Vibration type actuator, optical device, and electronic device

Abstract

To provide a vibration type actuator with improved design freedom.SOLUTION: A vibration type actuator includes a vibrator having an electromechanical energy conversion element and an elastic body, and a contact body that contacts the vibrator, in which the vibrator and the contact body move relatively in a first direction. The vibration type actuator holds a base and the vibrator, and includes a holding member that is held by the base, a rotating body that is held on the base and has a rotation axis extending in a second direction intersecting the first direction, contacts the holding member, and rotates with the relative movement of the vibrator, and an output section that is held by the base so as to be movable in a third direction intersecting the second direction, contacts the rotating body, and moves with the rotation of the rotating body.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration actuator, an optical device, and an electronic device. [Background technology]

[0002] Generally, a vibration actuator obtains driving force by bringing a vibrating body and a driven body into pressurized contact and frictionally driving the vibrating body and the driven body relative to each other using vibration excited in the vibrating body. Therefore, a vibration actuator has a simple structure and a thin shape, and is capable of high-precision and quiet driving. Vibration actuators have been used as driving motors in rotation drive devices such as lens barrels and camera heads, production equipment such as FA equipment (factory automation equipment), and office automation equipment.

[0003] For example, a vibration actuator is known that includes a driven body, a vibrating body in which two protrusions protruding from one surface of a flat elastic body and a piezoelectric element is bonded to the back surface of the elastic body, and a pressure member for pressurizing and contacting the two protrusions with a contact body. Here, the back surface of the elastic body refers to the surface on which the protrusions described below are not formed. In the following, the driven body is also referred to as a "contact body."

[0004] In the vibration actuator having the above-mentioned configuration, a predetermined AC voltage (hereinafter also referred to as "driving voltage") is applied to the electromechanical energy conversion element. The application of the AC voltage generates elliptical or circular motion at the tips of the two protrusions within a plane including the direction connecting the two protrusions and the protruding direction of the protrusions. As a result, the contact body receives a frictional driving force from the two protrusions (vibrating body), and the vibrator and the contact body can be moved relatively in the direction connecting the two protrusions.

[0005] As a linear motion type vibration actuator that performs translational motion, a configuration is known in which the relative movement of a contact body and a vibrator is utilized to obtain an output having the same amount of movement and direction as the relative movement of the contact body and the vibrator through an output unit connected to either the contact body or the vibrator. For example, Patent Document 1 discloses a configuration in which the contact body and the vibrator move relative to each other, and an output unit fixed to a holding member that holds the vibrator moves in accordance with the relative movement of the contact body and the vibrator. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2023-19753 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the vibration actuator shown in the above conventional example, since a vibrator having two protrusions and a rectangular shape that is long in one direction is used, the direction of the output motion (output direction) is limited to the same output direction as the longitudinal direction of the vibrator. Also, since the relative movement between the vibrator and the contact body is used as the output, the amount of movement that is output is limited to the amount of relative movement.

[0008] That is, one object of the present invention is to provide a vibration actuator with improved design freedom, and another object is to provide optical and electronic devices having a vibration actuator with improved design freedom. [Means for solving the problem]

[0009] The vibration actuator of the present invention is a vibration actuator comprising a vibrator having an electromechanical energy conversion element and an elastic body, and a contact body in contact with the vibrator, where the vibrator and the contact body move relatively in a first direction. The vibration actuator of the present invention is characterized by having a base, a holding member that holds the vibrator and is held by the base, a rotor that is held by the base and has a rotation axis extending in a second direction intersecting the first direction, contacts the holding member, and rotates with the relative movement of the vibrator, and an output section that is held by the base so as to be movable in a third direction intersecting the second direction, contacts the rotor, and moves with the rotation of the rotor. Effect of the Invention

[0010] According to the present invention, it is possible to provide a vibration actuator with improved design freedom. Also, according to the present invention, it is possible to provide an optical device and an electronic device having a vibration actuator with improved design freedom. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a vibration actuator according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the vibration actuator shown in FIG. [Diagram 3] 2 is a perspective view for explaining a first vibration mode and a second vibration mode excited in a vibrator that constitutes the vibration actuator shown in FIG. 1. [Figure 4] 1. (a) is a diagram of the vibration actuator shown in FIG. 1 as viewed on the XZ plane, and (b) is a diagram as viewed on the XY plane. [Diagram 5] 2A and 2B are diagrams showing the vibration actuator shown in FIG. 1 as viewed on the XY plane, where (a) shows the vibrating body at the left end of the stroke, (b) at the center, and (c) at the right end. [Figure 6] 1 shows a vibration actuator according to a modified example of the first embodiment of the present invention as viewed in an XY plane. [Figure 7]2A shows a view of a vibration actuator according to a second embodiment of the present invention as viewed in the XZ plane, and FIG. 2B shows a view as viewed in the XY plane. [Figure 8] 8 is a diagram of the vibration actuator shown in FIG. 7 as viewed on the XY plane, where (a) shows the vibrating body at the left end of the stroke, (b) at the center, and (c) at the right end. [Figure 9] FIG. 11 is a perspective view of a vibration actuator according to a third embodiment of the present invention. [Figure 10] FIG. 11 is a perspective view of a vibration actuator according to a modified example of the third embodiment of the present invention. [Figure 11] FIG. 1 is a top view showing a schematic configuration of an imaging device including a vibration type actuator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in further detail below with reference to preferred embodiments.

[0013] In a vibration actuator of the translational movement type, a vibrator having two protrusions and a rectangular shape long in one direction is used, so the direction of the output motion (output direction) is limited to the same output direction as the longitudinal direction of the vibrator. In addition, since the relative movement between the vibrator and the contact body is used as the output, the output movement amount is limited to the relative movement amount. Therefore, the inventors have considered how to improve the design freedom of the vibration actuator. As a result, they have found that by providing a rotating body having a rotation axis extending in a second direction intersecting with the direction (first direction) of the relative movement of the vibrator and the contact body, it is possible to change the output direction of the vibration actuator, thereby improving the design freedom.

[0014] The rotor is held on a base and in contact with a holding member that holds the vibrator, so that the rotor rotates around a rotation axis extending in a second direction in response to relative movement of the vibrator and the contact body. Furthermore, the rotor comes into contact with an output section that is held on the base so as to be movable in a third direction intersecting the second direction, so that the output section moves in response to the rotation of the rotor. Thus, the present invention can convert the output of a vibration actuator, improving the freedom of design.

[0015] Furthermore, whereas conventionally the size of the vibration actuator in the driving direction needed to be larger than the driving amount of the vibrator, by converting the output direction it is possible to reduce the size in the output direction even in a configuration that drives a very small amount.

[0016] Hereinafter, examples of the configuration of the present invention will be described in detail as examples.

[0017] <Example 1> [Configuration of vibration actuator] Fig. 1 is a perspective view showing a schematic configuration of a vibration actuator 100 according to a first embodiment of the present invention. Fig. 2 is an exploded perspective view of the vibration actuator 100.

[0018] The vibration actuator 100 includes a vibrating body 2, a holding member 6, a pressure spring 7, a contact body 8, a vibration-damping rubber 9, a first guide member 10, a second guide member 12, a screw 13, a base 14, a rotating body 15, and an output section 16.

[0019] The vibrating body 2 has an elastic body 3, a piezoelectric element 4, and a flexible printed circuit board (not shown).

[0020] The elastic body 3 is provided with a rectangular main body 3c, two protrusions 3a provided on one surface of the elastic body 3, and a plurality of extensions 3b (four in this embodiment) extending from a plurality of positions (two in this embodiment) in the X direction of the main body 3c. The plurality of extensions 3b protrude from a plurality of positions (four in this embodiment) of the main body 3c that are different in the X direction and the Y direction.

[0021] The piezoelectric element 4, which is an electro-mechanical energy conversion element that converts electrical energy into mechanical energy, is adhered by an adhesive to the surface of the elastic body 3 opposite to the surface on which the protrusions 3a are provided. The piezoelectric element 4 has a structure in which electrodes of a predetermined shape are formed on both sides of a plate-like piezoelectric ceramic. In addition, a flexible printed circuit board (not shown) is fixed to the surface of the piezoelectric element 4 opposite to the surface on which the elastic body 3 is fixed. A drive voltage (AC voltage) of a predetermined frequency is applied to the electrodes of the piezoelectric element 4 from the flexible printed circuit board.

[0022] The elastic body 3 is a metallic elastic member, and is made of, for example, martensitic stainless steel. The elastic body 3 is subjected to, for example, quenching as a hardening treatment to enhance durability. The protrusion 3a is formed integrally with the elastic body 3, for example, by pressing the plate material constituting the elastic body 3. Here, the protrusion 3a has a spring property because it is formed with a predetermined thickness. However, this is not limited thereto, and the protrusion 3a may be fixed to the elastic body 3 by welding or the like. The tip (upper surface) of the protrusion 3a is subjected to a hardening treatment such as quenching to enhance wear resistance, since it is in frictional sliding contact with the contact body 8.

[0023] Here, the X direction, Y direction, and Z direction are defined. The X direction is the direction connecting the two protrusions 3a (tips) of the vibrating body 2, and is also the longitudinal direction of the vibrating body 2. The Z direction is the protruding direction of the protrusions 3a of the vibrating body 2, and is also the direction in which the vibrating body 2 and the contact body 8 are in pressure contact. The Y direction is a direction perpendicular to the X direction and the Z direction, and is also the short side direction of the vibrating body 2. In this specification, up and down correspond to the upward and downward directions in the Z direction, respectively.

[0024] Next, the pressure mechanism according to this embodiment will be described. A holding member 6 that presses and holds the vibrating body 2 is provided below the vibrating body 2, and a second guide member 12 is provided above the vibrating body 2. Two pressure support points 6e provided at one end of the holding member 6 in the X direction and two fitting parts 12b provided on the second guide member 12 are fitted to each other so as to be rotatable around the Y axis direction. A pressure spring 7 is provided between a spring installation part 6f provided at the other end of the holding member 6 in the X direction and the second guide member 12. For example, a tension coil spring can be used as the pressure spring 7. Two protrusions 6a are provided on the holding member 6 at approximately the center position in the X direction between the pressure support point 6e and the pressure spring 7, and the two protrusions 6a are in contact with the vibrating body 2.

[0025] In this way, the pressure mechanism according to this embodiment applies pressure to the vibrating body 2 in the Z direction by the principle of a lever, with the pressure fulcrum 6e as the fulcrum, the spring installation portion 6f as the force point, and the protrusion 6a as the point of action. A contact body 8 is provided above the vibrating body 2, and is in pressure contact with the protrusion 3a of the elastic body 3 in the Z direction by the pressure applied to the vibrating body 2 by the pressure mechanism. This pressure mechanism allows the vibrating body 2, the holding member 6, and the second guide member 12 to move integrally in the X direction. The rotating body receiving portion 6g provided on the surface of the holding member 6 opposite the protrusion 6a will be described later.

[0026] In this embodiment, the pressure fulcrum 6e is provided at one end in the X direction of the holding member 6, and the spring installation portion 6f is provided at the other end. However, the pressure fulcrum 6e and the spring installation portion 6f are not limited to being provided at the ends in the X direction of the holding member 6, and may be provided at positions where they can function as a fulcrum and a point of force of the principle of leverage with the protrusion 6a as the point of action, respectively.

[0027] A vibration-damping rubber 9, a first guide member 10, and a second guide member 12 are provided above the contact body 8. The contact body 8 is fixed to the first guide member 10 by the adhesive force of the vibration-damping rubber 9. The vibration-damping rubber 9 is made of butyl rubber, silicone rubber, or the like, which has high vibration damping performance, and suppresses the generation of unnecessary vibrations in the contact body 8 while the vibration actuator 100 is in operation, thereby suppressing the generation of abnormal noise and preventing a decrease in output. The vibration-damping rubber 9 also plays a role in vibration insulation, making it difficult for vibrations from the vibrating body 2 to be transmitted to the first guide member 10.

[0028] The first guide member 10 is fixed to a base 14, which is a fixed member, by screws 13. The contact body 8, the first guide member 10, and the vibration damping rubber 9 may be fixed by adhesive or screw fastening. The contact body 8 is made of a metal material such as stainless steel, and the friction sliding surface with the protrusion 3a is subjected to a hardening treatment such as nitriding to increase wear resistance.

[0029] The first guide member 10 and the second guide member 12 provided as a guide mechanism are each provided with two rolling grooves 10a, 12a, which sandwich two rolling balls 11. As a result, when the vibration actuator 100 is driven, the rolling balls 11 roll in the rolling grooves 10a, 12a, allowing the vibrating body 2, the holding member 6, and the second guide member 12 to move smoothly in the X direction. The first guide member 10 and the second guide member 12 are required to have a certain level of hardness in order to receive pressure in the respective rolling grooves 10a, 12a, and therefore metal, particularly stainless steel, is used for them from the viewpoint of workability.

[0030] The base 14 is provided with two fixing parts 14a provided with screw holes and retaining parts for fixing the first guide member 10 and holes for fixing the base 14 to a device to be driven, a connecting part 14b connecting them, a groove part 14c, and a collision prevention part 14d. The groove part 14c is formed in a part of the connecting part 14b along the X direction. The groove part 14c and the tilt regulation part 12c provided on the second guide member 12 are fitted loosely, that is, fitted in a state with a predetermined play, so that the rotation of the vibrator 2 and the like around the X axis can be regulated. The collision prevention part 14d extends from the fixing part 14a to the holding member 6 side in the X direction, and can prevent the pressure support fulcrum 6e and the spring installation part 6f of the holding member 6 from colliding with the fixing part 14a as the holding member 6 moves. The base 14 is formed of a resin material from the viewpoint of workability and slidability.

[0031] [Driving principle of vibration actuator] Next, the vibration modes excited in the vibrating body 2 will be described with reference to Figures 3(a) and 3(b). In this embodiment, an AC voltage is applied to the piezoelectric element 4 through a flexible printed circuit board to excite standing waves (out-of-plane bending vibrations) that are out of phase with each other in the vibrating body 2, and a vibration that combines these out-of-plane bending vibrations is generated. Figure 3(a) shows the vibrating body 2 vibrating in mode A, which is the first vibration mode, and Figure 3(b) shows the vibrating body 2 vibrating in mode B, which is the second vibration mode.

[0032] Mode A, which is the first vibration mode, is a primary out-of-plane bending vibration mode in which two nodes appear parallel to the X direction, which is the longitudinal direction of the vibrating body 2. Vibration in mode A displaces the two protrusions 3a in the Z direction, which is the pressure direction. Mode B, which is the second vibration mode, is a secondary out-of-plane bending vibration mode in which three nodes appear approximately parallel to the Y direction, which is the short-side direction of the vibrating body 2. Vibration in mode B displaces the two protrusions 3a in the X direction.

[0033] By combining the vibrations of Mode A and Mode B, the two protrusions 3a perform elliptical or circular motion within the XZ plane. By bringing the contact body 8 into pressure contact with the protrusions 3a, a frictional force is generated in the X direction, generating a driving force that moves the vibrating body 2 and the contact body 8 relatively. In this embodiment, since the contact body 8 is fixed to the base 14 as described above, the vibrating body 2 moves in the X direction. In other words, the vibrating body 2 moves in the same direction as the longitudinal direction of the rectangular vibrating body 2.

[0034] In order to efficiently drive the vibration actuator 100, it is necessary to support the vibrating body 2 without impeding the vibrations of the two vibration modes excited in the vibrating body 2, and for this purpose, it is desirable to support the vicinity of the nodes of the two vibration modes. For this reason, two protrusions 6a are provided on the holding member 6 in order to pressurize and hold the common node of the two vibration modes excited in the vibrating body 2. In addition, by positioning the vibrating body 2 in the X and Y directions with the retaining portion 6c provided on the holding member 6, the two protrusions 6a can be brought into contact with the vibrating body 2 near the nodes of the two vibration modes.

[0035] Furthermore, the protrusions 6a not only pressurize the vibrating body 2, but also hold the vibrating body 2 in the X and Y directions by frictional force. In this embodiment, the maximum value of the static frictional force between the protrusions 6a and the vibrating body 2 is always greater than the reaction force that the vibrating body 2 receives from the contact body 8 when driving the vibrating body 2, so the vibrating body 2 does not move relative to the holding member 6. This enables driving that performs high-precision positioning.

[0036] [Output transmission mechanism] Next, the output transmission mechanism according to this embodiment will be described with reference to FIGS.

[0037] FIG. 4(a) is a diagram of the vibration actuator 100 as viewed on the XZ plane, and FIG. 4(b) is a diagram as viewed on the XY plane.

[0038] The output transmission mechanism according to this embodiment is composed of a rotor receiving portion 6 g provided on the holding member 6 , a rotor 15 , and an output portion 16 .

[0039] The rotor 15 is composed of a roller portion 15a, which is a roller-shaped rotating portion acting as a smooth roller, and a rotor shaft portion 15b. The roller portion 15a is a metallic roller, and is rotatable about the Z axis, which is the axial direction of the rotor shaft portion 15b. The roller portion 15a is in contact with a rotor contact surface 6h of the rotor receiving portion 6g of the holding member 6. The rotor contact surface 6h is a surface parallel to the XZ plane consisting of the driving direction and pressure direction of the vibration actuator 100, and has a smooth surface. The roller portion 15a is not limited to being made of metal, and may be made of a rubber roller, a resin roller, or the like, and may be appropriately selected depending on the environment and the magnitude of the thrust.

[0040] The rotor shaft portion 15b is fixed to the shaft fixing portion 14e of the base 14a, and is disposed so that the rotor contact surface 6h and the roller portion 15a are biased with a predetermined force in the Y-axis direction. This drives the vibration actuator 100, and the holding member 6 moves in the X-direction, which is the first direction. The roller portion 15a of the rotor 15 rolls on the rotor contact surface 6h according to the amount of movement, and rotates around the Z-axis with respect to the rotor shaft portion 15b, which is a rotation axis extending in the Z-axis direction (second direction).

[0041] Here, the rotating body 15 is preferably disposed so as to be located inside the holding member 6 in the Y and X directions. In other words, it is preferable that the rotating body 15 is shorter in length in the Y direction than the holding member 6 and is located inside the position occupied by the holding member. More preferably, in a plane including the Y and X directions, the rotating body 15 is shorter in length in the Y and X directions than the holding member 6 and is located inside the area projected by the holding member. With this configuration, even if the rotating body 15 is provided, the vibration actuator 100 does not become larger, and a small shape can be maintained.

[0042] The output section 16 has a D-cut surface 16a, part of which is a flat surface parallel to the YZ plane, and is supported so as to be movable in the Y direction relative to the output guide section 14f of the base 14. In addition, the D-cut surface 16a supports the output section 16 so as not to rotate around the Y axis relative to the output guide section 14f.

[0043] The D-cut surface 16a is also in contact with the roller portion 15a of the rotating body 15, and is arranged so as to be biased with a predetermined force in the X-axis direction. As a result, when the roller portion 15a rotates around the Z-axis, the output portion 16 translates in the Y-direction according to the amount of rotation.

[0044] That is, when the vibration actuator 100 is driven and the holding member 6 translates in the X direction, the roller portion 15a of the rotor 15 in contact with the rotor receiving portion 6g rotates around the Z axis, and the output portion 16 in contact with the roller portion 15a translates in the Y direction, which is the third direction. Thus, the translational movement of the vibration actuator 100 in the X direction is converted into the translational movement of the output portion 16 in the Y direction at a ratio of 1:1 and output. Note that although the third direction here is the Y direction, the output direction of the output portion is not limited to the Y direction. That is, the configuration is not limited to the configuration in which the vibrator and the contact body relatively translate in the X direction, which is the first direction, and the output portion translates in the Y direction, which is approximately perpendicular to the X direction, but may be a configuration in which the output portion moves in a direction different from or opposite to the Y direction, as described later.

[0045] This makes it possible to convert and output the direction of relative movement between the vibrating body 2 and the contact body 8 of the vibration actuator 100, thereby improving the degree of freedom in designing the vibration actuator 100.

[0046] Here, with reference to FIG. 5, a case where the driving amount is 2 mm will be described as an example of driving the output section in this embodiment.

[0047] FIG. 5 is a diagram of the vibration actuator 100 viewed on the XY plane, where (a) shows the vibrating body 2 at the left end of the stroke, (b) at the center, and (c) at the right end.

[0048] 5, when the vibrating body 2 moves 2 mm from the left end to the right end in the X direction relative to the contact body 8, the roller portion 15a of the rotating body 15 rotates counterclockwise around the Z axis, and the output portion 16 moves 2 mm from bottom to top in the Y direction. Conversely, when the vibrating body 2 moves 2 mm from the right end to the left end, the roller portion 15a of the rotating body 15 rotates clockwise around the Z axis, and the output portion 16 moves 2 mm from top to bottom in the Y direction. In other words, the relative movement in the X direction between the vibrating body 2 and the contact body 8 of the vibration actuator 100 is converted into a translational movement in the Y direction of the output portion 16 at a ratio of 1:1 by the rolling of the rotation of the roller portion 15a of the rotating body 15, and is output.

[0049] The dimension L1 in the X direction, which is the relative movement direction of the vibrating body 2 and the contact body 8 of the vibration actuator 100, is larger than the stroke because the contact body 8 and the first guide member 10 require a certain length in the X direction. Furthermore, when two protrusions 3a are provided on the vibrating body 2 as in this embodiment, the contact body 8 needs to be in constant contact with the two protrusions 3a. Therefore, the contact body 8 needs to be larger in the X direction by the distance between the protrusions 3a in addition to the stroke, which further increases the dimension L1.

[0050] On the other hand, the dimension L2 of the vibration actuator 100 in the Y direction, which is the output direction of the output section 16, is determined by the size of the vibrating body 2 in the Y direction and the size of the connecting section 14b of the base 14 in the Y direction, and is much smaller than the dimension L1 in the X direction.

[0051] As a result, in the case of 2 mm drive as in this embodiment, the movement range of the output section 16 falls within the L2 dimension of the base 14, making it possible to reduce the size of the vibration actuator 100 in the output direction.

[0052] When driving an optical device such as a lens barrel, in the past, even if one wanted to make the barrel thinner in the optical axis direction, there was a limit to how far the barrel could be miniaturized because the direction of relative movement between the vibrating body 2 and contact body 8 of the vibration actuator 100 was the same as the output direction of the vibration actuator 100.

[0053] On the other hand, as in this embodiment, by converting the drive in the relative movement direction of the vibrating body 2 and contact body 8 of the vibration actuator 100 into an output (movement) in the Y direction, the Y direction of the vibration actuator 100 can be arranged in the optical axis direction of the lens barrel. This makes it possible to reduce the size of the lens barrel in the optical axis direction. Note that, since the X direction of the vibration actuator 100 can be arranged in the radial direction of the lens barrel where there is relatively more space, it is possible to prevent the radial dimension of the lens barrel from becoming large.

[0054] In this embodiment, the output direction is changed by the rolling of the roller portion 15a. Therefore, the movement of the vibrating body 2 can be transmitted to the output portion 16 without any backlash, and the vibration actuator 100 can be driven with high precision with quiet operation and good controllability. In order to drive with high precision, the frictional forces between the rotating body contact surface 6h and the roller portion 15a, and between the D-cut portion 16a of the output portion 16 and the roller portion 15a are made sufficiently large relative to the thrust force to be generated, so that the force can always be transmitted by rolling without slippage.

[0055] In this embodiment, the roller part is biased to the output part by a biasing force generated by holding the roller part in a fixed position so that the roller part is in a position where a desired frictional force can be obtained. However, this is not limited to this, and the roller part may be biased to the output part by a biasing force of a spring or an attractive force of a magnet.

[0056] Furthermore, in this embodiment, an encoder may be provided that detects the rotational position of the roller portion 15a of the rotor 15. This makes it possible to detect the amount of rotation, and therefore the amount of drive of the vibration actuator 100 in the translational direction.

[0057] Conventionally, an encoder for translational drive requires a scale, which is the part to be detected by the encoder, for the stroke in the drive direction, and therefore requires space. In this embodiment, translational motion is converted into rotational motion, and then converted back into translational motion, so that the final translational motion amount can be detected by detecting the amount of rotation. Therefore, a scale for the stroke of the translational drive amount is not necessary, and it is sufficient to detect the amount of rotation, so that a vibration actuator 100 that is smaller in size and capable of position detection can be realized.

[0058] In this embodiment, the stroke is set to 2 mm, but this is not limiting, and a stroke required for the object to be driven may be appropriately selected and applied.

[0059] In the present embodiment, the driving direction is changed by transmitting rotation through the rolling of the roller portion 15a, but the present invention is not limited to this configuration.

[0060] [Variations] FIG. 6 shows a vibration actuator 200 in a first modified example of the vibration actuator according to this embodiment, viewed on the XY plane.

[0061] 6, when the requirement for positioning accuracy of the drive of the vibration actuator 200 is relatively low and a simpler configuration is desired, it is possible to change the drive direction using gears and a rack. That is, it is possible to provide the rotor with a gear part 115a, which is a gear-shaped rotating part, and provide a gear contact surface 106h, which is a rack part that meshes with and comes into contact with the gear part 115a, on the rotor receiving part 106g of the holding member 106.

[0062] The rotating body 115 is composed of a gear part 115a on which a gear is formed and a rotating body shaft part 115b. The gear part 115a is a resin gear and is rotatable around the Z axis, which is the axial direction of the rotating body shaft part 115b. The gear part 115a meshes with a gear contact surface 106h formed on the rotating body receiving part 106g of the holding member 106. The gear contact surface 106h acts as a so-called rack with respect to the gear part 115a. As a result, when the vibration type actuator 200 is driven and the holding member 106 moves in the X direction, the gear part 115a of the rotating body 115 rotates around the Z axis with respect to the rotating shaft part 115b by meshing with the gear contact surface 106h according to the amount of movement. The gear part 115a is not limited to being made of resin, and may be made of metal or the like.

[0063] The output part 116 also has a gear contact surface 116a, which meshes with the gear part 115a of the rotating body 115 and acts as a so-called rack. As a result, when the gear part 115a rotates around the Z axis, the output part 116 translates in the Y direction according to the amount of rotation.

[0064] In other words, when the vibration actuator 200 is driven and the holding member 106 translates in the X direction, the gear part 115a of the rotor 115 in contact with the rotor receiving part 106g rotates around the Z axis, and further the output part 116 in contact with the gear part 115a translates in the Y direction. Therefore, the translational movement of the vibration actuator 200 in the X direction is converted into the translational movement of the output part 116 in the Y direction at a ratio of 1:1 and output.

[0065] This makes it possible to convert and output the direction of relative movement between the vibrating body 102 and the contact body 108 of the vibration actuator 200, thereby improving the degree of freedom in designing the vibration actuator 200.

[0066] Furthermore, because transmission is by gears, there is no need for a means for applying a biasing force or high-precision processing, as compared with transmission by rolling, so the vibration actuator 200 can be made smaller and simpler, and manufacturing costs can be reduced. In addition, because no slippage occurs, it is possible to transmit a higher thrust than by rolling.

[0067] <Example 2> As Example 2, a configuration example of a vibration actuator having a different form from Example 1 will be described with reference to Fig. 7. This example differs from the structure shown in Fig. 1 in that two output sections 216 are provided as shown in Fig. 7, as compared to Example 1. The other elements of this example are the same as the corresponding ones in Example 1 described above, and description thereof will be omitted.

[0068] FIG. 7(a) shows a view of the vibration actuator 300 of this embodiment as viewed on the XZ plane, and FIG. 7(b) shows a view as viewed on the XY plane.

[0069] The output transmission mechanism of the vibration actuator 300 shown in FIG. 7 is made up of a rotating body receiving portion 206g provided on the holding member 206, a rotating body 215, and two output portions 216-1 and 216-2.

[0070] The rotor 215 is made up of a roller portion 215a that acts as a smooth roller and a rotor shaft portion 215b. The roller portion 215a is rotatable around the Z axis, which is the axial direction of the rotor shaft portion 215b. The roller portion 215a is in contact with a rotor contact surface 206h of the rotor receiving portion 206g of the holding member 206. The rotor contact surface 206h is a surface parallel to the XZ plane consisting of the drive direction and pressure direction of the vibration actuator 100, and has a smooth surface.

[0071] The rotor shaft portion 215b is fixed to the shaft fixing portion 214e of the base 214a, and is disposed so that the rotor contact surface 206h and the roller portion 215a are biased with a predetermined force in the Y-axis direction. As a result, when the vibration actuator 300 is driven and the holding member 206 moves in the X-axis direction, the roller portion 215a of the rotor 215 rolls on the rotor contact surface 206h according to the amount of movement, thereby rotating around the Z-axis relative to the rotor shaft portion 215b.

[0072] The two output sections 216-1, 216-2 have D-cut surfaces 216-1a, 216-2a that are partially planar surfaces parallel to the YZ plane, and are supported slidably in the Y direction relative to the base 214 and supported so as not to rotate around the Y axis. In addition, the two output sections 216-1, 216-2 are supported so that the D-cut surfaces 216-1a, 216-2a face each other in the X direction.

[0073] The D-cut surfaces 216-1a and 216-2a are arranged so as to come into contact with the roller portion 215a of the rotating body 215 and are biased with a predetermined force in the X-axis direction. As a result, when the roller portion 215a rotates around the Z-axis, the output portions 216-1 and 216-2 translate in the Y-direction according to the amount of rotation.

[0074] Here, with reference to FIG. 8, a case where the driving amount is 2 mm will be described as an example of driving the output section in this embodiment.

[0075] FIG. 8 is a diagram of the vibration actuator 300 viewed on the XY plane, where (a) shows the vibration body 202 at the left end of the stroke, (b) at the center, and (c) at the right end.

[0076] As shown in FIG. 8, when the vibrating body 202 moves 2 mm from the left end to the right end in the X direction, which is the first direction, relative to the contact body 208, the roller part 215a of the rotating body 215 rotates in the counterclockwise direction around the Z axis, which is the rotation axis extending in the second direction. As a result, the output part 216-1 moves 2 mm from bottom to top in the Y direction, and the output part 216-2 moves 2 mm from top to bottom in the Y direction. Conversely, when the vibrating body 2 moves 2 mm from the right end to the left end, the roller part 215a of the rotating body 215 rotates in the clockwise direction around the Z axis. As a result, the output part 216-1 moves 2 mm from top to bottom in the Y direction, and the output part 216-2 moves 2 mm from bottom to top in the Y direction.

[0077] In other words, the relative movement in the X direction between the vibration body 202 and the contact body 208 of the vibration actuator 300 is converted into translational movement in the Y direction of the output units 216-1 and 216-2 at a ratio of 1:1 and outputted by the rotation and rolling of the roller unit 215a of the rotating body 215. In addition, the output units 216-1 and 216-2 move in opposite directions to each other in the Y direction, which is a third direction.

[0078] By using a configuration in which the actuators move in opposite directions, for example, the opening and closing operation of a gripper of a robot, which is an electronic device, can be realized by one vibration actuator 300. When the vibration actuator of the present invention is used for a gripper of a robot, for example, by providing one member constituting a gripper in each of the output units 216-1 and 216-2 and driving them, it is possible to pinch and release a target object between the members. In addition, since the direction of the opening and closing operation and the relative movement direction of the vibrating body 202 and the contact body 208 of the vibration actuator 300 are perpendicular to each other, it is possible to arrange the vibration actuator 300 without increasing the gripper size in the opening and closing operation direction.

[0079] In this embodiment as well, the output direction is changed by the rolling of the roller portion 215a. Therefore, the movement of the vibrating body 202 can be transmitted to the output portion 216 without any backlash, and the vibration actuator 300 can be driven quietly and with good controllability with high accuracy.

[0080] <Example 3> As Example 3, a configuration example of a vibration actuator having a different form from Example 1 will be described with reference to Fig. 9. This example differs from Example 1 in that a rotor 315 as shown in Fig. 9 is used. Other elements of this example are the same as those corresponding to Example 1 described above, and description thereof will be omitted.

[0081] FIG. 9 is an enlarged perspective view of a portion of a vibration actuator 400 according to this embodiment.

[0082] The output transmission mechanism of the vibration actuator 400 shown in FIG. 9 is made up of a rotor receiving portion 306g provided on the holding member 306, a rotor 315, and an output portion 316. The output transmission mechanism of the vibration actuator 400 shown in FIG.

[0083] Rotating body 315 is a first rotating part and a second rotating part, and is composed of first roller part 315a-1 and second roller part 315a-2 acting as smooth rollers, and rotating body shaft part 315b. Note that the first rotating part and the second rotating part are not limited to smooth rollers, and may be gear-shaped rotating parts shown as a modified example.

[0084] The two roller portions 315a-1 and 315a-2 are rotatable around the Z axis, which is the axial direction of the rotor shaft portion 315b. The diameter of the first roller portion 315a-1 is twice as large as the diameter of the second roller portion 315a-2.

[0085] The first roller portion 315a-1 is in contact with a rotating body contact surface 306h of the rotating body receiving portion 306g of the holding member 306. The rotating body contact surface 306h is a surface parallel to the XZ plane consisting of the driving direction and pressure direction of the vibration actuator 300, and has a smooth surface.

[0086] The rotor shaft portion 15b is fixed to the shaft fixing portion 14e of the base 14a, and is disposed so that the rotor contact surface 6h and the roller portion 15a are biased with a predetermined force in the Y-axis direction. As a result, when the vibration actuator 100 is driven and the holding member 6 moves in the X-axis direction, the roller portion 15a of the rotor 15 rolls on the rotor contact surface 6h according to the amount of movement, thereby rotating around the Z-axis relative to the rotor shaft portion 15b.

[0087] The output section 316 has a D-cut surface 316a, part of which is a flat surface parallel to the YZ plane, and is supported so as to be slidable in the Y direction relative to a base 314 (not shown), and is supported by the D-cut surface 316a so as not to rotate around the Y axis.

[0088] The D-cut surface 316a is in contact with the second roller portion 315a-2 of the rotating body 315, and when the second roller portion 315a-2 rotates around the Z axis, the output portion 316 translates in the Y direction according to the amount of rotation.

[0089] In other words, when the vibration actuator 400 is driven and the holding member 306 translates in the X direction, the first roller portion 315a-1 and the second roller portion 315a-2 of the rotor 315 in contact with the rotor receiving portion 306g rotate integrally around the Z axis. Furthermore, the output portion 316 in contact with the second roller portion 315a-2 translates in the Y direction. Therefore, the translational movement of the vibration actuator 400 in the X direction is decelerated at a ratio of 2:1 and converted into the translational movement of the output portion 316 in the Y direction and output.

[0090] This makes it possible to convert and output the direction of relative movement between the vibrating body 302 and the contact body 308 of the vibration actuator 400, thereby making it possible to reduce the size of the vibration actuator 400 in the output direction.

[0091] Furthermore, by making the diameter of the second roller portion 315a-2 half that of the first roller portion 315a-1, the force can be reduced by a double reduction ratio and output, thereby doubling the thrust of the vibration actuator 400. Therefore, the relationship between thrust and speed can be changed by changing the diameters of the two roller portions of the rotor 315 according to the specifications of the object to be driven, making it possible to accommodate a variety of objects to be driven.

[0092] In this embodiment, the ratio of the diameters of the first roller portion 315a-1 and the second roller portion 315a-2 in the configuration of the speed reduction mechanism is set to 2:1, but this is not limited to this and may be changed as appropriate. Note that the speed and the amount of movement decrease as the thrust increases.

[0093] Also, the diameter of the second roller portion 315a-2 may be made larger than the diameter of the first roller portion 315a-1, and used as a speed increasing mechanism. This allows output at a speed faster than the speed of the relative movement between the vibrating body 2 and the contact body 8 of the vibration actuator 100. At the same time, the stroke can be lengthened. However, the thrust force is correspondingly reduced.

[0094] Furthermore, although the rotating body 315 is formed of two roller parts with different diameters, this is not limited to this, and it may be formed of two gears with different diameters, and racks may be provided on the rotating body receiving part and the output part, respectively.

[0095] Furthermore, the movement of the vibration actuator 400 in the X direction is converted into the Y direction by decelerating it, but the present invention is not limited to this.

[0096] For example, as in the modified example of this embodiment shown in FIG. 10, the output unit 416 may be arranged so as to be movable in the same direction as the X direction, which is the first direction. In this way, the vibration actuator 500 is driven, and the holding member 406 translates in the X direction from left to right in the figure. Furthermore, the first roller portion 415a-1 and the second roller portion 415a-2 of the rotating body 415 in contact with the rotating body receiving portion 406g rotate integrally around the Z axis. As a result, the output unit 416 in contact with the second roller portion 415a-2 translates in the Y direction from right to left in the figure.

[0097] In other words, the output direction (X direction) remains the same, but the direction can be reversed to produce a decelerated output.

[0098] <Example 4> 11 is a top view showing a schematic configuration of an imaging device 60, which is an example of an optical device equipped with the vibration actuator 100 of the present invention. The imaging device 60 has an imaging device body 61 having an imaging element (not shown) on which light passing through a lens described later forms an image, and a lens barrel 62 that is detachable from the imaging device body 61. The lens barrel 62 includes a plurality of lens groups 63 (lenses), which are examples of optical elements, a focus adjustment lens 64 (lens), and the vibration actuator 100. A lens holding frame (not shown) that holds the focus adjustment lens 64 is connected to an output section 16, which is a moving body in the vibration actuator 100. By driving the vibration actuator 100, the focus adjustment lens 64 can be driven in the optical axis direction to focus on a subject.

[0099] When a zoom lens is arranged in the lens barrel 62, the vibration actuator 100 can also be used as a drive source for moving the zoom lens in the optical axis direction. Furthermore, when an image blur correction lens is arranged in the lens barrel 62, the vibration actuator 100 can be used as a drive source for driving the image blur correction lens in a plane perpendicular to the optical axis.

[0100] Although the present invention has been described in detail based on the preferred embodiments, the present invention is not limited to these specific embodiments, and various forms within the scope of the gist of the present invention are also included in the present invention. Furthermore, each of the above-mentioned embodiments shows only one embodiment of the present invention, and each embodiment can be appropriately combined.

[0101] The disclosure of this embodiment includes the following configuration.

[0102] (Configuration 1) A vibration actuator comprising: a vibrator having an electromechanical energy conversion element and an elastic body; and a contact body in contact with the vibrator, the vibrator and the contact body moving relatively in a first direction, Foundation, a holding member that holds the vibrator and is held by the base; a rotor that is supported by the base and has a rotation axis that extends in a second direction that intersects the first direction, the rotor being in contact with the support member and rotating in accordance with the relative movement of the transducer; and an output section that is held by the base so as to be movable in a third direction intersecting the second direction, that comes into contact with the rotating body, and that moves in accordance with the rotation of the rotating body; A vibration actuator comprising:

[0103] (Configuration 2) The vibration actuator described in configuration 1, characterized in that the rotating body has a length shorter than that of the holding member in the third direction and is located inside the position occupied by the holding member.

[0104] (Configuration 3) The vibration actuator described in configuration 1 or 2, characterized in that, in a plane including the first direction and the third direction, the rotating body has a length in the first direction and a length in the third direction smaller than those of the holding member, and is located inside the area projected by the holding member.

[0105] (Configuration 4) The rotating body has a roller-shaped rotating portion, 4. The vibration actuator according to any one of configurations 1 to 3, wherein the rotating portion is in contact with the holding member.

[0106] (Configuration 5) The rotating body has a gear-shaped rotating part, 4. The vibration actuator according to any one of configurations 1 to 3, wherein the holding member has a rack portion that meshes with and comes into contact with the rotating portion.

[0107] (Configuration 6) the vibration actuator has two output sections, 6. The vibration actuator according to any one of configurations 1 to 5, wherein the two output sections move in opposite directions to each other in the third direction.

[0108] (Configuration 7) the rotating body has a first rotating portion in contact with the holding member and a second rotating portion in contact with the output portion, 7. The vibration actuator according to any one of configurations 1 to 6, wherein the first rotating portion and the second rotating portion have different diameters.

[0109] (Configuration 8) 8. The vibration actuator according to configuration 7, wherein the diameter of the first rotating part is larger than the diameter of the second rotating part.

[0110] (Configuration 9) 8. The vibration actuator according to configuration 7, wherein the diameter of the first rotating part is smaller than the diameter of the second rotating part.

[0111] (Configuration 10) 10. The vibration actuator according to any one of configurations 1 to 9, wherein the first direction and the third direction are substantially perpendicular to each other.

[0112] (Configuration 11) 10. The vibration actuator according to any one of configurations 1 to 9, wherein the first direction and the third direction are the same direction.

[0113] (Configuration 12) 12. The vibration actuator according to any one of configurations 1 to 11, wherein the vibrator has a rectangular shape, and a longitudinal direction of the vibrator and the first direction are the same direction.

[0114] (Configuration 13) 13. The vibration actuator according to any one of configurations 1 to 12, wherein the elastic body has two protrusions, and the protrusions and the contact body are in contact with each other.

[0115] (Configuration 14) A vibration actuator according to any one of configurations 1 to 13, An optical device comprising at least one of an optical element and an imaging element driven by the vibration type actuator.

[0116] (Configuration 15) The material, 14. An electronic device comprising the vibration actuator according to any one of configurations 1 to 13 for driving the member. [Explanation of symbols]

[0117] 2. Vibration body 3 Elastic body 4. Piezoelectric element (electromechanical energy conversion element) 6 Holding part 6g Rotating body receiving part 8 Contact body 14 Foundation 15 Rotating Body 15a Roller part 16 Output section

Claims

1. A vibration actuator comprising: a vibrator having an electromechanical energy conversion element and an elastic body; and a contact body in contact with the vibrator, the vibrator and the contact body moving relatively in a first direction, Foundation, a holding member that holds the vibrator and is held by the base; a rotor that is supported by the base and has a rotation axis that extends in a second direction that intersects the first direction, the rotor being in contact with the support member and rotating in accordance with the relative movement of the transducer; and an output section that is held by the base so as to be movable in a third direction intersecting the second direction, that comes into contact with the rotating body, and that moves in accordance with the rotation of the rotating body; A vibration actuator comprising:

2. 2. The vibration actuator according to claim 1, wherein the rotor has a length shorter than that of the holding member in the third direction and is located inside a position occupied by the holding member.

3. The vibration actuator according to claim 2, characterized in that, in a plane including the first direction and the third direction, the rotating body has a length in the first direction and a length in the third direction smaller than those of the holding member, and is located inside the area projected by the holding member.

4. The rotating body has a roller-shaped rotating portion, 2. The vibration actuator according to claim 1, wherein the rotating portion is in contact with the holding member.

5. The rotating body has a gear-shaped rotating part, 2. The vibration actuator according to claim 1, wherein the holding member has a rack portion that meshes with and contacts the rotating portion.

6. the vibration actuator has two output sections, 2. The vibration actuator according to claim 1, wherein the two output portions move in opposite directions to each other in the third direction.

7. the rotating body has a first rotating portion in contact with the holding member and a second rotating portion in contact with the output portion, 2. The vibration actuator according to claim 1, wherein the first rotating portion and the second rotating portion have different diameters.

8. 8. The vibration actuator according to claim 7, wherein the diameter of the first rotating part is larger than the diameter of the second rotating part.

9. 8. The vibration actuator according to claim 7, wherein the diameter of the first rotating part is smaller than the diameter of the second rotating part.

10. 2. The vibration actuator according to claim 1, wherein the first direction and the third direction are substantially perpendicular to each other.

11. 2. The vibration actuator according to claim 1, wherein the first direction and the third direction are the same direction.

12. 2. The vibration actuator according to claim 1, wherein the vibrator has a rectangular shape, and a longitudinal direction of the vibrator is the same as the first direction.

13. 2. The vibration actuator according to claim 1, wherein the elastic body has two protrusions, the protrusions and the contact body are in contact with each other.

14. A vibration actuator according to any one of claims 1 to 13, An optical device comprising at least one of an optical element and an imaging element driven by the vibration type actuator.

15. The material, 14. An electronic device comprising the vibration actuator according to claim 1 for driving the member.

Images