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 further includes a holding member that holds a base and the vibrator, has an inclined plane that is held by the base and intersects with the first direction, and moves in the first direction with the relative movement of the vibrator, and an output section that is held by the base so as to be movable in a second direction that intersects with the first direction, abuts against the inclined plane, and moves with the movement of the holding member.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] There are various known configurations of vibration actuators using electromechanical energy conversion elements such as piezoelectric elements that convert electrical energy into mechanical energy. For example, there is a vibration actuator having a contact body, a vibrator in which two protrusions are provided on the 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 the two protrusions and the contact body. Here, the back surface of the elastic body refers to the surface on which the protrusions described later are not formed.

[0003] In this vibration actuator, by applying a predetermined AC voltage (hereinafter also referred to as "driving voltage") to the electromechanical energy conversion element, elliptical or circular motion is generated 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 (vibrators), and the vibrator and the contact body can be moved relatively (hereinafter also referred to as "relative movement") in the direction connecting the two protrusions.

[0004] A vibration actuator obtains power to drive a driven body from such relative movement. For example, in the vibration actuator disclosed in Patent Document 1, a tension spring is arranged with an axis provided on a holding member that holds a vibrator as a fulcrum, a protrusion as a point of application, and a spring installation part formed on a pressure member that engages with the axis as a point of force. The vibrator is biased by the tension spring using the principle of a lever, and is in pressure contact with the contact body. Then, an output part formed on the holding member engages with the driven body, thereby transmitting the driving force of the vibration actuator to the driven body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-19753 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the vibration actuator described in Patent Document 1 uses a vibrator that has two protrusions and is rectangular in shape and long in one direction, so 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.

[0007] 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]

[0008] 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, has a slope that intersects with the first direction, and moves in the first direction with the relative movement of the vibrator, and an output section that is held by the base so as to be movable in a second direction that intersects with the first direction, abuts against the slope, and moves with the movement of the holding member. Effect of the Invention

[0009] 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]

[0010] [Figure 1] FIG. 1 is an exploded perspective view of a vibration actuator according to a first embodiment of the present invention. [Diagram 2] 1A is an isometric projection view, FIG. 1B is a front view, FIG. 1C is an AA cross-sectional view, and FIG. 1D is a BB cross-sectional view of a vibration actuator according to a first embodiment of the present invention. [Diagram 3] FIG. 2 is a vibration mode diagram in the first embodiment of the present invention. [Figure 4] 1A is a bottom view of a vibration actuator according to a first embodiment of the present invention when outputting in the Y direction, and FIG. 1B is an enlarged bottom view of the vibration actuator. [Diagram 5] 1A and 1B are bottom views showing the generation of force of the vibration actuator when configured to output in the Y direction in Example 1 of the present invention, where (a) is a bottom view when driven to the left side of the page, and (b) is a bottom view when driven to the right side of the page. [Figure 6] 1A is an isometric projection view, FIG. 1B is an enlarged front view showing the generation of force of a vibration actuator in a configuration for outputting in the Z direction in Example 1 of the present invention, and FIG. 1C is a front view when driven to the right side of the page. [Figure 7] 1A is a bottom view of Example 2 of the present invention, FIG. 1B is an enlarged bottom view, and FIG. 1C is a bottom view showing the generation of force of a vibration actuator when driven to the left side of the page. [Figure 8] 13A is a bottom view of the third embodiment of the present invention, FIG. 13B is an enlarged bottom view, and FIG. 13C is a bottom view of the third embodiment when driven to the left side of the page. [Figure 9] 13A and 13B are a top view and a block diagram showing a schematic configuration of an imaging device using a vibration actuator according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in further detail below with reference to preferred embodiments.

[0012] 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 cam member having a slope and an output part abutting the slope to a holding member that holds the vibrator, it is possible to obtain an output in a second direction that intersects with the first direction, which is the direction of the relative movement of the vibrator.

[0013] That is, in the configuration of the present invention, the drive direction and output direction can be converted by the following mechanism. First, the vibrator moves in a first direction, and the holding member that holds the vibrator moves with the movement of the vibrator. The output section that abuts against the slope of the holding member is held on the base so as to be movable in a second direction that intersects with the first direction, and therefore moves in the second direction with the movement of the holding member. This makes it possible to obtain an output in a direction different from the drive direction, and to provide a vibration actuator with improved design freedom.

[0014] 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.

[0015] Hereinafter, examples of the configuration of the present invention will be described in detail as examples.

[0016] Example 1 This embodiment is an example in which the present invention is applied to a reciprocating vibration actuator, and its details will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is an exploded perspective view of a vibration actuator 1 in the first embodiment of the present invention, and Fig. 2 is an isometric projection view of the vibration actuator in the first embodiment. Here, the relative movement direction of the vibrator 2 is defined as the X direction, the pressure direction as the Z direction, and the direction perpendicular to the X direction and the Z direction as the Y direction.

[0017] The elastic body 3 has a rectangular main body 3c and a plurality of (here, 2 locations x 2 = 4) extension parts 3b extending from a plurality of positions (here, 2 locations) in the X direction of the main body 3c. The plurality of (here, 4) extension parts 3b are located at different positions in the X direction of the main body 3c and at different positions in the direction perpendicular to the X direction and the Z direction. It can also be said that they protrude from a plurality of positions (here, 4 locations) of the main body 3c.

[0018] A piezoelectric element 4, which is an electromechanical energy conversion element, is fixed to the elastic body 3 with an adhesive or the like, and further a flexible printed circuit board (not shown) is fixed to the piezoelectric element 4 on the side opposite the elastic body 3, these forming the vibrator 2. The piezoelectric element 4 and the flexible printed circuit board are fixed together using an anisotropic conductive paste or anisotropic conductive film that allows electricity to flow only in the Z direction.

[0019] The elastic body 3 is preferably made of a material with low vibration damping, such as metal or ceramics. The elastic body 3 may be manufactured by forming the protrusion 3a integrally therewith by press molding or cutting, or it may be manufactured separately and then fixed by welding or adhesive. The elastic body 3 may have a plurality of protrusions 3a as in this embodiment, or may have only one protrusion.

[0020] The piezoelectric element 4 uses lead zirconate titanate. Alternatively, it may be made mainly of a lead-free piezoelectric material such as barium titanate or bismuth sodium titanate. Electrode patterns are formed on both sides of the piezoelectric element 4, and power is supplied from a flexible printed circuit board. The elastic body 3, piezoelectric element 4, and flexible printed circuit board constitute the vibrator 2.

[0021] A pressure mechanism (to be described later) causes the vibrator 2 to come into pressure contact with the contact body 7, and an elliptical motion of the vibrator 2 (to be described later) allows the vibrator 2, holding member 5, pressure spring 6, and second guide member 11 to move together in the X direction. The flexible printed circuit board is fixed to the holding member 5 with double-sided tape or the like.

[0022] The contact body 7 is fixed to the first guide member 9 by the adhesive force of the rubber 8. The rubber 8 also plays a role in vibration damping, making it difficult for vibrations from the vibrator 2 to be transmitted to the first guide member 9. The contact body 7, the second guide member 11, and the rubber 8 may be fixed by adhesive or screws. The contact body 7 is made of highly wear-resistant metal, ceramic, resin, or a composite material thereof. In particular, a material made by nitriding stainless steel such as SUS420J2 is preferable from the standpoint of wear resistance and mass production. The first guide member 9 is also fixed to the base 13, which is a fixed member, by screws 12.

[0023] Next, the linear guide mechanism of this embodiment will be described. The first guide member 9 and the second guide member 11 are each provided with two rolling grooves 9a and 11a, which sandwich two balls 10. As a result, when the vibration actuator 1 is driven, the balls 10 roll in the rolling grooves, allowing the vibrator 2, the holding member 5, the pressure spring 6, and the second guide member 11 to move smoothly in the X direction. The materials of the first guide member 9 and the second guide member 11 need to be hard in order to receive pressure from the two rolling grooves 9a and 11a, respectively, and in addition, metal, especially stainless steel, is preferable from the viewpoint of workability.

[0024] Furthermore, a groove 13c provided on the base 13 and a tilt regulation portion 11c provided on the second guide member 11 are fitted together with a certain amount of play, thereby regulating rotation around the X-axis. The base 13 is made up of two fixing portions 13a provided with screw holes and retaining portions for fixing the first guide member 9, holes for fixing the base 13 to the outside, and a connecting portion 13b connecting them. The groove 13c is formed in a part of this connecting portion 13b along the X-direction. The base 13 is made of resin from the viewpoints of workability and slidability.

[0025] A flexible printed circuit board is fixed to the connecting portion 13b, which also serves the function of accommodating the curved portion of the flexible printed circuit board that moves while curving together with the movement of the transducer 2 and the holding member 5.

[0026] Next, the vibration mode excited in the vibrator 2 will be described with reference to Fig. 3. In this embodiment, an AC voltage is applied to the piezoelectric element 3 through a flexible printed circuit board to excite standing waves (out-of-plane bending vibrations) having different phases in the vibrator 2, and a vibration that is a composite of these out-of-plane bending vibrations is generated.

[0027] Mode A, 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 vibrator 2. Vibration in mode A displaces the two protrusions 3a in the Z direction, which is the pressure direction. Mode B, 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 vibrator 2. Vibration in mode B displaces the two protrusions 3a in the X direction.

[0028] By combining the vibrations of these modes A and B, the two protrusions 3a perform elliptical or circular motion in the XZ plane. By bringing the contact body 7 into pressure contact with the protrusions 3a, a frictional force is generated in the X direction, generating a driving force (thrust) that moves the vibrator 2 and the contact body 7 relatively. In this embodiment, since the contact body 7 is fixed to the base 13 as described above, the vibrator 2 moves in the X direction.

[0029] In order to efficiently drive the vibration type actuator 1, it is necessary to support the vibrator 2 without impeding the vibration (displacement) of the two vibration modes excited in the vibrator 2, and for this purpose, it is desirable to support the vicinity of the nodes of these two vibration modes. For this reason, two protrusions 5a are provided on the holding member 5 in order to pressurize and hold the common node of the two vibration modes excited in the vibrator 2. In addition, by positioning the vibrator 2 with the retaining portion 5b provided on the holding member 5, it is possible to bring the two protrusions 5a into contact with the vicinity of the nodes of the two vibration modes, respectively.

[0030] Furthermore, the protrusion 5a not only presses the vibrator 2, but also holds the vibrator 2 in the X and Y directions by friction. The maximum value of the static friction force between the protrusion 5a and the vibrator 2 is always greater than the reaction force that the vibrator 2 receives when the contact body 7 is driven, so the vibrator 2 does not move relative to the holding member 5. This allows for precise driving. There is a notch 5e above the retaining portion 5b as shown in FIG. 2(d). When a strong force is applied, such as a drop impact, this notch 5e collides with the first guide member 9, which also serves as a stopper to prevent the ball 10 from coming off each of the rolling grooves 9a, 11a.

[0031] Here, the pressure mechanism of this embodiment will be described. A holding member 5 that presses and holds the vibrator 2 is provided below the vibrator 2. The material of the holding member 5 is metal or resin, but resin material is preferable in terms of workability and sliding properties. Two pressure fulcrums 5c provided on the holding member 5 and two fitting parts 11b provided on the second guide member 11 are fitted to be rotatable in the Y-axis direction. A pressure spring 6 is provided between the holding member 5 and the second guide member 11. The pressure spring 6 is a tension coil spring, but the coil shape is simply illustrated as a cylinder. The convex part 5a is located approximately at the center in the X-direction between the pressure fulcrum 5c and the pressure spring 6, and is in contact with the vibrator 2. In this way, a pressure force in the Z direction is applied to the vibrator 2 by the principle of a lever, with the pressure fulcrum 5c as the fulcrum, the spring installation part 5d as the force point, and the convex part 5a as the point of action. The vibrator 2 is in pressure contact with the contact body 7 by this pressure force.

[0032] The output conversion mechanism of this embodiment will now be described with reference to Fig. 4. Fig. 4(a) is a bottom view of the vibration actuator 1 when the drive amount is 2 mm in the X direction and output is in the Y direction, and Fig. 4(b) is an enlarged view of the cam member 14 in the bottom view. The direction in the Z direction in which the protrusion 3a of the elastic body 3 is formed is defined as the top, and hereinafter, the bottom view is defined as a drawing seen from the bottom. The output conversion mechanism of this embodiment is composed of the cam member 14, the abutment plate 14e, and the output section 15.

[0033] The cam member 14 is formed integrally with the back surface of the holding member 5 when the surface on which the protrusions 5a and the retaining portion 5b of the holding member 5 are formed is defined as the front surface, and has a triangular shape with an apex protruding in the Z direction. The cam member 14 is disposed so as to be contained within the inside of the base 13.

[0034] Here, it is preferable that the cam member 14 having the slope 14d is disposed so as to be located inside the holding member 5 in the Y direction and the X direction. That is, it is preferable that the cam member 14 is shorter in length in the Y direction than the holding member 5 and is located inside the position occupied by the holding member 5. More preferably, in a plane including the Y direction and the X direction, the cam member 14 is shorter in length in the Y direction and the X direction than the holding member 5 and is located inside the area projected by the holding member 5. With this configuration, even if the cam member 14 is provided, the vibration actuator 100 does not become larger, and a small shape can be maintained.

[0035] The cam member 14 is formed on the holding member 5 at a position such that it is located at the center of the holding member 5 in the X direction, and is located in the Y direction so that the base 14a of the cam member 14 is aligned with the long side of the holding member 5 located at the bottom of the paper. An oblique side 14c is drawn at an angle A1 from the base, and an inclined surface 14d is formed so as to protrude in the Z direction. The cam member 14 is made of a metal or resin material, but it is preferable that the same material as the holding member 5 be used from the viewpoint of ease of processing.

[0036] The output section 15 is composed of a contact ball 15a, a shaft 15b, and a contact ball receiving section 15c. The contact ball receiving section 15c is formed on the shaft 15b, and the contact ball 15a is fixed using an adhesive material. Alternatively, the contact ball 15a may be fixed rotatably so that it can roll in the direction of movement. The contact ball 15a is preferably a sphere from the viewpoint of sliding properties, and a magnet with weak magnetic force such as a ferrite magnet is used as the material. Note that the output section 15 may be integrally molded with a rounded tip of the shaft from the viewpoint of sliding properties without using the contact ball 15a and the contact ball receiving section 15c. The shaft 15b is preferably made of a metal such as SUS304 or SUS420J2 from the viewpoint of durability.

[0037] The contact plate 14e is fixed using an adhesive material so that the entire surface of the widest surface of the contact plate 14e contacts the inclined surface 14d of the cam member 14. The contact plate 14c is made of a magnetic metal such as SUS430 or SUS410. A magnetic metal may be used for the contact ball 15a and a magnet may be used for the contact plate 14c, so that the output part having the contact ball contacts the inclined surface having the contact plate by magnetic force. Alternatively, the contact part may not be provided with a contact plate, and the shaft 15b may be biased by a compression spring to bring the inclined surface 14d of the cam member 14 into direct contact with the inclined surface 15a of the output part 15 for frictional drive.

[0038] The cam member 14 formed integrally with the holding member 5 drives the vibrator 2 in the X direction together with the vibrator 2. The amount of drive can be adjusted as necessary and is not limited. The contact plate 14e attached to the inclined surface 14d of the cam member 14 is attracted by a weak magnetic force that does not allow the contact ball 15a of the output part 15 to separate, and contacts the inclined surface. The contact ball 15a contacting the inclined surface 14d of the cam member 14 slides up and down on the inclined surface. The shaft 15b to which the contact ball 15a is attached is engaged with the contact ball receiving part 15c so as to be movable in the Y direction with two connecting parts 13e provided on the base 13, and the shaft 15b transmits the force of the contact ball 15a moving up and down on the inclined surface in the Y direction. To stabilize the sliding of the output part 15, it is preferable to have two connecting parts, but the number is not limited. An output transmission mechanism (not shown) is fixed to the shaft 15b, and output is output to the driven body. The output transmission mechanism is, for example, a mechanism in which a hollow part that can slide is prepared using the shaft 15 as a guide and moves linearly. Therefore, the driving force of the holding member 5 in the X direction (first direction) can be converted into the Y direction (second direction intersecting the first direction) by using the mechanism of the cam member 14 and the output part 15. In this embodiment, an example will be described in which the first direction, which is the driving direction, and the second direction, which is the output direction, are approximately perpendicular to each other, but the first direction and the second direction may form an acute angle.

[0039] FIG. 5(a) is a bottom view showing the direction of force generation of the vibration actuator 1 when the holding member 5 moves to the left side of the paper. FIG. 5(b) is a bottom view showing the direction of force generation of the vibration actuator 1 when the holding member 5 moves to the right side of the paper. The direction in which the vibrator 2 and the contact body 7 move relatively is defined as the drive direction, and the direction in which the shaft 15b of the output unit 15 moves is defined as the output direction. When the holding member 5 is driven in the direction shown in FIG. 5(a), the shaft 15b moves in the output direction to the upper side of the paper via the contact ball 15a of the output unit 15 that abuts against the slope 14d of the cam member 14. Similarly, when the holding member 5 is driven in the direction shown in FIG. 5(b), the shaft 15b moves in the output direction to the lower side of the paper via the contact ball 15a of the output unit 15 that abuts against the slope 14d of the cam member 14.

[0040] By using this output conversion mechanism, it is possible to convert only the output direction to the Y-axis direction without changing the drive direction. By setting the angle A1 = 45° of the inclined surface 14d provided on the cam member 14 that intersects with the X-direction to form an isosceles right-angled triangle, the two sides of the base 14a and height 14b other than the hypotenuse 14c are the same length. As a result, the drive amount and the output amount are equal, so when driven 1 mm to the left and right, an output of 1 mm is generated up and down. In addition, by locating the output conversion mechanism inside the vibration actuator 1, the conversion mechanism does not increase the size, and compactness can be achieved.

[0041] The output direction is not limited to the Y direction, but may be the Z direction.

[0042] 6(a) is an isometric projection diagram showing a vibration actuator 1 in a first modified example of the vibration actuator 1 according to this embodiment. It is an isometric projection diagram when the drive amount is 2 mm in the X direction and the output is in the Z direction. A cam member 14 is disposed on the side surface of the holding member 5.

[0043] FIG. 6(b) is an enlarged view of the cam member 14 in the front view, and FIG. 6(c) is a front view showing the direction in which the force of the vibration actuator 1 is generated, in which the holding member 5 moves to the right side of the page.

[0044] The cam member 14 is formed in a triangle shape so that the surface of the holding member 5 on which the convex portion 5a and the retaining portion 5b of the holding member 5 are formed is the front surface, and the holding member 5 is extended in the Y direction and is integral with the surface so as to be convex in the Z direction. The cam member 14 is arranged so as to fit inside the base 13. The position at which the cam member 14 is formed on the holding member 5 is the center of the holding member 5 in the X direction, and in the Y direction, the holding member 5 is arranged so that the surface of the holding member 5 and the base side 14a of the cam member are aligned with the portion where the holding member 5 is extended in the Y direction. A hypotenuse 14c is drawn at an angle A1 from the base side, and a slope 14d is formed so as to protrude in the Z direction.

[0045] Using the same principle as the configuration for outputting in the Y direction described above, the force driving the holding member 5 in the X direction can be converted into the Z axis direction by using the mechanism of the cam member 14 and the output portion 15.

[0046] As described above, in the past, output was limited to the same direction as the drive direction, but in the embodiment, the output conversion mechanism is used to convert the output direction to the Y direction or Z direction without changing the drive direction, thereby improving design freedom.

[0047] Furthermore, depending on the configuration of the vibration actuator, the dimension in the output direction can be made the smallest by setting either the Y direction or the Z direction, whichever has the smaller dimension of the vibration actuator, as the output direction.

[0048] In the linear vibration actuator of the present invention, the method of generating an elliptical or circular motion on the contact surface is not limited to the above method. For example, vibrations of bending vibration modes different from those described above may be combined, or a longitudinal vibration mode that expands and contracts an elastic body in the longitudinal direction may be combined with a bending vibration mode.

[0049] This method generates elliptical and circular motions on the contact surface by combining a vibration mode that displaces the contact surface in the direction of movement of the contact body and a vibration mode that displaces the contact surface in the direction of pressure application, and any driving method may be used as long as it has a common node for pressure application and retention.

[0050] 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 the cam member 14 provided on the holding member 5 is configured as shown in FIG. 7. Other elements of this example are the same as those of the corresponding elements of Example 1 described above, so the explanation will be omitted by making the last two digits of the figure numbers the same. This example is configured to obtain more output than the driving force. FIG. 7(a) is a bottom view when the driving amount is 2 mm in the X direction and the output is in the Y axis direction, FIG. 7(b) is an enlarged view of the cam member 114 in the bottom view, and FIG. 7(c) is a bottom view showing the generation of force of the vibration actuator when driven to the left side of the paper.

[0051] In this embodiment, the angle A101 of the inclined surface 114d provided on the cam member 114 is set to about 27°. Any angle of the inclined surface greater than 0° and less than 45° is applicable to this embodiment.

[0052] The angle A101 of the inclined surface 114d provided on the cam member 114 is set to about 27° to form a right-angled triangle. As a result, the base 14a:height 14b=2:1, and when the holding member 105 moves 1 mm in the drive direction shown in FIG. 7(b), the output part 115 that abuts on the inclined surface of the cam member 114 moves 0.5 mm in the output direction to the upper side of the paper. When driven to the right side of the paper, it drives in the same way in the opposite direction to the left side of the paper, although this is omitted since it was explained in the first embodiment using FIG. 5. In other words, a reduction mechanism is realized in which the amount of movement is halved and the thrust is doubled.

[0053] Therefore, this embodiment makes it possible to obtain a configuration that can obtain a thrust force greater than the driving force. Therefore, when a thrust force greater than that of the first embodiment is required, it is possible to increase the thrust force without changing the size of the vibration actuator 1.

[0054] 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. 8. This example differs from the structure shown in FIG. 1 in that the cam member 14 provided on the holding member 5 is configured as shown in FIG. 8. Other elements of this example are the same as those of the corresponding ones in Example 1 described above, so the explanation will be omitted by making the last two digits of the figure numbers the same. This example is configured to obtain a movement amount in the output direction that is greater than the movement amount in the drive direction. FIG. 8(a) is a bottom view when the drive amount is 2 mm in the X direction and output is made in the Y axis direction, FIG. 8(b) is an enlarged view of the cam member 214 in the bottom view, and FIG. 8(c) is a bottom view showing the generation of force of the vibration actuator when driven to the left side of the paper.

[0055] In this embodiment, the angle A201 of the inclined surface 214d provided on the cam member 214 is set to about 64°. Any angle of the inclined surface greater than 45° and less than 90° is applicable to this embodiment.

[0056] The angle A201 of the inclined surface 214d provided on the cam member 214 is set to about 64° to form a right-angled triangle. As a result, the base 14a:height 14b=1:2, and when the holding member 5 moves 1 mm in the drive direction shown in Fig. 7(b), the output part 215 that abuts on the inclined surface of the cam member 14 moves 2 mm in the output direction to the upper side of the paper. When driven to the right side of the paper, it is driven in the same way in the opposite direction to the left side of the paper, although this is omitted since it was explained in the first embodiment using Fig. 5.

[0057] Therefore, in this embodiment, it is possible to make the amount of movement in the output direction greater than the amount of movement in the drive direction. Therefore, if it is desired to make the amount of movement in the output direction greater than in the first embodiment, it is possible to increase the amount of movement in the output direction without changing the size of the vibration actuator 1. Furthermore, if the same amount of movement in the output direction as in the first embodiment is required, the amount of movement in the drive direction is half the amount of movement in the output direction, making it possible to further reduce the size in the X direction.

[0058] Example 4 The vibration actuator can be used, for example, to drive a lens in an imaging device, which is an example of an optical device. Here, as an example, an imaging device that uses a vibration actuator to drive a lens arranged in a lens barrel will be described.

[0059] 9A is a top view showing a schematic configuration of an imaging device 700. The imaging device 700 includes a camera body 730 equipped with an imaging element 710 and a power button 720. The imaging device 700 also includes a lens barrel 740 having a first lens group (not shown), a second lens group 320, a third lens group (not shown), and a fourth lens group 340, which are examples of optical elements, and vibration type actuators 620 and 640. The lens barrel 740 is replaceable as an interchangeable lens, and a lens barrel 740 suitable for a subject to be photographed can be attached to the camera body 730. In the imaging device 700, the second lens group 320 and the fourth lens group 340 are driven by the two vibration type actuators 620 and 640, respectively.

[0060] Although the detailed configuration of the vibration actuator 620 is not shown, the vibration actuator 620 has a vibration actuator and a drive circuit for the vibration actuator. The rotor 211 is disposed in the lens barrel 740 so that the radial direction is substantially perpendicular to the optical axis. In the vibration actuator 620, the rotor 211 is rotated around the optical axis, and the rotation output of the contact body is converted into linear motion in the optical axis direction via a gear or the like (not shown), thereby moving the second lens group 320 in the optical axis direction. The vibration actuator 640 has a configuration similar to that of the vibration actuator 620, and moves the fourth lens group 340 in the optical axis direction.

[0061] 9(b) is a block diagram showing a schematic configuration of the imaging device 700. The first lens group 3a0, the second lens group 320, the third lens group 330, the fourth lens group 340, and the light amount adjustment unit 350 are disposed at predetermined positions on the optical axis inside the lens barrel 740. Light passing through the first lens group 3a0 to the fourth lens group 340 and the light amount adjustment unit 350 forms an image on the imaging element 710. The imaging element 710 converts the optical image into an electrical signal and outputs it, and the output is sent to the camera processing circuit 750.

[0062] The camera processing circuit 750 performs amplification, gamma correction, and the like on the output signal from the image sensor 710. The camera processing circuit 750 is connected to the CPU 790 via an AE gate 755, and is also connected to the CPU 790 via an AF gate 760 and an AF signal processing circuit 765. The video signal that has been subjected to a predetermined process in the camera processing circuit 750 is sent to the CPU 790 via the AE gate 755, the AF gate 760, and the AF signal processing circuit 765. The AF signal processing circuit 765 extracts high frequency components from the video signal to generate an evaluation value signal for autofocus (AF), and supplies the generated evaluation value to the CPU 790.

[0063] The CPU 790 is a control circuit that controls the overall operation of the imaging device 700, and generates control signals for determining exposure and adjusting focus from the acquired video signal. The CPU 790 adjusts the optical axis positions of the second lens group 320, the fourth lens group 340, and the light amount adjustment unit 350 by controlling the driving of the vibration actuators 620, 640, and the meter 630 so as to obtain the determined exposure and an appropriate focus state. Under the control of the CPU 790, the vibration actuator 620 moves the second lens group 320 in the optical axis direction, the vibration actuator 640 moves the fourth lens group 340 in the optical axis direction, and the light amount adjustment unit 350 is driven and controlled by the meter 630.

[0064] The optical axis direction position of the second lens group 320 driven by the vibration actuator 620 is detected by a first linear encoder 770, and the detection result is notified to the CPU 790, thereby feeding back the driving of the vibration actuator 620. Similarly, the optical axis direction position of the fourth lens group 340 driven by the vibration actuator 640 is detected by a second linear encoder 775, and the detection result is notified to the CPU 790, thereby feeding back the driving of the vibration actuator 640. The optical axis direction position of the light amount adjustment unit 350 is detected by an aperture encoder 780, and the detection result is notified to the CPU 790, thereby feeding back the driving of the meter 630.

[0065] Another configuration of the present invention may be an electronic device having the vibration actuator described in any one of the first to third embodiments and a member driven by the vibration actuator. The electronic device is, for example, a factory automation device (FA device) or an office automation device.

[0066] The disclosure of this embodiment includes the following configuration.

[0067] (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, is held by the base, has a slope that intersects with the first direction, and moves in the first direction in response to relative movement of the vibrator; and an output section that is held by the base so as to be movable in a second direction intersecting the first direction, that is in contact with the inclined surface, and that moves in accordance with the movement of the holding member; A vibration actuator comprising:

[0068] (Configuration 2) The vibration actuator according to configuration 1, wherein the inclined surface has a length shorter than that of the holding member in the second direction and is located inside a position occupied by the holding member.

[0069] (Configuration 3) The vibration actuator described in configuration 1 or 2, characterized in that, in a plane including the first direction and the second direction, the inclined surface has a length in the first direction and a length in the second direction smaller than those of the retaining member, and is located inside the area projected by the retaining member.

[0070] (Configuration 4) 4. The vibration actuator according to any one of configurations 1 to 3, wherein the output portion is in contact with the inclined surface by at least one of a magnet and a spring.

[0071] (Configuration 5) 5. The vibration actuator according to any one of configurations 1 to 4, wherein the angle between the inclined surface and the first direction is 45°.

[0072] (Configuration 6) 5. The vibration actuator according to any one of configurations 1 to 4, wherein the angle formed by the inclined surface and the first direction is greater than 0° and smaller than 45°.

[0073] (Configuration 7) 5. The vibration actuator according to any one of configurations 1 to 4, wherein the angle formed by the inclined surface and the first direction is greater than 45° and smaller than 90°.

[0074] (Configuration 8) 8. The vibration actuator according to any one of configurations 1 to 7, wherein the first direction and the second direction are substantially perpendicular to each other.

[0075] (Configuration 9) 9. The vibration actuator according to any one of configurations 1 to 8, wherein the vibrator has a rectangular shape, and a longitudinal direction of the vibrator and the first direction are the same direction.

[0076] (Configuration 10) 10. The vibration actuator according to any one of configurations 1 to 9, wherein the elastic body has two protrusions, and the protrusions and the contact body are in contact with each other.

[0077] (Configuration 11) A vibration actuator according to any one of configurations 1 to 10, An optical device comprising at least one of an optical element and an imaging element driven by the vibration type actuator.

[0078] (Configuration 12) The material, 11. An electronic device comprising the vibration actuator according to any one of configurations 1 to 10 for driving the member. [Explanation of symbols]

[0079] 1. Vibration actuator 2 Transducers 3 Elastic body 5, 105, 205 Retaining member 7 Contact body 13, 113, 213 Foundation 14, 114, 214 Cam member 15, 115, 215 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, is held by the base, has a slope that intersects with the first direction, and moves in the first direction in response to relative movement of the vibrator; and an output section that is held by the base so as to be movable in a second direction intersecting the first direction, that is in contact with the inclined surface, and that moves in accordance with the movement of the holding member; A vibration actuator comprising:

2. 2. The vibration actuator according to claim 1, wherein the inclined surface has a length shorter than that of the holding member in the second 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 second direction, the inclined surface has a length in the first direction and a length in the second direction smaller than those of the retaining member, and is located inside the area projected by the retaining member.

4. 2. The vibration actuator according to claim 1, wherein the output portion is brought into contact with the inclined surface by at least one of a magnet and a spring.

5. 2. The vibration actuator according to claim 1, wherein the inclined surface forms an angle of 45 degrees with the first direction.

6. 2. The vibration actuator according to claim 1, wherein an angle formed by the inclined surface and the first direction is greater than 0° and smaller than 45°.

7. 2. The vibration actuator according to claim 1, wherein an angle formed by the inclined surface and the first direction is greater than 45 degrees and smaller than 90 degrees.

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

9. 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.

10. 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.

11. A vibration actuator according to any one of claims 1 to 10, An optical device comprising at least one of an optical element and an imaging element driven by the vibration type actuator.

12. The material, 11. An electronic device comprising the vibration actuator according to claim 1, which drives the member.

Images