JP4555165B2 - Driving device and driving method thereof - Google Patents

Description

  The present invention relates to a driving device (actuator) for driving a driven body or a displaced body using an electromechanical conversion element, and a driving method thereof.

  Conventionally, in addition to driving lenses in optical devices such as projection lenses such as camera photographing lenses and overhead projectors, binocular lenses, and copier lenses, there are drive units such as devices such as plotters and XY drive tables. As a general driving technique of the apparatus, there are the following Patent Documents 1 to 4 and the like.

  First, Patent Document 1 will be described with reference to the schematic diagram of FIG. In the piezoelectric actuator 300 of FIG. 28, 310 is a protrusion, 322B is a support, and 322C is a fixed part. 321 is a piezoelectric element, 321A is a central electrode, and 321B and 321C are symmetrical electrodes. The piezoelectric element 321 expands and contracts (longitudinal vibration) in the longitudinal direction by the central electrode 321A, flexurally vibrates by the symmetrical electrode 321B or 321C, and generates elliptical motion in the protrusion 310 by a combination of the two vibrations as a driving force. I'm taking it out. The rotational direction of the elliptical motion is controlled by selecting the symmetrical electrodes 321B and 321C that are reversed by the symmetrical electrodes 321B and 321C and excite bending vibration.

  Patent Document 2 has a configuration as shown in FIG. 29. On the main surface of a rectangular piezoelectric body 410 having long edge portions 440 and 442 and short edge portions 428 and 443, electrodes 414, 416, 418, 420 is formed. The electrodes 414 and 420 are electrically connected by a path 422, and the electrodes 416 and 418 are electrically connected by a path 424. The movement of the piezoelectric body 410 is restricted by the fixed supports 432 and 434 and the spring loaded supports 436 and 438, and the spring loaded support 444 provided at the center of the short edge 443 is used to It is pressed against the movable object 430 through a ceramic spacer 426 attached at the center. It is desirable that the resonance frequency in the x direction and the resonance frequency in the y direction overlap each other, and the length of the long edge portion is reduced so that the interval between the resonance of the high-order mode of the short edge portion and the resonance of the low-order mode of the long edge portion is narrowed. The length of the short edge is limited. In such a mechanism, a unipolar asymmetric pulse voltage or alternating voltage having a frequency at which the short edge portion and the long edge portion resonate is applied to the opposing electrodes 416 and 418 or the electrodes 414 and 420, so that FIG. The piezoelectric body 410 is deformed in the −x or x direction, and the movable object 430 is driven in the −x or x direction. Also, Patent Document 4 discloses a technique in which a four-divided electrode is arranged on one surface of a piezoelectric element on a flat plate and a driven body is brought into contact with an end portion to apply a driving force by vibration.

Furthermore, in the technique of Patent Document 3, as shown in FIG. 30, a protrusion 536 that is brought into contact with the rotor 500 is provided at one end 535 in the longitudinal direction of the diaphragm 510 on which the piezoelectric elements are stacked. The vibration plate 510 is supported by the first support member 511a and the second support member 511b so as to vibrate at sides 510a and 510b extending in the longitudinal direction. Here, the width of the first support member 511a is different from the width of the second support member 511b, and therefore the support structure is unbalanced. Under such a configuration, by combining two vibrations of bending vibration orthogonal to the longitudinal vibration in the longitudinal direction of the piezoelectric element, the protrusion 536 is moved elliptically, and the rotor 500 is moved in the direction indicated by the arrow in the figure. Rotate. In this technique, the configuration is unbalanced, so that the vibration of the protrusion 536 is expanded to extract a large rotational motion.
JP 2004-254417 A JP-A-7-184382 JP 2001-327180 A JP 2002-233174 A

  Incidentally, in recent years, lens modules for digital cameras of mobile phones have been required to achieve high functionality such as high pixel density, zoom, autofocus, and camera shake prevention at low cost. However, the background art as described above has the following disadvantages. First, since the technique described in Patent Document 1 does not drive if the resonance between longitudinal vibration and bending vibration shifts, it is necessary to control element dimensions and input signals with high accuracy, making it difficult to reduce the size and cost. There is. Further, in the technique of Patent Document 2, since the driving force is reduced when the vibrations in the long edge direction and the short edge direction are poorly overlapped, the accuracy of the element is required. In addition, since the structure of the element is complicated and the control of the drive circuit is required, it is difficult to reduce the size and cost. The same applies to the technique of Patent Document 4. Furthermore, the technique of Patent Document 3 requires a combination of two longitudinal vibrations and bending vibrations, and has a disadvantage that the rotation direction cannot be freely changed because the rotation direction is fixed by right rotation.

  The present invention focuses on the above points, and an object of the present invention is to provide a driving device and a driving method thereof that are small and lightweight and capable of stable displacement and positioning, or freely controlling the driving direction or the rotating direction. It is to be.

In order to achieve the above object, a driving apparatus according to the present invention includes a piezoelectric vibration plate in which a piezoelectric element including a piezoelectric layer and a driving electrode sandwiching both main surfaces of the piezoelectric layer is provided on one main surface of the vibration plate. And a protrusion formed so as to be symmetrical in the radial direction at a position corresponding to a vibration node or antinode of the outer peripheral portion of the diaphragm, and a substantially cylindrical rotor, and the piezoelectric element The diaphragm has a substantially ring shape with a part of a circle cut out, and the piezoelectric element has a drive electrode that is not divided on the main surface on the diaphragm side, and the other main surface is divided symmetrically. The vibration plate is supported by a support portion disposed so as to be bilaterally symmetric on a surface where no piezoelectric element is provided, and the protrusion portion contacts the inner surface of the rotor. It is characterized by.

In order to achieve the above object, the driving method of the driving apparatus of the present invention is characterized in that a driving signal asymmetric with respect to time is input between the driving electrodes of the driving apparatus according to claim 1 .

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

The present invention provides a piezoelectric diaphragm having a piezoelectric layer and a drive electrode sandwiching both principal surfaces of the piezoelectric layer provided on one principal surface of the diaphragm, and vibration of an outer peripheral portion of the diaphragm. A drive device is composed of a protrusion formed so as to be bilaterally symmetrical in the radial direction and a substantially cylindrical rotor at a position corresponding to a node or an antinode, and the piezoelectric element and the vibration plate are part of a circle. The piezoelectric element is provided with a drive electrode that is not divided on the main surface on the diaphragm side, and a drive electrode that is divided symmetrically on the other main surface. The vibration plate is supported by a support portion arranged so as to be bilaterally symmetrical on a surface where no piezoelectric element is provided, and the protrusion portion is in contact with the inner surface of the rotor. Since a driving signal asymmetric with respect to time is input between the driving electrodes , a stable driving force (or displacement force) in a single direction can be obtained, and the driving direction can be reversed. It is. Further, since only one vibration is used, the frequency control is easy and the dimensions are not limited, and the drive device can be reduced in size, weight, and thickness.

  Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples.

  First, Embodiment 1 of the present invention will be described with reference to FIGS. In this embodiment, the present invention is used as a driving device (actuator) for a focusing lens of an optical device. FIG. 1 is a plan view of the entirety of this embodiment as viewed from the optical axis direction of the lens. 2A is a front view of the driving device shown in FIG. 1 as viewed from the direction of the arrow F1a and a driving circuit, FIG. 2B is a side view of the driving device as viewed from the direction of the arrow F1b, and FIG. FIG. 5 is a diagram showing a modification of the drive device and the drive circuit of the present embodiment. 3 (A-1) to 3 (A-3) are diagrams showing the relationship between the drive voltage applied to the drive device and time, and FIGS. 3 (B-1) and 3 (B-2) are diagrams for driving. It is a figure which shows the locus | trajectory of a projection part. 4 is an end view of FIG. 1 cut along line # A- # A. (A) is a state where the lens barrel is raised, (B) is a state where the lens barrel is not displaced, and (C) is a state where FIG. It is a figure which shows the state which the lens-barrel fell. FIG. 5 is a diagram showing the relationship between the displacement speed of the lens barrel of this embodiment and the drive voltage.

  The drive device 10 of this embodiment is for moving or displacing a lens barrel 34 that is a displaced object in the passage 30 in the optical axis direction of the lens 36 (vertical direction in FIG. 4). As shown in FIGS. 2 and 4, the drive device 10 is disposed along the optical axis direction and has a cantilever structure in which one end is fixed to the bottom surface 32 of the passage. In this embodiment, for ease of explanation, the lens barrel 34 is described as being displaced up and down in the passage 30, but the displacement direction is arbitrary, and in that case, the expression of the bottom surface 32 and the like is also expressed. It is changed appropriately. The lens barrel 34 supports a lens 36 at an appropriate position, and a substantially cylindrical guide 38 is provided on the outer peripheral surface thereof. A plurality of slits (or grooves) 40 are formed in the guide 38 along the optical axis direction at appropriate intervals.

  In the illustrated example, four slits 40 are provided, and convex portions 34A and 34B projecting radially from the outer periphery of the lens barrel 34 are engaged with a pair of opposed slits 40 therein. Yes. When the lens barrel 34 is displaced, the convex portions 34A and 34B move in the slit 40, so that the displacement of the lens barrel 34 in the optical axis direction is guided and the rotation is suppressed. Further, the projection 14 of the driving device 10 is in contact with the lens barrel 34 through one of the remaining slits 40. The protrusion 14 is urged against the lens barrel 34 by a spring 44 that extends from the inner surface 42 of the passage 30 toward the center of the passage 30 in a direction substantially orthogonal to the optical axis.

  The driving device 10 has a bimorph structure in which piezoelectric elements 16 and 22 are provided on both main surfaces of a substantially rectangular diaphragm 12. The piezoelectric element 16 is provided with drive electrodes 20 and 21 on both main surfaces of the piezoelectric body 18. The other piezoelectric element 22 also includes drive electrodes 26 and 27 on both main surfaces of the piezoelectric body 24. The drive electrodes 21 and 27 and the diaphragm 12 are all at the same potential, and are connected to one terminal of the drive power supply 28 as shown in FIG. The other drive electrodes 20 and 26 are connected to the other terminal of the drive power supply 28. These piezoelectric elements 16 and 22 are set shorter than the diaphragm 12 so that one end side of the diaphragm 12 is exposed when the piezoelectric elements 16 and 22 are bonded to the main surface of the diaphragm 12. As the diaphragm 12, for example, a metal plate or the like is used, and the piezoelectric bodies 18 and 24 are formed of, for example, PZT, Bi-based perovskite structure ceramics, Bi layered structure compound-based ceramics, Nb acid-based ceramics, or the like. The drive electrodes 20, 21, 26, and 27 are made of, for example, Ag or an Ag / Pd alloy, but are not limited thereto, and can be made of various known materials. On one main surface of the exposed portion 12A of the diaphragm 12, a protrusion 14 is formed at a position corresponding to a vibration node, as shown in FIG. The protrusion 14 is made of the same material as that of the diaphragm 12, for example. In the drive device 10 having such a configuration, the end opposite to the exposed portion 12A is fixed to the bottom surface 32 of the passage 30 by appropriate means.

  Next, the operation of this embodiment will be described with reference to FIGS. FIGS. 3A-1 to 3A-3 are diagrams showing the relationship between the drive voltage applied to the drive device 10 of this embodiment and time, the vertical axis shows the drive voltage, and the horizontal axis Indicates time. FIGS. 3A-1 and 3A-3 are examples in which the lens barrel 34 is raised, and FIG. 3A-2 is an example in which the lens barrel 34 is lowered. 3 (B-1) and 3 (B-2) are diagrams showing the trajectory of the protrusion 14, the vertical axis represents the optical axis direction, and the horizontal axis corresponds to the nodal line 15 in FIG. To do. When the piezoelectric elements 16 and 22 bonded to the vibration plate 12 are excited and driven by the input of an alternating signal, the driving device 10 vibrates symmetrically, so that the protrusion 14 is shown in FIG. As shown, the tip 14A vibrates around the nodal line 15 so as to draw an arc vertically.

  However, for example, when the piezoelectric elements 16 and 22 are excited by inputting an asymmetric drive signal with respect to the time for repeating the gentle rising portion L1 and the steep falling portion L2 shown in FIG. In the driving device 10, after the piezoelectric element 16 is contracted slowly and the piezoelectric element 22 is extended slowly and the protrusion 14 is slowly turned upward, the piezoelectric element 16 is extended quickly and the piezoelectric element 22 is quickly contracted, The protrusion 14 quickly turns downward. At this time, the tip 14A of the protrusion 14 vibrates asymmetrically with respect to time while passing through the locus shown in FIG. Here, when the protrusion 14 quickly turns downward, the inertia of the object to be displaced (in this embodiment, the lens barrel 34) becomes larger than the frictional force between the protrusion 14 and the object to be displaced, and the object to be displaced Power does not work. On the other hand, when the protrusion 14 slowly faces upward, the frictional force becomes larger than the inertial force, and an upward force acts on the object to be displaced. By repeating this, an upward driving force acts on the object to be displaced, and for example, the lens barrel 34 is moved so as to change from the non-displaced state shown in FIG. 4 (B) to the raised state shown in FIG. 4 (A). It is possible to drive upward.

  On the other hand, when the piezoelectric elements 16 and 22 are excited by inputting an asymmetric drive signal with respect to the time for repeating the gentle falling portion L3 and the steep rising portion L4 shown in FIG. Similarly, while taking the trajectory of FIG. 3 (B-1), a driving force in the downward direction acts on the lens barrel 34, contrary to the above-described operation. In other words, the lens barrel 34 can be driven so as to change from the non-displaced state shown in FIG. 4B to the lowered state shown in FIG. Therefore, the displacement direction of the object to be displaced can be reversed by applying a drive signal that is asymmetric with respect to time to the piezoelectric element by inverting the voltage.

  Further, the piezoelectric elements 16 and 22 are supplied with an asymmetric drive signal with respect to the time of repeating the gentle rising portion L5 and the steep falling portion L6 as described above with the positive voltage shown in FIG. When input and excited, the piezoelectric element 16 is slowly contracted and the piezoelectric element 22 is slowly extended, and the protrusion 14 is slowly upward. Then, the piezoelectric element 16 is rapidly extended and the piezoelectric element 22 is rapidly contracted. The locus shown in FIG. 3 (B-2) where the protrusion 14 quickly returns to the horizontal direction is taken. Here, when the protrusion 14 slowly turns upward, the frictional force becomes larger than the inertial force, and an upward force acts on the object to be displaced. On the other hand, when the protrusion 14 quickly returns to the horizontal direction, the inertia of the object to be displaced (in this embodiment, the lens barrel 34) becomes larger than the friction force between the protrusion 14 and the object to be displaced, Power does not work. By repeating this, an upward driving force acts on the object to be displaced, and for example, the lens barrel 34 is moved so as to change from the non-displaced state shown in FIG. 4B to the raised state shown in FIG. It is possible to drive upward. Therefore, the displacement direction of the object to be displaced can also be reversed by inputting a driving signal that is asymmetric with respect to time to the piezoelectric element while switching the voltage change.

  FIG. 5 shows the relationship between the displacement speed of the lens barrel of this embodiment and the drive voltage. In FIG. 5, the horizontal axis represents the drive voltage Vp [V], and the vertical axis represents the displacement speed [mm / s]. It was confirmed that a displacement speed of 4 mm / s was obtained when the input peak voltage was 5V.

  In the above description, in order to drive the protrusion 14 asymmetrically, a driving signal that is asymmetric with respect to time is input to each of the piezoelectric elements 16 and 22, but (1) a driving signal that is asymmetric with respect to time is input. The same effects as in the previous embodiment except that the displacement amount is reduced by inputting to only one of the elements, or (2) providing a piezoelectric element only on one main surface of the diaphragm. Is obtained.

Thus, according to the first embodiment, there are the following effects.
(1) Piezoelectric elements 16 and 22 are bonded to both main surfaces of the diaphragm 12, and a protrusion 14 is provided at a position corresponding to a vibration node on the main surface of the exposed portion 12A of the diaphragm to be urged. As a result, the projection 14 is brought into contact with the lens barrel 34 that is the object to be displaced. Since the protrusion 14 is driven asymmetrically with respect to time by inputting a drive signal that is asymmetric with respect to time, a stable driving force (or displacement) in a single direction can be obtained. it can.
(2) By inverting the voltage of the drive signal that is asymmetric with respect to time, the displacement direction of the object to be displaced can be reversed. Moreover, it becomes possible to reverse the displacement direction of a to-be-displaced object by switching the drive signal asymmetric with respect to time by changing the voltage change rate.
(3) Since it can be used with only one vibration, frequency control is easy. In addition, since the size and shape of the piezoelectric element are not limited, the drive device 10 can be reduced in size, weight, and thickness.
(4) Since the projecting portion 14 is urged toward the lens barrel 34 by the spring 44, stable driving can be obtained.

  <Modification of Example 1> FIG. 2 (C) is a modification in which the piezoelectric element 22 is provided only on one main surface of the diaphragm 12, and the piezoelectric diaphragm has a unimorph structure. The piezoelectric element 22 includes drive electrodes 26 and 27 on both main surfaces of the piezoelectric body 24. One drive electrode 27 and the diaphragm 12 have the same potential, and are connected to one terminal of the drive power supply 28 as shown in FIG. The other drive electrode 26 is connected to the other terminal of the drive power supply 28. Other points are the same as those in the above-described embodiment, and the same actions and effects can be obtained.

  <Other Modifications of First Embodiment> Next, with reference to FIGS. 6 and 7, another modification of the present embodiment will be described. FIG. 6 is a plan view of the present modification viewed from the optical axis direction. 7 is an end view of FIG. 6 cut along the line # B- # B. (A) is a state where the lens barrel is raised, (B) is a state where it is not displaced, and (C) is a state where it is lowered. Shows the state. In the embodiment shown in FIGS. 1 to 5, the protrusion 14 of the driving device 10 is brought into contact with only one part of the lens barrel 34, but in the modification shown in FIGS. 6 and 7, the driving device is used. 10 are provided one by one at positions facing each other across the lens barrel 34. Thus, by providing the driving device 10 on both sides of the lens barrel 34, a displacement speed about twice that of the configuration shown in FIGS. 1 to 5 can be obtained.

  Next, Embodiment 2 of the present invention will be described with reference to FIGS. In addition, the same code | symbol shall be used for the component which is the same as that of Example 1 mentioned above, or respond | corresponds. FIG. 8A is a plan view of the entire second embodiment viewed from the optical axis direction, FIG. 8B is a perspective view showing the main part of the driving device of the present embodiment, and FIG. FIG. 4 is a perspective view showing a main part of a driving device of a modified example using a unimorph type piezoelectric diaphragm in which the piezoelectric elements of the present embodiment are combined. FIG. 9 is an end view of FIG. 8A cut along line # C- # C. (A) is a state where the lens barrel is raised, (B) is a state where it is not displaced, (C) Indicates a lowered state.

  In the driving device 50 of this embodiment, piezoelectric elements 56 and 58 are joined to both main surfaces of the diaphragm 52, and one end is fixed to the passage bottom surface 32 so that the main surface is parallel to the optical axis. It has a lifting structure. In the modification of the present embodiment shown in FIG. 8C, the piezoelectric element 56 is bonded to only one main surface of the diaphragm 52. In the above-described embodiment, the protruding portion 54 for contacting the lens barrel 34 is provided on the side surface 52 </ b> A of the diaphragm 52, at a position serving as a vibration node. The configurations of the piezoelectric elements 56 and 58 are the same as those of the piezoelectric elements 16 and 22 of the first embodiment. The driving device 50 excites both piezoelectric elements with a driving signal that is asymmetric with respect to the time shown in FIGS. 3A-1 to 3A-3 so that the primary vibration of the bending occurs. Conversely, it is configured to be electrically switched.

  When an alternating signal is input to both the piezoelectric elements 56 and 58 and driven, the driving device 50 causes the center line of the piezoelectric diaphragm to be between a broken line and a one-dot broken line in the figure as shown in FIG. As shown in FIG. 3 (B-1), the protrusion 54 vibrates around the nodal line 15 so that the tip of the projection 54 forms an arc vertically. However, for example, when the piezoelectric elements 56 and 58 are excited by inputting an asymmetric drive signal with respect to the time for repeating the gentle rising portion L1 and the steep falling portion L2 as in FIG. In the driving device 50, after the piezoelectric elements 56 and 58 are slowly bent in the lateral direction in the plane so that the respective center lines are along the one-dot broken line and the protrusion 54 is gently upward, the piezoelectric elements 56 and 58 is quickly bent laterally in the plane so that the respective center lines are along the broken line, and the protrusions 54 are quickly turned downward. At this time, the tip of the protrusion 54 vibrates asymmetrically with respect to time while passing through the locus shown in FIG. Here, when the projecting portion 54 quickly turns downward, the inertia of the object to be displaced (in this embodiment, the lens barrel 34) becomes larger than the frictional force between the projecting portion 54 and the object to be displaced, and the object to be displaced becomes Power does not work. On the other hand, when the protrusion 54 slowly faces upward, the frictional force becomes larger than the inertial force, and an upward force acts on the object to be displaced. By repeating this, an upward driving force acts on the object to be displaced, and for example, the lens barrel 34 is moved from the non-displaced state shown in FIG. 9 (B) to the raised state shown in FIG. 9 (A). It is possible to drive upward.

  On the contrary, when the piezoelectric elements 56 and 58 are excited by inputting an asymmetric drive signal with respect to the time for repeating the gradual falling portion L3 and the steep rising portion L4 as shown in FIG. In the same manner as described above, a downward driving force is applied to the lens barrel 34, contrary to the above-described operation, while taking the trajectory of FIG. 3 (B-1). That is, the lens barrel 34 can be driven so as to change from the state shown in FIG. 9B to the lowered state shown in FIG. 9C. Therefore, the displacement direction of the object to be displaced can be reversed by applying a drive signal that is asymmetric with respect to time to the piezoelectric element by inverting the voltage.

  Further, the piezoelectric elements 56 and 58 are supplied with asymmetric driving signals with respect to the time of repeating the gentle rising portion L5 and the steep falling portion L6 as described above with the positive voltage shown in FIG. When input and excited, the piezoelectric elements 56 and 58 slowly bend in the lateral direction in the plane so that the respective center lines follow the one-dot broken line, and the protrusion 54 slowly faces upward. 58 takes a locus similar to that shown in FIG. 3B-2, in which the center line is quickly bent laterally in the plane so that the center line returns to the vertical direction, and the protrusion 54 quickly returns to the horizontal direction. Here, when the projecting portion 54 quickly turns downward, the inertia of the object to be displaced (in this embodiment, the lens barrel 34) becomes larger than the frictional force between the projecting portion 54 and the object to be displaced, and the object to be displaced becomes Power does not work. On the other hand, when the projection 54 slowly returns to the horizontal direction, the frictional force becomes larger than the inertial force, and an upward force acts on the object to be displaced. By repeating this, an upward driving force acts on the object to be displaced, and for example, the lens barrel 34 is moved from the non-displaced state shown in FIG. 9 (B) to the raised state shown in FIG. 9 (A). It is possible to drive upward. Therefore, the displacement direction of the object to be displaced can also be reversed by inputting a drive signal that is asymmetric with respect to time to the piezoelectric element by switching the voltage change.

  According to this example, a displacement speed of 10 mm / s was obtained when the input peak voltage was 5V. The operations and effects of the present embodiment are basically the same as those of the first embodiment described above. In the above description, in order to drive the protrusion 54 asymmetrically, a driving signal that is asymmetric with respect to time is input to each of the piezoelectric elements 56 and 58. (1) A driving signal that is asymmetric with respect to time is input. The same as in the previous embodiment except that the amount of displacement can be reduced by inputting to only one of the elements, or (2) providing a piezoelectric element only on one main surface of the diaphragm. An effect is obtained.

  <Other Modifications of Second Embodiment> Next, with reference to FIGS. 10 and 11, another modification of the second embodiment will be described. FIG. 10 is a plan view of the present modification viewed from the optical axis direction. FIG. 11 is an end view of FIG. 10 cut along line # D- # D. (A) is a state where the lens barrel is raised, (B) is a state where it is not driven, and (C) is a state where it is lowered. Shows the state. In the example shown in FIGS. 8 and 9, the protrusion 54 of the driving device 50 is brought into contact with only one part of the lens barrel 34. However, the example shown in FIGS. These are provided one by one at opposite positions across the lens barrel 34. In this manner, by providing the drive devices 50 on both sides of the lens barrel 34, a displacement speed approximately twice that of the configuration shown in FIGS. 8 and 9 can be obtained.

  Next, Embodiment 3 of the present invention will be described with reference to FIGS. 12A is a plan view of the entire third embodiment viewed from the optical axis direction, FIG. 12B is a perspective view showing the main part of the driving device of the present embodiment, and FIG. It is the side view which looked at the drive device of a present Example from the direction orthogonal to an optical axis. 13A and 13B are end views taken along line # C- # C in FIG. 12A. FIG. 13A is a state where the lens barrel is raised, FIG. 13B is a state where it is not displaced, and FIG. Indicates a lowered state. In the first and second embodiments described above, a protrusion is provided at a position corresponding to the vibration node of the diaphragm to which the piezoelectric element is attached, and the lens barrel 34 is driven using the rotational movement of the protrusion. However, in the second embodiment, a protrusion is provided at a position corresponding to the antinode of vibration of the diaphragm to which the piezoelectric element is attached, and the lateral vibration of the protrusion is used.

  In the driving device 50 of this embodiment, piezoelectric elements 56 and 58 are joined to both main surfaces of the diaphragm 52, and one end is fixed to the passage inner surface 42 so that the main surfaces are orthogonal to the optical axis. It has a lifting structure. In the present embodiment, a protrusion 54 for contacting the lens barrel 34 is provided on the side surface 52A of the vibration plate 52 at a position where the vibration is caused. The configurations of the piezoelectric elements 56 and 58 are the same as those of the piezoelectric elements 16 and 22 of the first embodiment. The driving device 50 excites both piezoelectric elements with a driving signal that is asymmetric with respect to the time shown in FIGS. 3A-1 to 3A-3 so that the primary vibration of the bending occurs. Conversely, it is configured to be electrically switched.

  When an alternating signal is input to both the piezoelectric elements 56 and 58 and driven, the driving device 50 causes the center line of the piezoelectric diaphragm to be between the broken line and the one-dot broken line in the figure, as shown in FIG. Therefore, the protrusion 54 is displaced vertically in the vertical direction. However, for example, when the piezoelectric elements 56 and 58 are excited by inputting an asymmetric drive signal with respect to the time for repeating the gentle rising portion L1 and the steep falling portion L2 as in FIG. In the driving device 50, after the piezoelectric element 56 is slowly contracted, the piezoelectric element 58 is slowly extended, the center line is bent in the thickness direction along the one-dot broken line, and the projecting portion 54 is slowly displaced upward, the piezoelectric element 56 The piezoelectric element 58 rapidly shrinks, the center line is bent in the thickness direction so as to follow the broken line, and the projection 54 is quickly displaced downward. At this time, the tip of the protrusion vibrates asymmetrically with respect to time while passing through the vertical trajectory. Here, when the protrusion 54 is quickly displaced downward, the inertia of the object to be displaced (in this embodiment, the lens barrel 34) becomes larger than the frictional force between the protrusion 54 and the object to be displaced, and the object to be displaced The force does not act on. On the other hand, when the protrusion 54 is slowly displaced upward, the frictional force becomes larger than the inertial force, and an upward force acts on the object to be displaced. By repeating this, an upward driving force acts on the object to be displaced, and for example, the lens barrel 34 is moved so as to change from the non-displaced state shown in FIG. 13B to the raised state shown in FIG. It is possible to drive upward.

  On the other hand, when the piezoelectric elements 56 and 58 are excited by inputting an asymmetric drive signal with respect to the time for repeating the gradual falling portion L3 and the steep rising portion L4 as shown in FIG. As described above, the protrusion 54 takes a vertical trajectory and, contrary to the above-described operation, vibrates asymmetrically with respect to time, and a downward driving force acts on the lens barrel 34. That is, the lens barrel 34 can be driven so as to change from the state shown in FIG. 13B to the lowered state shown in FIG. Therefore, the displacement direction of the object to be displaced can be reversed by applying a drive signal that is asymmetric with respect to time to the piezoelectric element by inverting the voltage. On the other hand, according to this example, a displacement speed of 10 mm / s was obtained when the input peak voltage was 5V. The operations and effects of the present embodiment are basically the same as those of the first embodiment described above.

  Further, the piezoelectric elements 56 and 58 are supplied with asymmetric driving signals with respect to the time of repeating the gentle rising portion L5 and the steep falling portion L6 as described above with the positive voltage shown in FIG. When the drive device 50 is excited by the input, the piezoelectric element 56 is contracted slowly, the piezoelectric element 58 is extended slowly, the center line is bent in the thickness direction along the one-dot broken line, and the protrusion 54 is slowly displaced upward. After that, the piezoelectric element 56 is quickly extended and the piezoelectric element 58 is quickly contracted to return so that the center line is in the horizontal direction, and the protrusion 54 is quickly displaced downward. At this time, the tip of the protrusion vibrates asymmetrically with respect to time while passing through the vertical trajectory. Here, when the protrusion 54 quickly returns to the horizontal direction, the inertia of the object to be displaced (in this embodiment, the lens barrel 34) becomes larger than the frictional force between the protrusion 54 and the object to be displaced, and the object to be displaced The force does not act on. On the other hand, when the protrusion 54 is slowly displaced upward, the frictional force becomes larger than the inertial force, and an upward force acts on the object to be displaced. By repeating this, an upward driving force acts on the object to be displaced, and for example, the lens barrel 34 is moved so as to change from the non-displaced state shown in FIG. 13 (B) to the raised state shown in FIG. 13 (A). It is possible to drive upward. Therefore, the displacement direction of the object to be displaced can also be reversed by inputting a driving signal that is asymmetric with respect to time to the piezoelectric element while switching the voltage change. According to this example, a displacement speed of 10 mm / s was obtained when the input peak voltage was 5V. The operations and effects of the present embodiment are basically the same as those of the first embodiment described above. In the above description, in order to drive the protrusion 54 asymmetrically, a driving signal that is asymmetric with respect to time is input to each of the piezoelectric elements 56 and 58. (1) A driving signal that is asymmetric with respect to time is input. Similar to the above-described embodiment except that only one element is input, or (2) the piezoelectric element is provided only on one main surface of the diaphragm 52, the displacement amount is reduced. The effect is obtained.

  <Modified Example of Third Embodiment> Next, a modified example of the present embodiment will be described with reference to FIGS. 14 and 15. FIG. 14 is a plan view of the present modification viewed from the optical axis direction. FIG. 15 is an end view of FIG. 14 cut along line # D- # D. (A) is a state where the lens barrel is raised, (B) is a state where it is not driven, and (C) is a state where it is lowered. Shows the state. In the example shown in FIGS. 12 and 13, the protrusion 54 of the driving device 50 is brought into contact with only one part of the lens barrel 34. However, the example shown in FIGS. These are provided one by one at opposite positions across the lens barrel 34. In this manner, by providing the driving devices 50 on both sides of the lens barrel 34, a displacement speed approximately twice that of the configuration shown in FIGS. 12 and 13 can be obtained.

  Next, Embodiment 4 of the present invention will be described with reference to FIGS. FIG. 16A is a plan view of the entirety of the fourth embodiment viewed from the optical axis direction, and FIG. 16B is a side view of the fourth embodiment. FIG. 17 is an end view of FIG. 16A cut along the line # E- # E. FIG. 17A is a state where the lens barrel is raised, FIG. 17B is a state where it is not displaced, and FIG. Indicates a lowered state. The present embodiment is the same as the third embodiment in that a protrusion is provided at a position corresponding to the antinode of vibration of the diaphragm to which the piezoelectric element is attached, and the lateral vibration of the protrusion is used. In the fourth embodiment, the bending vibration in the thickness direction of the piezoelectric diaphragm is used. However, the fourth embodiment is different in that the vibration in the lateral surface of the piezoelectric diaphragm is used.

  As shown in FIGS. 16A and 16B, the configuration of the driving device 10 used in this embodiment is the same as that of the first embodiment, but in this embodiment, one end of the driving device 10 is a passage. It has a cantilever structure that is fixed to the inner surface 42 instead of the bottom surface. That is, it is installed by changing the direction by 90 ° from that in the first embodiment. The driving device 10 is different from the above-described embodiment so that the center line of the diaphragm is driven between the broken line and the one-dot broken line in FIG. The frequency is changed, and driving is performed with a driving signal that is asymmetric with respect to the time of the shapes of FIGS. 3 (A-1) to (A-3).

  As shown in FIG. 3 (A-1), the piezoelectric elements 16 and 22 attached to the diaphragm 12 are each excited by inputting an asymmetric driving signal with respect to time. Is slowly displaced upward along the broken line in FIG. 16B, and then vibrates so as to be quickly displaced downward along the dashed line. Here, by this, when the protrusion 14 attached to the diaphragm quickly moves downward, the inertia of the object to be displaced (in this embodiment, the lens barrel 34) causes the inertia between the protrusion 14 and the object to be displaced. It becomes larger than the frictional force, and no force acts on the object to be displaced. On the other hand, when the diaphragm attached with the protrusion 14 slowly returns to the horizontal direction, the frictional force becomes larger than the inertial force, and an upward force acts on the object to be displaced. By repeating this, an upward driving force acts on the object to be displaced, and for example, the lens barrel 34 is moved from the non-displaced state shown in FIG. 17B to the raised state shown in FIG. It is possible to drive upward. On the other hand, when the piezoelectric elements 16 and 22 are excited by inputting an asymmetric drive signal with respect to the time for repeating the gradual falling portion L3 and the steep rising portion L4 as shown in FIG. This is opposite to the above-described operation, and a downward driving force acts. That is, the lens barrel 34 can be driven so as to change from the non-displaced state shown in FIG. 17B to the lowered state shown in FIG. Therefore, the displacement direction of the object to be displaced can be reversed by applying a drive signal that is asymmetric with respect to time to the piezoelectric element by inverting the voltage.

  <Modification of Embodiment 4> Next, a modification of the present embodiment will be described with reference to FIGS. FIG. 18 is a plan view of the present modification viewed from the optical axis direction. FIG. 19 is an end view of FIG. 18 cut along line # F- # F. (A) is a state where the lens barrel is raised, (B) is a state where it is not displaced, and (C) is a state where it is lowered. Shows the state. In the example shown in FIGS. 16 and 17, the protrusion 14 of the driving device 10 is brought into contact with only one part of the lens barrel 34. However, the examples shown in FIGS. 18 and 19 show the driving device 10. These are provided one by one at opposite positions across the lens barrel 34. Thus, by providing the driving device 10 on both sides of the lens barrel 34, a displacement speed approximately twice that of the configuration shown in FIGS. 16 and 17 can be obtained. It is the same.

  Next, Embodiment 5 of the present invention will be described with reference to FIGS. FIG. 20A is a plan view of the entirety of Example 5 viewed from the optical axis direction, and FIG. 20B is a front view of FIG. 20A viewed from the direction of arrow F20. FIGS. 21A and 21B are end views taken along line # G- # G in FIG. 20A, where FIG. 21A is a state where the lens barrel is raised, FIG. 21B is a state where it is not driven, and FIG. Indicates a lowered state. The present embodiment is an example in which the lateral vibration of the drive device is used as in the fourth embodiment.

  The driving device 60 of this embodiment has a unimorph structure in which a piezoelectric element 66 is provided on one main surface of the diaphragm 62. The piezoelectric element 66 has a structure in which drive electrodes 70 and 72 are formed on both main surfaces of the piezoelectric body 68, and is designed to be shorter and wider than the diaphragm 62 as a whole. . The diaphragm 62 has a double-supported structure in which both ends are supported by the passage inner surface 42, and the main surface on which the piezoelectric element 66 is not provided has a position corresponding to the antinode of vibration. In addition, a protrusion 64 that contacts the barrel 34 is provided. The operation and effect of the present embodiment is the same as that of the above-described third embodiment. By using the in-plane vibration of the driving device 60, the lens barrel 34 is shown in FIG. 21B in one vibration mode. The state can be stably displaced along the optical axis so that the state shown in FIG. 21 (A) or (C) is obtained.

  <Modification of Embodiment 5>... Next, a modification of the present embodiment will be described with reference to FIGS. FIG. 22 is a plan view of the present modification viewed from the optical axis direction. FIG. 23 is an end view of FIG. 22 cut along the line # H- # H. (A) is a state where the lens barrel is raised, (B) is a state where it is not driven, and (C) is a state where it is lowered. Shows the state. In the example shown in FIGS. 20 and 21, the protrusion 64 of the driving device 60 is brought into contact with only one part of the lens barrel 34. However, in the examples shown in FIGS. These are provided one by one at opposite positions across the lens barrel 34. Thus, by providing the drive devices 60 on both sides of the lens barrel 34, a displacement speed approximately twice that of the configuration shown in FIGS. 20 and 21 can be obtained.

  Next, Embodiment 6 of the present invention will be described with reference to FIGS. 24A is an exploded perspective view showing the configuration of this embodiment, FIG. 24B is a plan view, and FIG. 24C is a front view of FIG. 24B viewed from the direction of arrow F24. is there. 25A and 25B are diagrams showing the relationship between the driving voltage applied to the driving device of this embodiment and time. FIG. 25A shows a case where the rotated body rotates clockwise, and FIG. 25B shows a counterclockwise rotation. FIG. In each of the first to fifth embodiments described above, the object to be displaced is displaced along the optical axis direction. However, the present embodiment is an example in which the present invention is applied to a rotary motor that rotates the body to be rotated. .

  As shown in FIG. 24, the rotary motor 80 of the present embodiment rotates the rotor 100 supported by the shaft 102, and is arranged on one main surface side of the rotor 100. The rotary motor 80 is obtained by bonding a ring-shaped piezoelectric element 86 to one main surface of a flat plate-shaped diaphragm 82. On one main surface of the piezoelectric element 86, drive electrodes 92 </ b> A to 92 </ b> F having polar coordinates at the center of the ring and divided into a plurality (six in the illustrated example) are formed. In addition, one drive electrode 90 that is not divided is formed on the other main surface of the piezoelectric element 86, that is, the surface in contact with the diaphragm 82. Furthermore, the diaphragm 82 is supported by the support portion 96 between the divided electrodes so as to be an even interval with an integral multiple of the drive electrodes 92A to 92F divided into a plurality. Then, a projection 84 is provided on the main surface of the diaphragm 82 on the side where the piezoelectric element 86 is not attached at an intermediate angle between the support portions 96, and the projection 84 is brought into contact with the rotor 100 that is the rotated body. It has a structure. In the case of the present embodiment, both the projecting portion 84 and the support portion 96 are arranged on the drive electrode dividing line 94, that is, at a position corresponding to the vibration node of the diaphragm.

  In this embodiment, as shown in the figure, the drive electrodes 92A, 92C, and 92E are positively polarized and the drive electrodes 92B, 92D, and 92F are negatively polarized, and all of them are connected to one terminal of the drive power source 104. ing. The drive electrode 90 is connected to the other terminal of the drive power supply 104. When the driving device 80 having such a configuration is driven by a driving signal that is asymmetric with respect to the time at which the gentle rising portion L7 and the steep falling portion L8 are repeated as shown in FIG. Of the pair of electrodes adjacent to each other with the mounting position of the projection 84 on the main surface side, the positively polarized 92A, 92C, 92E and the electrode 90 on the other main surface side of the piezoelectric element 86 are sandwiched, respectively. And the second region sandwiched between the negatively polarized 92F, 92B, and 92D and the electrode 90 on the other main surface side of the piezoelectric element 86 is gradually contracted. Asymmetric vibration occurs with respect to the time when the first region contracts quickly and the second region extends quickly. As a result, the tip of the protrusion 84 attached at a position sandwiched between the first region and the second region moves back and forth so as to draw an arc asymmetrically with respect to time, and the tip of the protrusion slowly arcs. When drawing and moving, the contact frictional force between the tip of the protrusion 84 and the rotor 100 exceeds the inertial force of the rotor 100, and generates a force that rotates the rotor 100, which is a non-rotating body, clockwise. On the other hand, when the tip of the projection 84 moves quickly, the inertial force of the rotor 100 is superior to the contact friction force between the tip of the projection 84 and the rotor 100, so that the original position is not affected without significant interference with the rotation of the rotor 100. You can return to

  Also, as shown in FIG. 25B, when driven by an asymmetric drive signal that repeats a gradual falling portion L9 and a steep rising portion L10, the first region extends quickly and the second region A protrusion attached at a position sandwiched between the first region and the second region due to the occurrence of asymmetric vibration with respect to the time that the first region contracts slowly and the second region extends slowly after being quickly contracted. The tip of the portion 84 reciprocates so as to draw an arc asymmetrically with respect to time, and generates a force that rotates the rotor 100, which is a non-rotating body in contact therewith, counterclockwise as opposed to the above. .

  As described above, according to this embodiment, by driving the protrusion 84 asymmetrically, torque is applied from the protrusion 84 to the rotor 100, and the rotor 100 rotates in a certain direction. In addition, the direction of rotation can be freely switched by inverting the input drive voltage in terms of time. Also in this embodiment, since only one vibration is used as in Embodiments 1 to 5 described above, it is easy to control the frequency, and it is not necessary to combine a plurality of vibrations with the dimensions of the driving device. However, it is possible to achieve a reduction in size, weight and thickness without limitation. In the present embodiment, the electrodes of the piezoelectric element 86 are divided, but the drive electrodes are not necessarily divided, and may be divided as necessary. Further, in this embodiment, a part of the load of the piezoelectric diaphragm to which the protrusion is attached is used as the urging means.

  Due to the above-described action, torque is applied to the rotor 100 from the protrusion 84, and the rotor 100 rotates in a certain direction. Further, the direction of rotation can be reversed by inverting the voltage of the drive signal for excitation.

  Next, Embodiment 7 of the present invention will be described with reference to FIG. 26A is a plan view of the present embodiment, FIG. 26B is a side view of FIG. 26A viewed from the direction of arrow F26a, and FIG. 26C is the above-described FIG. It is the front view which looked at from arrow F26b direction. In the present embodiment, similarly to the sixth embodiment, the driven body is rotated by the driving device. As shown in FIG. 26, the rotary motor 120 of this embodiment has a shape cut out in an arc shape from the ring, and is disposed on one main surface side of the rotor 100. In the rotary motor 120, a piezoelectric element 126 is attached to one main surface of the diaphragm 122, and an appropriate position (vibration node position) of the other main surface is in contact with the main surface of the rotor 100. The projecting portion 124 is in contact with the projection 124. The diaphragm 122 is supported by a support part 134 at an appropriate position on the side surface. In addition, the piezoelectric element 126 has a drive electrode 130 that is not divided on the side to be bonded to the diaphragm 122, and is divided into a plurality (four in the illustrated example) on the other main surface. A drive electrode is formed. In the illustrated example, among the divided electrodes, the drive electrodes 132A and 132C are positively polarized, and the other drive electrodes 132B and 132D are negatively polarized. As described above, even when the rotary motor 120 is substantially arc-shaped, the same effect as in the sixth embodiment can be obtained. That is, the rotor 100 can be rotated by driving the protrusion 124 asymmetrically by inputting an asymmetric signal with respect to time. Note that the drive electrodes are not necessarily formed separately as in the sixth embodiment. Further, in this embodiment, as in the embodiment shown in FIG. 24, a part of the load of the piezoelectric diaphragm with the protrusions attached is used as the biasing means.

  Next, Embodiment 8 of the present invention will be described with reference to FIG. 27A is a plan view of the present embodiment, FIG. 27B is a cross-sectional view of FIG. 27A taken along line # I- # I and viewed in the direction of the arrow, and FIG. FIG. 27A is a cross-sectional view of FIG. 27A taken along line # J- # J and viewed in the direction of the arrow. As shown in FIG. 27, the rotary motor 150 of the present embodiment is disposed inside a substantially cylindrical rotor 164 and has a shape in which a part of a circle is cut out as a whole. The rotary motor 150 includes a piezoelectric element 156 on one main surface of a diaphragm 152 having a shape obtained by cutting out a part of a circle. The piezoelectric element 156 includes a drive electrode 160 that is not divided on the main surface of the piezoelectric body 158 on the side to be bonded to the diaphragm 152, and the drive electrode 160 that is divided symmetrically on the other main surface. 162A and 162B are provided. In addition, a protrusion 154 is formed at a position corresponding to the vibration node on the outer peripheral portion of the diaphragm 152 so as to be symmetrical in the radial direction, and the protrusion 154 has a vertical height of the bare surface. It contacts the inner surface of the cylindrical rotor 164 taken. Further, the diaphragm 152 is supported by a support portion 166 that is arranged to be bilaterally symmetrical on the surface on which the piezoelectric element 156 is not provided. The driving method is the same as in the sixth embodiment, and is performed by inputting a driving signal that is asymmetric with respect to time.

  For example, when the piezoelectric element is excited by the asymmetric drive signal shown in FIG. 25, asymmetric vibration is generated, and when the excited portion vibrates in the lateral plane, the direction in which the protrusion 154 rotates, that is, the rotor 164 A driving force is generated in the tangential direction of the arc, and the rotor 164 rotates in one direction. Similarly, when the voltage of the input driving signal is inverted, the driving force that rotates in the opposite direction acts on the rotor 164 to perform reverse rotation. The effect of the present embodiment is the same as that of the sixth embodiment. In the above embodiment, the protrusion is provided at a position corresponding to the vibration node of the diaphragm. However, the protrusion is provided at a position corresponding to the antinode of vibration of the diaphragm, and an asymmetric drive signal with respect to time is provided. As in the third embodiment, the rotor 164 can be rotated in one direction by in-plane vibration as in the third embodiment.

In addition, this invention is not limited to the Example mentioned above, A various change can be added in the range which does not deviate from the summary of this invention. For example, the following are also included.
(1) The materials, shapes, and dimensions shown in the above-described embodiments are examples, and can be appropriately changed so as to achieve the same effect. For example, in the fifth to seventh embodiments, the drive electrode is divided, but may be divided as necessary. Moreover, when dividing | segmenting, the number of division | segmentation may be increased / decreased suitably as needed.
(2) The spring 44 and the support portions 96, 134, and 166 are examples, and can be appropriately changed so as to achieve the same operation.
(3) The structure of the piezoelectric element may be either a unimorph or a bimorph. Further, the piezoelectric element itself may have a laminated structure in which piezoelectric layers and electrode layers are alternately laminated, and the number of laminated layers, the connection pattern of internal electrodes, the lead structure, and the like can be appropriately changed as necessary.
(4) The applied voltage waveform for driving may also be set as appropriate according to the driving mode.
(5) It is also possible to drive the driven body in a certain direction by inputting a drive signal to only one of the piezoelectric elements, or by providing only one piezoelectric element and driving the protrusion asymmetrically.
(6) The driving device and the rotation motor of the above-described embodiment are examples, and the present invention is not limited to a lens for an optical device such as a camera photographing lens, a projection lens such as an overhead projector, a binocular lens, or a copier lens. In addition to driving, the present invention can be applied to a device having a drive unit such as a device such as a plotter or an XY drive table.

According to the present invention, a piezoelectric diaphragm provided with a piezoelectric layer and a drive electrode sandwiching both principal surfaces of the piezoelectric layer on one principal surface of the diaphragm, and an outer peripheral portion of the diaphragm A drive device is composed of a protrusion formed so as to be symmetrical in the radial direction and a substantially cylindrical rotor at a position corresponding to a vibration node or antinode, and the piezoelectric element and the vibration plate are one of a circle. The piezoelectric element has a drive electrode that is not divided on the main surface on the diaphragm side, and a drive electrode that is divided symmetrically on the other main surface. The vibration plate is supported by a support portion arranged so as to be bilaterally symmetric on a surface where no piezoelectric element is provided, and the protrusion portion is in contact with the inner surface of the rotor. And, by inputting a driving signal that is asymmetric with respect to time between the driving electrodes of the driving device, the protrusion can be driven asymmetrically with respect to time, and a stable driving force in a single direction can be obtained. Since the driving direction can be reversed, the driving direction can be applied to precision devices and communication devices that require stable operation. In particular, it is suitable for the use of a drive device that requires a reduction in size, weight, and thickness.

It is the top view which looked at Example 1 of the present invention from the optical axis direction. 2A is a front view of FIG. 1 viewed from the direction of arrow F1a, FIG. 1B is a side view of FIG. 1 viewed from the direction of arrow F1b, and FIG. These are front views which show the modification of the drive device of the said Example 1. FIG. (A-1) to (A-3) are diagrams showing the relationship between the driving voltage applied to the driving device of Example 1 and time, and (B-1) and (B-2) are projections. It is a figure which shows a locus | trajectory. FIG. 2 is an end view of FIG. 1 cut along line # A- # A, where (A) shows a state in which the lens barrel has moved up, (B) shows a state before the movement, and (C) has moved down. It is a figure which shows a state. It is a figure which shows the relationship between the displacement speed of the lens-barrel of the said Example 1, and a drive voltage. It is the top view which looked at the modification of the said Example 1 from the optical axis direction. FIG. 7 is an end view of FIG. 6 cut along line # B- # B, where (A) shows a state in which the lens barrel has moved upward, (B) shows a state before movement, and (C) has moved downward. It is a figure which shows a state. It is a figure which shows Example 2 of this invention, (A) is the top view seen from the optical axis direction, (B) is a perspective view which shows a principal part, (C) is a perspective view which shows the modification of a principal part. is there. FIG. 8A is an end view of FIG. 8A cut along line # C- # C. FIG. 8A is a state where the lens barrel is moved upward, FIG. 8B is a state before displacement, and FIG. It is a figure which shows the state which moved to. It is the top view which looked at the modification of the said Example 2 from the optical axis direction. FIG. 11 is an end view of FIG. 10 cut along the line # D- # D, where (A) shows a state in which the lens barrel has moved upward, (B) shows a state before displacement, and (C) has moved downward. It is a figure which shows a state. It is a figure which shows Example 3 of this invention, (A) is the top view seen from the optical axis direction, (B) is a perspective view which shows a principal part, (C) is the front seen from the direction orthogonal to an optical axis FIG. 12A is an end view of FIG. 12A cut along line # C- # C. FIG. 12A is a state in which the lens barrel is moved upward, FIG. 12B is a state before the movement, and FIG. It is a figure which shows the state which moved to. It is the top view which looked at the modification of the said Example 3 from the optical axis direction. FIG. 15 is an end view of FIG. 14 cut along line # D- # D, where (A) shows a state in which the lens barrel has moved upward, (B) shows a state before movement, and (C) has moved downward. It is a figure which shows a state. It is a figure which shows Example 4 of this invention, (A) is the top view seen from the optical axis direction, (B) is the front view seen from the direction orthogonal to an optical axis. FIG. 17 is an end view of FIG. 16 cut along the line # E- # E, where (A) shows a state in which the lens barrel has moved up, (B) shows a state before the movement, and (C) has moved down. It is a figure which shows a state. It is the top view which looked at the modification of the said Example 4 from the optical axis direction. FIG. 19 is an end view of FIG. 18 cut along line # F- # F, where (A) shows a state in which the lens barrel has moved upward, (B) shows a state before movement, and (C) has moved downward. It is a figure which shows a state. It is a figure which shows Example 5 of this invention, (A) is the top view seen from the optical axis direction, (B) is the front view which looked at the said (A) from the arrow F20 direction. FIG. 20A is an end view of FIG. 20A cut along line # G- # G. FIG. 20A is a state in which the lens barrel is moved upward, FIG. 20B is a state before the movement, and FIG. It is a figure which shows the state which moved to. It is the top view which looked at the modification of the said Example 5 from the optical axis direction. FIG. 23 is an end view of FIG. 22 cut along the line # H- # H, where (A) shows a state in which the lens barrel has moved up, (B) shows a state before the movement, and (C) has moved down. It is a figure which shows a state. It is a figure which shows Example 6 of this invention, (A) is a disassembled perspective view, (B) is a top view, (C) is the side view which looked at the said (B) from the arrow F24 direction. It is a figure which shows the relationship between the drive voltage applied to the drive device of the said Example 6, and time. It is a figure which shows Example 7 of this invention, (A) is a top view, (B) is the side view which looked at the said (A) from the arrow F26a direction, (C) is the said (A) from the arrow F26b direction. FIG. It is a figure which shows Example 8 of this invention, (A) is a top view, (B) is sectional drawing which cut | disconnected said (A) along the # I- # I line | wires, and looked at the arrow direction, (C) FIG. 4 is a cross-sectional view taken along line # J- # J as viewed in the direction of the arrow (A). It is a figure which shows an example of background art. It is a figure which shows an example of background art. It is a figure which shows an example of background art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Drive device 12: Diaphragm 12A: Exposed part 14: Protrusion part 14A: Tip 15: Nodal line 16, 22: Piezoelectric element 18, 24: Piezoelectric 20, 21, 26, 27: Drive electrode 28: Drive power supply 30 : Passage 32: Bottom 34: Lens tube 34A, 34B: Convex part 36: Lens 38: Guide 40: Slit (or groove)
42: Inner surface 44: Spring 50: Drive device 52: Vibration plate 52A: Side surface 54: Protrusion 56, 58: Piezoelectric element 60: Drive device 62: Vibration plate 64: Protrusion 66: Piezoelectric element 68: Piezoelectric body 70, 72 : Driving electrode 80: Rotating motor 82: Diaphragm 84: Projection part 86: Piezoelectric element 88: Piezoelectric body 90, 92A to 92F: Driving electrode 94: Dividing line 96: Supporting part 100: Rotor 102: Shaft 104: Driving power supply 120 : Rotary motor 122: Diaphragm 124: Protruding part 126: Piezoelectric element 128: Piezoelectric bodies 130 and 132A to 132D: Drive electrode 134: Supporting part 150: Rotating motor 152: Diaphragm 154: Protruding part 156: Piezoelectric element 158: Piezoelectric Body 160, 162A, 162B: Drive electrode 164: Rotor 166: Support part

Claims (2)

A piezoelectric diaphragm provided with a piezoelectric element having a piezoelectric layer and a drive electrode sandwiching both principal surfaces of the piezoelectric layer on one principal surface of the diaphragm;
A protrusion formed so as to be symmetrical in the radial direction at a position corresponding to a vibration node or antinode of the outer peripheral portion of the diaphragm;
A substantially cylindrical rotor;
Consists of
The piezoelectric element and the diaphragm have a substantially ring shape with a part of a circle cut out,
The piezoelectric element includes a drive electrode that is not divided on the main surface on the vibration plate side, and a drive electrode that is divided symmetrically on the other main surface,
The diaphragm is supported by a support portion arranged so as to be bilaterally symmetrical on a surface where no piezoelectric element is provided,
The drive device according to claim 1, wherein the protrusion is in contact with an inner surface of the rotor. 2. A driving method for a driving apparatus, comprising: a driving signal asymmetric with respect to time is input between the driving electrodes of the driving apparatus according to claim 1.

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