Vibration body, vibration wave motor, and optical device

Abstract

A vibration body has a mechatronic conversion element that is a piezoelectric ceramic composed of sodium niobate / potassium niobate metal oxide, an absolute value of a temperature characteristic of a relative dielectric constant in a temperature range of -40°C to 170°C is 500 [ppm / °C] or less, and a vibration wave is generated by excitation of the mechatronic conversion element. A vibration wave motor has the vibration body and a relative motion member having a sliding surface in pressure contact with a driving surface of the vibration body, and the relative motion member is caused to perform relative motion by the vibration wave.

Description

[0001] [Related References]

[0002] This application claims priority to Japanese Application JP Special Pursuit 2020-97583, filed on June 4, 2020 (Reiwa 2), and is incorporated herein by reference to the contents of that application. Technical Field

[0003] It involves vibrating bodies, vibrating wave motors, and optical equipment. Background Technology

[0004] As described in Patent Document 1, a vibration wave motor utilizes the expansion and contraction of a piezoelectric element to generate a traveling vibration wave (hereinafter referred to as a traveling wave) on the driving surface of an elastic body. This traveling wave causes the driving surface to undergo elliptical motion, thereby driving a moving body that comes into pressure contact with the crest of the elliptical motion. However, Patent Document 1 does not consider the problem of reduced driving performance caused by the material of the piezoelectric element.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: JP Patent Publication No. 1-17354 Summary of the Invention

[0008] The vibrating body of the first disclosure has an electromechanical conversion element, which is a piezoelectric ceramic made of sodium niobate / potassium niobate metal oxide. The absolute value of the temperature characteristic of the relative permittivity is less than 500 [ppm / ℃] in the temperature range of -40℃ to 170℃. Vibration waves are generated by excitation of the electromechanical conversion element.

[0009] The vibrator of the second disclosure has an electromechanical conversion element, which is a piezoelectric ceramic made of sodium niobate / potassium niobate metal oxide. The absolute value of the temperature characteristic of the relative permittivity is below 390 [ppm / ℃] in the temperature range of 0℃ to 60℃. Vibration waves are generated by excitation of the electromechanical conversion element.

[0010] The vibration wave motor of the third disclosure technology includes: a vibrating body of the first or second disclosure technology; and a relative motion member having a sliding surface that pressurizes and contacts the driving surface of the vibrating body, and the relative motion member is moved relative to the vibrating body by means of the vibration wave. Attached Figure Description

[0011] Figure 1 This is a cross-sectional view showing the vibration wave motor of Embodiment 1.

[0012] Figure 2 It is a three-dimensional image after cutting away a portion of the vibrating body and the moving body.

[0013] Figure 3 This is a block diagram showing the drive device of the vibration wave motor according to Embodiment 1.

[0014] Figure 4 This is an explanatory diagram showing the piezoelectric element of Embodiment 1.

[0015] Figure 5 This is an explanatory diagram showing the vibrator of Embodiment 1.

[0016] Figure 6 This is a table showing the constants (A-E), electromechanical coupling coefficient, relative permittivity, piezoelectricity, and temperature characteristics (-40-170℃, 0-60℃) of the chemical formulas (1) of materials α-γ.

[0017] Figure 7 It is a temperature characteristic diagram of the relative permittivity.

[0018] Figure 8A This is a graph showing the temperature characteristics of the electrostatic capacitance of materials α and β of the piezoelectric element in Embodiment 1.

[0019] Figure 8B This is a graph showing the temperature characteristics of the electrostatic capacitance of the material γ of the piezoelectric body in Embodiment 1.

[0020] Figure 9A This is a graph showing the temperature characteristics of the electrostatic capacitance of the vibrating body when materials α and β are used.

[0021] Figure 9B This is a graph showing the temperature characteristics of the electrostatic capacitance of the vibrating body under the condition of material γ.

[0022] Figure 10 This is a graph showing the current consumption at various temperatures for the vibration wave motor of Embodiment 1 and the vibration wave motor of the PZT mount.

[0023] Figure 11 This is an explanatory diagram showing the equivalent circuit of the vibrating body of a vibration wave motor.

[0024] Figure 12 This is a table showing the minimum voltage of the drive signal that can be driven by the vibration wave motor of Embodiment 1.

[0025] Figure 13 This is a cross-sectional view showing a lens barrel equipped with a vibration wave motor.

[0026] Figure 14 This is a cross-sectional view showing a lens barrel in which the annular vibration wave motor of Embodiment 2 is mounted.

[0027] Figure 15This is an explanatory diagram showing the vibrator of Embodiment 3.

[0028] Figure 16 This is an explanatory diagram showing the driving principle of the vibrator in Embodiment 3.

[0029] Figure 17 This is an explanatory diagram showing an example of the dustproof device according to Embodiment 4.

[0030] Figure 18 This is a graph showing an example of the temperature characteristics of the electrostatic capacitance of PZT (Fuji ceramic), a material used in piezoelectric elements manufactured for vibrating wave motors.

[0031] Figure 19 It is shown in the Figure 18 A graph showing the temperature characteristics of the electrostatic capacitance of the vibrating body of a vibrating wave motor when PZT is used as the piezoelectric material.

[0032] Figure 20 This is a graph showing the input current at various temperatures measured for the vibration wave motor of the PZT-equipped component. Detailed Implementation

[0033] A vibratory wave motor utilizes the expansion and contraction of a piezoelectric element to generate a traveling wave on the driving surface of an elastic body. This traveling wave causes the driving surface to undergo elliptical motion, which in turn drives a moving body that comes into pressure contact with the crest of the elliptical motion wave. Vibratory wave motors are characterized by high torque even at low rotational speeds, and when integrated into a drive unit, gears in the drive unit can be omitted. Therefore, quiet operation can be achieved by eliminating gear noise, and positioning accuracy can be improved.

[0034] The vibrating body of this type of vibration wave motor is typically composed of an electromechanical conversion element (hereinafter referred to as a piezoelectric element) and an elastomer. The piezoelectric element is usually made of a material such as lead zirconate titanate, commonly known as PZT.

[0035] Figure 18 This is a graph showing the temperature characteristics of the electrostatic capacitance of PZT (made by Fuji Ceramic), a material used in the manufacture of vibrating wave motors. It can be seen that it has a slope of approximately 4.4 [pF / ℃] (≈2750 [ppm / ℃]) relative to temperature.

[0036] Figure 19 It is shown in the Figure 18 A graph illustrating the temperature characteristics of the electrostatic capacitance of the vibrating body of a vibratory wave motor using PZT as the piezoelectric material is provided. It can be seen that the capacitance exhibits a slope of approximately 6.2 [pF / ℃] (≈4430 [ppm / ℃]) relative to temperature. This slope indicates, for example, that the electrostatic capacitance of the piezoelectric material decreases at lower temperatures and increases at higher temperatures.

[0037] Figure 20 This is a graph showing the input current at various temperatures measured for the vibration wave motor of the PZT-equipped component. Each measurement measured the current input to the vibration wave motor when the drive voltage was set to 70 [Vrms] and driven at a specified rotational speed. It can be observed that, relative to the current at room temperature, the input current decreases at lower temperatures but increases at higher temperatures. This phenomenon is related to... Figure 19 The electrostatic capacitance values ​​of the vibrators shown are consistent with temperature characteristics.

[0038] Because the lower the temperature, the lower the capacitance of the vibrating body, the higher the impedance, and thus the lower the input current. Conversely, because the higher the temperature, the higher the capacitance of the vibrating body, the lower the impedance, and correspondingly the higher the input current. Therefore, the higher the temperature, the higher the capacitance of the vibrating body, making it impossible to effectively drive a vibrating wave motor.

[0039] The vibratory wave motor generates driving force according to the driving signal supplied from the driving device. Under the condition of a certain driving signal, such as at an appropriate voltage value, the desired driving performance can be obtained, but the voltage of the driving signal varies according to the electrostatic capacitance of the piezoelectric material.

[0040] It also includes a drive device with a matching circuit for matching the impedance of the drive circuit driving the piezoelectric motor to the impedance of the piezoelectric motor. For example... Figure 18 As shown, PZT has a significant temperature characteristic. Therefore, even with an appropriate voltage adjustment at room temperature, the driving voltage at low and high temperatures will differ greatly in this type of drive device. Consequently, the driving performance (driving efficiency or driving force) of the vibration wave motor cannot be fully utilized.

[0041] In this embodiment, to address environmental concerns, a lead-free material is used for the piezoelectric element, thereby improving the driving performance of the vibration wave motor. Hereinafter, the vibrator and vibration wave motor of this embodiment will be described in Embodiments 1 to 4.

[0042] [Implementation Method 1]

[0043] <Vibration Wave Motor>

[0044] Figure 1 This is a cross-sectional view showing the vibration wave motor of Embodiment 1. Figure 2 This is a perspective view showing the vibrating body 10 and a portion of the moving body 20 cut off. In Embodiment 1, the vibrating body 10 is configured to be fixed to one side, driving the moving body 20 as an example of a relative motion member. The moving body 20 is made of a light metal such as aluminum. The sliding surface 20a of the moving body 20 is subjected to a surface treatment to improve wear resistance.

[0045] The vibrating body 10 is composed of an electromechanical conversion element (hereinafter referred to as a piezoelectric element) 11, such as a piezoelectric element or an electrostrictive element that converts electrical energy into mechanical energy, and an elastic body 12 to which the piezoelectric element 11 is joined, and generates a traveling vibration wave in the vibrating body 10.

[0046] The elastomer 12 is made of a metallic material with high resonance sharpness and is ring-shaped. A piezoelectric element 11 is bonded to one side of the elastomer 12 (the mating surface 12f), and a groove 12b is cut out on the side opposite to the mating surface 12f. Then, the front end of the protrusion (the part without the groove 12b) 12c becomes the driving surface 12a and makes pressurized contact with the sliding surface 20a of the moving body 20. The driving surface 12a is subjected to a lubricating surface treatment.

[0047] The portion of the elastomer 12 without the notched groove 12b is the base 12d, and the flange 12e extends from the base 12d toward the inner diameter side. The innermost diameter portion (radially innermost portion) of the flange 12e is fixed to the fixing member 13. A sliding member, such as a coating film or lubricating plating, is attached to the protruding portion 12c of the elastomer 12 in a manner that covers the entire portion.

[0048] The piezoelectric element 11 is made of sodium potassium niobate, which is a lead-free material and will be described in detail later. A flexible printed circuit board (FPC) 14 for transmitting drive signals is bonded to the side of the piezoelectric element 11 opposite to the bonding surface 12f of the elastomer 12 (the reverse bonding surface), and extends on the circuit board. Electrodes are disposed on the reverse bonding surface, and these electrodes are configured in two sets, divided into two phases (phase A and phase B) along the circumferential direction. The electrodes are arranged such that they are alternately polarized at 1 / 2 wavelength intervals in each phase, and there is a 1 / 4 wavelength interval between phase A and phase B.

[0049] The output shaft 21 is connected to the movable body 20 via a blocking member 23 inserted in a manner that fits into the rubber member 22 and the output shaft 21 in a D-cut manner. Moreover, the output shaft 21 and the blocking member 23 are fixed by a clamping member (E-clip) 24 and rotate integrally with the movable body 20.

[0050] The rubber member 22 between the blocking member 23 and the moving body 20 is preferably made of butyl rubber or similar material, which has the function of bonding the moving body 20 and the blocking member 23 using rubber-based adhesive properties and has the function of absorbing vibrations from the moving body 20 to the output shaft 21. A pressure member 25 is provided between the output gear 41 and the bearing 27 of the output shaft 21. With this configuration, the moving body 20 is in pressurized contact with the driving surface 12a of the elastic body 12.

[0051] <Driver for Vibration Wave Motor>

[0052] Figure 3This is a block diagram showing the drive device 300 of the vibration wave motor 1 according to Embodiment 1. The drive device 300 includes a control unit 301, an oscillation unit 302, a phase shifting unit 303, an amplification unit 304, a vibration wave motor 1, and a detection unit 305. The control unit 301 and the lens barrel 110 (see reference) Figure 13 The CPU310 is electrically connected to the internal or main body of the camera.

[0053] The control unit 301 controls the drive of the vibration wave motor 1 based on drive commands from the CPU 310 inside the lens barrel 110 or the camera body. The control unit 301 receives a detection signal from the detection unit 305 and obtains position and velocity information based on the value, and controls the frequency of the oscillation unit 302 in a way that positions it at the target position.

[0054] The oscillation unit 302 generates a drive signal of the desired frequency using instructions from the control unit 301. The phase shifter 303 splits the drive signal generated by the oscillation unit 302 into two drive signals with different phases. The amplification unit 304 boosts the two drive signals separated by the phase shifter 303 to the desired voltages. The drive signal from the amplification unit 304 is transmitted to the vibration wave motor 1, and by applying this drive signal, the vibrating body 10 generates a traveling wave, thereby driving the moving body 20.

[0055] The detection unit 305 is composed of an optical encoder or a magnetic encoder, etc., and detects the position or speed of the driven object driven by the drive moving body 20, and transmits the detection value as an electrical signal to the control unit 301.

[0056] Next, the operation of the vibration wave motor 1 will be explained. When a drive command is issued from the control unit 301, the oscillation unit 302 generates a drive signal. This drive signal is split into two drive signals with a 90-degree phase difference by the phase shifter 303, and amplified to the desired voltage by the amplification unit 304. The amplified drive signal is applied to the piezoelectric element 11 of the vibration wave motor 1, and the piezoelectric element 11 is excited (vibrates). The excitation of the piezoelectric element 11 generates fourth-order bending vibration in the elastic body 12. The piezoelectric element 11 is divided into phase A and phase B, and the drive signal is applied to phase A and phase B respectively.

[0057] The fourth-order bending vibration generated from phase A and the fourth-order bending vibration generated from phase B are phase-shifted by 1 / 4 wavelength. In addition, the driving signal of phase A and the driving signal of phase B are phase-shifted by 90 degrees. Therefore, the two bending vibrations are combined to form a four-wave traveling wave.

[0058] Elliptical motion is generated at the crest of the traveling wave. Therefore, the moving body 20, which is in pressurized contact with the driving surface 12a, is frictionally driven by this elliptical motion. An optical encoder, serving as a detection unit 305, is configured on the driving body driven by the moving body 20. Electrical pulses are generated from the optical encoder and transmitted to the control unit 301. The control unit 301 can obtain the current position and current speed based on the signal of these electrical pulses.

[0059] <Piezoelectric element 11>

[0060] Figure 4 This is an explanatory diagram showing the piezoelectric element 11 of Embodiment 1. Figure 4 (a) is a diagram showing the surface 11A of the piezoelectric material 11. Figure 4 (b) is a diagram showing the back side 11B of the piezoelectric element 11. Figure 5 This is an explanatory diagram showing the vibrator 10 of Embodiment 1. Figure 5 (a) is a view showing the side of the vibrator 10. Figure 5 (b) is a diagram of the vibrating body 10 as viewed from the surface 11A side of the piezoelectric body 11.

[0061] In surface 11A, electrode 16 is divided into two phases (phase A and phase B) along the circumferential direction. Electrode 16 is printed onto substrate 18 of piezoelectric body 11 using silver paste, with alternating polarization at 1 / 2 wavelength intervals in each phase and a 1 / 4 wavelength interval between phase A and phase B. Electrode 16 can be a metal plating such as NiP or gold. Substrate 18 of piezoelectric body 11 is mainly composed of sodium potassium niobate, i.e., a lead-free material.

[0062] On the back side 11B, an electrode 19, which is not an electrode pattern like the electrode 16, is printed using silver paste, forming a substrate 18 in which the piezoelectric body 11 can be observed on both the outer and inner peripheral sides. The electrode 19 can be a metal plating layer such as NiP or gold. The back side 11B is bonded to the elastomer 12 using a room temperature curing adhesive.

[0063] In addition, in order to transmit the drive signal from the drive device 300, an FPC 14 is bonded to surface 11A and connected to the drive device 300. The GND line of the FPC 14 is bonded to the 1 / 4 wavelength electrode 16, but the 1 / 4 wavelength electrode 16 and the metal part of the elastomer 12 are bonded together in a bridging manner using a conductive coating (not shown), so that the metal part of the elastomer 12 is grounded.

[0064] Here, the material of piezoelectric element 11 is described. The material of piezoelectric element 11 is a piezoelectric ceramic composed of sodium niobate / potassium niobate metal oxide, for example, using the material and manufacturing method described below. The material of piezoelectric element 11 is shown in the following chemical formula (1).

[0065] (1-C-E)(Li A (Na B K (1-B) ) (1―A) NbO3+ C Ba(Zr D Ti (1―D) O3+ E BiFeO3 is here.

[0066] 0 <A<0.2、0.4≤B≤0.6、0<C≤0.1、0<D<1.00、0<E<0.02 (1)

[0067] In the material of this piezoelectric 11, the temperature characteristic of the relative permittivity is extremely small. Specifically, the absolute value of the rate of change of the relative permittivity is less than 500 [ppm / ℃] in the range of -40℃ to 170℃, that is, it falls within the range of -500 to +500 [ppm / ℃]. Therefore, the temperature characteristic of the capacitance of the piezoelectric 11 can become extremely small.

[0068] If sodium carbonate and potassium carbonate are used as raw materials, the pH of the slurry during mixing and grinding will become strongly alkaline. Therefore, in this embodiment, nano-sized sodium niobate and potassium niobate, produced by hydrothermal synthesis, are used as raw materials. This allows the pH to be set to weakly alkaline.

[0069] Furthermore, the sodium to niobate and potassium to niobate ratios (x) of nano-sodium niobate and potassium niobate can be in the range of 1.00 ≤ x ≤ 1.01. In the manufacturing method shown below, the range of (x) is varied to confirm the difference between the case where (x) is 1.00 and the case where (x) is 1.01.

[0070] The manufacturing method is described in detail below. As a component of niobium-based lead-free piezoelectric ceramic materials, it is expressed in chemical formula... (1-C-E) (Li A (Na B K (1-B) ) (1―A) Using NbO3 as a reference, A and B are varied within the following ranges to implement the process.

[0071] 0.055≤A≤0.1

[0072] 0.4≤B≤0.6

[0073] It is assumed that barium zirconate titanate and bismuth ferrite have been added to it.

[0074] (1-C-E) (Li A (Na B K (1-B) ) (1―A) NbO3+ C Ba(ZrD Ti (1―D) O3+ E BiFeO3

[0075] (0.055≤A≤0.1, 0.4≤B≤0.6, 0.05≤C≤0.1, 0.17≤D≤0.83, 0.005≤E≤0.01)

[0076] The formulation method of this embodiment uses lithium carbonate (0.055 mol to 0.1 mol), barium carbonate (0.05 mol to 0.1 mol), zirconium oxide (0.05 mol to 0.1 mol), titanium oxide (0.05 mol to 0.1 mol), bismuth oxide (0.005 mol to 0.01 mol), and iron oxide (0.005 mol to 0.01 mol) in a ratio of 0.005 mol to 0.01 mol.

[0077] Additionally, as a representative example, this illustrates a formulation where the overall amount is on the order of 100g. Figure 6 The proportions of the components of material α and its preparation method.

[0078] Figure 6 This is a table showing the constants (A~E), electromechanical coupling coefficient, relative permittivity, piezoelectric constant, and temperature characteristics (rate of change) of the relative permittivity for each material according to its chemical formula (1). The temperature characteristics of the relative permittivity were measured over two temperature ranges (-40~170℃, 0~60℃). The larger the electromechanical coupling coefficient, the more effectively electrical energy is converted into mechanical energy. In addition to this component, 0.1wt% Cu was added to material γ. This resulted in a higher mechanical quality coefficient (in... Figure 11 (As will be discussed later) has been improved.

[0079] exist Figure 6 In the formulation and preparation method of material α, the components are prepared in the following proportions: lithium carbonate 0.057 mol, barium carbonate 0.05 mol, zirconium oxide 0.0415 mol, titanium oxide 0.0085 mol, bismuth oxide 0.005 mol, and iron oxide 0.005 mol. The mixture is then ground in 300 ml of water using a ball mill for 24 hours to produce a primary mixed grinding slurry. Additionally, relative to... Figure 6 The proportions of the components in material α are determined by the proportions of components A to E in other Nos relative to material α.

[0080] A mixture was prepared by mixing 0.444 mol of nano-sodium niobate and 0.444 mol of potassium niobate in a ratio of 0.444 mol using a hydrothermal synthesis method involving a solvothermal reaction at 150℃~300℃ for 1~12 hours with the primary mixed grinding slurry. This mixture was then further mixed and ground again in 300 ml of water at room temperature for 24 hours to prepare a secondary mixed grinding slurry. Subsequently, this secondary mixed grinding slurry was dried at 85℃ for 48 hours under a weakly alkaline condition (pH 8.9~9.8, below pH 10) to obtain a dried product.

[0081] Next, two temporary sintering processes were carried out on the dried material within the temperature range of 700℃ to 800℃. The first temporary sintering was performed in an electric furnace at 800℃ for two hours. After that, the calcined powder was ground in 300ml of water using a ball mill for 24 hours and dried in a constant temperature bath at 85℃ for 48 hours. After producing the primary temporary sintered ground and dried powder, a second temporary sintering was carried out.

[0082] The second temporary sintering was performed at 800°C for two hours, the same temperature range as the first temporary sintering. However, the first and second temporary sinterings can also be performed at different sintering temperatures. In this embodiment, the sintering ambient gas is used, but it can also be performed in an ambient gas other than the atmosphere. For example, oxygen can be used as the ambient gas.

[0083] Regarding the grinding method of calcined powder, in the method of using ball mill, bead mill, etc., to make the particle size of the secondary calcined and ground dried powder less than 1μm, the second calcined powder is ground in 300ml of water for 24 hours using a ball mill, and then dried in a constant temperature bath at 85℃ for 48 hours to produce the secondary calcined and ground dried powder.

[0084] Subsequently, the calcined and ground dried powder was mixed with 10 wt% binder, passed through a 40-mesh sieve, and dried in a constant temperature bath at 110°C for 1 hour to produce granular whole powder.

[0085] After granulation, to The granulated powder is fed into a mold, and pressure is applied using a hydraulic press (200-ton press) to shape it into a pellet with a density of approximately 2.3 g / cm³. 3 ~2.6g / cm 3 The molding density (ρ) is [value missing] and the thickness of the molded body is 1.5 mm. The pressure is applied for 1 to 10 seconds. Furthermore, the molding density (ρ) is approximately 2.3 to 2.6 g / cm³. 3 The molding density is at an upper limit of 2.6 g / cm³. 3 Lower limit 2.3 g / cm 3 The change was implemented. The result was 2.5 g / cm³.3 Most suitable.

[0086] After molding, degreasing is performed in an electric furnace at a temperature range of 700°C to 800°C. However, in this embodiment, it is preferable to maintain the temperature at 700°C for 4 hours, followed by firing at a temperature range of 1100°C to 1250°C. In this embodiment, firing was performed at 1200°C. The ambient gas during firing was atmospheric or similar.

[0087] After firing, the fired body was machined to a thickness of T = 0.5 mm using a grinding mill (6BN, HAMAI, #800 abrasive). Then, silver paste (SR-2099, manufactured by NAMICS Corporation) was applied to the surface of the machined component using screen printing. Silver electrodes were then placed in an electric furnace at 800°C. The component with the silver electrodes was polarized by applying a voltage of 4.0 kV / mm for 10 minutes in insulating oil (silicone oil) at 50°C, thus manufacturing a niobium-based lead-free piezoelectric ceramic.

[0088] In addition, the method for measuring niobium-based lead-free piezoelectric ceramic materials was as follows: after polarization treatment, the material was left to stand for 24 hours, and then measured using an impedance analyzer (Agilent Instruments 4294A) employing the resonance-anti-resonance method. Furthermore, the equivalent piezoelectric constant was measured using a d33 instrument (ZJ-43, Institute of Acoustics, Chinese Academy of Sciences).

[0089] The niobium-based lead-free piezoelectric ceramic of this embodiment was obtained using this manufacturing method. The electromechanical coupling coefficient, relative permittivity, piezoelectric constant, temperature characteristics of relative permittivity, and temperature characteristics of Curie point of the obtained niobium-based lead-free piezoelectric ceramic were measured using the following methods.

[0090] <Measuring Apparatus and Methods>

[0091] This describes a method for measuring the temperature characteristics of the relative permittivity of the niobium-based lead-free piezoelectric ceramic material manufactured in the manufacturing method of this embodiment.

[0092] Regarding the diameter obtained here The piezoelectric element 11 in the shape of the object was placed for 24 hours. Then, the capacitance at a frequency of 1 kHz and a voltage of 0.5 V was measured using an impedance analyzer (Agilent Device 4294A) at 10 °C intervals from -40 °C to 170 °C and from 170 °C to -40 °C. The relative permittivity was calculated. Figure 7 The result is shown.

[0093] Figure 7 This is a temperature characteristic diagram of the relative permittivity. Figure 7The diagram illustrates the change in relative permittivity as the temperature range of the measurement is increased from -40°C to 170°C, and conversely, as the temperature is decreased from 170°C to -40°C. In this embodiment, the difference in relative permittivity between the value measured at the low temperature of -40°C during the temperature increase and the value measured at the high temperature of 170°C during the temperature decrease is at most 38, which is a very small difference, and the hysteresis value of the relative permittivity before and after the phase transition is in the range of 32 to 38.

[0094] Typically, it is known that materials such as crystal have almost no change in relative permittivity within a temperature range of -40°C to 170°C. In this embodiment, by... Figure 7 It is understood that the material is considered to be of sufficient practicality within this scope.

[0095] <Temperature characteristics of the capacitance of piezoelectric element 11>

[0096] Figure 8A This is a graph showing the temperature characteristics of the electrostatic capacitance of materials α and β of the piezoelectric body 11 in Embodiment 1. Figure 8B This is a graph showing the temperature characteristics of the electrostatic capacitance of the material γ of the piezoelectric element 11 in Embodiment 1. Figure 8A as well as Figure 8B For example, a range greater than -20°C and below 0°C is defined as the low-temperature range, a range greater than 0°C and below 25°C is defined as the normal-temperature range, and a range greater than 25°C and below 60°C is defined as the high-temperature range. Regarding the changes in the capacitance of materials α, β, and γ from low to high temperatures, with 60°C as a reference, material α changes by approximately 2% at 0°C and approximately 10% at -20°C. Material β changes by approximately 4% at 0°C and approximately 11% at -20°C. Material γ changes by approximately 1% at 0°C and approximately 5% at -20°C.

[0097] <Temperature characteristics of the electrostatic capacitance of vibrator 10>

[0098] Figure 9A This is a graph showing the temperature characteristics of the electrostatic capacitance of the vibrator 10 when materials α and β are used. Figure 9BThis is a graph showing the temperature characteristics of the capacitance of the vibrator 10 in Embodiment 1 when material γ is used. Regarding the change in capacitance of the vibrator 10 from a low temperature to a high temperature, based on 60°C, material α changes by approximately 8% at 0°C and approximately 18% at -20°C. Material β changes by approximately 10% at 0°C and approximately 20% at -20°C. Material γ changes by approximately 6% at 0°C and approximately 16% at -20°C. This is very small compared to the rate of change when PZT is used, which is 25% at 0°C and 31-33% at -20°C.

[0099] <Current Consumption Measurement>

[0100] Figure 10 This is a graph showing the current consumption at various temperatures for the vibration wave motor 1 of Embodiment 1 and the vibration wave motor with PZT mounting. Each measurement measured the current input to the vibration wave motor when the drive voltage was set to 70 [Vrms] and driven at a specified rotational speed. It can be seen that the vibration wave motor 1 with materials α, β, and γ has almost no temperature characteristic of receiving input current. It can be seen that when compared with... Figure 19 When comparing the temperature characteristics of the input current of the PZT mount shown, especially at high temperatures, it can be driven more effectively than the PZT mount. As mentioned above, this phenomenon is caused by the temperature characteristics of the capacitance of the vibrator 10. Using Figure 11 Explain this phenomenon.

[0101] Figure 11 This is an explanatory diagram showing the equivalent circuit of the vibrating body 10 of the vibrating wave motor 1. The equivalent circuit 1100 of the vibrating body 10 is composed of the capacitance C of the piezoelectric body 11, the equivalent inductance L, the equivalent capacitance C, and the resonant resistance R. The current Ia of the vibrating body 10 is the sum of the current Ib (equation (2) below) flowing to the capacitance Cd component of the piezoelectric body 11 and the current Ic (equation (3) below) flowing to the LCR series side.

[0102]

Mathematical Formula 1

[0103] lb=E / (1 / jωcd) (2)

[0104] Here, E is the driving voltage, ω is the angular frequency 2πf, and f is the frequency of the driving signal.

[0105]

[0106] Here, in the state 1 / jωcd << R+j(ωL+1 / ωC), Ia≈Ib.

[0107] Typically, the vibratory wave motor is driven at a resonant frequency where the impedance of the equivalent circuit 900 is extremely small, or at a driving frequency that deviates slightly towards the higher frequency side compared to the anti-resonant frequency where the impedance of the equivalent circuit 900 is extremely large. Under this driving frequency, the value of 1 / ωCd, which is the denominator of the current Ib, becomes very small compared to the value of R+(ωL-1 / ωC), which is the denominator of the current Ic. Therefore, the current Ia input to the vibrator 10 becomes essentially equal to the current Ib. That is, the current consumed by the vibrator 10 is essentially dependent on the value of the capacitance Cd of the piezoelectric element 11.

[0108] Therefore, when the capacitance of the vibrator 10 changes with temperature, the impedance also changes, and the input current changes. Even at high temperatures, the capacitance of the materials α, β, and γ does not increase significantly; therefore, the input current also increases very little.

[0109] Furthermore, conventional vibratory wave motors are designed to match the impedance of the drive device with the impedance of the vibratory wave motor. Therefore, when the capacitance Cd of the piezoelectric element 11 changes, the voltage of the drive signal (drive voltage E) also changes. Thus, when the capacitance Cd of the piezoelectric element 11 varies due to ambient temperature, the voltage of the drive signal also changes.

[0110] Even when the voltage of a PZT-equipped vibration wave motor is adjusted appropriately at room temperature, the driving voltage at low and high temperatures varies significantly. Specifically, the voltage increases at low temperatures and decreases at high temperatures relative to room temperature. At low temperatures, the driving voltage is set higher than necessary, and this high voltage affects the driving efficiency of the drive circuit itself. Compared to the PZT-equipped model, the vibration wave motor 1 of Embodiment 1 exhibits very little change in capacitance at low and high temperatures. Therefore, the variation in driving voltage is minimized, thereby improving the driving efficiency of the drive device 300 itself.

[0111] In equation (4) below, Q is the mechanical quality coefficient. The value of the equivalent inductance L or equivalent capacitance C affects the resonance characteristics of the vibrating body 10. The mechanical quality coefficient Q is a measure of resonance characteristics; the larger the value of the mechanical quality coefficient Q, the better the resonance characteristics. The larger the value of Lm, the larger the mechanical quality coefficient Q becomes. Figure 6 The material shown has a larger mechanical quality coefficient Q and improved resonance characteristics compared to material β.

[0112]

Mathematical Formula 2

[0113]

[0114] Furthermore, it is known that the temperature characteristics of the drive voltage of the vibration wave motor 1 in Embodiment 1 are very small.

[0115] Figure 12 This table shows the lowest voltage (hereinafter referred to as the driveable voltage) of the drive signal that can be driven by the vibration wave motor 1 of Embodiment 1. The vibration wave motor 1 cannot be driven with a drive voltage E lower than the driveable voltage. Regarding materials α, β, and γ, it is known that the driveable voltage remains almost unchanged within the temperature range of 0–50°C where the capacitance hardly changes. The driveable voltage increases slightly at -20°C, but the change is very small compared to the case where PZT is used.

[0116] Experiments conducted by the inventors of this invention have shown that the driving voltage is related to the electrostatic capacitance of the vibrating body 10. The reason for this will be explained here. The electromechanical coupling coefficient Kvn of the vibrating body 10 is the amount of conversion from the electrical energy Ui stored in the vibrating body 10 to the mechanical energy Ut as the strain energy of vibration, and is expressed by the following equation (5).

[0117] Kvn=(Ut / Ui) 0.5 (5)

[0118] The electrical energy Ui stored in the vibrating body 10 is essentially stored in the piezoelectric body 11. On the other hand, the energy Pf stored in the piezoelectric body 11 is as shown in the following equation (6).

[0119] Pf=E×ω×Cdv (6)

[0120] E represents the driving voltage, ω represents the angular frequency, and Cdv represents the capacitance of the vibrating body 10. The drivable state of the vibrating wave motor 1 can be considered as a state where the strain energy exceeds a certain threshold. When the electromechanical coupling coefficient Kvn and ω are set to constant values, the strain energy at a certain threshold depends on the value of the capacitance Cdv of the vibrating body 10 and the applied voltage. However, considering that the capacitance Cdv of the vibrating body 10 of the PZT mount varies with temperature, the drivable voltage also changes accordingly.

[0121] When driven by a drive signal of a certain voltage, the PZT mount sets the drive voltage E based on a drive voltage that increases at -20°C. However, the difference between the drive voltage E and the drive voltage increases at room temperature or high temperature, resulting in an input current that is more than necessary. On the other hand, the temperature characteristic of the drive voltage of the vibration wave motor 1 in Embodiment 1 is very small, and the difference between the drive voltage and the drive voltage remains essentially unchanged at each temperature, thus the necessary current is input at each temperature.

[0122] <Lens tube>

[0123] Figure 13This is a cross-sectional view showing a lens barrel 110 equipped with a vibration wave motor 1. The lens barrel 110 has an outer fixing barrel 31, an inner fixing barrel 32, and a vibration wave motor 1. The outer fixing barrel 31 is, for example, cylindrical and covers the outer periphery of the lens barrel 110. The outer fixing barrel 31 has a protruding piece 31a that protrudes from its inner peripheral surface toward the optical axis OA. The protruding piece 31a supports the inner fixing barrel 32. The inner fixing barrel 32 is, for example, cylindrical and is located on the inner peripheral side compared to the outer fixing barrel 31. The vibration wave motor 1 is located between the outer fixing barrel 31 and the inner fixing barrel 32.

[0124] Within the inner fixing cylinder 32, a first lens group L1, a second lens group L2, a third lens group L3, and a fourth lens group L4 are arranged along the same optical axis OA, starting from the subject side. The third lens group L3 is an AF lens held by a circular AF (Auto Focus) ring 119. The first lens group L1, the second lens group L2, and the fourth lens group L4 are fixed to the inner fixing cylinder 32. The third lens group L3 is configured to move relative to the inner fixing cylinder 32 in the direction of the optical axis OA (hereinafter referred to as the optical axis direction) by moving the AF ring 119.

[0125] The vibration wave motor 1 is mounted on the gear unit module 113. The gear unit module 113 is mounted on the inner fixing cylinder 32 of the lens barrel 110. The output gear 41 of the vibration wave motor 1 transmits rotational motion to the cam ring 116 via the reduction gear 115 of the gear unit module 113, thereby driving the cam ring 116 to rotate.

[0126] A keyway 117 is cut out at an angle relative to the circumference on the cam ring 116. The AF ring 119 has a retaining pin 118. The retaining pin 118 is inserted into the keyway 117. The AF ring 119 is configured to be driven in the linear direction in the optical axis OA by rotating the cam ring 116 with the retaining pin 118 inserted into the keyway 117, and can be stopped at a desired position. Figure 2 The drive device 300 shown is located between the outer fixing cylinder 31 and the inner fixing cylinder 32 of the lens barrel 110, and performs the driving, control, and rotation speed detection of the aforementioned vibration wave motor 1.

[0127] Thus, according to Embodiment 1, the vibration wave motor 1 exhibits reduced temperature characteristics in terms of current consumption compared to the PZT mount. Furthermore, since the change in capacitance Cdv of the vibrator 10 at low and high temperatures is minimal compared to the PZT mount, the variation in drive voltage E is significantly reduced, improving the drive efficiency of the drive device 300 itself. Moreover, because the capacitance Cdv of the vibrator 10 is less susceptible to change due to ambient temperature compared to the PZT mount, the temperature variation of the drive voltage of the vibration wave motor 210 can also be reduced.

[0128] [Implementation Method 2]

[0129] Embodiment 2 is an example in which the vibration wave motor 1 of Embodiment 1 is configured as a ring-shaped vibration wave motor. The same reference numerals are used for components that are the same as those in Embodiment 1, and their descriptions are omitted.

[0130] Figure 14 This is a cross-sectional view showing a lens barrel in which the annular vibration wave motor of Embodiment 2 is mounted. The lens barrel 200 has an outer fixing cylinder 31 and an inner fixing cylinder 32, and a motor unit with an annular vibration wave motor 210 is fixed to the outer fixing cylinder 31 and the inner fixing cylinder 32. A drive device 300 is provided between the outer fixing cylinder 31 and the inner fixing cylinder 32 of the lens barrel 200, and performs driving, control, and speed detection of the vibration wave motor 210. The drive device 300 is configured to match the impedance of the drive device 300 with the impedance of the vibration wave motor.

[0131] Next, the configuration of the vibration wave motor 210 will be described. The vibrating body 211 is constructed similarly to that in Embodiment 1, using a piezoelectric body 11 made of sodium niobate / potassium niobate metal oxide and an elastic body 214 bonded to the piezoelectric body 11. It is assumed that a traveling wave is generated in the vibrating body 211, but in Embodiment 2, a 9-wave traveling wave will be described as an example.

[0132] The elastomer 214 is made of a metallic material with high resonance sharpness. The elastomer 214 is annular in shape. A groove is cut into the opposite side of the elastomer 214 to which the piezoelectric element 11 engages. The reason for cutting the groove is to bring the neutral surface of the traveling wave as close as possible to the piezoelectric element 11, thereby increasing the amplitude of the traveling wave on the driving surface 216a. The surface without the groove becomes the driving surface 216a, which makes pressurized contact with the moving body 220. To ensure driving performance and improve durability, a lubricating coating is applied to the surface of the driving surface 216a of the elastomer 214.

[0133] Similar to Embodiment 1, the piezoelectric element 11 is divided into two phases (phase A and phase B) along the circumference. In each phase, elements are arranged with alternating polarization at intervals of 1 / 2 wavelength, and a 1 / 4 wavelength interval is separated between phase A and phase B. The material of the piezoelectric element 11 is the same as in Embodiment 1, utilizing a material with extremely low temperature characteristics of relative permittivity, that is, a material with very low temperature characteristics of capacitance Cd.

[0134] A nonwoven fabric 252 and a pressure member 250 are disposed below the piezoelectric body 11. The nonwoven fabric 252, taking felt as an example, is disposed below the piezoelectric body 11 and does not transmit the vibration of the vibrator 211 to the pressure member 250.

[0135] The pressure member 250 is positioned below the pressure plate (not shown) to generate pressure. In Embodiment 2, the pressure member 250 is a disc spring. It may also be a coil spring or a wave spring, but not a disc spring. The pressure member 250 is held in place by fixing the pressing ring 251 to the fixing member 223.

[0136] The moving body 220 is made of a lightweight metal such as aluminum, and a sliding material is provided on the surface of the sliding surface to improve wear resistance. A vibration absorbing member 243, such as rubber, is disposed on the moving body 220 to absorb longitudinal vibrations of the moving body 220, and an output transmission member 242 is disposed thereon.

[0137] The output transmission member 242 is configured to limit the pressure direction and radial direction of the moving body 220 by using a bearing 253 provided on the fixed member 223. The output transmission member 242 has a protrusion 241 from which a fork connected to the cam ring 315 is fitted, and the cam ring 315 rotates together with the rotation of the output transmission member 242.

[0138] A keyway 317 is cut out at an angle relative to the circumference on the cam ring 315. A fixing pin 318 provided on the AF ring 319 engages with the keyway 317, causing the cam ring 315 to rotate and drive. Thus, the AF ring 319 is driven in the straight direction in the optical axis direction and can be stopped at the desired position.

[0139] By using screws to install the pressing ring 251 to mount the fixing member 223, a motor unit is formed from the output transmission member 242 to the moving body 220, the vibrating body 211, and the pressurizing member 250.

[0140] The vibration wave motor 210 using the vibrator 211 in Embodiment 2 also exhibits significantly lower temperature characteristics in terms of current consumption compared to the PZT mount, similar to Embodiment 1. Furthermore, impedance matching between the drive device 300 and the vibration wave motor 210 is achieved. In the vibration wave motor 210 of Embodiment 2, compared to the PZT mount, the change in capacitance Cdv of the vibrator 10 at low and high temperatures is also smaller. Therefore, the variation in drive voltage E can be reduced to a very small extent, improving the drive efficiency of the drive device 300 itself. Moreover, since the capacitance Cdv of the vibrator 10 is less susceptible to change due to ambient temperature, the temperature variation of the driveable voltage of the vibration wave motor 210 is also small, similar to Embodiment 1.

[0141] [Implementation Method 3]

[0142] The vibration wave motor in Embodiment 3 is of the type where the vibrating body is composed solely of a piezoelectric element 11, and the drive rail, which serves as the relative motion component, is a linear drive type. The same reference numerals are used for components identical to those in Embodiments 1 and 2, and their descriptions are omitted.

[0143] Figure 15 This is an explanatory diagram showing the vibrator of Embodiment 3. Figure 15 (A) is a front view and a back view of the vibrator 1500. Figure 15 (B) is a schematic three-dimensional view of the vibrating body 1500. Figure 15 (C) is an explanatory diagram showing an example of the installation of the vibrator 1500.

[0144] In Embodiment 3, the vibrating body 1500 of the vibration wave motor 1 is composed only of a piezoelectric element 11, and the drive rail 1550, which serves as a relative motion member, is of the linear drive type. Similar to Embodiment 1, the vibrating body 1500 is constructed using a piezoelectric element 11 made of sodium niobate / potassium niobate metal oxide and a sliding member 1560 provided at the end.

[0145] The vibrating body 1500 is pressurized against the drive rail 1550 by a compression spring 1525. A linear guide rail 1527 is provided between the fixed member 1513 and the drive rail 1550. The linear guide rail fixing part 1527a is fixed to the fixed member 1513, and the movable part 1527b is engaged with the drive rail 1550. The drive rail 1550 can only move in the left and right direction as shown in the figure. An elliptical motion is generated at the position of the sliding member 1560 of the vibrating body 1500, and the drive rail 1550 is driven linearly.

[0146] The vibrator 1500 has a two-layer structure. An electrode 1510 is located on the first surface 1501 of the first layer, and an electrode 1520 of the same shape is located on the opposite second surface 1502. The A-phase drive signal is input to the electrode 1510 on the first surface 1501, while the electrode 1520 on the second surface 1502 becomes the ground plane (GND). The input of the A-phase drive signal generates a standing wave of longitudinal first-order mode vibration in the vibrator 1500.

[0147] The third surface 1503 of the second layer is provided with four electrodes 1531 to 1534, with the polarization directions of the four electrodes 1531 to 1534 alternating. On the opposite side, the fourth surface 1504 also has an electrode 1540 of the same shape as the first layer. A B-phase drive signal is input to the electrodes 1531 to 1534 on the third surface 1503 side, while the electrode 1540 on the fourth surface 1504 side becomes GND. The input of the B-phase drive signal generates a standing wave of second-order bending mode vibration in the vibrator 1500.

[0148] The first and second layers are joined together by the second surface 1502 of the first layer's GND and the fourth surface 1504 of the second layer's GND, forming a common GND. A groove 1505 is provided in the central part of the vibrator 1500. By fitting the pressure spring 1525 into this groove, misalignment of the pressure position can be prevented, and support can also be achieved in the long side direction of the drive rail 1550.

[0149] The sliding member 1560 is made of engineering plastic material with excellent wear resistance and is located at the position shown in the figure where the amplitude of the standing wave of the longitudinal first-order mode vibration is the largest and the amplitude of the standing wave of the bending second-order mode vibration is the largest.

[0150] <The Operating Principle of Vibrating Body 1500>

[0151] Figure 16 This is an explanatory diagram showing the driving principle of the vibrator 1500 in Embodiment 3. Hereinafter, according to... Figure 16 The order of (a) to (e) illustrates the time series. Figure 16 In the curves at the left end of (a) to (e), t represents time, the vertical axis represents voltage, and the horizontal axis represents time.

[0152] At t=1, the voltage of phase A is 0, and the voltage of phase B is negative. At this time, the displacement of the first-order longitudinal vibration is zero, and a second-order bending vibration with displacement in the negative direction at point C and the positive direction at point D is generated.

[0153] At t=2: the voltage of phase A is positive, and the voltage of phase B is 0. At this time, the longitudinal first-order vibration of the production line in the positive direction and the bending second-order vibration displacement are zero.

[0154] At t=3: the voltage of phase A is 0, and the voltage of phase B is positive. At this time, the longitudinal first-order vibration displacement is zero, and a bending second-order vibration with displacement in the positive direction at point C and the negative direction at point D is generated.

[0155] At t=4: the voltage of phase A is positive, and the voltage of phase B is 0. At this time, a longitudinal first-order vibration with displacement in the negative direction is generated, and the displacement of the bending second-order vibration is zero.

[0156] t=5: Return to the case of t=1. In the case of vibration as described above, at points C and D where the sliding member 1560 is in contact, such as... Figure 16 The right end generates an elliptical motion. When the moving body is pressed into contact with the sliding member 1560, the moving body is driven by friction due to the elliptical motion. In Embodiment 3, by using the same material as Embodiment 1 for the piezoelectric element 11, the same effect as Embodiment 1 can be obtained.

[0157] [Implementation Method 4]

[0158] Embodiment 4 illustrates an example of applying a vibration wave motor 1 to a dustproof device on a camera. The same reference numerals are used for components identical to those in Embodiment 1, and their descriptions are omitted.

[0159] Figure 17 This is an explanatory diagram showing an example of the dustproof device according to Embodiment 4. The dustproof device 1700 is located near the imaging element 1701, and removes dust adhering to the optical filter 1702 by vibrating the piezoelectric element 11 to cause the optical filter 1702 to vibrate. The dustproof device 1700 of Embodiment 4 also consists of a piezoelectric element 11 and a drive device 300. The issue of voltage fluctuation caused by the driving vibration from the drive device 300 due to the value of the electrostatic capacitance Cd of the piezoelectric element 11 is the same as that of the vibrating body 10 of the vibrating wave motor 1. In Embodiment 4, by using the same material as in Embodiment 1 for the piezoelectric element 11, the same effect as in Embodiment 1 can be obtained.

[0160] Furthermore, the above embodiments are not limited to the above-described contents, and these embodiments can be combined arbitrarily. In addition, other forms conceivable within the scope of the technical concept of the above embodiments are also included within the scope of these embodiments.

[0161] Explanation of reference numerals in the attached figures

[0162] 1. Vibration wave motor, 10. Vibrating body, 11. Piezoelectric body, 12. Elastomer, 12a. Driving surface, 12f. Joint surface, 20. Moving body, 20a. Sliding surface, 30. Driving device, 110. Lens barrel, 200. Lens barrel, 210. Vibration wave motor, 211. Vibrating body, 214. Elastomer, 216a. Driving surface, 220. Moving body, 1400. Vibrating body, 1700. Dustproof device.

Claims

1. A vibrating body comprising an electromechanical conversion element, the electromechanical conversion element being a piezoelectric ceramic composed of sodium niobate / potassium niobate metal oxide, wherein the absolute value of the temperature characteristic of the relative permittivity is less than 500 ppm / ℃ in a temperature range of -40℃ to 170℃, or less than 390 ppm / ℃ in a temperature range of 0℃ to 60℃. Vibration waves are generated by the excitation of the electromechanical conversion element. The electromechanical conversion element coupled to the vibrator has a capacitance of 15% to 22% at -20°C relative to 60°C within a temperature range of -20°C to 60°C.

2. The vibrating body according to claim 1, wherein, The electromechanical conversion element is composed of the chemical formulas of the following substances: （1-C-E） (Li) A (Na) B K （1-B） ) （1―A） NbO3+ C Ba(Zr) D You （1―D） )O3+ E BiFeO3 Here, 0 <A<0.2、0.4≤B≤0.6、0<C≤0.1、0<D<1.00、0<E<0.02。 3. The vibrating body according to claim 1 or 2, wherein, Copper is added to the electromechanical conversion element.

4. The vibrating body according to claim 1 or 2, wherein, Before being coupled to the vibrator, the electromechanical conversion element has a capacitance that varies from -20°C to 60°C at a rate of 4% to 12% at -20°C relative to that at 60°C within a temperature range of -20°C to 60°C.

5. The vibrating body according to claim 1 or 2, wherein, Before being coupled to the vibrator, the electromechanical conversion element has a capacitance that varies from 0°C to 60°C at a rate of 0.5% to 3.9% at 0°C relative to that at 60°C within a temperature range of 0°C to 60°C.

6. The vibrating body according to claim 1 or 2, wherein, Before being coupled to the vibrator, the electromechanical conversion element has a capacitance that varies from -0.2% to 0.7% at 0°C to 25°C within a temperature range of 0°C to 25°C.

7. The vibrating body according to claim 1 or 2, wherein, The electromechanical conversion element coupled to the vibrator has a capacitance of 6 to 11% at 0°C relative to 60°C within a temperature range of 0°C to 60°C.

8. The vibrating body according to claim 1 or 2, wherein, The electromechanical conversion element coupled to the vibrator has a capacitance of 3% to 7% at 0°C relative to 25°C within a temperature range of 0°C to 25°C.

9. A vibration wave motor, comprising: The vibrating body according to any one of claims 1 to 8; and A relative motion component having a sliding surface that pressurizes and contacts the driving surface of the vibrating body, and the relative motion component is caused to move relative to the vibrating body by means of the vibration wave.

10. An optical device comprising: The vibration wave motor according to claim 9; and Optical elements driven by the vibration wave motor.

11. An optical device comprising: The vibrating body according to any one of claims 1 to 8; and Optical elements driven by the vibrating body.

Images