JP6388077B2 - Drive device - Google Patents

Description

  The present invention relates to a drive device that moves a moving body by driving a piezoelectric element.

  Conventionally, various drive devices using piezoelectric elements have been proposed as drive devices for moving a lens of a camera or the like.

  The following Patent Document 1 discloses an ultrasonic motor using bending vibration and other vibrations. Here, the cylindrical moving body is inserted into the through hole of the disk-shaped base. The cylindrical moving body is configured to move in the axial direction thereof. Piezoelectric elements are provided on both sides of the disk-shaped substrate. A combined resonance of the bending vibration and radial vibration of the disk is used.

  Conventionally, in some commercially available digital cameras, piezoelectric linear actuators are used for autofocus applications. In this type of autofocus-use piezoelectric linear actuator, it is required to suppress the rotation of a moving body including a lens. For this reason, the moving body including the lens is provided with a protrusion for preventing rotation, and on the other hand, a concave portion in which the protrusion is fitted is provided in the case.

JP-A-1-298968

  As described above, conventionally, in a driving device using a piezoelectric element, a combination of protrusions and recesses has been used to prevent rotation around the axial direction of the moving body, that is, rotation around the moving direction. However, in such a structure, there is a gap between the protrusion and the recess. For this reason, the moving body including the lens may rattle around the axial direction. In addition, the driving state of the moving body is not stable, and performance variation tends to occur.

  An object of the present invention is to provide a drive device that can suppress the rotation of the moving body around the moving direction and can move the moving body stably.

  The drive device according to the present invention has an elastic body having first and second main surfaces facing each other and having an opening penetrating from the first main surface toward the second main surface. And a drive unit having a piezoelectric element bonded to at least one main surface of the first and second main surfaces of the elastic body, and inserted into the opening of the elastic body, A movable body that is moved in a direction connecting the first main surface and the second main surface of the elastic body by driving the drive unit, and is fixed to the movable body, and the opening And a spring member having an outer surface having a plurality of pressure-contact portions pressed against the inner wall, and driving the piezoelectric element causes the drive unit to be at least one type different from the bending vibration and the bending vibration. Or the bending vibration and the bending vibration It is configured to vibrate by a coupled mode vibration formed by coupling with at least one other vibration, and the other vibration or the coupled mode vibration can move the moving body. The movable state in which the spring member is pressed against the inner wall of the opening of the elastic body, and the inner wall of the opening of the elastic body are separated from the spring member, or more than in the movable state The spring member has a vibration state that realizes a release state in which the spring member is in contact with the inner wall of the opening of the elastic body with a low frictional engagement force, as viewed from the first main surface side of the elastic body. Sometimes, the diameter of the spring member is increased radially outward in a portion other than the pressure contact portion so that the curvature of the spring member in at least one pressure contact portion is reduced.

  In a specific aspect of the drive device according to the present invention, the movable body is moved by the bending vibration and the other vibration of the drive unit or by the vibration of the coupling mode.

  In another specific aspect of the drive device according to the present invention, the diameter of the spring member is expanded radially outward in a portion other than the pressure contact portion by the moving body.

  In another specific aspect of the drive device according to the present invention, the spring member has a slit extending in a direction connecting the first main surface and the second main surface in a part of the circumferential direction of the cylindrical body. In this case, the spring member can be easily fixed to the outer peripheral surface of the moving body.

  In another specific aspect of the drive device according to the present invention, the opening has a radius of a circle circumscribing the spring member when viewed from the first main surface side of the elastic body. It is larger than the radius of the circle inscribed in the part.

  In another specific aspect of the drive device according to the present invention, when viewed from the first main surface side of the elastic body, the movable body has a rectangular shape with rounded corners, When the slit of the spring member is located in a rounded portion of one corner, and the spring member is seen by the drive body from the first main surface side of the elastic body, five locations are provided. In contact. In this case, it is possible to reduce variations in the press contact state at the plurality of press contact portions of the spring member.

  In another specific aspect of the driving apparatus according to the present invention, the moving body has a prismatic shape extending in a direction connecting the first main surface and the second main surface of the driving body.

  In still another specific aspect of the drive device according to the present invention, in order to partially increase the curvature of the spring member in a portion other than the pressure contact portion between the spring member and the moving body, A curvature increasing member in contact with the inner surface of the spring member is provided.

  In still another specific aspect of the drive device according to the present invention, the curvature increasing member may be provided between an end of the spring member and the moving body.

  In the drive device according to the present invention, the curvature increasing member may be formed integrally with the moving body. In this case, the number of parts can be reduced.

  In still another specific aspect of the drive device according to the present invention, the curvature increasing member may be integrally provided on the inner surface of the spring member.

  In still another specific aspect of the drive device according to the present invention, the spring member has a plurality of spring members arranged in a circumferential direction of the drive body. Thus, the spring member may be divided into a plurality of spring members.

  According to the drive device of the present invention, rotation of the moving body around the moving direction can be suppressed, and the moving body can be moved stably.

FIG. 1 is a front view of the elastic body of the drive device according to the first embodiment of the present invention as viewed from the first main surface side. FIG. 2 is a perspective view showing the drive unit used in the first embodiment of the present invention. FIG. 3 is a diagram illustrating the relationship between the bending frequency generated when the drive unit illustrated in FIG. 2 is excited and the spreading vibration, and the resonance frequency with respect to the thickness of the elastic body. The figure is a perspective view showing a moving body used in the first embodiment of the present invention. FIG. 5 is a perspective view showing a spring member used in the first embodiment of the present invention. In the driving apparatus according to the first embodiment of the present invention, FIG. 6A is a schematic diagram for explaining an initial state. FIG. 6B is a schematic diagram for explaining the released state. In the drive device according to the first embodiment of the present invention, FIG. 7A and FIG. 7B are schematic views for explaining a state in which each moving body is moved. FIG. 8 is a diagram illustrating the trajectory of the moving body in the driving device of the comparative example. FIG. 9 is a diagram illustrating the trajectory of the moving body in the driving apparatus of the experimental example of the first embodiment. FIG. 10 is a perspective view of a moving body used in the driving apparatus according to the second embodiment of the present invention. FIG. 11 is a front view showing a state in which a spring member is attached around a moving body in the second embodiment. FIG. 12 is a perspective view of a moving body used in the driving apparatus according to the third embodiment of the present invention. FIG. 13 is a front view of a driving apparatus according to the fourth embodiment of the present invention. FIG. 14 is a front view of a driving apparatus according to the fifth embodiment of the present invention. FIG. 15 is a front view of a driving apparatus according to the sixth embodiment of the present invention. FIG. 16 is a perspective view showing a modification of the spring member used in the driving device of the present invention.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  It should be pointed out that each embodiment described in this specification is an exemplification, and a partial replacement or combination of configurations is possible between different embodiments.

(First embodiment)
FIG. 1 is a front view of a drive device according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a drive unit used in the drive device, and FIG. 4 is a perspective view showing a moving body. FIG. 5 is a perspective view showing a spring member attached to the moving body.

  As shown in FIG. 1, the drive device 1 includes a drive unit 2, a moving body 3, and a spring member 4 attached to the moving body 3.

  As shown in FIG. 2, the drive unit 2 has an elastic body 5. The elastic body 5 has a first main surface 5a and a second main surface 5b facing each other. The elastic body 5 is made of an appropriate rigid material such as metal. In this embodiment, the elastic body 5 has a rectangular frame shape and has an opening 5c in the center. A plurality of piezoelectric elements 6 to 9 are joined on the first main surface 5a.

  The plurality of piezoelectric elements 6 to 9 may be bonded to the second main surface 5b instead of the first main surface 5a. A plurality of piezoelectric elements may be bonded to both main surfaces.

  Each of the piezoelectric elements 6 to 9 includes a piezoelectric layer and a pair of electrodes provided so as to face each other with the piezoelectric layer interposed therebetween. By applying an alternating voltage to the piezoelectric elements 6 to 9, the elastic body 5 vibrates due to bending vibration and spreading vibration.

  In the present embodiment, a coupling mode of this bending vibration and spreading vibration is used. A plurality of coupled modes can be generated by adjusting the resonance frequency of the bending vibration and the spreading vibration.

  FIG. 3 is a diagram showing the relationship between the resonance frequency of the bending vibration and the resonance frequency of the spreading vibration and the thickness of the elastic body 5. As shown in FIG. 3, by adjusting the thickness of the elastic body 5, the resonance frequency of the bending vibration and the resonance frequency of the spreading vibration can be adjusted, and a coupling mode of both can be generated. As will be described later, two coupling modes of a first coupling mode and a second coupling mode among a plurality of coupling modes are used.

  As shown in FIG. 1, a spring member 4 is attached to the moving body 3. As shown in FIG. 4, the moving body 3 has a substantially quadrangular prism shape. That is, the moving body 3 has a first main surface 3a and a second main surface 3b opposite to the first main surface 3a. Side surfaces 3c to 3f connect the first main surface 3a and the second main surface 3b.

  The direction connecting the first main surface 3 a and the second main surface 3 b is the axial direction, which is the moving direction of the moving body 3.

  FIG. 1 is a front view of the driving device 1 as seen from the first main surface 3a side. The paper surface-paper back direction in FIG. 1 is the moving direction described above.

  The first main surface 3a is rounded so that the four corner portions are rounded. As shown in FIG. 4, in the moving body 3, the four corner portions where the side surfaces 3 c to 3 f are adjacent to each other are rounded.

  The moving body 3 is made of an appropriate material such as ceramics, metal, or synthetic resin.

  As shown in FIG. 5, the spring member 4 has a substantially cylindrical shape. But a part of cylinder is notched and the slit 4a is formed. The axial direction of the spring member 4 is the moving direction of the moving body 3 described above. And the slit 4a is extended in the direction parallel to this moving direction. Accordingly, the spring member 4 has end portions 4a1 and 4a2 facing the slit 4a. The end portions 4a1 and 4a2 extend in a direction parallel to the moving direction.

  The spring member 4 is made of a material having spring properties such as metal. The inner diameter of the spring member 4 is selected so that the spring member 4 is pressed against the moving body 3 when the spring member 4 is extrapolated to the moving body 3. That is, the inner diameter of the spring member 4 before attachment is made smaller than the maximum width dimension in the cross section orthogonal to the moving direction of the moving body 3. Therefore, when attaching, the spring member 4 is expanded in diameter and attached to the moving body 3. In the attached state, a force that reduces the diameter of the spring member 4 acts, so that the spring member 4 is securely fixed to the moving body 3.

  By driving the drive unit 2 described above, the moving body 3 is moved along the moving direction described above together with the spring member 4 attached to the moving body 3. Details of this moving operation will be described later. However, when moving, the elastic body 5 is arranged so that the inner wall of the opening of the drive unit 2 is in contact with the spring member 4 in the pressure contact portions A1 to A4 shown in FIG. Displace. Thereby, the moving body 3 is moved together with the spring member 4.

  In the present embodiment, the moving member 3 expands the diameter of the spring member 4 to the outside in the radial direction by the moving body 3 so as to reduce the curvature of the spring member 4 in the pressure contact portions A1 to A4. Yes.

  As shown in FIG. 1, the spring member 4 is expanded at the contact points B <b> 1 to B <b> 5 so that the spring member 4 is in contact with the moving body 3 at the contact points B <b> 1 to B <b> 5. Here, the contact points B1 to B3 are located at the center of the three corner portions of the first main surface 3a when viewed from the first main surface 3a. On the other hand, the contact points B4 and B5 are portions where both sides of the slit 4a described above, that is, the end 4a1 and the end 4a2 are in contact with the moving body 3.

  As described above, at the contact points B1 to B5, the spring member 4 is deformed in the direction of expanding the diameter. For this reason, the curvature at the pressure contact portions A1 to A4 is made smaller than the curvature at the contact points B1 to B5. Therefore, since the curvature of the spring member 4 is reduced in the pressure contact portions A1 to A4, the spring member 4 is difficult to rotate around the moving direction of the moving body 3. That is, since the curvature when viewed from the first main surface 3a of the spring member 4 is reduced in the pressure contact portions A1 to A4, the rotation of the moving body 3 around the moving direction can be suppressed.

  In other words, when viewed from the first main surface 5a side of the elastic body 5, the radius of the circle circumscribing the spring member 4 is larger than the radius of the circle inscribed in the opening 5c at least at one location. . Therefore, as described above, the rotation of the moving body 3 around the moving direction is reliably suppressed.

  Further, as described above, since the end portions 4a1 and 4a2 on both sides of the slit 4a are in contact with the moving body 3, variations in the pressure contact state of the pressure contact portions A1 to A4 are unlikely to occur.

  Next, the driving operation in the driving device 1 will be described.

  When an AC voltage is applied to the plurality of piezoelectric elements 6 to 9, the above-described bending vibration and spreading vibration are generated. In the present embodiment, a coupling mode in which the bending vibration and the spreading vibration are coupled is used. That is, a plurality of coupling modes having different resonance frequencies appear as coupling modes of the bending vibration and the spreading vibration. In the present embodiment, the first coupling mode and the second coupling mode are used. The vibration in the first and second coupling modes is caused by the movable state in which the inner wall of the opening 5c of the elastic body 5 is pressed against the spring member 4 and the inner wall of the opening 5c separated from the spring member 4. Or has a vibrating state that realizes a released state in contact with the spring member 4 with a lower frictional engagement force than the movable state. That is, in any case of the first coupling mode and the second coupling mode, a vibration state that realizes the two states is generated.

  However, in the first coupling mode, the movable body 3 is moved to one side in the axial direction by the first coupling mode in the movable state. If this is a forward movement, in the second coupling mode, the movable body 3 and the spring member 4 are retracted by the inner wall of the opening 5c in the movable state. That is, the moving body 3 can be moved forward or backward by switching the driving frequency so that the first coupling mode and the second coupling mode are generated.

  As described above, in the present embodiment, the first and second coupling modes in which the vibration state realizing the release state and the movable state are generated are used. In order to make the coupling, it is preferable that the resonance frequency of the bending vibration and the resonance frequency of the spreading vibration are matched. However, the resonance frequencies of both may not be exactly the same, and the absolute value of the difference between the resonance frequency of the bending vibration and the resonance frequency of the spread vibration is the resonance frequency in the first coupling mode and the second coupling mode. What is necessary is just to be in the range within 15% of the average value of resonance frequency.

  In the present embodiment, a combined mode of bending vibration and spreading vibration is used, but bending vibration and combined mode may be used. Further, vibration modes other than bending vibration such as bending vibration and spreading vibration may be used.

  FIG. 6 (a) shows the initial state when operating the drive device 1, and as shown in FIG. 6 (b) by driving the drive unit 2 to produce the first coupling mode as described above. Thus, the release state is assumed. 6A, 6B, 7A, and 7B, the spring member 4 is not shown. That is, the opening of the elastic body 5 is pressed against the spring member attached to the moving body 3. In this state, by moving in the first coupling mode, as shown in FIG. 7A, the moving body 3 can be advanced in the arrow direction, that is, in one axial direction. In the first coupling mode, the forward state is stopped by realizing the release state. By repeating these steps, the moving body 3 can be pitched forward.

  In the case of retreating, the movable body 3 and the spring member 4 can be retreated by generating the second coupling mode and driving in the second coupling mode.

  By the way, the feature of this embodiment is that, as described above, when the moving body 3 and the spring member 4 are moved, the rotation of the moving body 3 and the spring member 4 around the moving direction is suppressed. It is to be able to move stably. This will be described based on a specific experimental example.

  FIG. 9 is a diagram illustrating a trajectory of the moving body 3 when the process of moving the moving body 3 forward and backward is repeated five times in the driving device 1 configured according to the above embodiment. Here, the horizontal axis and the vertical axis indicate the inclination angles in the X direction and Y direction of the center of the moving body 3 in the axial direction.

  On the other hand, as a comparative example, in place of the spring member 4 and the movable body 3, the above-mentioned implementation is performed except that the movable body is configured so that the curvature of the spring member is not smaller than that of the other portions at the press contact portion. A drive device having the same structure as that of the embodiment was prepared. FIG. 8 is a diagram showing the trajectory of the moving body when the process of moving the moving body of the driving device of this comparative example forward and backward is repeated five times.

  Experimental conditions are shown below. First, the drive device is installed on the pedestal. Next, a laser beam is irradiated to the moving body, and a voltage (3 V) for moving the moving body forward and backward is applied to the driving device five times. At this time, the tilt angle of the moving moving body is measured at the same time using a laser type tilt measuring device to obtain a locus. As is clear from a comparison between FIG. 8 and FIG. 9, it can be seen that according to the above embodiment, rotation around the moving direction can be reliably suppressed.

(Second Embodiment)
FIG. 10 is a perspective view of the moving body 3A used in the drive device according to the second embodiment of the present invention, and FIG. 11 shows the spring member 4 around the moving body 3A in the second embodiment. It is the front view seen from the 1st main surface side of 3 A of moving bodies which shows the state attached.

  In the present embodiment, the moving body 3A is inclined such that the corner portion is not rounded on the first main surface 3a and forms an angle of about 45 ° with respect to the sides on both sides. As shown in FIG. 11, the spring member 4 is extrapolated and attached to such a moving body 3A. Also in the present embodiment, the spring member 4 is expanded in diameter by the moving body 3A at portions other than the pressure contact portions A1 to A4 so that the curvatures at the pressure contact portions A1 to A4 are relatively small. . Here, the spring member 4 is in contact with the moving body 3A at 8 points of contact points B1 to B8. As described above, since contact is made at two points in the corner portion, variations in the pressure contact force at the pressure contacts A1 to A4 hardly occur. Also in this embodiment, the same effect as the first embodiment can be obtained.

(Third embodiment)
FIG. 12 is a perspective view of a moving body used in the driving apparatus according to the third embodiment. The moving body 3 used in the third embodiment has a cylindrical main body 3i. A flange portion 3j is provided on the main surface on one end side in the moving direction of the main body portion 3i. A flange portion 3k is provided on the main surface on the other end side in the movement direction of the main body portion 3i. The diameters of the flange portions 3j and 3k are larger than the diameter of the main body portion 3i. Although not shown, the spring member is attached between the flange portion 3j and the flange portion 3k. A plurality of ribs 3m are provided on the side surface of the main body 3i. The plurality of ribs 3m protrude outward in the radial direction from the side surface of the main body 3i. Each rib 3m extends in the moving direction.

  The plurality of ribs 3m are provided to expand the diameter of a spring member to be attached. Accordingly, the plurality of ribs 3m are provided in a portion other than the press contact portion, and act to increase the curvature in the portion other than the press contact portion, compared to the above-described curvature of the spring member in the press contact portion.

  Thus, in order to relatively reduce the curvature at the pressure contact portion of the spring member, the structure for expanding the diameter of the spring member can be variously modified. If the plurality of ribs 3m are provided at five locations, the spring member is easily frictionally engaged with the movable body, which is efficient. Also in this embodiment, the same effect as the first embodiment can be obtained.

(Fourth embodiment)
FIG. 13 is a front view of the moving body 33 of the driving device 31 according to the fourth embodiment as viewed from the first main surface 33a side. In the drive device 31, the moving body 33 is cylindrical. Thus, the columnar moving body 33 may be used. In this case, the spring member 4 is attached to the columnar moving body 33 by extrapolation. The spring member 4 has a slit 4a. A curvature increasing member 34 is provided between the spring member 4 and the moving body 33. That is, the curvature increasing member 34 is fixed to the side surface of the moving body 33 at a portion other than the pressure contact portion. The curvature increasing member 34 extends the entire length of the moving body 33 in the axial direction. Specifically, the curvature expanding member 34 is a rib provided on the side surface of the moving body 33 so as to protrude radially outward. In the portion where the spring member 4 is in contact with the curvature expanding member 34, the curvature of the spring member 4 is increased. Therefore, the curvature of the spring member 4 at the press contact portion can be made smaller than the curvature at the portion where the curvature expanding member 34 is provided. Thus, the curvature expanding member 34 may be provided between the moving body 33 and the spring member 4 in order to increase the curvature of a part of the spring member 4 when viewed in the axial direction of the spring member 4. In the present embodiment, the curvature increasing member 34 is provided integrally with the moving body 33, but may be constituted by another member. Alternatively, the curvature increasing member 34 may be provided integrally on the inner peripheral surface of the spring member 4. Also in this embodiment, the same effect as the first embodiment can be obtained.

(Fifth embodiment)
FIG. 14 is a front view for explaining the drive device according to the fifth embodiment. In the drive device 41, the spring member is divided into a substantially arc-shaped first spring member 42 and a second spring member 43 when viewed from the first main surface 33 a side of the moving body 33. In this way, a plurality of spring members 42 and 43 may be used. In this case, curvature expanding members 44 and 45 are provided between the spring members 42 and 43 and the moving body 33, respectively. Thereby, the curvature of the spring members 42 and 43 in the press contact portion is made smaller than the curvature in the portion where the curvature increasing members 44 and 45 are provided. Therefore, the rotation of the moving body 33 and the spring members 42 and 43 around the moving direction is suppressed.

(Sixth embodiment)
FIG. 15 is a front view for explaining the drive device according to the sixth embodiment. In the driving device 51, the spring member 4 is divided into a substantially arc-shaped first spring member 52 and a second spring member 53 when viewed from the first main surface 33 a side of the moving body 33. . Further, curvature increasing members 54 and 55 are provided between the ends of the spring members 52 and 53 and the moving body 33, respectively. Thereby, the curvature of the spring members 52 and 53 at the press contact portion is made smaller than the spring member curvature at the portion where the curvature increasing members 54 and 55 are provided. Therefore, the rotation of the moving body 33 and the spring member 4 around the moving direction is suppressed.

  Further, the spring member may be divided into two or more spring members.

  Further, in the embodiment described above, the substantially cylindrical spring member 4 having the slit 4a is used, but a cylindrical spring member 4B may be used as in the modification shown in FIG.

DESCRIPTION OF SYMBOLS 1 ... Drive device 2 ... Drive unit 2a ... Opening part 3, 3A ... Moving body 3a, 3b ... 1st, 2nd main surface 3c-3f ... Side surface 3i ... Main-body part 3j, 3k ... Flange part 3m ... Rib 4, 4B ... Spring member 4a ... Slits 4a1, 4a2 ... End 5 ... Elastic bodies 5a, 5b ... First and second main surfaces 5c ... Openings 6-9 ... Piezoelectric elements 31, 41, 51 ... Driving device 33 ... Movement Body 34 ... curvature increasing member 42, 52 ... first spring member 43, 53 ... second spring member 44, 45, 54, 55 ... curvature increasing member A1-A4 ... pressure contact part B1-B8 ... contact point

Claims (12)

An elastic body having opposing first and second main surfaces and having an opening penetrating from the first main surface toward the second main surface; and the first of the elastic bodies A drive unit having a piezoelectric element bonded to at least one of the first main surface and the second main surface;
A movable body that is inserted into the opening of the elastic body and is moved in a direction connecting the first main surface and the second main surface of the elastic body by driving the drive unit; ,
A spring member fixed to the movable body and having a plurality of press contact portions on the outer surface thereof pressed against the inner wall of the opening;
With
By driving the piezoelectric element, the drive unit is configured to bend at least one other vibration different from the bending vibration or at least one other vibration different from the bending vibration. It is configured to vibrate with the vibration of the coupled mode formed by coupling with the vibration of
A movable state in which the spring member is in pressure contact with the inner wall of the opening of the elastic body so that the vibration of the other mode or the coupling mode can move the moving body; The inner wall of the opening is separated from the spring member, or the spring member is in contact with the inner wall of the opening of the elastic body with a lower frictional engagement force than the movable state. Each has a vibration form to realize,
When viewed from the first main surface side of the elastic body, the spring member expands radially outward at a portion other than the pressure contact portion so that the curvature of the spring member at at least one pressure contact portion is reduced. The drive device that is diameter.   2. The drive device according to claim 1, wherein the movable body is moved by the bending vibration and the other vibration of the drive unit or by the vibration of the coupling mode.   The drive device according to claim 1, wherein the diameter of the spring member is expanded radially outward in a portion other than the pressure contact portion by the moving body.   The drive according to any one of claims 1 to 3, wherein the spring member has a slit extending in a direction connecting the first main surface and the second main surface in a part of a circumferential direction of the cylindrical body. apparatus.   The radius of a circle circumscribing the spring member when viewed from the first main surface side of the elastic body is larger than a radius of a circle inscribed in the opening at at least one position. Item 5. The drive device according to any one of Items 1 to 4.   When viewed from the first main surface side of the elastic body, the moving body has a rectangular shape with rounded corners, and the slit of the spring member rounds one corner. 5. The drive device according to claim 4, wherein the drive device is located in a banded portion, and the spring member is in contact with the drive body at five locations when viewed from the first main surface side of the elastic body. .   6. The driving device according to claim 1, wherein the moving body has a prismatic shape extending in a direction connecting the first main surface and the second main surface of the driving body. .   In order to partially increase the curvature of the spring member in a portion other than the pressure contact portion, a curvature increasing member that is in contact with the inner surface of the spring member is provided between the spring member and the movable body. The drive device according to claim 1, wherein the drive device is provided.   The drive device according to claim 8, wherein the curvature increasing member is provided between an end of the spring member and the moving body.   The drive device according to claim 8 or 9, wherein the curvature increasing member is formed integrally with the movable body.   The drive device according to claim 8 or 9, wherein the curvature increasing member is integrally provided on an inner surface of the spring member.   The drive device according to claim 1, wherein the spring member has a plurality of spring members arranged in a circumferential direction of the drive body.

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