The disclosure relates to an ultrasonic actuator formed of a plate having a base, a cover surface which is geometrically similar to the base, and a lateral surface which interconnects the base and the cover surface, wherein the plate includes an electromagnetic material. Electrodes for inciting periodic deformations of the plate are arranged on the base of the plate and on the cover surface of the plate opposite the base. The base includes at least two faces which are arranged in parallel with one another and form contact portions of the lateral surface, and the two faces of the base arranged in parallel with one another, together with connecting lines which interconnect the respective end points of the faces arranged in parallel, form a parallelogram inscribed in the base, in which parallelogram an angle different from 90° is enclosed between adjacent faces. A motor having such an ultrasonic actuator is also disclosed.

A method of manufacturing a piezoelectric actuator includes preparing a laminate including a substrate, a first electrode layer disposed on the substrate, a piezoelectric layer disposed on the first electrode layer, and a second electrode layer disposed on the piezoelectric layer, and forming a contour shape of the piezoelectric layer. The forming of the contour shape includes dry etching the piezoelectric layer from the second electrode layer side to dig the piezoelectric layer halfway in a thickness direction, covering, with a resist film, a dry etched surface formed on a side surface of the piezoelectric layer by the dry etching, and wet etching the piezoelectric layer from the second electrode layer side to dig the piezoelectric layer until the first electrode layer is reached.

A piezoelectric driving device includes a substrate, a plurality of piezoelectric elements disposed on the substrate, a first groove section provided between the plurality of piezoelectric elements, and a first wire provided in at least a part of a side surface and a bottom section of the first groove section.

A piezoelectric stepper drive includes a piezoelectric drive apparatus with at least two drive sections, each acted upon by at least two piezoelectric actuators, and a driven member which is advanced by at least one of the drive sections when control voltages are applied to the actuators. The drive apparatus is configured approximately in the shape of a triangle, at the tip of which the drive sections are arranged. At least one of the drive sections is biased against the driven member, in the absence of control voltages applied to the actuators, such that the drive section blocks advance of the driven member, where each of the drive sections is mounted individually resilient relative to a base of the triangle.

A vibration wave motor has a vibrator vibrating by a drive voltage to be applied, a flexible printed circuit board supplying the drive voltage to the vibrator, a contact member with which a pressure contact portion formed in the vibrator is brought into pressure contact, and a pressurizing section pressurizing the vibrator against the contact member, in which the vibrator and the contact member move relative to each other, and the flexible printed circuit board extends along the relative movement direction from a side portion of the vibrator and further extends so as to surround the vibrator.

An ultrasonic motor, is disclosed having an ultrasonic actuator in the form of a rectangular piezo-electric plate, which has two generators for acoustic standing waves and on which at least two friction elements are arranged, an element to be driven, and an electric excitation device. The piezoelectric plate of the actuator is divided into two pairs of diagonally oppositely disposed sections by two virtual planes which extend perpendicularly to each other and which extend through the center line of the main surfaces of the actuator, wherein each of the generators includes two parts which can be operated in an antiphase manner and each of which is arranged in a diagonal section of the piezoelectric plate, and the friction elements are arranged on one or two end faces of the piezoelectric plate.

A vibration-wave motor includes a vibrator, a first holding member configured to hold the vibrator, a second holding member configured to hold the first holding member, a plurality of pressing members arranged around the vibrator and configured to press the vibrator against a contacting member that contacts the vibrator, a movable plate disposed opposite to the vibrator with respect to the contacting member, and a coupling part configured to couple the second holding member and the movable plate with each other. The vibrator and the contacting member move relatively to each other due to a vibration generated by the vibrator. One of the second holding member and the movable plate includes a transmitting part configured to transmit a driving force of the vibration-wave motor to a driven member.

A piezoelectric drive device includes a piezoelectric element, a vibrating plate with a concave portion provided in a side surface, and a projecting portion provided between two side surfaces of the concave portion and having a spherical shape, an elliptical shape, or an egg shape, wherein a plurality of the piezoelectric elements and a plurality of the vibrating plates are stacked, and the concave portion includes a bottom surface.

A control method for a piezoelectric drive device includes a first step of executing first control to decrease a frequency of a drive voltage applied to a piezoelectric vibrator from a predetermined first frequency while acquiring a pickup voltage representing vibration amplitude of the piezoelectric vibrator, and a second step of executing second control to increase the frequency of the drive voltage applied to the piezoelectric vibrator to a second frequency as a frequency of the drive voltage applied before a second time when the pickup voltage is higher from a first time to the second time and the pickup voltage is lower from the second time to a third time.

A piezoelectric drive device includes first and second piezoelectric vibration modules pressed toward a driven portion and including a vibration portion and a transmission portion abutting the driven portion and transmitting vibration to the driven portion and a controller. A pressing force of the second module to the driven portion is greater than that of the first module. The controller drives the second module so that the transmission portion of the second module performs longitudinal vibration vibrating in the pressing direction while driving the first module so that the transmission portion of the first module performs bending vibration that is a composite of longitudinal vibration in a pressing direction and lateral vibration intersecting the pressing direction.