JP2016039756A - Vibrator, vibration type actuator, imaging apparatus and stage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make uniform the displacement distribution of a contact surface of a protrusion that frictionally drives a driven body, in the case where the protrusion is brought into press-contact with the driven body, in a vibration type actuator including the protrusion.SOLUTION: In a vibrator 10, a piezoelectric element 11 is bonded onto one principal surface of a tabular elastic body 12, and a protrusion 13 is provided on another principal surface. In the vibrator 10, the protrusion 13 includes: a contact part 17 including a contact surface 18 in contact with the driven body; a continuous sidewall part 15 having a hollow structure; and a tabular connection part 16 which is flexible in a direction orthogonal with the contact surface 18, connected with the contact part 17 at a central side and connected with a top face of the sidewall part 15 at an outer peripheral side while forming a step to the contact surface 18 so as not to be in contact with the driven body. The connection part 16 is made thinner at the central side where the connection part is connected with the contact part 17, than at the outer peripheral side where the connection part is connected with the sidewall part 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibrator that is driven by combining vibrations in different vibration modes, a vibration type actuator including the vibration element, an imaging device including the vibration type actuator, and a stage apparatus.

  There is known a vibration type actuator that includes a vibrator in which driving vibration is excited and a driven body that is in pressure contact with the vibrator, and that relatively moves the vibrator and the driven body by driving vibration. As an example, one that drives a driven body linearly is known.

  FIG. 12 is a diagram for explaining the schematic structure and driving principle of a known linear drive type vibration actuator 100. The driving principle of the vibration type actuator 100 will be described in detail here in order to be used in a vibration type actuator according to an embodiment of the present invention described later.

  FIG. 12A is a perspective view showing a schematic structure of the vibration type actuator 100. FIG. 12B is a plan view showing a schematic structure of the piezoelectric element 114 that is a component of the vibration type actuator 100. FIG. 12C is a diagram for explaining a first vibration mode (hereinafter referred to as “mode A”) excited by the vibrator 115 constituting the vibration type actuator 100. FIG. 1D is a diagram for explaining a second vibration mode (hereinafter referred to as “mode B”) excited by the vibrator 115 constituting the vibration type actuator 100.

  The vibration type actuator 100 includes a driven body 111 and a vibrator 115. The vibrator 115 is generally formed in a substantially rectangular and flat elastic body 113, a piezoelectric element 114 that is an electro-mechanical energy conversion element bonded to one surface of the elastic body 113, and the other surface of the elastic body 113. It is comprised from the two projection parts 112 provided. The driven body 111 is configured so as to be in pressure contact with the vibrator 115.

  In the vibration type actuator 100, a plurality of desired vibration modes are excited by applying a voltage of a specific frequency to the piezoelectric element 114, and a vibration for driving is formed by superimposing these vibration modes. For example, the driven body can be driven by exciting two bending vibration modes.

  As shown in FIG. 12B, the piezoelectric element 114 is formed with, for example, an electrode region divided into two equal parts in the longitudinal direction, and the polarization direction in each electrode region is the same direction (+). . Of the two electrode regions of the piezoelectric element 114, the alternating voltage VB is applied to the right electrode region in the drawing, and the alternating voltage VA is applied to the left electrode region in the drawing. When the alternating voltages VB and VA are alternating voltages having a frequency in the vicinity of the resonance frequency of the first vibration mode and the same phase, the entire piezoelectric element 114 (two electrode regions) extends at a certain moment, and at another moment. Shrink to. As a result, vibration of the first vibration mode (hereinafter referred to as “mode A”) shown in FIG. If the alternating voltages VB and VA are alternating voltages having a frequency in the vicinity of the resonance frequency of the second vibration mode and the phase is shifted by 180 °, the electrode region on the right side of the piezoelectric element 114 in the drawing has a certain moment. The electrode region on the left side of the figure expands as it shrinks. At the other moment, the relationship is reversed. As a result, vibration in the second vibration mode (hereinafter referred to as “mode B”) shown in FIG.

  In the vibration type actuator 100, the vibrator 115 is excited with two bending vibration modes shown in FIG. 1 (c) and FIG. 1 (d). These two bending vibration modes A and B are both bending vibration modes in the out-of-plane direction of the plate-like vibrator 115. Mode A is a primary out-of-plane bending vibration mode in which two nodes appear approximately parallel to the long side of the vibrator 115. Mode B is a secondary out-of-plane bending vibration mode in which three nodes appear approximately parallel to the short side of the vibrator 115.

  The protrusion 112 is disposed in the vicinity of a position that becomes a vibration node in mode A vibration and in the vicinity of a position that becomes an antinode of vibration in mode B vibration. Therefore, the tip surface of the protrusion 112 reciprocates in the X direction by performing a pendulum motion with the mode A vibration node as a fulcrum, and reciprocates in the Z direction by the mode B vibration. Therefore, by exciting and superimposing at the same time so that the vibration phase difference between modes A and B is in the vicinity of ± π / 2, elliptical motion in the XZ plane can be generated on the tip surface of the protrusion 112. Since a frictional force due to pressure contact is acting between the protrusion 112 and the driven body 111, a driving force (thrust) for driving the driven body 111 in the X direction is generated by the elliptical motion of the protrusion 112. Can be generated.

  Here, in the vibration type actuator, a smooth contact state can be realized by providing the contact member to be pressed and contacted with a spring property, and thereby, a good driving performance can be obtained. However, in the vibration type actuator 100, the protrusion 112 provided on the elastic body 113 and the driven body 111 have almost no spring property. Therefore, a vibrator having a structure in which a protrusion has a spring property has been proposed as a vibrator used in a vibration type actuator using the driving principle described with reference to FIG. 12 (see Patent Document 1).

  13A and 13B are a perspective view and a perspective sectional view showing a schematic structure of the vibrator 120 in which the protrusion 123 provided on the upper surface of the elastic body 122 has a spring property. The vibrator 120 is integrated with the elastic body 122 at two locations: the elastic body 122, the piezoelectric element 121 bonded to one surface (lower surface) of the elastic body 122, and the other surface (upper surface) of the elastic body 122. And formed protrusions 123. Each of the two protrusions 123 includes a cylindrical side wall 125, a contact part 127 having a contact surface 128 with a driven body (not shown), and a connecting part 126 that connects the side wall part 125 and the contact part 127. Become.

  A step is provided between the connecting portion 126 and the contact portion 127 so that the driven body does not come into contact with the connecting portion 126, and the connecting portion 126 reduces the thickness in the Z direction by reducing the thickness. , Springiness can be imparted. Note that a thin portion 124 is formed in the elastic body 122 at the connection portion with the projection portion 123. By forming the thin-walled portion 124 when the elastic body 122 is pressed to integrally form the protruding portion 123, the thinned portion of this portion is caused to flow into the sidewall portion 125, and the thickness of the sidewall portion 125 is secured. , Rigidity can be ensured.

JP 2001-234608 A

  However, in the structure of the vibrator 120 shown in FIG. 13, a displacement distribution occurs on the contact surface 128 when pressure is applied from the driven body. FIG. 14 is a cross-sectional view for explaining the displacement distribution of the contact surface 128 when the protrusion 123 receives pressure from the driven body. When the protrusion 123 receives the applied pressure F, bending deformation occurs not only in the connection portion 126 but also in the contact portion 127 as shown by a broken line in the figure, and as a result, the contact surface 128a after deformation is more than the outer peripheral portion. A displacement distribution in which the displacement in the Z direction increases in the central portion is generated. When the contact portion 127 comes into contact with the driven body in the state of the contact surface 128a, the surface pressure near the outer periphery of the upper surface of the contact portion 127 increases and local wear due to driving occurs. The contact state with the driven body changes, and the driving performance changes.

  The present invention provides a technique for making the displacement distribution of the contact surface of the projection portion uniform when the projection portion is brought into pressure contact with the driven body in a vibration type actuator having a projection portion that frictionally drives the driven body. The purpose is to provide.

  The vibrator according to the present invention has an electro-mechanical energy conversion element and a plate-like shape, the electro-mechanical energy conversion element is bonded to one main surface orthogonal to the thickness direction, and the thickness An elastic body provided with a protrusion on the other main surface orthogonal to the vertical direction, wherein the protrusion has a contact portion having a contact surface in contact with the driven body, and the elastic body A continuous side wall portion having a hollow structure projecting in the thickness direction from the other main surface of the first and second surfaces, and being flexible in a direction perpendicular to the contact surface and not contacting the driven body. A plate-like connecting portion that forms a step with respect to the surface and is connected to the contact portion on the central side and to the upper surface of the side wall portion on the outer peripheral side, and the thickness of the connecting portion Is the center connected to the contact part rather than the outer peripheral side connected to the side wall part. Characterized in that in thin.

  Another vibrator according to the present invention has an electro-mechanical energy conversion element and a plate-like shape, and the electro-mechanical energy conversion element is bonded to one main surface orthogonal to the thickness direction. And an elastic body provided with a protrusion on the other main surface orthogonal to the thickness direction, wherein the protrusion has a contact portion having a contact surface in contact with the driven body; A cylindrical continuous side wall portion protruding in the thickness direction from the other main surface of the elastic body, and flexibility in a direction orthogonal to the contact surface so as not to contact the driven body A plate-like connecting portion that is connected to the contact portion on the center side and connected to the upper surface of the side wall portion on the outer peripheral side. The length of the outer periphery of the root portion of the portion protruding from the connecting portion is the outer periphery of the contact surface Characterized in that less than the length.

  According to the present invention, in a vibration type actuator having a protrusion that frictionally drives a driven body, the displacement distribution of the contact surface of the contact portion can be made uniform. Thereby, generation | occurrence | production of the local wear in a contact part can be avoided, the wear of the whole contact part can be suppressed, and the wear which arises in a projection part with time can be made uniform. Thus, in the vibration type actuator according to the present invention, the driving performance can be stabilized from the initial stage of use, and the driving characteristics can be maintained for a long time.

FIG. 3 is a partial cross-sectional view of the vibrator according to the first embodiment of the invention. FIG. 6 is a partial cross-sectional view of a vibrator according to a second embodiment of the invention. FIG. 6 is a partial cross-sectional view of a vibrator according to a third embodiment of the invention. It is a fragmentary sectional view of the vibrator concerning a 4th embodiment of the present invention. It is a fragmentary sectional view of the vibrator concerning a 5th embodiment of the present invention. It is a fragmentary sectional view of the vibrator concerning a 6th embodiment of the present invention. It is a fragmentary sectional view of a vibrator concerning a 7th embodiment of the present invention. It is the external appearance perspective view of the vibrator | oscillator concerning 8th Embodiment of this invention, a partial perspective sectional view, and the top view of a projection part. It is a top view of the projection part which constitutes the vibrator concerning a 9th embodiment of the present invention. It is a perspective view which shows schematic structure of the lens-barrel which mounts the vibration type actuator which concerns on embodiment of this invention. It is an external appearance perspective view of the microscope carrying the vibration type actuator which concerns on embodiment of this invention. It is a figure explaining the general | schematic structure and drive principle of the well-known linear drive type vibration type actuator. FIG. 4 is a perspective view and a perspective sectional view showing a schematic structure of a known vibrator in which a protrusion provided on the upper surface of an elastic body has a spring property. FIG. 14 is a cross-sectional view for explaining the displacement distribution of the contact surface when the protrusion of the vibrator of FIG. 13 receives a pressing force from the driven body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, the vibration type actuator includes a vibrator in which driving vibration is excited and a driven body that is in pressure contact with the vibrator, and the vibrator and the driven body are relatively moved by driving vibration. It shall refer to what has the structure moved to. That is, it means that the drive output of the vibrator can be extracted by relative movement between the vibrator and the driven body.

<First Embodiment>
FIG. 1 is a partial cross-sectional view of the vibrator 10 according to the first embodiment of the present invention. More specifically, FIG. 1 is an enlarged cross-sectional view of the vibrator 10 near the protrusion 13. Note that the overall structure of the vibrator 10 conforms to the overall structure of the vibrator 120 shown in FIG. That is, the vibrator 10 includes a substantially rectangular and flat elastic body 12, a piezoelectric element 11 that is an electro-mechanical energy conversion element bonded to one main surface (lower surface) of the elastic body 12, and the elastic body 12. Projections 13 projecting in the thickness direction of the elastic body 12 are provided at two locations on the other main surface (upper surface). In addition, the main surface of the elastic body 12 refers to the surface (surface orthogonal to the thickness direction) having the largest area among the surfaces appearing in the appearance of the elastic body 12.

  The two protruding portions 13 have a hollow structure, and are formed integrally with the elastic body 12 at a predetermined interval on a straight line that divides the short side of the elastic body 12 equally and is parallel to the long side. FIG. 1 shows an XZ cross section of one protrusion 13 according to FIG. The protruding portion 13 has a cylindrical side wall portion 15 continuous with the elastic body 12 and a contact surface 18 with a driven body (not shown), and the inner side of the side wall portion 15 when viewed from a direction orthogonal to the contact surface 18. And a plate-like connecting part 16 connected to the upper surface of the side wall part 15 on the outer peripheral side and connected to the contact part 17 on the center side.

  In addition, the protrusion part 13 is formed by pressing the elastic body 12 which consists of metal materials, such as a stainless material. Therefore, the protruding portion 13 is made of the same metal material that is continuous with the elastic body 12, and the side wall portion 15, the contact portion 17, and the connecting portion 16 constituting the protruding portion 13 are also made of the same continuous metal material. Further, the elastic body 12 is formed with a thin portion 14 at a connection portion with the projection portion 13, and a step is provided between the connecting portion 16 and the contact portion 17 in the Z direction. The reason for forming the thin portion 14 and the reason for providing a step between the connecting portion 16 and the contact portion 17 are the reason for forming the thin portion 124 and the connecting portion 126 and the contact portion in the vibrator 120 shown in FIG. Since this is the same as the reason for providing a step with respect to 127, a description thereof is omitted here. Furthermore, the driving principle of the vibration type actuator including the vibrator 10 and vibrators 20, 30, 40, 50, 60, 70, 80 according to second to eighth embodiments described later will be described with reference to FIG. That's right. That is, when a predetermined drive voltage is applied to the piezoelectric element 11, the two protrusions 13 are elliptically moved in a plane perpendicular to the contact surface 18 and parallel to the long side of the elastic body 12. Occurs.

  In the vibrator 10, since the side wall portion 15 is continuous in a cylindrical shape, the rigidity in the driving direction of the protrusion 13 is maintained, and the driving speed can be increased without impairing the driving force. Here, increasing the driving speed of the protrusion 13 means that vibration having high responsiveness to vibration generated in the elastic body 12 can be generated.

  In the connecting portion 16, when the first portion and the second portion are defined as the second portion being closer to the contact portion 17 than the first portion, the thickness of the first portion is the first thickness. It is larger than the thickness of part 2. Specifically, the connecting portion 16 is not uniform in thickness, and the inner peripheral portion 16a connected to the contact portion 17 is formed so that the thickness decreases toward the inner peripheral side. As a result, the connecting portion 16 is flexible in the Z direction, which is a direction orthogonal to the contact surface 18, and has a structure in which the rigidity of the inner peripheral portion 16 a is sufficiently smaller than the rigidity in the contact portion 17. ing.

  In FIG. 1, a broken line indicates a state in which the connecting portion 16 is deformed due to an applied pressure F substantially orthogonal to the contact surface 18 acting on the contact surface 18. When a pressing force F from a driven body (not shown) acts on the contact surface 18, the connecting portion 16 is deformed as indicated by a broken line. However, the deformation in the protruding portion 13 stops at the connecting portion 16, and no bending deformation occurs in the contact portion 17. That is, the entire surface of the contact surface 18a that has received the applied pressure F can be displaced in the Z direction almost uniformly by the deformation of the connecting portion 16 (that is, a substantially uniform displacement distribution can be generated on the entire surface).

  Thus, in the vibrator 10 according to the first embodiment, the contact portion 17 is prevented from locally increasing the surface pressure in the vicinity of the outer periphery of the contact surface 18, and is prevented from being locally worn by driving. be able to. As a result, the abrasion which arises in a projection part with time can be made uniform. Thus, in the vibration type actuator including the vibrator 10, the driving performance can be stabilized from the initial stage of use, and the driving characteristics can be maintained for a long time.

Second Embodiment
FIG. 2 is a partial cross-sectional view of the vibrator 20 according to the second embodiment of the present invention. More specifically, FIG. 2 is an enlarged cross-sectional view of the vibrator 20 near the protrusion 23. The overall structure of the vibrator 20 conforms to the overall structure of the vibrator 120 shown in FIG. That is, the vibrator 20 includes an elastic body 22, a piezoelectric element 21 bonded to the lower surface of the elastic body 22, and protrusions 23 integrally formed with the elastic body 22 at two locations on the upper surface of the elastic body 22. It is configured. FIG. 2 shows an XZ cross section of one protrusion 23 according to FIG.

  The projecting portion 23 has a cylindrical side wall portion 25 and a contact surface 28 with a driven body (not shown), and the contact portion 27 located inside the side wall portion 25 when viewed from a direction orthogonal to the contact surface 28. And a connecting portion 26 that connects the side wall portion 25 and the contact portion 27. The elastic body 22 is formed with a thin portion 24 at a connection portion with the projection portion 23, and a step is provided between the connecting portion 26 and the contact portion 27 in the Z direction. Also in the vibrator 20, since the side wall portion 25 is continuous in a cylindrical shape, the rigidity in the driving direction of the protruding portion 23 is maintained, and the driving speed can be increased without impairing the driving force.

  The connecting portion 26 is provided with an inclination on the upper surface 26a so that the thickness gradually decreases from the outer peripheral side toward the inner peripheral side. Thereby, similarly to the vibrator 10 according to the first embodiment, the rigidity at the inner peripheral portion of the connecting portion 26 can be made sufficiently smaller than the rigidity of the contact portion 27. Therefore, when a pressing force corresponding to the pressing force F shown in FIG. 1 acts on the contact surface 28, the deformation in the protrusion 23 stops at the connecting portion 26, and the bending deformation is prevented from occurring inside the contact portion 27. Can do. That is, the entire contact surface 28 that receives the applied pressure is displaced in the Z direction almost uniformly by the deformation of the connecting portion 26. Therefore, the vibrator 20 according to the second embodiment also has the same effect as the vibrator 10 according to the first embodiment.

<Third Embodiment>
FIG. 3 is a partial cross-sectional view of the vibrator 30 according to the third embodiment of the present invention. More specifically, FIG. 3 is an enlarged cross-sectional view in the vicinity of the protrusion 33 in the vibrator 30. Note that the overall structure of the vibrator 30 conforms to the overall structure of the vibrator 120 shown in FIG. That is, the vibrator 30 includes an elastic body 32, a piezoelectric element 31 bonded to the lower surface of the elastic body 32, and protrusions 33 formed integrally with the elastic body 32 at two locations on the upper surface of the elastic body 32. It is configured. FIG. 3 shows an XZ cross section of one protrusion 33 according to FIG.

  The protruding portion 33 has a cylindrical side wall portion 35 and a contact surface 38 with a driven body (not shown), and a contact portion 37 located inside the side wall portion 35 when viewed from a direction orthogonal to the contact surface 38. And a connecting portion 36 that connects the side wall portion 35 and the contact portion 37. The elastic body 32 is formed with a thin portion 34 at a connection portion with the projection portion 33, and a step is provided between the connecting portion 36 and the contact portion 37 in the Z direction. Also in the vibrator 30, since the side wall portion 35 is continuous in a cylindrical shape, the rigidity in the driving direction of the projection portion 33 is maintained, and the driving speed can be increased without impairing the driving force.

  The connecting portion 36 is provided with a slope on the lower surface 36a so that the thickness gradually decreases from the outer peripheral side toward the inner peripheral side. Thereby, similarly to the vibrator 20 according to the second embodiment, the rigidity of the inner peripheral portion of the connecting portion 36 can be made sufficiently smaller than the rigidity of the contact portion 37. Therefore, when a pressing force corresponding to the pressing force F shown in FIG. 1 is applied to the contact surface 38, the deformation in the protrusion 33 stops at the connecting portion 36, and the bending deformation is prevented from occurring inside the contact portion 37. Can do. That is, the entire contact surface 38 that receives the applied pressure is displaced in the Z direction almost uniformly by the deformation of the connecting portion 36. Therefore, the vibrator 30 according to the third embodiment also has the same effect as the vibrator 20 according to the second embodiment, that is, the same effect as the vibrator 10.

<Fourth embodiment>
FIG. 4 is a partial cross-sectional view of the vibrator 40 according to the fourth embodiment of the present invention. More specifically, FIG. 4 is an enlarged cross-sectional view in the vicinity of the protrusion 43 in the vibrator 40. The overall structure of the vibrator 40 conforms to the overall structure of the vibrator 120 shown in FIG. That is, the vibrator 40 includes an elastic body 42, a piezoelectric element 41 bonded to the lower surface of the elastic body 42, and protrusions 43 formed integrally with the elastic body 42 at two locations on the upper surface of the elastic body 42. It is configured. FIG. 4 shows an XZ cross section of one protrusion 43 according to FIG.

  The protrusion 43 has a cylindrical side wall 45 and a contact surface 48 with a driven body (not shown), and is a contact portion 47 located inside the side wall 45 when viewed from a direction orthogonal to the contact surface 48. And a connecting portion 46 that connects the side wall portion 45 and the contact portion 47. The elastic body 42 is formed with a thin portion 44 at the connection portion with the projection portion 43, and a step is provided between the connecting portion 46 and the contact portion 47 in the Z direction. Also in the vibrator 40, since the side wall 45 is continuous in a cylindrical shape, the rigidity in the driving direction of the protrusion 43 is maintained, and the driving speed can be increased without impairing the driving force.

  The connecting portion 46 has an outer R (curvature of outer corner portion) 46d that is smaller than an inner R (curvature of inner corner portion) 46c of the ridge formed by the side wall portion 45, so that the plate thickness of the connecting portion 46 is the outer peripheral portion thickness 46a. The inner peripheral portion 46b is configured to be thinner than the inner peripheral portion 46b. Thereby, similarly to the vibrator 10 according to the first embodiment, the rigidity at the inner peripheral portion of the connecting portion 46 can be made sufficiently smaller than the rigidity of the contact portion 47. Therefore, when a pressing force corresponding to the pressing force F shown in FIG. 1 acts on the contact surface 48, the deformation in the protrusion 43 stops at the connecting portion 46, and the bending deformation is prevented from occurring inside the contact portion 47. Can do. That is, the entire contact surface 48 that receives the applied pressure is displaced in the Z direction almost uniformly by the deformation of the connecting portion 46. Therefore, the vibrator 40 according to the fourth embodiment also has the same effect as the vibrator 10 according to the first embodiment.

<Fifth Embodiment>
FIG. 5 is a partial cross-sectional view of the vibrator 50 according to the fifth embodiment of the present invention. More specifically, FIG. 5 is an enlarged cross-sectional view in the vicinity of the protrusion 53 of the vibrator 50. The overall structure of the vibrator 50 conforms to the overall structure of the vibrator 120 shown in FIG. That is, the vibrator 50 includes an elastic body 52, a piezoelectric element 51 bonded to the lower surface of the elastic body 52, and protrusions 53 integrally formed with the elastic body 52 at two locations on the upper surface of the elastic body 52. It is configured. FIG. 5 shows an XZ cross section of one protrusion 53 according to FIG.

  The protruding portion 53 has a cylindrical side wall portion 55 and a contact surface 58 with a driven body (not shown), and the contact portion 57 located inside the side wall portion 55 when viewed from a direction orthogonal to the contact surface 58. And a connecting portion 56 that connects the side wall portion 55 and the contact portion 57. The elastic body 52 is formed with a thin portion 54 at a connection portion with the projection portion 53, and a step is provided between the connecting portion 56 and the contact portion 57 in the Z direction. Also in the vibrator 50, since the side wall portion 55 is continuous in a cylindrical shape, the rigidity in the driving direction of the protruding portion 53 is maintained, and the driving speed can be increased without impairing the driving force.

  The contact portion 57 includes a root portion 57a and a tip portion 57b. By making the outer circumference length (or outer diameter) of the root portion 57a shorter than the outer circumference length (or outer diameter) of the tip portion 57b, The rigidity of the contact portion 57 is smaller at the outer peripheral portion than at the inner peripheral portion. Thereby, when a pressing force corresponding to the pressing force F shown in FIG. 1 acts on the contact surface 58, the contact surface 58 tends to deform in the same manner as the contact surface 128a of FIG. Since bending deformation that cancels the deformation occurs, as a result, the entire contact surface 58 is uniformly displaced in the Z direction substantially. Therefore, the vibrator 50 according to the fifth embodiment can achieve the same effects as the vibrator 10 according to the first embodiment.

<Sixth Embodiment>
FIG. 6 is a partial cross-sectional view of the vibrator 60 according to the sixth embodiment of the present invention, and more specifically, an enlarged cross-sectional view of the vicinity of the protrusion 63 in the vibrator 60. Note that the overall structure of the vibrator 60 conforms to the overall structure of the vibrator 120 shown in FIG. That is, the vibrator 60 includes an elastic body 62, a piezoelectric element 61 bonded to the lower surface of the elastic body 62, and protrusions 63 integrally formed with the elastic body 62 at two locations on the upper surface of the elastic body 62. It is configured. FIG. 6 shows an XZ cross section of one protrusion 63 according to FIG.

  The protruding portion 63 has a cylindrical side wall portion 65 and a contact surface 68 with a driven body (not shown), and a contact portion 67 located inside the side wall portion 65 when viewed from a direction orthogonal to the contact surface 68. And a connecting portion 66 for connecting the side wall portion 65 and the contact portion 67. The elastic body 62 is formed with a thin portion 64 at a connection portion with the projection portion 63, and a step is provided between the connecting portion 66 and the contact portion 67 in the Z direction. Also in the vibrator 60, since the side wall portion 65 is continuous in a cylindrical shape, the rigidity in the driving direction of the protruding portion 63 is maintained, and the driving speed can be increased without impairing the driving force.

  The contact portion 67 includes a root portion 67a and a tip portion 67b, and is configured such that the outer diameter of the root portion 67a decreases as the distance from the tip portion 67b increases (approaches the connecting portion 66). The rigidity in the part 67 can be made smaller at the outer peripheral part than at the inner peripheral part. Therefore, when a pressing force corresponding to the pressing force F shown in FIG. 1 acts on the contact surface 68 of the contact portion 67, the contact surface 68 tends to deform in the same manner as the contact surface 128a of FIG. Bending deformation that cancels out the deformation occurs inside, and as a result, the entire surface of the contact surface 68 is displaced substantially uniformly in the Z direction. Therefore, the vibrator 60 according to the sixth embodiment also has the same effect as the vibrator 50 according to the fifth embodiment, that is, the same effect as the vibrator 10.

<Seventh embodiment>
FIG. 7 is a partial cross-sectional view of a vibrator 70 according to a seventh embodiment of the present invention. More specifically, FIG. 7 is an enlarged cross-sectional view in the vicinity of the protrusion 73 of the vibrator 70. Note that the overall structure of the vibrator 70 conforms to the overall structure of the vibrator 120 shown in FIG. That is, the vibrator 70 includes an elastic body 72, a piezoelectric element 71 bonded to the lower surface of the elastic body 72, and protrusions 73 integrally formed with the elastic body 72 at two positions on the upper surface of the elastic body 72. It is configured. 7 shows an XZ cross section of one protrusion 73 in accordance with FIG.

  The protruding portion 73 has a cylindrical side wall portion 75 and a contact surface 78 with a driven body (not shown), and the contact portion 77 located inside the side wall portion 75 when viewed from a direction orthogonal to the contact surface 78. And a connecting portion 76 that connects the side wall portion 75 and the contact portion 77. The elastic body 72 is formed with a thin portion 74 at a connection portion with the projection 73, and a step is provided between the connecting portion 76 and the contact portion 77 in the Z direction. Also in the vibrator 70, since the side wall 75 is continuous in a cylindrical shape, the rigidity in the driving direction of the protrusion 73 is maintained, and the driving speed can be increased without impairing the driving force.

  The contact portion 77 is configured such that its outer diameter becomes shorter from the contact surface 78 toward the base of the contact portion 77 (the connection portion 66 side), and thus the rigidity of the contact portion 77 is increased to the inner peripheral portion. The structure is smaller at the outer periphery. Thereby, when a pressing force corresponding to the pressing force F shown in FIG. 1 acts on the contact surface 78, the contact surface 78 tends to deform in the same manner as the contact surface 128a of FIG. A bending deformation that cancels the deformation occurs, and as a result, the entire surface of the contact surface 78 is uniformly displaced in the Z direction. Therefore, the vibrator 70 according to the seventh embodiment also has the same effect as the vibrator 50 according to the fifth embodiment, that is, the same effect as the vibrator 10.

<Eighth Embodiment>
8A and 8B are diagrams showing a schematic structure of a vibrator 80 according to the eighth embodiment of the present invention. FIG. 8A is an external perspective view of the whole vibrator 80, and FIG. FIG. 8C is a top perspective view (plan view) of the protrusion 83. The vibrator 80 includes an elastic body 82, a piezoelectric element 81 bonded to the lower surface of the elastic body 82, and protrusions 83 formed integrally with the elastic body 82 at two locations on the upper surface of the elastic body 82. ing.

  The protruding portion 83 has a cylindrical side wall portion 85 and a contact surface 88 with a driven body (not shown), and is a contact portion 87 located inside the side wall portion 85 when viewed from a direction orthogonal to the contact surface 88. And a connecting portion 86 for connecting the side wall portion 85 and the contact portion 87. The elastic body 82 is formed with a thin portion 84 at a connection portion with the projection 83, and a step is provided between the connecting portion 86 and the contact portion 87 in the Z direction. Also in the vibrator 80, since the side wall portion 85 is continuous in a cylindrical shape, the rigidity in the driving direction of the protruding portion 83 is maintained, and the driving speed can be increased without impairing the driving force.

  The connecting portion 86 has a substantially sector shape in which the inner peripheral portion width 86b is shorter than the outer peripheral portion width 86a, and is erected on the contact portion 87 and the side wall portion 85 at equal intervals in the circumferential direction. The holes 89 are formed at regular intervals between the connecting portions 86. In the connecting portion 86 thus divided into a plurality of parts, the rigidity in the Z direction is lowered and the spring property is obtained. Further, since the connecting portion 86 has the inner peripheral portion width 86b shorter than the outer peripheral portion width 86a, the rigidity of the inner peripheral portion of the connecting portion 86 can be made relatively sufficiently smaller than the rigidity of the contact portion 87. it can. Therefore, similarly to the vibrators 10 to 40 according to the first to fourth embodiments, the vibrator 80 has the protrusion 83 at the protrusion 83 when a pressure corresponding to the pressure F shown in FIG. The deformation stops at the connecting portion 86, and bending deformation can be prevented from occurring inside the contact portion 87. That is, the entire contact surface 88 that receives the applied pressure is displaced in the Z direction almost uniformly by the deformation of the connecting portion 86. Therefore, the vibrator 20 according to the eighth embodiment has the same effect as the vibrator 10 according to the first embodiment.

<Ninth Embodiment>
FIG. 9 is a top view (plan view) of the protrusion 93 constituting the vibrator according to the ninth embodiment of the invention. Note that the overall structure of the vibrator including the protrusions 93 conforms to the vibrator 80 according to the eighth embodiment, and illustration and description thereof are omitted here.

  The connecting portion 96 of the protrusion 93 has a corner portion 96 that connects the curvature 96d with the contact portion 97 so that the inner peripheral portion width 96b is shorter than the outer peripheral portion width 96a. The curvature is larger than 96c. In the connecting portion 96 thus divided into a plurality of parts, the rigidity in the Z direction is reduced and the spring has a spring property. Further, since the connecting portion 96 has the inner peripheral portion width 96b shorter than the outer peripheral portion width 96a, the rigidity of the inner peripheral portion of the connecting portion 96 can be made relatively sufficiently smaller than the rigidity of the contact portion 97. it can. That is, since the entire contact surface 98 that has received the applied pressure is displaced in the Z direction almost uniformly by the deformation of the connecting portion 96, the vibrator according to the ninth embodiment is also the vibrator 10 according to the first embodiment. Has the same effect as

<Tenth Embodiment>
A configuration of an imaging apparatus (optical apparatus) such as a camera, which is an example of an apparatus including a vibration type actuator using various vibrators according to the above-described embodiment, will be described with reference to FIG. FIG. 10 is a perspective view showing a schematic structure of the lens driving mechanism 300 of the lens barrel. The lens driving mechanism unit 300 includes a lens holder 302 that is a driven body, a vibrator 301 that drives the lens holder 302, a pressure magnet 305, a first guide bar 303, a second guide bar 304, and a base (not shown). Prepare.

  The lens holder 302 is formed in a first guide part by fitting with a cylindrical main body part 302 a, a holding part 302 b that holds the vibrator 301 and the pressing magnet 305, and a first guide bar 303. 1 guide part 302c and drop-off prevention part 302d. A lens 307 is held on the main body 302a. The first guide bar 303 and the second guide bar 304 are arranged in parallel to each other, and both ends of the first guide bar 303 and the second guide bar 304 are fixed to a base (not shown). .

  The pressurizing magnet 305 constituting the pressurizing means includes a permanent magnet and two yokes disposed at both ends of the permanent magnet. A magnetic circuit is formed between the pressing magnet 305 and the second guide bar 304, and an attractive force is generated between these members. As a result, the tips of the two protrusions provided on the vibrator 301 are held while being pressed against the second guide bar 304 with a predetermined force, thereby forming the second guide part.

  Note that the pressurizing magnet 305 is disposed at a distance from the second guide bar 304 and is not in contact with the second guide bar 304. For this reason, when the second guide portion receives an external force or the like, there is a possibility that the protruding portion of the vibrator 301 and the second guide bar 304 are separated from each other. However, at that time, the drop-off prevention portion 302d provided on the lens holder 302 comes into contact with the second guide bar 304, and the holding portion 302b of the lens holder 302 returns to its original position, so that the protruding portion of the vibrator 301 is moved. The state returns to the state in which the second guide bar 304 abuts.

  The vibrator 301 has the same structure as that of the vibrator 10 according to the first embodiment. Therefore, the driving method of the vibrator 301 has been described with reference to FIG. The driving method of the vibrator 115 is the same. In other words, by applying a predetermined alternating voltage to the vibrator 301, elliptical vibration is generated at two protrusions, thereby generating a frictional driving force between the vibrator 301 and the second guide bar 304. At this time, since the first guide bar 303 and the second guide bar 304 are fixed, the length of the first guide bar 303 and the second guide bar 304 is changed by the generated friction driving force. It can be moved along the direction.

  In the lens driving mechanism unit 300, the magnetic force (the pressurizing magnet 305) is used as the pressurizing mechanism, but the present invention is not limited to this, and an urging force by a spring may be used. Here, the lens driving mechanism unit 300 is configured as a linear vibration type actuator, but is not limited thereto, and may be configured as a rotation type vibration type actuator. That is, the rotating member of the driven body is used to rotate the annular member holding the lens, and at this time, the rotation amount of the annular member in the optical axis direction is changed using a method such as engagement between the cam pin and the cam groove. Convert to linear travel. Thereby, the lens can be moved in the optical axis direction.

  The driving of the lens by the vibration type actuator is suitable for driving the autofocus lens, but is not limited to this, and the zoom lens can be driven by the same configuration. The vibration type actuator can also be used for driving an image sensor on which light that has passed through the lens forms an image, and for driving a lens or an image sensor at the time of camera shake correction.

<Eleventh embodiment>
A configuration of a stage apparatus such as a microscope, which is an example of an apparatus including a vibration type actuator using various vibrators according to the present embodiment described above, will be described with reference to FIG. FIG. 11 is an external perspective view of the microscope 400. The microscope 400 includes an imaging unit 410 that includes an imaging device and an optical system, and an automatic stage 430 that is provided on a base and includes a stage 420 that is moved by a vibration actuator. As the vibrator of the vibration actuator, the above-described vibrator 10 according to the present embodiment can be used.

  An object to be observed is placed on the upper surface of the stage 420 and an enlarged image is taken by the imaging unit 410. When the observation range is wide, a large number of captured images are acquired by driving the automatic stage 430 and moving the object to be observed by moving the stage 420 in the X direction or Y direction within the plane. By combining the captured images by image processing with a computer (not shown), it is possible to acquire a single image with a wide observation range and high definition.

<Other embodiments>
Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. For example, the vibrator according to the present invention is not limited to the linear vibration actuator shown in FIG. 12A, but is a rotary vibration actuator or a vibration actuator having multiple degrees of freedom. It can also be applied to. Further, the shape of the protrusion 13 and the like included in the vibrator is not limited to a cylindrical shape, and may be a cylindrical shape in which the side wall 15 and the like are continuous. Furthermore, each embodiment mentioned above shows only one embodiment of this invention, and it is also possible to combine each embodiment suitably.

10, 20, 30, 40, 50, 60, 70, 80 Vibrator 11, 21, 31, 41, 51, 61, 71, 81 Piezoelectric element 12, 22, 32, 42, 52, 62, 72, 82 Elasticity Body 13, 23, 33, 43, 53, 63, 73, 83, 93 Protrusion 15, 25, 35, 45, 55, 65, 75, 85, 95 Side wall 16, 26, 36, 46, 56, 66 , 76, 86, 96 Connecting portion 17, 27, 37, 47, 57, 67, 77, 87, 97 Contact portion 18, 28, 38, 48, 58, 68, 78, 88, 98 Contact surface

Claims (11)

An electromechanical energy conversion element;
An elastic body having a plate shape, wherein the electro-mechanical energy conversion element is bonded to one surface orthogonal to the thickness direction, and a protrusion is provided on the other surface orthogonal to the thickness direction A vibrator comprising:
The protrusion is
A continuous side wall forming a hollow structure protruding in the thickness direction from the other surface of the elastic body;
A contact portion that is in contact with the driven body, and a contact portion that is located inside the side wall when viewed from a direction orthogonal to the contact surface;
Having flexibility in a direction perpendicular to the contact surface, and having a connecting portion provided between the contact portion and the upper surface of the side wall portion,
The thickness of the 1st part of the said connection part is larger than the thickness of the 2nd part nearer to the said contact part than the said 1st part, The vibrator | oscillator characterized by the above-mentioned. An electromechanical energy conversion element;
An elastic body having a plate shape, wherein the electro-mechanical energy conversion element is bonded to one surface orthogonal to the thickness direction, and a protrusion is provided on the other surface orthogonal to the thickness direction A vibrator comprising:
The protrusion is
A continuous side wall forming a hollow structure protruding in the thickness direction from the other surface of the elastic body;
A contact portion that is in contact with the driven body, and a contact portion that is located inside the side wall when viewed from a direction orthogonal to the contact surface;
Having flexibility in a direction orthogonal to the contact surface, and having a connecting part provided between the contact part and the side wall part,
The vibrator characterized in that the rigidity of the first portion of the connecting portion is larger than the rigidity of the second portion closer to the contact portion than the first portion. An electromechanical energy conversion element;
An elastic body having a plate shape, wherein the electro-mechanical energy conversion element is bonded to one surface orthogonal to the thickness direction, and a protrusion is provided on the other surface orthogonal to the thickness direction A vibrator comprising:
The protrusion is
A continuous side wall forming a hollow structure protruding in the thickness direction from the other surface of the elastic body;
A contact portion that is in contact with the driven body, and a contact portion that is located inside the side wall when viewed from a direction orthogonal to the contact surface;
Having flexibility in a direction orthogonal to the contact surface, and having a connecting part provided between the contact part and the side wall part,
In the contact portion, the length of the outer periphery of the base portion of the portion protruding from the connecting portion is shorter than the length of the outer periphery of the contact surface.   4. The vibrator according to claim 1, wherein in the protrusion, the side wall is made of the same metal material that is continuous with the elastic body. 5.   5. The vibrator according to claim 1, wherein the side wall portion, the connecting portion, and the contact portion are made of the same continuous metal material.   The vibrator according to claim 1, wherein the connecting part is divided into a plurality of parts.   The vibrator according to any one of claims 1 to 6, wherein the side wall portion of the protruding portion is cylindrical. The elastic body has a substantially rectangular shape,
The protrusions are formed at two locations at predetermined intervals on a straight line that equally divides the short side of the elastic body and parallel to the long side,
When the driving voltage is applied to the electro-mechanical energy conversion element, the protrusion portion has an elliptical motion in a plane orthogonal to the contact surface and parallel to the long side. The vibrator according to claim 1. The vibrator according to any one of claims 1 to 8,
A driven body in pressure contact with the contact surface of the vibrator;
Urging means for pressing and contacting the contact surface to the driven body by pressing the vibrator against the driven body;
A vibratory actuator, wherein the vibrator and the driven body are relatively moved by bringing the vibrator into pressure contact with the driven body to excite predetermined vibration in the vibrator. The vibration type actuator according to claim 9,
A lens driven by a driven body of the vibration type actuator;
An image pickup device comprising: an image pickup device provided at a position where light passing through the lens forms an image. The vibration type actuator according to claim 9,
And a stage as a driven body in the vibration type actuator.

Images