A vibration type actuator control apparatus is configured to control driving of a vibration type actuator configured to move a moving body that is one of the vibrator and a contact body that contacts a vibrator. The vibration type actuator includes the vibrator in which a vibration is excited when a two-phase drive signal having a phase difference is applied to an electro-mechanical energy conversion element. The vibration type actuator control apparatus includes a drive signal generator configured to generate the two-phase drive signal. The drive signal generator changes a phase difference of the two-phase drive signal from an initial phase difference when the moving body is moved from a stopped state. The initial phase difference is determined based on a phase difference shift indicative of a shift from a phase difference set so as to stop the moving body.

A method of driving a vibration actuator. The vibration actuator includes a vibration element including a piezoelectric element as an electromechanical energy conversion element and an elastic body which is joined to the piezoelectric element, and a driven element which is brought into pressure contact with the elastic body. Driving vibration is excited in the vibration element by applying a drive signal to the piezoelectric element, whereby the vibration element and the driven element are moved relative to each other. The driving vibration is vibration in which at least n-th-order vibration and 2n-th-order vibration are combined, n being a natural number.

An ultrasonic motor includes a vibration section having a piezoelectric element configured to generate vibration by receiving a drive voltage, a driven section, a convex section connected to the vibration section and configured to transmit vibration of the vibration section to the driven section, a drive circuit configured to generate the drive voltage, an encoder configured to detect a movement amount of the driven section, a storage section configured to store a specified voltage value, and a determination section configured to receive position information from the encoder when the driven section starts to move and a voltage value at the time of start up from the drive circuit and to determine that least one of the convex section or the driven section is worn out when the voltage value at the time of start up is larger than the specified voltage value.

A piezoelectric device drive circuit applies a drive signal to a piezoelectric device. An H-bridge circuit includes a first input terminal, a second input terminal, a first output terminal, and a second output terminal, the first output terminal and the second output terminal being connected to the piezoelectric device. A resistor is connected between the piezoelectric device and the first output terminal. A differential amplifier circuit receives, as an input, a voltage across the resistor. An inverting circuit has an input terminal connected to an output terminal of the differential amplifier circuit. A comparator has an input terminal connected to an input terminal of the inverting circuit, and an output terminal connected to the first input terminal. A comparator has an input terminal connected to an output terminal of the inverting circuit, and an output terminal connected to the second input terminal.

A vibration-type actuator that is capable of reducing an unnecessary vibration during driving. A vibration body is configured by connecting an electro-mechanical energy conversion element and an elastic body. A driven body is in pressure contact with the vibration body. A controller moves the vibration body and the driven body relatively by a vibration that is excited in the vibration body by applying driving voltage to the electro-mechanical energy conversion element so that a difference between a resonance frequency in a natural vibration mode of the vibration body that is higher than an upper limit frequency of a predetermined driving frequency range and that is nearest to the upper limit frequency and a frequency of the driving voltage is larger than a difference between a resonance frequency in a natural vibration mode used for moving the vibration body and the driven body relatively and the frequency of the driving voltage.

A control apparatus capable of improving responsiveness in a minute movement of a vibration-type actuator that has a vibration body (a piezoelectric device and an elastic body) and a driven body that pressure contact with the vibration body. A driving unit moves the driven body by causing a thrust-up vibration in a pressurizing direction and a conveyance vibration in a perpendicular direction in the vibration body by applying alternating voltages to the piezoelectric device. A control unit feedback-controls a position of the driven body by using a first operational parameter that defines an amplitude ratio of the conveyance vibration to the thrust-up vibration and a second operational parameter that defines amplitudes of the conveyance vibration and amplitude of the thrust-up vibration. A correction unit corrects a control amount of the first or second operational parameter so as to increase as the amplitude ratio decreases.

An electromechanical actuator comprises a volume comprising electromechanically active material, a set of electrodes and a single drive pad. The single drive pad protrudes in a direction parallel to the third axis. The volume of electromechanically active material has a first and second part volume situated at a first longitudinal side, along the first axis, and a third and fourth part volume are situated at a second opposite longitudinal side. The first and third part volumes are situated at a first transverse side and the second and fourth part volumes are situated oppositely. The set of electrodes is provided for allowing excitation of the part volumes independently of each other. A motor comprising such an actuator is also disclosed as well as methods for driving the actuator and motor.

A vibration motor controller controls driving velocity of a vibration motor relatively moving a vibrator and a contactor contacting the vibrator, the vibrator oscillated by an electromechanical energy transducer to which first and second frequency signals having a phase difference are applied, and includes a phase difference determiner storing a relationship between the frequency and phase difference between the first and second frequency signals, and determines the phase difference with respect to the frequency based on the relationship, and a controller controlling velocity of the vibration motor based on the frequency of the first and second frequency signals and the phase difference determined by the phase difference determiner based on the frequency. The relationship between the frequency and phase difference in the phase difference determiner does not include a relationship between frequency lower than a resonance frequency in frequency-velocity characteristics of the vibration motor, and the phase difference.

A driving circuit for a vibration type actuator includes an inductor and a capacitor which are connected in series to an electric-mechanical energy conversion element, in which, in a case where a series resonance frequency based on the inductor and the capacitor is set as fs, and a resonance frequency in a vibration mode other than vibration used for driving of the vibrator is set as fu, 0.73.Math.fu<fs<1.2.Math.fu is satisfied.

Provided is a method for calculating a scanning pattern of light and an optical scanning apparatus. The method includes the steps of: detecting a resonance frequency and an attenuation coefficient of an oscillation part of an optical fiber which guides light from a light source and irradiates an object with the light; and calculating a scanning pattern of the light, based on the detected resonance frequency and attenuation coefficient. The apparatus includes: an optical fiber which guides light from a light source and irradiates an object with the light; a scanning part which drives an oscillation part oscillatably supported of the optical fiber; a detector which detects a resonance frequency of the oscillation part; a calculation part which determines an irradiation position of the light using a scanning pattern calculated based on the resonance frequency detected by the detector and the attenuation coefficient obtained in advance.