 15.

[0026] Figure 5 illustrates the shape of the second pressure transmission member 14, with Figure 5(a) being a top view and Figure 5(b) being a front view. The second pressure transmission member 14 is substantially plate-shaped and has one positioning portion 14b1 and two positioning portions 14b2 used for positioning relative to the first pressure transmission member 13. The positioning portions 14b1 and 14b2 are each provided as holes penetrating in the Z direction. Positioning portion 14b1 has an elongated hole shape extending in the Y direction, and the two positioning portions 14b2, which are provided so as to sandwich positioning portion 14b1 in the X direction, also have elongated hole shapes extending in the X direction. These positioning portions 14b1 and 14b2 engage with positioning portions 13b1 and 13b2 provided on the first pressure transmission member 13, respectively.

[0027] Figure 6 shows the positioning of the second pressure transmission member 14 and the first pressure transmission member 13, with Figure 6(a) being a top view and Figure 6(b) being a front view. The positioning portion 14b1 of the second pressure transmission member 14 is a hole extending in the Y direction, but in the X direction it is formed with a width that allows it to engage with the positioning portion 13b1 of the first pressure transmission member 13. Therefore, by the engagement of the positioning portion 14b1 with the positioning portion 13b1, the second pressure transmission member 14 is positioned without play in the X direction relative to the first pressure transmission member 13. In addition, the two positioning portions 14b2 of the second pressure transmission member 14 are holes extending in the X direction, but in the Y direction they are formed with a width that allows them to engage with the positioning portion 13b2 of the first pressure transmission member 13. Therefore, the two positioning parts 14b2 engage one-to-one with the two positioning parts 13b2, so that the second pressure transmission member 14 is positioned without any play in the Y direction relative to the first pressure transmission member 13, and rotation around an axis parallel to the Z direction is also restricted.

[0028] The second pressure transmission member 14 has a contact surface 14c that abuts against the semicircular portion 13c of the first pressure transmission member 13 while being positioned (engaged) with the first pressure transmission member 13. The semicircular portion 13c and the contact surface 14c are in contact because they are pressurized in the -Z direction by the pressure members 15, and the inclination around the contact point and the relative position in the Z direction are determined by the balance of forces of the four pressure members 15.

[0029] In other words, the positioning portions 13b1, 13b2 of the first pressure transmission member 13 and the positioning portions 14b1, 14b2 of the second pressure transmission member 14 determine the relative positions of the first pressure transmission member 13 and the second pressure transmission member 14 in the XY plane. Furthermore, the semicircular portion 13c of the first pressure transmission member 13 and the contact surface 14c of the second pressure transmission member 14 determine the relative positions of the first pressure transmission member 13 and the second pressure transmission member 14 in the Z direction. In addition, the inclination of the second pressure transmission member 14 relative to the first pressure transmission member 13 is determined by the balance of forces of the pressure member 15.

[0030] Figure 7 shows the state in which the vibrating body holding member 3, the first pressure transmission member 13, and the second pressure transmission member 14 are positioned. Figure 7(a) is a top view, and Figure 7(b) is a cross-sectional view taken along the line AA shown in Figure 7(a).

[0031] As described above, the positions of the first pressure transmission member 13 and the second pressure transmission member 14 in the XY plane are determined by the positioning parts 13b1 and 13b2 of the first pressure transmission member 13 and the positioning parts 14b1 and 14b2 of the second pressure transmission member 14. The height of the first pressure transmission member 13 in the +Z direction is determined in relation to the vibrating body holding member 3 via the vibrating body 2 and the buffer member 12, and the position of the second pressure transmission member 14 in the Z direction is determined by contact with the semicircular portion 13c of the first pressure transmission member 13.

[0032] Because the vibrating body holding member 3 directly holds the vibrating body 2, it is easily excited, and gaps in positioning with contacting parts can cause high-frequency collisions, which may be heard as abnormal noise by the user. To address this problem, the vibrating actuator 1 has a structure in which the first pressure transmission member 13 is in contact with the vibrating body holding member 3, and the second pressure transmission member 14 is in contact with the first pressure transmission member 13. In other words, the second pressure transmission member 14 is positioned relative to the vibrating body holding member 3 via the first pressure transmission member 13, so the second pressure transmission member 14 and the vibrating body holding member 3 are not in contact. In this way, the number of parts in contact with the vibrating body holding member 3 is reduced, and the number of areas where the aforementioned collisions occur is reduced, making it possible to reduce abnormal noise.

[0033] Next, we will explain the method for vibration damping and noise reduction. As mentioned above, the first pressure transmission member 13 constituting the pressurizing mechanism of the vibration-type actuator 1 is made of resin, and the second pressure transmission member 14 is a metal plate. When the vibration damping rate of the first pressure transmission member 13 is δ1 and the vibration damping rate of the second pressure transmission member 14 is δ2, the materials are selected such that the relationship between the vibration damping rates is 'δ1 > δ2'. This is for the following reason. That is, the position of the first pressure transmission member 13 is determined by contact with the vibrating body holding member 3, which is most easily excited by the vibrating body 2, and the position of the second pressure transmission member 14 is determined by contact with the first pressure transmission member 13. The vibration excited in the vibrating body 2 is transmitted from the vibrating body 2 through the vibrating body holding member 3 to the first pressure transmission member 13, and further transmitted from the first pressure transmission member 13 to the second pressure transmission member 14. Therefore, by using a material with a high vibration damping rate for the member that is first excited, and selecting materials with decreasing vibration damping rates for the members to which the vibration is transmitted, the propagation of vibration can be efficiently dampened. As a result, it is possible to suppress the propagation of vibration throughout the entire pressurizing mechanism and the generation of abnormal noise. Although the first pressurizing transmission member 13 is made of resin and the second pressurizing transmission member 14 is made of metal, the materials of these members are not limited to these, and for example, combinations of resins with different vibration damping rates or combinations of metals may also be used.

[0034] Next, a method for reducing abnormal noise using a damping member will be explained. Figure 8 is a partially enlarged view of Figure 7(b), showing the structure near the positioning portions 13b1 and 13b2 of the first pressure transmission member 13. The damping member 16 is positioned near the positioning portions 13b1 and 13b2 of the first pressure transmission member 13 and is in contact with both the first pressure transmission member 13 and the second pressure transmission member 14. As mentioned above, vibrations are transmitted from the vibrating body 2 to the second pressure transmission member 14 via the first pressure transmission member 13, and abnormal noise is generated by high-frequency collisions between the positioning portions of the first pressure transmission member 13 and the second pressure transmission member 14. Therefore, by providing the damping member 16 at the positioning portions of the first pressure transmission member 13 and the second pressure transmission member 14, the vibrations transmitted from the first pressure transmission member 13 to the second pressure transmission member 14 can be attenuated, thereby suppressing the generation of abnormal noise. For example, the damping member 16 can be made of an elastic resin adhesive or vibration-damping rubber.

[0035] Next, we will explain the mechanism by which the generation of abnormal noise is suppressed by a change in the posture and contact state of the second pressure transmission member 14 with respect to the first pressure transmission member 13. Figure 9 is a cross-sectional view showing the state in which the second pressure transmission member 14 is tilted with respect to the first pressure transmission member 13. In the state shown in Figure 9, the position and posture of the second pressure transmission member 14 are determined by the balance of forces of the four pressure members 15 (not shown in Figure 9), with the contact point with the kamaboko-shaped portion 13c of the first pressure transmission member 13 tilted clockwise around the center of rotation. As mentioned above, the positioning portion 14b1 of the second pressure transmission member 14 is a hole extending in the Y direction, and the positioning portion 14b2 is a hole extending in the X direction, so the second pressure transmission member 14 can tilt around an axis parallel to the Y direction as the center of rotation, as shown in Figure 9.

[0036] The positioning parts 13b1 and 14b1 are positioned at the pressurizing center S of the pressurizing mechanism, and the positioning part 13b1 engages with the positioning part 14b1 without any play in the X direction. When the second pressurizing transmission member 14 tilts, the positioning part 14b1 becomes twisted relative to the positioning part 13b1. However, since the second pressurizing transmission member 14 is substantially thin plate-shaped and the fitting length between the positioning part 13b1 and the positioning part 14b1 is short, the twisting between the parts can be reduced.

[0037] Furthermore, the positioning parts 13b1 and 14b1 are positioned on the kamaboko-shaped part 13c such that they are coaxial with the kamaboko-shaped part 13c in the Z direction (the central axes of the positioning parts 13b1 and 14b1 coincide with an axis passing through the apex of the kamaboko-shaped part 13c and parallel to the Z direction). Therefore, the contact point between the kamaboko-shaped part 13c and the second pressure transmission member 14 becomes the center of rotation, and the positioning parts 13b1 and 14b1 are located near the center of rotation. In this way, by having the center of rotation of the part near the positioning part, twisting of the engagement part due to the tilt of the part can be minimized, and as a result, the generation of abnormal noise can be suppressed.

[0038] Next, the contact state between the positioning portion 13b2 and the positioning portion 14b2 will be described. The positioning portion 13b2 and the positioning portion 14b2 are each located at a predetermined distance D in the X direction from the pressurizing center S of the pressurizing mechanism. Furthermore, the positioning portion 13b2 engages with the positioning portion 14b2 without any play in the Y direction. Since the positioning portion 14b2 is an elongated hole extending in the X direction, it can relieve the twisting of the engagement portion caused by the tilting of the second pressurizing transmission member 14 (making it difficult for the positioning portions 13b2 and 14b2 to rub against each other).

[0039] Furthermore, in the pressurizing mechanism of the vibrating actuator 1, it is desirable that the pressurizing center S and the center of the vibrating body 2 coincide as much as possible in order to equalize the surface pressure on the projection 2b of the vibrating body 2. Since the pressurizing center S is the position of the semi-circular portion 13c provided on the first pressurizing transmission member 13, it is necessary to position the vibrating body 2 and the first pressurizing transmission member 13 with relatively high precision. For this purpose, it is preferable that the first pressurizing transmission member 13 be positioned by directly contacting the vibrating body holding member 3. Accordingly, as described above with reference to Figures 3 and 4, in the vibrating actuator 1, the first pressurizing transmission member 13 is positioned by directly contacting the vibrating body holding member 3. The positioning of the first pressurizing transmission member 13 relative to the vibrating body holding member 3 is not limited to a configuration using contact portions 13a1 and 13a2.

[0040] Furthermore, to prevent the second pressure transmission member 14 from transmitting unnecessary moments to the vibrating body 2, it is desirable that the second pressure transmission member 14 be freely rotatable relative to the vibrating body holding member 3 and the first pressure transmission member 13. From this viewpoint, in the vibrating actuator 1, the positioning portion 13b1 of the first pressure transmission member 13, which determines the position in the X direction, and the positioning portion 14b1 of the second pressure transmission member 14 are arranged coaxially with the kamaboko-shaped portion 13c, which is the pressure center S in the Z direction. Then, the positioning portions 13b2 and 14b2, which determine the position in the Y direction, are arranged at a predetermined distance D in the X direction from the pressure center S. As a result, the twisting of the positioning portion caused by the tilting of the second pressure transmission member 14 is absorbed by the play of the positioning portion 14b2, and the transmission of unnecessary moments due to twisting between members can be avoided. In other words, the second pressure transmission member 14 can rotate freely without twisting relative to the first pressure transmission member 13.

[0041] Next, as an example of an optical device using the vibration actuator 1, the lens barrel (lens barrel) that constitutes the imaging device will be described. Figure 10 is a cross-sectional view showing the schematic configuration of the imaging device. The imaging device is broadly composed of a lens barrel 101 and an imaging device body 102. An image sensor 104 is arranged inside the imaging device body 102.

[0042] Here, the lens barrel 101 and the imaging device body 102 are assumed to be integrated, but the lens barrel 101 may be a so-called interchangeable lens that can be attached to and detached from the imaging device body 102. Inside the lens barrel 101, an optical lens 103, consisting of a lens and a lens retaining frame, is arranged to move in a direction parallel to the imaging optical axis P (in the optical axis direction) as one of several optical components. The optical lens 103 is connected to the connection part 6c of the movable guide member 6 of the vibrating actuator 1, and the lens driving device 1000 is composed of the vibrating actuator 1 and the optical lens 103.

[0043] The vibration actuator 1 has a movable part, including a vibrating body 2 and a movable guide member 6, arranged within the lens barrel 101 so as to be movable in the optical axis direction. Therefore, as the vibrating body 2 moves, the optical lens 103 also moves in the optical axis direction. If the optical lens 103 is a focusing lens, moving the focusing lens in the optical axis direction during imaging allows a subject image in focus to be formed on the image sensor 104. Furthermore, if the optical lens 103 is a zoom lens, moving the zoom lens in the optical axis direction makes it possible to change the imaging angle of view.

[0044] Furthermore, in a drive device that drives an object using the vibration-type actuator 1, the object to be driven is not limited to the optical lens 103 described above. For example, if the object to be driven is the image sensor 104 (or the holding frame that holds it), an image shake correction device can be configured that drives the image sensor 104 in a plane perpendicular to the optical axis P using the vibration-type actuator 1. Moreover, the vibration-type actuator 1 can be used in drive devices other than imaging devices, for example, in display devices such as head-mounted displays where the object to be driven is a diopter adjustment lens or display panel, or in microscopes where the object to be driven is a stage.

[0045] Although the present invention has been described in detail above based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various forms that do not depart from the spirit of the invention are also included in the present invention. [Explanation of Symbols]

[0046] 1. Vibration-type actuator 2. Vibrating body 3. Vibrating body holding member 3a1,3a2 Inner wall 10 Friction members 13 First pressure transmission member 13a1,13a2 Contact part 13b1, 13b2 Positioning section 13c Fish cake-shaped part 14. Second pressure transmission member 14b1, 14b2 Positioning section 15 Pressurizing member 16 Damping member 101 Lens barrel 103 Optical Lenses 1000 Lens drive device

Claims

1. A vibrating body and A driven body that comes into contact with the vibrating body, A holding member for holding the vibrating body, A vibrating actuator comprising a pressurizing member that pressurizes the vibrating body and the driven body, A first pressure transmission member positioned relative to the holding member, The system comprises a second pressure transmission member positioned relative to the first pressure transmission member, The first pressure transmission member is positioned between the vibrating body and the second pressure transmission member. The second pressure transmission member does not come into contact with the holding member. The first pressure transmission member has a third positioning portion that contacts the holding member and determines the position of the first pressure transmission member relative to the holding member in a plane substantially perpendicular to the direction of pressure applied by the pressure member. The holding member is surrounded by an inner wall that contacts the third positioning portion and has a contact surface having a housing space for housing the first pressure transmission member. A vibrating actuator characterized in that the inner wall is substantially parallel to the direction of pressure.

2. The vibration-type actuator according to claim 1, characterized in that the first pressure transmission member is made of a material that has a higher vibration damping rate than the second pressure transmission member.

3. The first pressure transmission member has a first positioning portion for determining the position of the second pressure transmission member relative to the first pressure transmission member, The vibration-type actuator according to claim 1 or 2, wherein the second pressure transmission member has a second positioning portion that fits with the first positioning portion, and when the first positioning portion and the second positioning portion are fitted together, the movement of the second pressure transmission member relative to the first pressure transmission member by the vibrating body in the driving direction is restricted, and the rotation of the second pressure transmission member relative to the first pressure transmission member about an axis parallel to the pressure direction by the pressure member is restricted.

4. The vibration-type actuator according to claim 3, characterized in that, with the first positioning portion and the second positioning portion fitted together, the second pressure transmission member is capable of tilting with respect to the first pressure transmission member about an axis parallel to the direction perpendicular to the driving direction and the pressurizing direction.

5. The first pressure transmission member extends in a direction perpendicular to the driving direction and the pressurizing direction, and has a substantially elliptical convex shape in a cross-section perpendicular to the extending direction. The vibration-type actuator according to claim 4, characterized in that the second pressure transmission member abuts the first pressure transmission member at or near the ridge of the convex-shaped portion.

6. The first positioning portion is a set of three protrusions provided along the driving direction, The second positioning portion is a set of three holes that engage with the three projections. The vibration actuator according to claim 5, characterized in that, of the three holes, the hole that engages with the middle projection of the three projections is an elongated hole extending in a direction perpendicular to the driving direction and the pressing direction, and the holes that engage with the remaining two projections are elongated holes extending in the driving direction.

7. The vibration-type actuator according to claim 6, characterized in that the central projection is provided on the convex-shaped portion.

8. The vibration-type actuator according to any one of claims 3 to 7, characterized in that it comprises a damping member that contacts the first positioning portion and the second positioning portion.

9. A vibrating actuator according to any one of claims 1 to 8, An optical device characterized by comprising an optical component driven by the aforementioned vibration actuator.

10. A vibrating actuator according to any one of claims 1 to 8, A drive device characterized by comprising an object to be driven by the aforementioned vibrating actuator.

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