Noise produced during phase-difference changes is minimized without decreasing the responsiveness of a vibration-wave motor. A lens-side MCU for a lens barrel controls a drive apparatus that applies a drive voltage to the vibration-wave motor by outputting an A-phase drive signal and a B-phase drive signal thereto. The lens-side MCU uses, for example, a drive-voltage setting unit and a duty-cycle change unit to change the drive voltage. Also, the lens-side MCU is provided with a phase-difference change unit that changes the phase difference between the A-phase drive signal and the B-phase drive signal. When driving the vibration-wave motor, the lens-side MCU changes the drive voltage to V.sub.reg, and when the phase-difference change unit is changing the aforementioned phase difference, the drive voltage is changed to V.sub.1, V.sub.1 being greater than zero and less than V.sub.reg.

A piezoelectric material includes a metal oxide containing at least Ba, Ca, Ti, Zr, and Mn, in which the piezoelectric material has a perovskite structure, in which: x, which represents a ratio of a content (mol) of Ca to A (mol) representing a total content of Ba and Ca, falls within a range of 0.10x0.18; y, which represents a ratio of a content (mol) of Zr to B (mol) representing a total content of Ti, Zr, and Mn, falls within a range of 0.055y0.085; and z, which represents a ratio of a content (mol) of Mn to the B (mol), falls within a range of 0.003z0.012, and in which the piezoelectric material satisfies a relationship of 0(|d.sub.31(20u)d.sub.31(20d)|)/|d.sub.31(20u)|0.08, and has a value of 130 pm/V or more for each of |d.sub.31(20u)| and |d.sub.31(20d)|.

A built-in piezoelectric type online dynamic balance actuator which includes two structurally identical left and right piezoelectric drive adjustment mechanisms at two sides of a housing. The piezoelectric drive adjustment mechanism includes a shaft having one end supported inside a housing chamber by bearing, a middle portion connected to an end cover by bearing, and the other end supported on bearing housing by bearing, a weight mass coupled to the shaft and positioned inside a tightening sleeve with one side connected to the bearing housing and another side connected to the end cover and the housing, and a stator fixedly connected to one side of the end cover, a mover pressed against a surface of the stator through a disk. Through a control center, the mass weights of the left and right piezoelectric drive adjustment mechanisms are fixed to a preset angle. As the main shaft rotates at a high speed, the two weight masses generate centrifugal force which combine to a balance vector to cancel the imbalance vector of the main shaft, improve the mass distribution of the main shaft and better fit the online dynamic balance requirements.

There is provided a vibration wave motor that includes a plurality of pressing parts separated by slits and can prevent an intervention member from protruding from the slits. The vibration wave motor includes a vibrator, a driven body configured to be brought into pressure contact with the vibrator and to move relative to the vibrator, a pressing member configured to move together with the driven body and to bring the driven body into pressure contact with the vibrator, and an intervention member intervening between the driven body and the pressing member, and configured to be pressed together with the driven body when the pressing member brings the driven body into pressure contact with the vibrator. The pressing member includes a plurality of pressing parts that is separated by slits and presses the intervention member. The intervention member is firmly fixed to the driven body.

A non-contact force type micro-rotating mechanism driven by attractive/repulsive force and a manufacturing method thereof, belongs to the field of intelligent micro devices, and mainly relates to micro electromechanical system technology, precision machining technology, precision assembly and the like. The mechanism adopts the interaction force between magnetic poles to replace the connection mode of a traditional through-hole bearing pressure spring positioning shaft, so that the component part structure of the mechanism can be optimized, and the space utilization rate can be greatly improved. Moreover, the attractive force type structure also has the effect of weakening the radial vibration of the motor, and the coaxiality of the rotor and the stator is improved in the running process of the motor. Meanwhile, the rotating mechanism does not directly output shaft work, a structure can be added on the disc-shaped rotor to realize different functions, an actuator and a control object are integrated.

A control apparatus for a vibration-type actuator which improves acceleration performance and deceleration performance in driving the vibration-type actuator. The vibration-type actuator moves a vibrating body and a driven body relatively to each other. A vibration state of the vibrating body is detected based on a vibrating voltage or driving current generated in response to vibrations of the vibrating body. A relative speed of the vibrating body and the driven body is detected, and based on the detected vibration state and the detected relative speed, the vibration state of the vibrating body is controlled.

A vibration wave motor includes an element configured to be displaced by application of voltage, and an annular elastic body having a bottom surface coming into contact with the element and a drive surface having a groove, configured to drive a moving element by a vibration wave produced on the drive surface by displacement of the element. The element has a density of 4.2 to 6.010.sup.3 kg/m.sup.3. A value of [(T/B) W] is in a range of 0.84 to 1.94, where T represents a depth of the groove, B represents a distance from a bottom part of the groove to the bottom surface, and W represents a radial width of the elastic body.

A vibration actuator that is capable of reducing differences in vibration phase and vibration amplitude without rising a voltage of a drive circuit when driving a contact member using a plurality of vibrators connected in series. A vibration actuator includes a vibrator device and a contact member that moves relative to the vibrator device. The vibrator device includes transformers of which primary coils are connected in series, and vibrators that are respectively connected in parallel to secondary coils of the transformers.

A vibration actuator that is capable of reducing difference of vibration velocities when a contact member is driven using a plurality of vibrators. The vibration actuator includes a vibrator device and a contact member that moves relative to the vibrator device. The vibrator device includes a plurality of vibrators that are connected in series, and a plurality of inductors that are connected in parallel to the respective vibrators.

A method of manufacturing 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 an elastic member and a hollow protrusion having a side wall portion protruding with respect to a surface of the elastic member, a contact portion configured to come into contact with a body, and a first connection portion connecting the side wall portion and the contact portion, the method includes, forming the hollow protrusion including the side wall portion and a distal end portion by performing drawing on an elastic plate and forming the contact portion and the first connection portion by performing drawing or squeezing on the distal end portion, wherein the contact portion is surrounded by the first connection portion.