System and method for detecting the presence and type of capacitive load that may be coupled to a power driver. The system includes a detection circuit to determine the presence and type of load based on a measured characteristic of the load in response to a drive voltage. The characteristic may be the load capacitance as measured by the current flow between the driver and load. The circuit may include a differential amplifier to generate a current-related voltage, comparators to generate pulses when the voltage exceeds respective thresholds, registers to output logic levels in response to the comparators, and a microcontroller to make the determination based on the logic levels. Alternatively, the circuit includes a differential amplifier to generate a current-related voltage, a rectifier to rectify the voltage, a peak and hold circuit to hold the peak voltage, an ADC to digitize the peak voltage, and a microcontroller to make its determination based on the digitized voltage.

A control apparatus controls driving a vibratory actuator. The control apparatus applies a signal to an electromechanical energy conversion device of a vibrator of the vibratory actuator to excite vibration on the vibrator and cause the vibrator and a driven object contacting the vibrator to move relative to one another by the vibration. If the vibratory actuator decelerates, the control apparatus changes a driving frequency of the signal to a frequency higher than a start-up frequency of the vibratory actuator and a preceding frequency at a deceleration start position. After changing the driving frequency of the signal, the control apparatus controls the signal driving frequency to perform deceleration control and fixes voltage of the signal in a deceleration period in which the vibratory actuator is decelerated.

A control device for a vibration actuator includes a detection signal acquisition section adapted to obtain an alternating-current detection signal corresponding to a vibration of the resonator body from the resonator bodies, a phase difference detection section adapted to detect a phase difference between the drive signal and the detection signal with respect to the resonator bodies, a resonator body selection section adapted to select one from the resonator bodies, and a drive signal control section adapted to adjust a frequency of the drive signal so that the phase difference in the resonator body selected comes closer to a target value.

A vibration-type driving apparatus that is capable of detecting an undesired vibration in a vibrating body more accurately than conventional detection methods even if a frequency of the undesired vibration falls inside a range of driving frequencies or is an integer multiple of a driving frequency. The driven body which is brought into contact with the vibrating body is driven by generating a driving vibration in the vibrating body through application of driving voltage to the electro-mechanical energy conversion element. An electro-mechanical energy conversion element of the vibrating body has a first sensor phase and a second sensor phase placed at different locations in the vibrating body. A vibration of the vibrating body is detected by using a result of comparison between an output signal from the first sensor phase and an output signal from the second sensor phase.

A vibration wave motor comprises a vibrator including a piezoelectric element and a vibrating body, a friction member including a first surface configured to come into contact with the vibrator, and a second surface, which is a surface on the opposite side of the first surface, the vibrator and the friction member moving relative to each other in a driving direction by a vibration generated by the vibrator, a supporting member configured to support the friction member on the second surface side; and a pressure member configured to bring the vibrator and the friction member into pressure contact with each other. A fixing portion configured to fix the friction member to the supporting member is provided in the friction member. The vibrator can move to a position where at least part of the vibrator and the fixing portion overlap each other in a pressure direction of the pressure member.

A control device controls driving of a vibration actuator that moves a vibrating body and a contacting body in contact with the vibrating body relative to each other by vibration of the vibrating body excited when a plurality of signals having a phase difference are applied to an electromechanical energy conversion element. The control device includes a first control unit that controls the phase difference between the signals to a first phase difference when the vibrating body and the contacting body do not move relatively and starts moving the vibrating body and the contacting body relatively. The first phase difference is such that the positive/negative sign of the relative position or the relative speed of the vibrating body and the contacting body immediately after the vibrating body and the contacting body start moving relatively is not opposite to the positive/negative sign of the target position or the target speed.

A vibration type driving apparatus includes a first vibrator including an electro-mechanical energy conversion element and configured to be in pressure contact with a driven member, a second vibrator including an electro-mechanical energy conversion element and configured to be in pressure contact with the driven member, and a first electric element connected in series with the second vibrator. The first vibrator is connected to a driving circuit, the second vibrator and the first electric element are connected in parallel with the first vibrator, the second vibrator is connected to the driving circuit via the first electric element, and a resonance frequency f of the first vibrator and a resonance frequency f2 of the second vibrator satisfy a relationship f1<f2.

A method for controlling an ultrasonic motor. From a starting velocity or starting position of the driven element, the method includes adjusting the frequency of the electrical excitation voltage such that it is equal to or close to the mechanical resonance frequency of the ultrasonic actuator; changing the frequency of the electrical excitation voltage using the signal of the velocity sensor or the position sensor towards the anti-resonance frequency of the ultrasonic actuator until an end velocity or an end position of the driven element is reached; and controlling the end velocity or position of the driven element with a predetermined accuracy by means of antiphase frequency change. Also disclosed is a corresponding control arrangement for an ultrasonic motor having an ultrasonic actuator with at least two acoustic wave generators, a driven element and a generator via a frequency adjustment.

The driving apparatus comprises a vibrating body which includes an electro-mechanical energy conversion device, and drives a vibration-wave motor which moves the vibrating body and a driven body relatively to each other. The electro-mechanical energy conversion device has sensor electrodes that output detecting signals corresponding to vibrations of the vibrating body. Based on the detecting signals, the driving apparatus determines a direction in which the vibrating body and the driven body are to be moved relatively to each other.

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.