JP2019160975A - Piezoelectric actuator, additional force detection method of piezoelectric actuator, resonance state detection method of piezoelectric actuator, piezoelectric drive device, hand, robot, electronic component transfer device, printer and projector - Google Patents

Abstract

To provide a piezoelectric actuator capable of detecting additional force or an additional force detection method thereof, a resonance state detection method of piezoelectric actuator for detecting resonance state of the piezoelectric actuator in drive state, and a piezoelectric drive device including the piezoelectric actuator, a hand, a robot, an electronic component transfer device, a printer and a projector.SOLUTION: A piezoelectric actuator has a vibration part including a piezoelectric material for driving and a piezoelectric element for driving including an electrode for driving, a fixing part for fixing the vibration part, and a connection for connecting the vibration part and the fixing part, and including a first piezoelectric element including a first piezoelectric material for detection and a first electrode for detection and a second piezoelectric element for detection including a second piezoelectric material for detection and a second electrode for detection.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a piezoelectric actuator, a method for detecting an applied force of a piezoelectric actuator, a method for detecting a resonance state of a piezoelectric actuator, a piezoelectric drive device, a hand, a robot, an electronic component transport device, a printer, and a projector.

  Conventionally, a driving device (piezoelectric actuator) including a piezoelectric element is known (see, for example, Patent Document 1). The drive device described in Patent Literature 1 includes a reinforcing plate and a vibrating body that is provided on both the front and back surfaces of the reinforcing plate and comes into contact with the rotating shaft. Then, the vibrating body rotates the rotation shaft by drawing a substantially elliptical locus.

  Such a vibrating body includes a piezoelectric element formed of a piezoelectric material and electrodes formed on both front and back surfaces. As the electrodes, a first drive electrode and a pair of second drive electrodes to which a drive signal is input, and a detection electrode that detects distortion of the piezoelectric element are used.

  By detecting the distortion of the piezoelectric element, this can be used to control the driving frequency.

JP 2007-166816 A

  However, in the piezoelectric actuator described in Patent Document 1, not only the drive electrode used for driving the vibrating body but also the detection electrode for detecting the distortion of the piezoelectric element is provided on the surface of the vibrating body. For this reason, when it is desired to detect the force applied to the piezoelectric actuator, the detection electrode cannot detect the force. Therefore, conventionally, a force sensor that detects a force applied to the piezoelectric actuator is used separately from the piezoelectric actuator.

  The present invention has been made to solve the above-described problems, and can be realized as the following application examples.

The piezoelectric actuator of this application example includes a vibration unit including a driving piezoelectric element including a driving piezoelectric body and a driving electrode;
A fixing part for fixing the vibrating part;
A first detection piezoelectric element that includes the first detection piezoelectric member and the first detection electrode, and a second detection piezoelectric member that includes the second detection piezoelectric member and the second detection electrode. A connecting portion including a piezoelectric element for use;
It is characterized by having.

It is the schematic which shows the whole structure of the piezoelectric actuator which concerns on 1st Embodiment of this invention. It is a top view which shows the piezoelectric vibrating body with which the piezoelectric actuator shown in FIG. 1 is provided. It is the sectional view on the AA line in FIG. It is a figure explaining operation | movement of the piezoelectric vibrating body shown in FIG. It is the BB sectional view taken on the line in FIG. It is a modification of sectional drawing shown in FIG. FIG. 3 is a graph showing an example of a relationship between elapsed time and a voltage of a detection signal in a state where a driving unit of the piezoelectric actuator shown in FIG. 2 is not driven. FIG. 10 is an example of a piezoelectric actuator used in creating the graphs of FIGS. 7 and 9 and a driven unit driven by the piezoelectric actuator. FIG. 3 is a graph showing an example of a relationship between elapsed time and a voltage of a detection signal in a state where a drive unit of the piezoelectric actuator shown in FIG. 2 is driven. It is a top view which shows the piezoelectric vibrating body with which the piezoelectric actuator which concerns on 2nd Embodiment of this invention is provided. It is sectional drawing which shows the piezoelectric vibrating body with which the piezoelectric actuator which concerns on 3rd Embodiment of this invention is provided. It is sectional drawing which shows the piezoelectric vibrating body with which the piezoelectric actuator which concerns on 4th Embodiment of this invention is provided. It is a figure which shows schematic structure of embodiment of the robot of this invention. It is the schematic explaining the hand with which the robot shown in FIG. 13 is provided. It is a perspective view which shows embodiment of the electronic component conveying apparatus of this invention. It is a perspective view of the electronic component holding part with which the electronic component conveyance apparatus shown in FIG. 15 is provided. 1 is a perspective view illustrating an embodiment of a printer of the present invention. It is a schematic diagram showing an embodiment of a projector of the present invention.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a piezoelectric actuator, an applied force detection method for a piezoelectric actuator, a resonance state detection method for a piezoelectric actuator, a piezoelectric drive device, a hand, a robot, an electronic component transport device, a printer, and a projector according to preferred embodiments shown in the accompanying drawings will be described below. This will be described in detail.

1. Piezoelectric Actuator First, an embodiment of the piezoelectric actuator of the present invention will be described.

<First Embodiment>
FIG. 1 is a schematic diagram showing the overall configuration of the piezoelectric actuator according to the first embodiment of the present invention. FIG. 2 is a plan view showing a piezoelectric vibrating body included in the piezoelectric actuator shown in FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a diagram for explaining the operation of the piezoelectric vibrating body shown in FIG.

  A piezoelectric actuator 1 shown in FIG. 1 acquires a piezoelectric vibrator 10 that generates a driving force applied to a driven part (not shown), a drive circuit 20 that drives the piezoelectric vibrator 10, and a detection signal from the piezoelectric vibrator 10. It has the detection circuit 30 and the control part 40 which controls the drive circuit 20 based on a detection signal. Hereinafter, each part of the piezoelectric actuator 1 will be described sequentially.

(Piezoelectric vibrator)
The piezoelectric vibrating body 10 shown in FIGS. 2 and 3 is provided across two piezoelectric element units 11, an adhesive layer 12 that joins the two piezoelectric element units 11 to each other, and the two piezoelectric element units 11. And a convex member 13. Here, the two piezoelectric element units 11 are configured symmetrically (vertically symmetrical in FIG. 3) with respect to the adhesive layer 12, and have the same configuration.

  Each piezoelectric element unit 11 includes a substrate 14, a plurality of driving piezoelectric elements 15 provided on the substrate 14, and a protective layer 16 covering the plurality of driving piezoelectric elements 15.

  As shown in FIG. 2, the substrate 14 includes a drive unit 141, a fixed unit 142, and a pair of connection units 143 a and 143 b that connect them. In the present embodiment, the drive unit 141 has a rectangular shape when viewed from the thickness direction of the substrate 14 (hereinafter also simply referred to as “planar view”). In addition, the fixing portion 142 is provided apart from the driving portion 141 along the outer periphery of a portion on one end side in the longitudinal direction of the driving portion 141 in a plan view. In addition, the pair of connection portions 143a and 143b are disposed on both sides in the width direction (direction orthogonal to the longitudinal direction) of the drive portion 141. The pair of connection portions 143 a and 143 b connect the center portion of the drive portion 141 in the longitudinal direction and the fixed portion 142. In addition, as long as desired deformation or vibration of the driving unit 141 is possible, the shape and arrangement of the driving unit 141, the fixing unit 142, and the pair of connection units 143a and 143b are not limited to those described above. For example, the fixing part 142 may be provided separately for each of the connection parts 143a and 143b. Further, the number, shape, arrangement, and the like of the connecting portions 143a and 143b are arbitrary.

  As the substrate 14, for example, a silicon substrate can be used. Although not shown, an insulating layer is provided on the surface of the substrate 14 on the side of the driving piezoelectric element 15. Although this insulating layer is not particularly limited, for example, when a silicon substrate is used as the substrate 14, it can be formed by thermally oxidizing the surface of the silicon substrate.

  A plurality of driving piezoelectric elements 15 are arranged on the driving unit 141 of the substrate 14. In the present embodiment, the plurality of driving piezoelectric elements 15 include five driving piezoelectric elements 15a, 15b, 15c, 15d, and 15e.

  The driving piezoelectric element 15 e is disposed along the longitudinal direction of the driving unit 141 at the center in the width direction of the driving unit 141. Driving piezoelectric elements 15a and 15b are arranged on one side in the width direction of the driving unit 141 with respect to the driving piezoelectric element 15e, and driving piezoelectric elements 15c and 15d are arranged on the other side. . The driving piezoelectric elements 15a, 15b, 15c, and 15d are arranged corresponding to four regions divided along the longitudinal direction and the width direction of the driving unit 141. In the present embodiment, the driving piezoelectric elements 15a and 15b are arranged on one side in the width direction of the driving unit 141, and the driving piezoelectric elements 15c and 15d are arranged on the other side in the width direction of the driving unit 141. ing. The driving piezoelectric elements 15a and 15c are disposed on one side (the convex member 13 side) in the longitudinal direction of the driving unit 141, and the driving piezoelectric elements 15b and 15d are disposed on the other side in the longitudinal direction of the driving unit 141. Is arranged.

  The driving piezoelectric elements 15 a, 15 b, 15 c, 15 d, and 15 e arranged in this way are the driving common electrode 151 provided on the substrate 14 and the driving provided on the driving common electrode 151, respectively. And a driving individual electrode 153 provided on the driving piezoelectric body 152.

  The driving common electrode 151 is a common electrode provided in common to the driving piezoelectric elements 15a, 15b, 15c, 15d, and 15e. On the other hand, the driving individual electrode 153 is an individual electrode provided individually for each of the driving piezoelectric elements 15a, 15b, 15c, 15d, and 15e. The driving common electrode 151 may also be provided individually for each of the driving piezoelectric elements 15a, 15b, 15c, 15d, and 15e.

  In the present embodiment, the driving piezoelectric body 152 is individually provided for each of the driving piezoelectric elements 15a, 15b, 15c, 15d, and 15e. The driving piezoelectric body 152 may be provided integrally and in common with at least two of the driving piezoelectric elements 15a, 15b, 15c, 15d, and 15e.

  Here, the plurality of individual driving electrodes 153 include individual driving electrodes 153a provided corresponding to the driving piezoelectric elements 15a, individual driving electrodes 153b provided corresponding to the driving piezoelectric elements 15b, Provided corresponding to the drive individual electrode 153c provided corresponding to the drive piezoelectric element 15c, the drive individual electrode 153d provided corresponding to the drive piezoelectric element 15d, and the drive piezoelectric element 15e. Drive individual electrode 153e.

The individual drive electrode 153a and the individual drive electrode 153d are electrically connected via a wiring (not shown). Similarly, the driving individual electrode 153b and the driving individual electrode 153c are electrically connected via a wiring (not shown). Further, an insulating film such as a SiO ₂ film (not shown) is appropriately provided on the driving individual electrode 153 and between the two wirings.

  The driving common electrode 151 is grounded (connected to the ground potential) via a wiring (not shown).

  Further, the driving common electrodes 151 of the two piezoelectric element units 11, the driving individual electrodes 153a or the driving individual electrodes 153d, the driving individual electrodes 153b or the driving individual electrodes 153c, and the driving individual electrodes Each of 153e is electrically connected via a wiring (not shown).

  For example, aluminum (Al), nickel (Ni), gold (Au), platinum (Pt), iridium (Ir), copper are used as the constituent materials of the driving common electrode 151 and the driving individual electrode 153. A metal material such as (Cu) is used. The driving common electrode 151 and the driving individual electrode 153 can be formed by sputtering.

  The driving piezoelectric body 152 is configured to expand and contract in a direction along the longitudinal direction of the driving unit 141 when an electric field in a direction along the thickness direction of the driving unit 141 is applied. Examples of the constituent material of the driving piezoelectric body 152 include lead zirconate titanate (PZT), barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, sodium tungstate, and oxide. Piezoelectric ceramics such as zinc, barium strontium titanate (BST), strontium bismuth tantalate (SBT), lead metaniobate, and lead scandium niobate can be used. The driving piezoelectric body 152 made of piezoelectric ceramics may be formed from, for example, a bulk material, or a wet method such as a sol-gel method or a dry method (evaporation method) such as a sputtering method. May be. As a constituent material of the driving piezoelectric body 152, polyvinylidene fluoride, quartz, or the like may be used.

  A protective layer 16 is provided on the plurality of driving piezoelectric elements 15a, 15b, 15c, 15d, and 15e having the above configuration so as to cover them collectively. As a constituent material of the protective layer 16, for example, a silicone resin, an epoxy resin, a polyimide resin, or the like can be used. Further, the protective layer 16 can be formed by using, for example, a spin coating method.

  Further, the laminated body including the driving common electrode 151, the driving piezoelectric body 152, the driving individual electrode 153, and the protective layer 16 as described above is also disposed on the fixing portion 142 of the substrate 14. Thereby, the two piezoelectric element units 11 can be stably bonded via the adhesive layer 12.

Here, FIG. 5 is a sectional view taken along line BB in FIG.
Of the two piezoelectric element units 11, the piezoelectric element unit 11 positioned above FIG. 3 includes a first detection piezoelectric element 18 and a second detection piezoelectric element 19. Specifically, the first detection piezoelectric element 18 is disposed on the connection portion 143a of the substrate 14 of the piezoelectric element unit 11, while the second detection is performed on the connection portion 143b of the substrate 14. A piezoelectric element 19 is disposed.

  The first detection piezoelectric element 18 arranged in this way has a first detection electrode 181 provided on the substrate 14 and a first detection electrode 181 provided on the first detection electrode 181 at the connection portion 143a. It has a detection piezoelectric member 182 and a first detection electrode 183 provided on the first detection piezoelectric member 182.

  Further, the second detection piezoelectric element 19 includes a second detection electrode 191 provided on the substrate 14 and a second detection piezoelectric body provided on the second detection electrode 191 at the connection portion 143b. 192 and a second detection electrode 193 provided on the second detection piezoelectric body 192.

  The first detection electrode 183 and the second detection electrode 193 are grounded (connected to the ground potential) via wirings not shown.

  Note that the first detection electrodes 181, the first detection electrodes 183, the second detection electrodes 191, and the second detection electrodes 193 of the two piezoelectric element units 11 have wirings (not shown), respectively. Is electrically connected.

  Examples of the constituent materials of the first detection electrode 181, the first detection electrode 183, the second detection electrode 191, and the second detection electrode 193 include the driving common electrode 151 and the driving electrode described above. The material is appropriately selected from the materials listed as the constituent materials of the individual electrode 153.

  The constituent materials of the first detection piezoelectric body 182 and the second detection piezoelectric body 192 are appropriately selected from, for example, the materials listed as the constituent materials of the driving piezoelectric body 152 described above.

  Further, a protective layer 16 is provided on the first detection piezoelectric element 18 and the second detection piezoelectric element 19 so as to cover them.

FIG. 6 is a modification of the cross-sectional view shown in FIG.
The driving piezoelectric member 152, the first detecting piezoelectric member 182 and the second detecting piezoelectric member 192 may be separate from each other as shown in FIG. 5, but may be integrated as shown in FIG. It may be. That is, in the piezoelectric vibrating body 10 ′ shown in FIG. 6, the driving piezoelectric body 152, the first detection piezoelectric body 182 and the second detection piezoelectric body 192 are connected to each other and integrated as a whole. In this case, the piezoelectric vibrating body 10 ′ can be easily manufactured, and the mechanical strength of the integrated piezoelectric body can be increased. Therefore, the reliability of the piezoelectric vibrating body 10 ′ can be increased.

  The protective layers 16 of the two piezoelectric element units 11 configured as described above are bonded to each other via the adhesive layer 12. Examples of the adhesive layer 12 include an epoxy resin.

  Moreover, the convex member 13 is being fixed to the edge part on the opposite side to the fixing | fixed part 142 of the drive part 141 of the two piezoelectric element units 11 with the adhesive agent, for example. In the present embodiment, the convex member 13 has a columnar shape, and a part thereof is provided so as to protrude from the drive unit 141. As a constituent material of the convex member 13, a material excellent in wear resistance is preferable, and examples thereof include ceramics. The shape of the convex member 13 is not limited to a cylindrical shape as long as the driving force can be transmitted to the driven part.

  In addition, the piezoelectric actuator 1 may include a plurality of piezoelectric vibrating bodies 10. Thereby, a driving force can be transmitted to a plurality of locations of the rotor 50 simultaneously. For this reason, a larger driving force can be transmitted.

  Further, the piezoelectric actuator 1 may have a stacked structure (stacked structure) in which the piezoelectric vibrating body 10 as shown in FIG. 3 is further stacked in the thickness direction of the substrate 14 instead of the piezoelectric vibrating body 10. . Thereby, a larger driving force can be transmitted to one place of the rotor 50. The number of stacked layers at this time is not particularly limited, but is, for example, 2 or more and 50 or less.

(Drive circuit)
As shown in FIG. 1, the drive circuit 20 is electrically connected to the drive individual electrodes 153 b and 153 d and the drive common electrode 151 of the piezoelectric vibrating body 10. The drive circuit 20 has a function of driving the drive piezoelectric elements 15a, 15b, 15c, and 15d by inputting a voltage signal whose voltage value periodically changes to each of the drive individual electrodes 153b and 153d as a drive signal. Have The drive circuit 20 has a function of driving the drive piezoelectric element 15e by inputting a voltage signal whose voltage value periodically changes to the drive individual electrode 153e as a drive signal. Although not shown, the drive circuit 20 has a drive voltage generation circuit that outputs a voltage signal whose voltage value changes periodically.

  When a drive signal whose voltage value periodically changes is input to the drive individual electrode 153b, each of the drive piezoelectric elements 15b and 15c repeats expansion and contraction in the direction indicated by the arrow a in FIG. As a result, the convex member 13 provided at one end in the longitudinal direction of the drive unit 141 reciprocates (vibrates) in the direction indicated by the arrow b in FIG. 4 with the bending vibration of the drive unit 141. By transmitting the driving force of the convex member 13 that vibrates in this way to the rotor 50 that is the driven part, the rotor 50 can be rotated around the rotation axis O in the direction indicated by the arrow c in FIG. it can. At this time, a driving signal synchronized with expansion and contraction of the driving piezoelectric elements 15b and 15c is input to the driving piezoelectric element 15e, so that the driving force applied from the convex member 13 to the rotor 50 is increased or the trajectory of the convex member 13 is changed. And can be controlled. Even when a drive signal whose voltage value changes periodically is input to the drive individual electrode 153d, the convex member 13 is similarly shown by an arrow b in FIG. 4 by driving the drive piezoelectric elements 15a and 15d. It can reciprocate (vibrate) in the direction. In this case, a drive signal may be input to the drive individual electrode 153b. In this case, for example, the phase of the drive signal may be shifted by 180 degrees with respect to the phase of the drive signal input to the drive individual electrode 153d. .

  The piezoelectric actuator 1 and the rotor 50 constitute a piezoelectric motor 100 (piezoelectric driving device). That is, the piezoelectric motor 100 includes a piezoelectric actuator 1 and a rotor 50 (driven portion) driven by the piezoelectric actuator 1. According to such a piezoelectric motor 100, since the force applied to the piezoelectric actuator 1 can be detected, the driving force is controlled based on the detected force, that is, the force received by the piezoelectric actuator 1 from the rotor 50. Is possible.

(Detection circuit)
As shown in FIG. 1, the detection circuit 30 is electrically connected to the first detection electrode 181, the first detection electrode 183, the second detection electrode 191, and the second detection electrode 193 of the piezoelectric vibrating body 10. Has been. As described above, when the drive unit 141 is driven, distortion is generated in the first detection piezoelectric element 18 and the second detection piezoelectric element 19 in accordance with the drive. Along with this distortion, detection signals are output from the first detection electrode 181 and the second detection electrode 191 due to the piezoelectric effect.

  The detection circuit 30 acquires detection signals output from the first detection electrodes 181 and 183 and the second detection electrodes 191 and 193.

(Control part)
The control unit 40 shown in FIG. 1 has a function of detecting a force applied to the piezoelectric actuator 1 based on a detection signal from the detection circuit 30. Thus, the force applied to the drive unit 141 can be detected without preparing a force sensor separately from the piezoelectric actuator 1. Based on the force detected in this manner, for example, a driving force can be applied to the rotor 50 while monitoring the force on the piezoelectric actuator 1, and the driving force can be controlled based on the detected force.

Further, the control unit 40 has a function of detecting the resonance state of the piezoelectric actuator 1 based on the detection signal from the detection circuit 30.
That is, the control unit 40 controls the operations of the drive circuit 20 and the detection circuit 30.

  As described above, the piezoelectric actuator 1 includes the driving unit 141 (vibrating unit) including the driving piezoelectric element 15 including the driving piezoelectric body 152 and the driving electrodes (the driving common electrode 151 and the driving individual electrode 153); The first detection piezoelectric element 18 including the first detection piezoelectric body 182 and the first detection electrodes 181 and 183, and the first detection piezoelectric element 18 that connects the drive unit 141 and the fixation unit 142, and the first detection piezoelectric element 18 that fixes the drive unit 141. And connecting portions 143a and 143b including a second detecting piezoelectric element 19 including a second detecting piezoelectric member 192 and second detecting electrodes 191 and 193.

  Further, the piezoelectric actuator 1 according to the present embodiment further includes a drive circuit 20 that inputs a drive signal to the drive common electrode 151 and the drive individual electrode 153 to drive the drive piezoelectric element 15, and a first detection electrode 181. , 183 and the second detection electrodes 191, 193, and a control circuit 40 that controls the operation of the drive circuit 20 and the detection circuit 30.

  According to such a piezoelectric actuator 1, the force applied to the drive unit 141 can be detected without preparing a force sensor separately. For this reason, simplification, size reduction, and cost reduction of the structure of the piezoelectric actuator 1 can be achieved.

  Further, the first detection piezoelectric element 18 and the second detection piezoelectric element 19 for detecting force are both provided in the connecting portions 143a and 143b. For this reason, it is not necessary to provide the detection piezoelectric element in the drive unit 141, and the area occupied by the drive piezoelectric element 15 can be increased accordingly. For this reason, the vibration capability of the drive part 141 can be improved, without causing enlargement. As a result, for example, the piezoelectric actuator 1 having a smaller size and a higher driving force can be realized.

  On the other hand, the resonance state of the piezoelectric actuator 1 can be detected based on the phases of the detection signals from the first detection piezoelectric element 18 and the second detection piezoelectric element 19. Thereby, based on the detected resonance state, the drive circuit 20 can be controlled and reflected in the drive signal. As a result, the piezoelectric actuator 1 that can generate a more stable driving force can be realized.

(Method for detecting applied force of piezoelectric actuator and method for detecting resonance state)
Hereinafter, based on FIG. 7 to FIG. 9, a method for detecting the force applied to the piezoelectric actuator 1 (method for detecting the applied force of the piezoelectric actuator according to the present embodiment) and the drive unit 141 are driven. A method for detecting the resonance state of the piezoelectric actuator 1 (method for detecting the resonance state of the piezoelectric actuator according to this embodiment) will be described.

-State where the vibration part is not driven-
First, detection of force in a state where the drive unit 141 of the piezoelectric actuator 1 is not driven will be described.

  FIG. 7 is a graph showing an example of the relationship between the elapsed time and the voltage of the detection signal in a state where the drive unit 141 of the piezoelectric actuator 1 shown in FIG. 2 is not driven. In FIG. 7, the force to be applied is changed with time, and FIG. 8 is a diagram for explaining how the force is applied to the piezoelectric actuator 1.

  FIG. 8 is an example of the piezoelectric actuator 1 used when creating the graphs of FIGS. 7 and 9 and a driven portion driven by the piezoelectric actuator 1. The driven portion 51 has a rod shape (linear shape), and the surface with which the piezoelectric actuator 1 abuts is a flat surface.

  Of the elapsed time shown on the horizontal axis in FIG. 7, the piezoelectric actuator 1 is pressed toward the driven portion 51 so that the force F1 increases from 0 to 2N with time in the range of 0 to 5 microseconds. . In addition, a constant force F1 is applied at 2N for 5 to 10 microseconds. In addition, during 10 to 20 microseconds, the driven portion 51 is forcibly moved at a speed of 1 m / s toward the left side of FIG. 7 while applying the force F1. On the other hand, during 20 to 30 microseconds, the driven part 51 is forcibly moved toward the right side of FIG. 7 at a speed of 1 m / s.

  In FIG. 7, the detection signal from the first detection piezoelectric element 18 is referred to as “first detection signal 185”, and the detection signal from the second detection piezoelectric element 19 is referred to as “second detection signal 195”.

  As described above, when the driven portion 51 is displaced, a force F2 is applied to the piezoelectric actuator 1 accordingly. The first detection signal 185 and the second detection signal 195 are output according to the force F2.

  In 0 to 5 microseconds, when the piezoelectric actuator 1 is displaced, the first detection signal 185 and the second detection signal 195 are output so that the voltage increases with time. In 5 to 10 microseconds, the first detection signal 185 and the second detection signal 195 having a constant voltage are output.

  In the period as described above, since there is no difference between the first detection signal 185 and the second detection signal 195, the force F2 of the horizontal component in FIG. 8 is not applied to the piezoelectric actuator 1 (the convex member 13). Is located at a neutral point in the left-right direction). Further, it can be detected that the first detection signal 185 and the second detection signal 195 increase with time, and that the force F1 of the vertical component in FIG. 8 increases with time.

  On the other hand, in 10 to 20 microseconds, the driven portion 51 is forcibly moved toward the left side in FIG. 8, and thus the convex member is caused by the frictional force between the convex member 13 and the driven portion 51. A force is applied to pull 13 to the left. For this reason, the first detection signal 185 and the second detection signal 195 change with time. In addition, since the first detection piezoelectric element 18 and the second detection piezoelectric element 19 are applied with different strains, there is a difference between the first detection signal 185 and the second detection signal 195.

  Specifically, in 10 to 13 microseconds in FIG. 7, the first detection signal 185 is large with time, the second detection signal 195 is small with time, and the difference 200 (first detection) The difference obtained by subtracting the second detection signal 195 from the signal 185 increases with time. On the other hand, in 13 to 20 microseconds, the first detection signal 185 and the second detection signal 195 each show a constant value. The change in the detection signal in the vicinity of 13 microseconds is that the pulling force by the driven part 51 exceeds the frictional force between the convex member 13 and the driven part 51, and the gap between the convex member 13 and the driven part 51 is This is based on the occurrence of slipping.

  Therefore, in 10 to 13 microseconds, since the second detection signal 195 is larger than the first detection signal 185 and the difference between them is increased with time, the force pulling the piezoelectric actuator 1 to the left side is increased over time. It is possible to detect that it is added so as to increase. Further, in 13 to 20 microseconds, since the second detection signal 195 is larger than the first detection signal 185 and the difference between them is constant, the force for pulling the piezoelectric actuator 1 to the left side is constantly applied. Can be detected.

  Further, in 20 to 30 microseconds, the driven portion 51 is forcibly moved toward the right side in FIG. 8, so that a force for pulling the convex member 13 to the right side is added.

  Specifically, in 20 to 23 microseconds in FIG. 7, the first detection signal 185 is small with time, the second detection signal 195 is large with time, and the difference between them is small with time. It has become. For this reason, during this period, it can be detected that the convex member 13 pulled to the left side is gradually returned toward the neutral point.

  In addition, in 23 to 25 microseconds in FIG. 7, the difference between the first detection signal 185 and the second detection signal 195 increases with time. For this reason, during this period, it can be detected that the force with which the convex member 13 pulls toward the right side of the neutral point is applied so as to increase with time. Further, in 25 to 30 microseconds, since the first detection signal 185 is larger than the second detection signal 195 and the difference between these is constant, the force for pulling the piezoelectric actuator 1 to the right side is added constantly. Can be detected.

  Since the first detection piezoelectric element 18 and the second detection piezoelectric element 19 provided in the connection portions 143a and 143b are provided in pairs, the first detection signal 185 output from them and The second detection signal 195 is output in a state where the phases are basically aligned. For this reason, by obtaining the difference between the first detection signal 185 and the second detection signal 195, the direction and magnitude of the force applied to the first detection piezoelectric element 18 and the second detection piezoelectric element 19 can be increased as needed. It can be detected with high accuracy.

  Specifically, the difference 200 between the first detection signal 185 and the second detection signal 195 is the difference between the magnitude of distortion generated in the first detection piezoelectric element 18 and the magnitude of distortion generated in the second detection piezoelectric element 19. Since it corresponds to the difference, it corresponds to the direction and magnitude of the force applied to the piezoelectric actuator 1. Therefore, by obtaining the difference between the first detection signal 185 and the second detection signal 195, the force F2 of the horizontal component in FIG. 8 can be detected. Further, according to the difference 200, it is possible to estimate the displacement direction and the displacement amount of the convex member 13 in the left-right direction in FIG.

-State where the vibration part is driven-
Next, detection of force in a state where the drive unit 141 of the piezoelectric actuator 1 is driven will be described.

  FIG. 9 is a graph showing an example of the relationship between the elapsed time and the voltage of the detection signal in a state where the drive unit 141 of the piezoelectric actuator 1 shown in FIG. 2 is driven.

  In the graph shown in FIG. 9, when a drive signal having a waveform having a constant frequency and amplitude is input and the drive unit 141 is driven, a detection signal having a waveform corresponding to the drive is illustrated. In FIG. 9, the detection signal from the first detection piezoelectric element 18 is referred to as “first detection signal 186”, and the detection signal from the second detection piezoelectric element 19 is referred to as “second detection signal 196”.

  In FIG. 9, the voltage of the first detection signal 186 is higher than that of the second detection signal 196. The difference 201 between the first detection signal 186 and the second detection signal 196 (the difference obtained by subtracting the second detection signal 196 from the first detection signal 186) is the direction of the force applied to the piezoelectric actuator 1 in the left-right direction in FIG. And corresponds to the size. Therefore, by acquiring the difference 201 between the first detection signal 186 and the second detection signal 196, the force F2 of the horizontal component in FIG. 8 can be detected even when the piezoelectric actuator 1 is driven. . Moreover, according to the difference 201, the displacement direction and displacement amount of the convex member 13 in the left-right direction in FIG. 8 can be estimated.

  Further, the sum 202 of the first detection signal 186 and the second detection signal 196 shown in FIG. 9 corresponds to the direction and magnitude of the force applied to the piezoelectric actuator 1 in the vertical direction of FIG. Therefore, by obtaining the sum 202 of the first detection signal 186 and the second detection signal 196, the force F1 of the vertical component in FIG. 8 can be detected even when the piezoelectric actuator 1 is driven. . Further, according to the sum 202, the displacement direction and the displacement amount of the convex member 13 in the vertical direction of FIG. 8 can be estimated.

  Further, by comparing the phase of the calculation signal generated by the sum 202 with the phase of the drive signal (not shown in FIG. 9) input to the drive unit 141, the drive unit 141 of the piezoelectric actuator 1 is compared. The resonance state can be monitored. That is, by acquiring the phase difference between the calculation signal generated by the sum 202 and the drive signal, it is possible to easily evaluate whether or not the drive unit 141 is stably resonating.

  Therefore, for example, by setting a driving condition for bringing the phase difference close to a predetermined value in the control unit 40 and controlling a driving signal output from the driving circuit 20 based on the driving condition, an appropriate resonance state is set in the driving unit 141. Can be maintained. Thereby, for example, the rotor 50 can be rotated at a higher speed by the piezoelectric actuator 1.

  In summary, the applied force detection method for the piezoelectric actuator 1 according to the present embodiment is a method for detecting the force applied to the piezoelectric actuator 1, and includes a driving unit 141 (vibrating unit) and a fixed unit 142. The first detection signal 186 output from the first detection piezoelectric element 18 (first detection electrode 181) provided in the connection portion 143a to be connected to the connection portion 143b that connects the drive portion 141 and the fixed portion 142 to each other. The step of obtaining the difference 200, 201 from the second detection signal 196 output from the provided second detection piezoelectric element 19 (second detection electrode 191), and the difference 200, 201 are added. Obtaining a force.

  According to such a detection method, the force can be detected without sacrificing the driving force of the piezoelectric actuator 1 or causing an increase in size.

  Further, the resonance state detection method of the piezoelectric actuator 1 according to the present embodiment is a method for detecting the resonance state of the piezoelectric actuator 1, and is a driving piezoelectric element 15 (for driving) provided in the driving unit 141 (vibrating unit). A step of inputting a drive signal to the common electrode 151 and the drive individual electrode 153) to drive the drive piezoelectric element 15, and a first detection piezoelectric provided in the connection portion 143 a connecting the drive portion 141 and the fixed portion 142. The first detection signal 186 output from the element 18 (first detection electrode 181) and the second detection piezoelectric element 19 (second detection use) provided in the connection portion 143b connecting the drive portion 141 and the fixed portion 142. A step of acquiring a calculation signal generated by the sum of the second detection signals 196 output from the electrode 191) and a step of acquiring a phase difference between the drive signal and the calculation signal.

  According to such a detection method, the resonance state of the piezoelectric actuator 1 can be detected based on the phase difference.

  The force detection method and the resonance state detection method have been described above. However, in order to detect with higher accuracy, the arrangement of the first detection piezoelectric element 18 and the second detection piezoelectric element 19 and the like are described as described later. It is preferable to be optimized.

  For example, both the first detection piezoelectric element 18 and the second detection piezoelectric element 19 may be arranged in the connection portion 143a (first connection portion), and both of them may be the connection portion 143b (second connection portion). However, in the present embodiment, they are arranged on the opposite sides via the drive unit 141 in a plan view. That is, the first detection piezoelectric element 18 is disposed in the connection portion 143a, and the second detection piezoelectric element 19 is disposed in the connection portion 143b located on the opposite side of the connection portion 143a via the drive portion 141. Yes.

  By being arranged in this way, for example, when a force F2 is applied to the piezoelectric actuator 1, the first detecting piezoelectric element 18 and the second detecting piezoelectric element 19 exhibit opposite behaviors. Therefore, by using the first detection signal 185 and the second detection signal 195 output from such an element, the force applied to the piezoelectric actuator 1 can be detected with higher accuracy.

  Note that either one of the connecting portion 143a (first connecting portion) and the connecting portion 143b (second connecting portion) that connect the driving portion 141 and the fixing portion 142 may be omitted (cantilever support). However, preferably, both the connection portion 143a and the connection portion 143b are provided as in this embodiment. That is, it is preferable that the connection part 143a and the connection part 143b are provided on the opposite sides via the drive part 141 as shown in FIG. As a result, as shown in FIG. 2, the drive unit 141 can be supported at both ends, so that the drive of the drive unit 141 can be stabilized and the mechanical strength of the piezoelectric vibrating body 10 can be increased.

  In addition, when the vertical bisector L2 of the line segment L1 connecting the connection portion 143a and the connection portion 143b is drawn in a plan view of the drive common electrode 151, in the present embodiment, the first detection piezoelectric element 18 and The second detection piezoelectric element 19 satisfies a line-symmetrical relationship with the vertical bisector L2 as an axis of symmetry. Specifically, the first detection piezoelectric element 18 is disposed to be biased toward the convex member 13 in the connection portion 143a, and the second detection piezoelectric element 19 is disposed in the convex member 13 in the connection portion 143b. As a result, the first detection piezoelectric element 18 and the second detection piezoelectric element 19 satisfy a line-symmetrical relationship with the vertical bisector L2 as an axis of symmetry.

  As a result, the first detection signal 185 and the second detection signal 195 also have good symmetry in the amplitude and phase of the waveform of the detection signal. For this reason, the force applied to the piezoelectric actuator 1 can be detected with higher accuracy.

Second Embodiment
Next, a second embodiment of the present invention will be described.

  FIG. 10 is a plan view showing a piezoelectric vibrating body included in the piezoelectric actuator according to the second embodiment of the present invention.

  In the following description, the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. In FIG. 10, the same reference numerals are given to the same configurations as those in the above-described embodiment.

  The piezoelectric vibrating body 10A according to the present embodiment is the same as that of the first embodiment described above except that the configurations of the first detection piezoelectric element and the second detection piezoelectric element are different.

  That is, in the first embodiment described above, the first detection piezoelectric element 18 is disposed on the connection portion 143a of the substrate 14 of the piezoelectric element unit 11, and the second detection element is disposed on the connection portion 143b of the substrate 14. A piezoelectric element 19 is arranged.

  On the other hand, in the present embodiment, both the first detection piezoelectric element 18 and the second detection piezoelectric element 19 are disposed on the connection portion 143a of the substrate 14 of the piezoelectric element unit 11.

  In addition, the first detection piezoelectric element 18 is arranged so as to be biased toward the convex member 13 side of the connection portion 143a. On the other hand, the second detection piezoelectric element 19 is arranged so as to be biased to the opposite side of the connecting portion 143a to the convex member 13.

  With this arrangement, the force applied to the piezoelectric actuator 1 and the resonance state of the piezoelectric actuator 1 can be detected also in this embodiment.

<Third Embodiment>
Next, a third embodiment of the present invention will be described.

  FIG. 11 is a cross-sectional view illustrating a piezoelectric vibrating body included in a piezoelectric actuator according to a third embodiment of the present invention.

  In the following description, the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. In FIG. 11, the same reference numerals are given to the same configurations as those in the above-described embodiment.

  The piezoelectric vibrating body 10B according to the present embodiment is the same as that of the first embodiment described above except that the configuration of the driving piezoelectric element, the first detecting piezoelectric element, and the second detecting piezoelectric element is different.

That is, the piezoelectric vibrating body 10 according to the first embodiment described above is configured by bonding the piezoelectric element units 11 to each other via the adhesive 12. On the other hand, the piezoelectric vibrating body 10B according to the present embodiment is different in that the substrates 14 are not laminated with such a structure but are laminated with a single-layer piezoelectric body.
In the third embodiment, the same effect as that of the first embodiment can be obtained.

  A plurality of piezoelectric vibrators 10B may be stacked in the thickness direction. That is, the piezoelectric actuator according to this embodiment may include a stacked body (stacked structure) formed by stacking a plurality of piezoelectric vibrating bodies 10B illustrated in FIG. 11 in the thickness direction. Thereby, a piezoelectric actuator capable of generating a larger driving force is obtained.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described.

  FIG. 12 is a cross-sectional view showing a piezoelectric vibrating body included in a piezoelectric actuator according to a fourth embodiment of the present invention.

  In the following description, the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. In FIG. 12, the same reference numerals are given to the same configurations as those in the above-described embodiment.

  The piezoelectric vibrating body 10C according to the present embodiment is the same as that of the third embodiment described above except that the configurations of the driving piezoelectric element, the first detecting piezoelectric element, and the second detecting piezoelectric element are different.

That is, in the piezoelectric vibrating body 10B according to the third embodiment described above, the driving piezoelectric body 152, the first detection piezoelectric body 182 and the second detection piezoelectric body 192 are separated from each other. On the other hand, in the piezoelectric vibrating body 10C according to the present embodiment, the driving piezoelectric body 152, the first detection piezoelectric body 182 and the second detection piezoelectric body 192 are connected to each other and integrated as a whole.
In the fourth embodiment, the same effect as in the first to third embodiments can be obtained.

  In this case, the piezoelectric vibrating body 10C can be easily manufactured, and the mechanical strength of the integrated piezoelectric body can be increased. Therefore, the reliability of the piezoelectric vibrating body 10C can be increased.

2. Next, an embodiment of the robot and hand of the present invention will be described.

  FIG. 13 is a diagram showing a schematic configuration of an embodiment of the robot of the present invention. FIG. 14 is a schematic diagram for explaining a hand included in the robot shown in FIG.

  A robot 1000 shown in FIG. 13 can perform operations such as feeding, removing, transporting, and assembling precision equipment and parts (objects) constituting the precision equipment.

  The robot 1000 is a six-axis vertical articulated robot, and includes a base 1100, a robot arm 1200 connected to the base 1100, and a force detector (not shown) provided at the tip of the robot arm 1200. Hand 1400. The robot 1000 also has a plurality of drive sources (drive sources including the piezoelectric actuator 1) that generate power for driving the robot arm 1200.

  The base 1100 is a part for attaching the robot 1000 to an arbitrary installation location. Note that the installation location of the base 1100 is not particularly limited, and examples thereof include a floor, a wall, a ceiling, and a movable carriage.

  The robot arm 1200 includes a first arm 1210, a second arm 1220, a third arm 1230, a fourth arm 1240, a fifth arm 1250, and a sixth arm 1260, which are on the proximal side. They are connected in this order from the (base 1100 side) toward the tip side. The first arm 1210 is connected to the base 1100. For example, a hand 1400 (end effector) that holds various components or the like is detachably attached to the tip of the sixth arm 1260. The hand 1400 has two fingers 1410, and the fingers 1410 can hold various parts, for example.

  The fifth arm 1250 is provided with a plurality of piezoelectric vibrating bodies 10 as a drive source for driving the sixth arm 1260. Although not shown, each of the base 1100, the first arm 1210, the second arm 1220, the third arm 1230, and the fourth arm 1240 is provided with a drive source having a motor and a speed reducer. Each drive source is controlled by a control device (not shown).

  As shown in FIG. 14, the plurality of piezoelectric vibrating bodies 10 provided on the fifth arm 1250 are provided side by side in the circumferential direction around the rotation axis O of the sixth arm 1260 with respect to the fifth arm 1250. Each piezoelectric vibrating body 10 applies a driving force around the rotation axis O to the end surface of the sixth arm 1260. Accordingly, the sixth arm 1260 can be rotated around the rotation axis O with respect to the fifth arm 1250.

  A hand 1400 that is a multi-finger hand is also provided with a plurality of piezoelectric vibrating bodies 10 corresponding to the fingers 1410, and each piezoelectric vibrating body 10 approaches or moves away from the rotation axis O of the finger 1410. The driving force in the direction to be applied is given. Thereby, the two fingers 1410 can be moved in the direction of approaching or separating.

  According to the robot 1000 and the hand 1400 as described above, since the piezoelectric actuator 1 is provided, the force applied to the piezoelectric actuator 1 can be detected. For this reason, for example, when the robot arm 1200 is stopped or driven, the driving force of the piezoelectric actuator 1 can be controlled based on the detected force. For example, when the hand 1400 is holding an object, the driving force of the piezoelectric actuator 1 can be controlled based on the detected force.

3. Next, an embodiment of the electronic component conveying device of the present invention will be described.

  FIG. 15 is a perspective view showing an embodiment of the electronic component carrying apparatus of the present invention. 16 is a perspective view of an electronic component holding unit provided in the electronic component transport apparatus shown in FIG. In the following, for convenience of explanation, three axes that are orthogonal to each other are referred to as an X axis, a Y axis, and a Z axis.

  An electronic component transport apparatus 2000 shown in FIG. 15 is applied to an electronic component inspection apparatus, and includes a base 2100 and a support base 2200 disposed on the side of the base 2100. Further, on the base 2100, the upstream stage 2110 on which the electronic component Q to be inspected is placed and transported in the Y-axis direction, and the inspected electronic component Q is placed and transported in the Y-axis direction. A downstream stage 2120 and an inspection table 2130 that is located between the upstream stage 2110 and the downstream stage 2120 and inspects the electrical characteristics of the electronic component Q are provided. Examples of the electronic component Q include semiconductors, semiconductor wafers, display devices such as CLD and OLED, crystal devices, various sensors, ink jet heads, various MEMS devices, and the like.

  The support table 2200 is provided with a Y stage 2210 that can move in the Y-axis direction with respect to the support table 2200, and the Y stage 2210 can move in the X-axis direction with respect to the Y stage 2210. A stage 2220 is provided. The X stage 2220 is provided with an electronic component holder 2230 that can move in the Z-axis direction with respect to the X stage 2220.

  Further, as shown in FIG. 16, the electronic component holding unit 2230 has a fine adjustment plate 2231 that can move in the X-axis direction and the Y-axis direction, and a rotation that can turn around the Z-axis with respect to the fine adjustment plate 2231. And a holding portion 2233 that is provided in the rotating portion 2232 and holds the electronic component Q. The electronic component holding unit 2230 includes a piezoelectric actuator 1 (1x) for moving the fine adjustment plate 2231 in the X-axis direction and a piezoelectric actuator 1 (1y) for moving the fine adjustment plate 2231 in the Y-axis direction. And a piezoelectric actuator 1 (1θ) for rotating the rotating unit 2232 around the Z-axis.

  The electronic component transport apparatus 2000 as described above includes the piezoelectric actuator 1. According to such an electronic component transport apparatus 2000, since the piezoelectric actuator 1 is provided, the force applied to the piezoelectric actuator 1 can be detected. For this reason, for example, when the electronic component transport apparatus 2000 is stopped or driven, the driving force of the piezoelectric actuator 1 can be controlled based on the detected force.

4). Printer FIG. 17 is a perspective view showing an embodiment of a printer of the present invention.

  A printer 3000 shown in FIG. 17 is an ink jet recording type printer. The printer 3000 includes an apparatus main body 3010 and a printing mechanism 3020, a paper feed mechanism 3030, and a control unit 3040 provided inside the apparatus main body 3010.

  The apparatus main body 3010 is provided with a tray 3011 for installing the recording paper P, a paper discharge port 3012 for discharging the recording paper P, and an operation panel 3013 such as a liquid crystal display.

  The printing mechanism 3020 includes a head unit 3021, a carriage motor 3022, and a reciprocating mechanism 3023 that reciprocates the head unit 3021 by the driving force of the carriage motor 3022. The head unit 3021 includes a head 3021a that is an ink jet recording head, an ink cartridge 3021b that supplies ink to the head 3021a, and a carriage 3021c on which the head 3021a and the ink cartridge 3021b are mounted. The reciprocating mechanism 3023 includes a carriage guide shaft 3023b that supports the carriage 3021c so as to reciprocate, and a timing belt 3023a that moves the carriage 3021c on the carriage guide shaft 3023b by the driving force of the carriage motor 3022. Yes.

  The paper feeding mechanism 3030 includes a driven roller 3031 and a driving roller 3032 that are in pressure contact with each other, and a piezoelectric motor 100 (piezoelectric actuator 1) that is a paper feeding motor that drives the driving roller 3032.

  The control unit 3040 controls the printing mechanism 3020, the paper feeding mechanism 3030, and the like based on print data input from a host computer such as a personal computer.

  In such a printer 3000, the paper feed mechanism 3030 intermittently feeds the recording paper P one by one to the vicinity of the lower portion of the head unit 3021. At this time, the head unit 3021 reciprocates in a direction substantially orthogonal to the feeding direction of the recording paper P, and printing on the recording paper P is performed.

  The printer 3000 as described above includes the piezoelectric actuator 1. According to such a printer 3000, since the piezoelectric actuator 1 is provided, the force applied to the piezoelectric actuator 1 can be detected. For this reason, for example, when the printer 3000 is stopped or driven, the driving force of the piezoelectric actuator 1 can be controlled based on the detected force.

5). Projector FIG. 18 is a schematic diagram showing an embodiment of a projector of the present invention.

  A projector 4000 shown in FIG. 18 includes a light source 4100R that emits red light, a light source 4100G that emits green light, a light source 4100B that emits blue light, lens arrays 4200R, 4200G, and 4200B, and a transmissive liquid crystal light valve. (Light modulation section) 4300R, 4300G, 4300B, cross dichroic prism 4400, projection lens (projection section) 4500, and piezoelectric driving device 4700 are provided.

  Light emitted from the light sources 4100R, 4100G, and 4100B is incident on the liquid crystal light valves 4300R, 4300G, and 4300B via the lens arrays 4200R, 4200G, and 4200B. Each of the liquid crystal light valves 4300R, 4300G, and 4300B modulates incident light according to image information.

  The three color lights modulated by the liquid crystal light valves 4300R, 4300G, and 4300B are incident on the cross dichroic prism 4400 and synthesized. The light synthesized by the cross dichroic prism 4400 enters a projection lens 4500 that is a projection optical system. The projection lens 4500 enlarges the image formed by the liquid crystal light valves 4300R, 4300G, and 4300B and projects the enlarged image onto the screen 4600 (display surface). Thus, a desired image is displayed on the screen 4600. Here, the projection lens 4500 is supported by a piezoelectric driving device 4700 having the piezoelectric actuator 1, and the position and orientation can be changed (positioning) by driving the piezoelectric driving device 4700. Thereby, the shape and size of the image projected on the screen 4600 can be adjusted.

  In the above-described example, a transmissive liquid crystal light valve is used as the light modulation unit, but a light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such a light valve include a reflective liquid crystal light valve and a digital micromirror device. Further, the configuration of the projection optical system is appropriately changed depending on the type of light valve used. Further, the projector may be a scanning projector that displays an image of a desired size on the display surface by scanning light on a screen.

  As described above, the projector 4000 includes the piezoelectric actuator 1. According to such a projector 4000, since the piezoelectric actuator 1 is provided, the force applied to the piezoelectric actuator 1 can be detected. For this reason, for example, when the projector 4000 is stopped or driven, the driving force of the piezoelectric actuator 1 can be controlled based on the detected force.

  As described above, the piezoelectric actuator, the piezoelectric driving device, the hand, the robot, the electronic component conveying device, the printer, and the projector of the present invention have been described based on the illustrated embodiment, but the present invention is not limited to this, The configuration of each part can be replaced with any configuration having a similar function. In addition, any other component may be added to the present invention. Moreover, you may combine each embodiment suitably.

  In the above-described embodiment, the configuration in which the piezoelectric actuator is applied to a piezoelectric driving device (piezoelectric motor), a hand, a robot, an electronic component conveying device, a printer, and a projector has been described. However, the piezoelectric actuator is an electronic device other than these. It can also be applied to.

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric actuator, 1x ... Piezoelectric actuator, 1y ... Piezoelectric actuator, 1theta ... Piezoelectric actuator, 10 ... Piezoelectric vibrator, 10A ... Piezoelectric vibrator, 10B ... Piezoelectric vibrator, 10C ... Piezoelectric vibrator 11 ... piezoelectric element unit, 12 ... adhesive layer, 13 ... convex member, 14 ... substrate, 15 ... driving piezoelectric element, 15a ... driving piezoelectric element, 15b ... driving piezoelectric element, 15c ... driving piezoelectric element, 15d DESCRIPTION OF SYMBOLS ... Drive piezoelectric element, 15e ... Drive piezoelectric element, 16 ... Protective layer, 18 ... 1st detection piezoelectric element, 19 ... 2nd detection piezoelectric element, 20 ... Drive circuit, 30 ... Detection circuit, 40 ... Control part , 50 ... rotor, 51 ... driven part, 100 ... piezoelectric motor, 141 ... drive part, 142 ... fixed part, 143a ... connection part, 143b ... connection part, 151 ... common for driving Pole, 152... Driving piezoelectric element, 153... Driving individual electrode, 153 a... Driving individual electrode, 153 b... Driving individual electrode, 153 c... Driving individual electrode, 153 d. , 181 ... 1st detection electrode, 182 ... 1st detection piezoelectric material, 183 ... 1st detection electrode, 185 ... 1st detection signal, 186 ... 1st detection signal, 191 ... 2nd detection electrode, 192 ... Second detection piezoelectric body, 193 ... second detection electrode, 195 ... second detection signal, 196 ... second detection signal, 200 ... difference, 201 ... difference, 202 ... sum, 1000 ... robot, 1100 ... base, 1200 ... Robot arm, 1210 ... First arm, 1220 ... Second arm, 1230 ... Third arm, 1240 ... Fourth arm, 1250 ... Fifth arm, 1260 ... Sixth arm, 1400 ... Hand , 1410 ... finger, 2000 ... electronic component transfer device, 2100 ... base, 2110 ... upstream stage, 2120 ... downstream stage, 2130 ... inspection table, 2200 ... support base, 2210 ... Y stage, 2220 ... X stage, 2230 ... Electronic component holder, 2231 ... Fine adjustment plate, 2232 ... Rotating part, 2233 ... Holder, 3000 ... Printer, 3010 ... Main body, 3011 ... Tray, 3012 ... Discharge port, 3013 ... Control panel, 3020 ... Print Mechanism, 3021 ... Head unit, 3021a ... Head, 3021b ... Ink cartridge, 3021c ... Carriage, 3022 ... Carriage motor, 3023 ... Reciprocating mechanism, 3023a ... Timing belt, 3023b ... Carriage guide shaft, 3030 ... Paper feed mechanism, 3031 ... Driven roller 303 ... driving roller, 3040 ... control unit, 4000 ... projector, 4100B ... light source, 4100G ... light source, 4100R ... light source, 4200B ... lens array, 4200G ... lens array, 4200R ... lens array, 4300B ... liquid crystal light valve, 4300G ... liquid crystal light Valve, 4300R ... Liquid crystal light valve, 4400 ... Cross dichroic prism, 4500 ... Projection lens, 4600 ... Screen, 4700 ... Piezoelectric drive, F1 ... Force, F2 ... Force, L1 ... Line segment, L2 ... Vertical bisector, O ... rotating shaft, P ... recording paper, Q ... electronic component, a ... arrow, b ... arrow, c ... arrow

Claims (13)

A vibrating portion including a driving piezoelectric element including a driving piezoelectric body and a driving electrode;
A fixing part for fixing the vibrating part;
A first detection piezoelectric element that includes the first detection piezoelectric member and the first detection electrode, and a second detection piezoelectric member that includes the second detection piezoelectric member and the second detection electrode. A connecting portion including a piezoelectric element for use;
A piezoelectric actuator characterized by comprising:   The piezoelectric actuator according to claim 1, wherein the driving piezoelectric body, the first detection piezoelectric body, and the second detection piezoelectric body are integrated.   3. The piezoelectric actuator according to claim 1, wherein the connection part includes a first connection part and a second connection part that are disposed on opposite sides of the vibration part. The first detection piezoelectric element is provided in the first connection portion,
The piezoelectric actuator according to claim 3, wherein the second detection piezoelectric element is provided in the second connection portion. A drive circuit for inputting a drive signal to the drive electrode and driving the drive piezoelectric element;
A detection circuit for obtaining a detection signal output from the first detection electrode and the second detection electrode;
A control unit for controlling operations of the drive circuit and the detection circuit;
The piezoelectric actuator according to claim 1, comprising: An additional force detection method for detecting a force applied to a piezoelectric actuator,
A first detection signal output from the first detection piezoelectric element provided in the connection portion connecting the vibrating portion and the fixed portion, and a second output from the second detection piezoelectric element provided in the connection portion. Obtaining a difference between the detection signal and the detection signal;
Obtaining the applied force based on the difference;
A method for detecting an additional force of a piezoelectric actuator, comprising: A resonance state detection method for detecting a resonance state of a piezoelectric actuator,
A step of inputting a driving signal to the driving piezoelectric element provided in the vibration unit to drive the driving piezoelectric element;
A first detection signal output from a first detection piezoelectric element provided at a connection portion connecting the vibrating portion and the fixed portion, and a second output from a second detection piezoelectric element provided at the connection portion. Obtaining a calculation signal generated by the sum of detection signals;
Obtaining a phase difference between the drive signal and the calculation signal;
A method for detecting a resonance state of a piezoelectric actuator, comprising: The piezoelectric actuator according to any one of claims 1 to 5,
A driven part driven by the piezoelectric actuator;
A piezoelectric drive device comprising:   A hand comprising the piezoelectric actuator according to any one of claims 1 to 5.   A robot comprising the piezoelectric actuator according to any one of claims 1 to 5.   An electronic component conveying apparatus comprising the piezoelectric actuator according to any one of claims 1 to 5.   A printer comprising the piezoelectric actuator according to claim 1.   A projector comprising the piezoelectric actuator according to claim 1.

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