Abstract: An actuator assembly including a slider configured to be slidable along a sliding direction; and a driving force applying unit comprising a plurality of contact portions disposed to be spaced apart from each other in a direction crossing the sliding direction of the slider and for applying force to the slider by vibrating the contact portions. An optical system including a lens assembly comprising a lens unit comprising at least one lens and a moveable lens frame supporting the lens unit; and an actuator assembly as disclosed above. A driving force applying unit including a plurality of contact portions configured to contact the base plate and disposed in the slider to be spaced apart from each other in a direction crossing the sliding direction and configured to apply force to the base plate by vibrating the contact portions.

Abstract: An ultrasonic actuator (2) includes an actuator body (4) which performs a longitudinal vibration and a bending vibration, and a driver element (8a, 8b) which is provided on one of side surfaces of the actuator body (4) which is a mounting surface (40a), and performs an orbital motion in accordance with the vibrations of the actuator body (4) to output a driving force. The driver element (8a, 8b) includes a first driver element (8a) and a second driver element (8b) which are provided on the mounting surface (40a) at different positions in a longitudinal direction of the actuator body (4). The first driver element (8a) and the second driver element (8b) are located at different positions in a thickness direction of the actuator body (4).

Abstract: A vibration wave driven apparatus includes a vibrator configured to generate vibration, a rotor configured to be in frictional contact with the vibrator and to rotate about an axis of rotation, and a transmitting member configured to rotate about the axis and to transmit rotation of the rotor to an external component. A part of the transmitting member forms a worm portion of a worm gear.

Abstract: A piezoelectric actuator mechanism including: a screw-driven feeding mechanism that has a feed screw (11) and a feed screw nut (14); a disc-shaped rotor (17) mounted on the rear-end face of the feed screw nut (14); an ultrasonic motor (18) having a piezoelectric vibrator (19) that comes in contact with the circumference face of the rotor (17); and a driven mounting portion that is pressed against the leading end of the feed screw 11 by spring force, and displaced and positioned by the feeding operation of the feed screw. The driven mounting portion can be made to be a mirror holder (1) for use in an optical system, or a movable table (21) of a linear stage.

Abstract: An ultrasonic motor includes a vibrator, a mobile unit, a holding mechanism, and a pressing mechanism. The vibrator generates elliptical vibration by degenerating different vibration modes and having a phase difference between the different vibration modes. The mobile unit is configured to be movable relative to the vibrator. The holding mechanism holds and fixes the vibrator in a direction substantially parallel to the direction of the relative movement of the mobile unit. The pressing mechanism presses the vibrator against the mobile unit. The holding mechanism includes an adjustment unit for adjusting the resonant frequencies of the different vibration modes of the vibrator to substantially match each other when the ultrasonic motor is driven.

Abstract: An elliptical vibration is generated by combining a longitudinal primary resonance vibration of the vibrator resulting from an expansion and a contraction of the vibrator in a direction of the central axis and a torsional resonance vibration resulting from twisting of the vibrator around the central axis as a torsional axis. The dimension ratio of the rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration resulting from the expansion and the contraction of the vibrator in the direction of the central axis and a resonance frequency of the torsional resonance vibrations resulting from twisting of the vibrator around the central axis as the torsional axis match. The ultrasonic motor further includes a vibration detecting electrode layer.

Abstract: A vibration wave driving apparatus capable of matching the vibration direction of a projecting portion of a vibrator to the displacement direction of a contacting portion of a driven body so that the projecting portion of the vibrator and the contacting portion of the driven body can be brought into contact and driven with stability is provided.

Abstract: In an ultrasonic motor, an elliptical vibration is generated by combining a longitudinal primary resonance vibration resulting from an expansion and a contraction of a vibrator in a direction of a central axis and a torsional secondary resonance vibration or a torsional tertiary resonance vibration resulting from twisting of a rotation axis. A dimension ratio of a rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration and a resonance frequency of the torsional secondary resonance vibration or the torsional tertiary resonance vibration match. The vibrator includes a plurality of regions in a surface orthogonal to the central axis, and deformations of the regions adjacent to each other along the direction of the central axis are mutually different. The vibrator expands and contracts in a direction along a polarization direction thereof.

Abstract: In an ultrasonic motor, an elliptical vibration is generated by combining a longitudinal primary resonance vibration resulting from an expansion and a contraction of the vibrator in a direction of the central axis and a torsional secondary resonance vibration or a torsional tertiary resonance vibration resulting from twisting of a rotation axis, and the dimension ratio of the rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration, resulting from the expansion and the contraction of the vibrator in the direction of the central axis and a resonance frequency of the torsional secondary resonance vibration or the torsional tertiary resonance vibration resulting from twisting of the rotation axis match. The vibrator includes a torsional piezoelectric body that generates a thickness shear vibration, and that is arranged at an anti-node position of the torsional secondary resonance vibration or the torsional tertiary resonance vibration.

Abstract: A piezoelectric device includes a piezoresonator body (3) having opposing first and second surfaces and opposing third and fourth surfaces. The device also includes at least one common electrode (8) disposed on the second surface (15) and electrodes (4a, 4b) disposed on the first surface (14) in pairs along a first longitudinal axis. The device further includes contact elements (5) disposed on the third (16) and the fourth (17) surfaces at contact locations along the first longitudinal axis and aligned between each pair of excitation electrodes. In the device, the piezoelectric body has a first order natural resonance frequency (?1) along a second longitudinal axis and an even order natural resonance frequency (?2) along the first longitudinal axis, where a percent difference between ?1 and ?2 is greater than 0% and less than or equal to 20%.

Abstract: A friction drive actuator, comprising: a vibration member which is configured to be driven to vibrate by expansion and contraction of a piezoelectric displacement portion which is included in the vibration member and driven by a driving signal; a sliding member which is in contact with the vibration member and is driven by the vibration member in a first direction with respect to the vibration member; a pressing member which causes the vibration member and the sliding member to come into a pressure contact therebetween; and a control member which is provided on each of the vibration member and the sliding member at a contact portion therebetween for controlling a relative movement of the sliding member with respect to the vibration member in a direction perpendicular to the first direction when the vibration member and the sliding member are pressedly contacted with each other by the pressing member.

Abstract: In an ultrasonic motor, an elliptical vibration is generated by combining a longitudinal primary resonance vibration resulting from an expansion and a contraction of a vibrator in a direction of a central axis and a torsional secondary resonance vibration or a torsional tertiary resonance vibration resulting from twisting around the central axis. A dimension ratio of a rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration and a resonance frequency of the torsional secondary resonance vibration or the torsional tertiary resonance vibration match. The vibrator includes a plurality of regions in a surface orthogonal to the central axis, and deformations of the regions adjacent to each other along the direction of the central axis are mutually different. The vibrator expands and contracts in a direction orthogonal to a polarization direction thereof.

Abstract: Elliptical vibrations are generated by combining longitudinal primary resonance vibrations resulting from expansion and contraction of a vibrator in a direction of a central axis and torsional secondary resonance vibrations or torsional tertiary resonance vibrations resulting from twisting of the vibrator around the central axis. A dimension ratio of a rectangle of the vibrator is set such that a resonance frequency of the longitudinal primary resonance vibrations and a resonance frequency of the torsional secondary resonance vibrations or the torsional tertiary resonance vibrations almost match. The vibrator includes a plurality of piezoelectric sheets. The longitudinal primary resonance vibrations and the torsional secondary resonance vibrations or the torsional tertiary resonance vibrations are generated because of formation of activation regions by polarization in a thickness direction of the piezoelectric sheets.

Abstract: An ultrasonic actuator includes an actuator body; and driver elements for outputting drive force, which are provided to the actuator body. The ultrasonic actuator further includes a holder which is provided to the actuator body, and which protrudes outwardly beyond principal surfaces in a direction crossing the principal surfaces of the actuator body; two supports for supporting the holder; contact rubber blocks limiting displacement of the actuator body by contacting the principal surfaces of the actuator body. The actuator body is biased toward a movable body side. A long hole extending in a biasing direction of the actuator body and into which the holder is fitted is formed in the support. At least two contact rubber blocks contact the principal surfaces of the actuator body at different positions in a longitudinal direction of the actuator body.

Abstract: An oscillator includes an electromechanical energy conversion element and an elastic body. The elastic body is bonded with the electromechanical energy conversion element by metallic bonding and is configured to be driven by deformation of the electromechanical energy conversion element.

Abstract: Provided is a vibration wave driving apparatus which can restrain increases in the number of components and in necessary space and which can maintain a stable contact state of frictional surfaces of a vibrator and a driven body.

Abstract: An ultrasonic actuator (2) includes an actuator body (4) which performs a longitudinal vibration and a bending vibration, and a driver element (8a, 8b) which is provided on one of side surfaces of the actuator body (4) which is a mounting surface (40a), and performs an orbital motion in accordance with the vibrations of the actuator body (4) to output a driving force. The driver element (8a, 8b) includes a first driver element (8a) and a second driver element (8b) which are provided on the mounting surface (40a) at different positions in a longitudinal direction of the actuator body (4). The first driver element (8a) and the second driver element (8b) are located at different positions in a thickness direction of the actuator body (4).

Abstract: The drive efficiency of a vibratory actuator is improved without increasing a weight of a driver element. An ultrasonic actuator (2) includes an actuator body (4) for generating longitudinal vibration and bending vibration, and driver elements (8), provided on a mounting surface (40a) which is one of side surfaces of the actuator body (4), for making an orbit motion according to the vibrations of the actuator body (4) to output driving force. In the driver element (8), a through hole (80) is provided.

Abstract: An oscillator holding mechanism capable of generating a stable vibration in an oscillator and an oscillation motor having the oscillator holding mechanism are disclosed. The oscillator holding mechanism present within an oscillation motor includes an oscillator that has a protruding output section on one end that generates a predetermined movement in the output section by vibration, a holding member that holds and accommodates the oscillator, and a buffer member that is made of an elastic material and is provided between the oscillator and the holding member. The buffer member has a first surface in contact with the holding member having a larger area than a second surface in contact with the oscillator and a cross sectional shape including a center axis that connects a center point of the first surface and a center point of the second surface that is axisymmetric with respect to the center axis.

Abstract: Disclosed herein is a piezoelectric actuator. According to the present invention, the manufacturing cost of the piezoelectric actuator can be reduced by simplifying the patterns of electrodes constituting the piezoelectric actuator, the piezoelectric actuator itself or an electronic product employing the piezoelectric actuator can be made smaller by using only planar simple translational movement of the piezoelectric actuator, and the piezoelectric actuator capable of independently performing linear translational movement in two directions on the plane can be provided.

Abstract: A microstepper motor which comprises two electromechanical drive elements, especially piezoelectric bending actuators, having effective directions that are perpendicular to each other, These actuators act upon a drive ring to thereby rotate a shaft. The actuators are non-radially hinged to the drive ring via an approximately square shear-flexible and torsion-proof frame structure, the drive ring being arranged inside said frame. The drive according to the invention is compact, the frame and the drive ring being configured as a single injection-molded drive module.

Abstract: Tubular linear piezoelectric motor (100, 300), and a method for exciting a tubular piezoelectric resonator (101, 301) used in such motor. The motor is comprised of a resonator (101, 301) formed of a cylindrical tube. The tube has length nL comprised of a piezoelectric material, where L is some length, and n is an even numbered integer, greater than zero. The piezoelectric material of the cylindrical tube is polarized in a radial direction, perpendicular at each point to the interior and exterior surface of the cylindrical tube. The resonator is excited with one signal having a single exciter frequency applied across an inner electrode (102, 302) and one or more first outer electrodes (103, 103a, 103b). The single exciter frequency is selected to move a contact site of one or more annular protrusions along an elliptical path when the resonator is excited.

Abstract: A piezoelectric motor includes a piezoresonator body (3) having opposing front and back surfaces and opposing first and second end surfaces. The front (17) and the back (18) surfaces are substantially parallel to first (15) and second (16) longitudinal axes of the piezoresonator body. The end surfaces (2) are substantially perpendicular to the first longitudinal axis and substantially parallel to the second longitudinal axis and are separated by a length (L) of the piezoresonator body. The motor also includes at least one common electrode (6) disposed on the back surface and at least 6n excitation electrodes (7-12) disposed across the front surface in two symmetric rows extending along L, where n is an integer ?1. In the motor, the piezoelectric body has an nth order longitudinal vibration frequency (?1) along L and a 3nth order bending vibration frequency (?2) along L, and where ?1 and ?2 are substantially equal.

Abstract: A vibratory actuator is provided in which a movable body can be stably driven even when a groove is formed in an abutment body by the friction between the driver element and the abutment body. An ultrasonic actuator (2) includes an actuator body (4) which performs a longitudinal vibration and a bending vibration, and a driver element (8a, 8b) which is provided on one of side surfaces of the actuator body (4) which is a mounting surface (40a), and performs an orbital motion in accordance with the vibrations of the actuator body (4) to output a driving force. The driver element (8a, 8b) includes a first driver element (8a) and a second driver element (8b) which are provided on the mounting surface (40a) at different positions in a longitudinal direction of the actuator body (4). The first driver element (8a) and the second driver element (8b) are located at different positions in a thickness direction of the actuator body (4).

Abstract: An electromechanical motor includes an actuator assembly and a body to be driven in a driving direction. The actuator assembly has an actuator backing, a first actuator and a second actuator. The actuators are mechanically attached by a respective single attachment to the actuator backing at a first end of the actuators. The actuators have a respective interaction portion constituting a second end opposite to the first end in an actuator direction transverse to the driving direction. The interaction portions are arranged for interaction with an interaction surface of the body by a respective contact area. The actuators include a respective unimorph member arranged for causing a movement of the respective contact area as a response of a respective electrical signal. The respective movements are transverse to the actuator direction, to the driving direction, and to each other.

Abstract: An ultrasonic motor includes a transducer configured to be assembled as one unit by a piezoelectric device, a holding member, and a friction contact member, a hollow rotor configured to contact the friction contact member, a first driving force transmitting member, a press member and a support mechanism. The support mechanism includes a second driving force transmitting member, a transmission shaft bearing having an inner ring in which the second driving force transmitting member is fitted, and a bearing support member configured to be disposed in the upper surface of the case member, the bearing support member supporting the transmission shaft bearing so that the second driving force transmitting member is drivable together with the first driving force transmitting member and so that the transmission shaft bearing is drivable.

Abstract: An ultrasonic motor includes a transducer configured to be assembled as one unit by a piezoelectric device, a holding member, and a friction contact member, a hollow rotor configured to contact the friction contact member, the rotor rotating around a shaft in a direction perpendicular to a plane direction of a elliptical vibration generating surface when a driving force is transmitted to the rotor from the friction contact member, a driving force transmitting member configured to be adhesively fixed to the rotor and which rotates together with the rotor, a case member configured to have a positioning groove to position the transducer and configured to house the transducer, and a press member configured to press the transducer housed in the case member toward the rotor. The holding member comes into line contact or point contact with the positioning groove when the case member houses the transducer.

Abstract: In an ultrasonic motor, an elliptical vibration is generated by combining a longitudinal primary resonance vibration, resulting from an expansion and a contraction of a vibrator in a direction of a central axis, and a torsional secondary resonance vibration or a torsional tertiary resonance vibration resulting from twisting of the vibrator about the central axis. A dimension ratio of a rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration, resulting from the expansion and the contraction of the vibrator in the direction of the central axis, and a resonance frequency of the torsional secondary resonance vibration or the torsional tertiary resonance vibration, resulting from twisting of the vibrator about rotation axis, substantially match.

Abstract: According to one embodiment, a transducer includes, a first transducer member, a second transducer member, and a coupling member. The first transducer member including a piezoelectric element in which longitudinal vibration and bending vibration are excited by application of a predetermined alternating signal. The second transducer member which is placed to make a predetermined angle with the first transducer member and in which longitudinal vibration and bending vibration are excited by application of a predetermined alternating signal. The coupling member configured to hold one end of the first transducer member and one end of the second transducer member.

Abstract: An anti-vibration unit has: an X-axis transducer generating elliptical vibration in drivers; a frame which is a fixing member having a holding portion for holding the X-axis transducer; an X frame having fixed thereto a slide element to which the drivers of the X-axis transducer are pressed and which moves in the X-axis direction with respect to the frame; a Y-axis transducer held by a holding portion provided in the X-frame and generating elliptical vibration in drivers; and a Y frame having fixed thereto a slide element to which the drivers of the Y-axis transducer are pressed and which moves in the Y-axis direction with respect to the X frame. The X-axis transducer and the Y-axis transducer have substantially same resonant frequency, and the slide elements differ in at least one of rigidity and density thereof, thereby providing a drive apparatus down-sized, large in driving force and high in efficiency.

Abstract: An ultrasonic motor drive apparatus comprises a piezoelectric element 107 having a plurality of piezoelectrically active regions, in which longitudinal vibration and flexural vibration are induced with application of alternate signals to the plurality of piezoelectrically active regions, a piezoelectric element holder 108 that is fixedly attached to the piezoelectric element, covering the neighborhood of a common node of the longitudinal vibration and the flexural vibration induced in the piezoelectric element all along the circumference of the central portion of the piezoelectric element with respect to the longitudinal direction, a vibrator holder 103 having a plurality of openings, a driven member 104 having a substantially spherical shape, an output shaft 106 attached to the driven member, through which power output of the driven member is transmitted, a pressing member 102 that brings the driven member 104 and the piezoelectric member into pressure contact with each other along the third direction, a cap

Abstract: A vibration-type driving apparatus including: a vibrator holder wherein a plurality of vibrators each having at least an electro-mechanical energy conversion element and a elastic member having a contact portion formed therein are connected to a vibrator holding member, for generating an ellipsoidal movement of the contact portion, to move, relative to the vibrator, a driving member contacting the contact portion, wherein the plurality of vibrators are connected to a surface of the holding member at a side at which the contact portion contacts the driving member, and on a surface of the vibrator holding member opposite to the side at which the contact portion contacts the driving member, a pressing member is placed to set the contact portion to be pressed and contacted to the driving member.

Abstract: A vibration-type driving device according to the present invention includes a plurality of vibrators in which contact portions perform an elliptical motion using a combination of vibrations in different vibration modes; and a driven object having contact regions that come into contact with the contact portions and move relative to the plurality of vibrators, wherein the contact regions for the individual vibrators differ in position so as not to overlap.

Abstract: Provided is a vibration wave actuator including: a vibrator including at least an electro-mechanical energy conversion element and an elastic body to which the electro-mechanical energy conversion element is joined, the elastic body including a contact portion formed therein, the vibrator being configured to provide elliptic motion to the contact portion; and a driven element that is in pressure contact with the contact portion of the vibrator, the driven element being moved by the elliptic motion, wherein the vibration wave actuator includes a vibrator holding portion that holds the vibrator via a first elastic member having a stiffness lower than that of the vibrator; and wherein a magnet is arranged on the vibrator holding portion, the driven element includes a magnetic substance, and the contact portion of the vibrator and the driven element are brought into pressure contact with each other by an attraction force of the magnet.

Abstract: An ultrasonic motor includes a driven object, a piezoelectric element for driving the driven object, a vibration plate including a notch having an inner peripheral surface of an arc-shaped form having a central angle larger than 180 degrees and being vibrated by the piezoelectric element, and a contact portion made of a material different from that of the vibration plate, having a portion overlapping the piezoelectric element in a plan view and being smaller in thickness than the piezoelectric element, attached to the notch of the vibration plate by press fitting or forced fitting and being in contact with the driven object. Thereby, the ultrasonic motor can have a high shock resistance and a high wear resistance, and can be driven with high efficiency.

Abstract: An ultrasonic motor and a manufacturing method thereof are provided. The ultrasonic motor includes an active layered section including a piezoelectric material; an inactive section disposed below the active layered section, which has a contact portion profile as a lowest layer; a first lower layer positioned one layer below an uppermost layer of the active layered section; a second lower layer formed with separated electrodes in an upper surface thereof and positioned two layers below the uppermost layer; and a repeated structure in the active layered section having a same structure as a combination structure comprising the first lower layer and the second lower layer, the repeated structure being downwardly layered from the combination structure.

Abstract: A vibration type actuator providing a satisfactory actuator performance even when an increase in speed is achieved and having a contact spring. The actuator includes a vibrator equipped with an electrical-mechanical energy conversion element, an elastic member to which the electrical-mechanical energy conversion element is fixed, and a protrusion provided on the elastic member. The vibrator can generate an elliptic movement in the protrusion. A driven body is configured to come into contact with the protrusion and to make a relative movement with respect to the vibrator. The protrusion includes a contact portion having a contact surface contacting the driven body, a continuous side wall portion protruding with respect to one end surface of the elastic member and forming a hollow structure, and a connection portion connecting the contact portion and the side wall portion and exhibiting flexibility in a direction normal to the contact surface.

Abstract: A vibration type driving apparatus is provided, in which a plurality of vibration members include rotation units that are formed so as to be rotatable around respective rotation axes that are parallel to respective directions of forces generated by elliptical movements; in which any vibration member that is positioned in a range where an angle between a direction of movement of a moving member and the corresponding rotation axis is greater than a predetermined angle is tilted by the rotation unit, and vibration mode for push-up moving is generated at the any vibration member; and in which the elliptical movement of any vibration member that is positioned in a range where the angle is less than the predetermined angle causes the moving member to move.

Abstract: A vibrator which constitutes a vibrating device of a vibration-type driving apparatus which comprises the vibrating device bonded to an electromechanical-energy-conversion element and comprising the vibrator having a projection portion, in which the vibrating device is constituted so that elliptic motion can arise at the projection portion by applying an alternating electric field to the electromechanical-energy-conversion element, and which moves by the elliptic motion a driven object being in contact with the projection portion in a direction intersecting with a width direction, wherein the vibrator comprises a base and the one/plural projection portions, the projection portion has at least two wall portions extending in a base out-of-plane direction and a contact portion having a contact surface with the driven object, and the contact surface connects the wall portions, and in boundary portions between the base and the wall portions, displacement directions are at a same position in a normal direction.

Abstract: A linear drive ultrasonic motor includes at least an ultrasonic vibrator having a piezoelectric element, a driven member which is driven by a frictional force between the driven member and the ultrasonic vibrator, a pressing member which presses the ultrasonic vibrator such that a frictional force is generated between the ultrasonic vibrator and the driven member, a guiding mechanism which movably supports the driven member, and a case member which accommodates the ultrasonic vibrator, the pressing member, and the guiding means. The case member includes a first opening portion for making the driven member pass through, and a second opening portion which opens in a direction different from a direction in which the first opening portion opens and a direction of pressing by the pressing member.

Abstract: The present invention relates to a piezoelectric linear motor that can make relatively low abrasion and accurate linear movement since stationary AC voltages are applied to two piezoelectric elements with a phase difference. The present invention provides a piezoelectric linear motor, comprising: a piezoelectric substrate having a first piezoelectric element and a second piezoelectric element, wherein AC voltages are applied to the first and second piezoelectric elements with a phase difference; a metallic elastic body having first and second elastic bodies coupled to the piezoelectric elements and a central protrusion protruded at the central portion connecting the first and second elastic bodies, wherein the central protrusion oscillates elliptically during an application of the voltage; and a mover brought into contact with the central protrusion of the metallic elastic body for a linear movement, and wherein the movement of the mover is orthogonal to the central protrusion.

Abstract: A drive unit which generates less heat may be provided. The drive unit includes a piezoelectric element (P1) having a piezoelectric layer (1), a drive power supply (14) configured to apply a driving voltage at a predetermined frequency to the piezoelectric element (P1) such that vibration including stretching vibration and bending vibration is generated in the piezoelectric element (P1), and a movable element (9) which is movable relative to the piezoelectric element (P1) according to the vibration of the piezoelectric element (P1). The difference between the resonance frequency of the bending vibration of the piezoelectric element (P1) and the anti-resonance frequency of the stretching vibration of the piezoelectric element (P1) is smaller than the difference between the resonance frequency of the bending vibration of the piezoelectric element (P1) and the resonance frequency of the stretching vibration of the piezoelectric element (P1).

Abstract: An elliptical vibration is generated by combining a longitudinal primary resonance vibration of the vibrator resulting from an expansion and a contraction of the vibrator in a direction of the central axis and a torsional resonance vibration resulting from twisting of the vibrator around the central axis as a torsional axis. The dimension ratio of the rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration resulting from the expansion and the contraction of the vibrator in the direction of the central axis and a resonance frequency of the torsional resonance vibrations resulting from twisting of the vibrator around the central axis as the torsional axis match. The ultrasonic motor further includes a vibration detecting electrode layer.

Abstract: An ultrasonic actuator may be provided in which generation of a stress is prevented in the connection face of the piezoelectric element between the electrodes and the conductive members. The ultrasonic actuator includes a piezoelectric element (P1) and flexible cables (F1). The piezoelectric element (P1) includes: a piezoelectric layer (1); a power supply electrode (2) provided on a principal surface of the piezoelectric layer (1); a counter electrode (3) provided to face the power supply electrode (2) with the piezoelectric layer (1) interposed therebetween; a power supply external electrode (4) which is provided on a short-side surface of the piezoelectric element (P1), and is electrically coupled to the power supply electrode (2); and a counter external electrode (5) which is provided on a short-side surface of the piezoelectric element (P1), and is electrically coupled to the counter electrode (3).

Abstract: An optical system includes a housing, a lens assembly, and a piezoelectric actuator assembly. The lens assembly includes a lens unit having at least one lens, and a lens frame that supports the lens unit and moves in the housing. The piezoelectric actuator assembly includes a base plate coupled to the housing, an elastic plate coupled to the base plate and including a protrusion protruding from a first surface of the elastic plate, a piezoelectric element coupled to a second surface of the elastic plate wherein the piezoelectric element vibrates when receiving electricity and transmits the vibration to the elastic plate, and a moving portion that supports the lens frame. The moving portion has a first end supported by the protrusion of the elastic plate and a second end slidably coupled to the base plate.

Abstract: An ultrasonic motor is configured as follows. Namely, the ultrasonic motor includes an oscillator which is configured to has a shape that conforms a resonant frequency of longitudinal oscillation exited in the oscillator to a resonant frequency of torsional oscillation, a driven body that comes into contact with an elliptic oscillation generation surface of the oscillator and is driven by the elliptic oscillation, and a pressing mechanism unit that welds the elliptic oscillation generation surface of the oscillator to the driven body by pressing, wherein the oscillator has a first polarization unit that is formed in a region associated with a node portion of the longitudinal oscillation and configured to excite the longitudinal oscillation in the oscillator, and a second polarization unit that is formed in a region associated with a ventral portion of the torsional oscillation and configured to excite the torsional oscillation in the oscillator.

Abstract: In an ultrasonic motor, an elliptical vibration is generated by combining a longitudinal primary resonance vibration resulting from an expansion and a contraction of a vibrator in a direction of a central axis and a torsional secondary resonance vibration or a torsional tertiary resonance vibration resulting from twisting around the central axis. A dimension ratio of a rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration and a resonance frequency of the torsional secondary resonance vibration or the torsional tertiary resonance vibration match. The vibrator includes a plurality of regions in a surface orthogonal to the central axis, and deformations of the regions adjacent to each other along the direction of the central axis are mutually different. The vibrator expands and contracts in a direction orthogonal to a polarization direction thereof.

Abstract: An ultrasonic motor is configured as follows. Namely, the ultrasonic motor includes an oscillator whose cross section vertical to a central axis has a rectangular shape which has a predetermined length ratio of a narrow side and a wide side, wherein the oscillator comprises driving electrodes and oscillation detecting electrodes near a node portion of the longitudinal oscillation and near ventral portions of the torsional oscillation, an external electrode achieving electrical conduction with the driving electrodes and an external electrode associated with one polarity of an external electrode achieving the electrical conduction with the oscillation detecting electrodes are formed on a first surface of outer surfaces of the oscillator, and an external electrode associated with the other polarity of the external electrode achieving the electrical conduction with the oscillation detection electrodes is formed on a second surface different from the first surface of the outer surfaces of the oscillator.

Abstract: In an ultrasonic motor, an elliptical vibration is generated by combining a longitudinal primary resonance vibration resulting from an expansion and a contraction of a vibrator in a direction of a central axis and a torsional secondary resonance vibration or a torsional tertiary resonance vibration resulting from twisting of a rotation axis. A dimension ratio of a rectangle of the vibrator is chosen such that a resonance frequency of the longitudinal primary resonance vibration and a resonance frequency of the torsional secondary resonance vibration or the torsional tertiary resonance vibration match. The vibrator includes a plurality of regions in a surface orthogonal to the central axis, and deformations of the regions adjacent to each other along the direction of the central axis are mutually different. The vibrator expands and contracts in a direction along a polarization direction thereof.

Abstract: A piezoelectric actuator has a piezoelectric element adapted to simultaneously generate first and second vibration modes in response to a voltage applied thereto. The piezoelectric element has one outer surface including a first region and a second region projecting from the first region, while the second region comes into contact with a body to be driven, so as to cause a frictional force with the body to be driven. Without restricting the size of the piezoelectric element, the piezoelectric actuator inhibits its driving state from fluctuating.