A control method for reducing vibration of a second casing of a mobile terminal includes: mounting an additional vibrator in a mounting area on the second casing, and measuring vibration responses in the mounting area under first and second preset conditions; calculating system transfer functions of the additional vibrator and a driving system formed by a first casing and an exciter; providing a signal processing unit; adjusting the value of the transfer function of the signal processing unit such that a vibration response in the mounting area under a third preset condition is at zero, and calculating the value of the transfer function H3(S) of the signal processing unit; and setting H3(S) as a preset transfer function of the signal processing unit. The present disclosure can counteract the vibration of the second casing induced by the driving system, thereby improving user experience.

A vibration-type drive apparatus provided to solve the task includes a control unit that outputs a command signal, a drive unit that outputs a drive signal in accordance with the command signal, a vibrator unit in which two or more vibrators that vibrate in accordance with the drive signal are connected, a drive signal analyzing unit that analyzes the drive signal and outputs an analysis result, and a determining unit that determines whether there is a break in wiring lines respectively coupled to the vibrators in accordance with the analysis result.

A control apparatus is 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 contacts 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 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.

A vibration type actuator including vibrating elements and a contact element that is brought into contact with each other in a first direction. The vibration of the vibrating elements includes vibration in a first vibration mode in the first direction and vibration in a second vibration mode in a second direction intersecting the first direction. In the vibrating elements, a minimum value of a resonance frequency in the second vibration mode is greater than or equal to a maximum value of a resonance frequency in the first vibration mode, and a ratio of a difference between the maximum value and the minimum value of the resonance frequency in the second vibration mode to the minimum value of the resonance frequency in the second mode is less than or equal to a predetermined value.

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 display device includes a display panel, a main vibrator disposed on the display panel configured to generate a main vibration wave, and a plurality of sub-vibrators disposed on the display panel and spaced apart from the main vibrator and configured to the plurality of sub-vibrators configured to generate sub-vibration waves, respectively, wherein the plurality of sub-vibrators includes a first sub-vibrator disposed at a first distance from the main vibrator in a plan view, the first sub-vibrator being configured to generate a first sub-vibration wave; and a second sub-vibrator disposed at a second distance from the main vibrator in the plan view, the second sub-vibrator being configured to generate a second sub-vibration wave having a phase different from the first sub-vibration wave, and, wherein the second distance is different from the first distance.

A piezoelectric vibrator has a first frequency region where the phase difference between a pickup signal representing the vibration of the piezoelectric vibrator and a drive signal that drives the piezoelectric vibrator does not monotonously change in accordance with the frequency of the drive signal and a second frequency region where the phase difference monotonously changes in accordance with the frequency of the drive signal. A method for controlling a piezoelectric driving apparatus including the piezoelectric vibrator controls the frequency of the drive signal in such a way that pickup voltage representing the amplitude of the pickup signal is fixed in the first frequency region and controls the frequency of the drive signal in such a way the pickup voltage is fixed with the phase difference maintained smaller than or equal to a prespecified value in the second frequency region.

Examples are disclosed that relate to scanning mirror systems for display devices. One example provides a scanning mirror system comprising a mirror portion, a flexure arm extending from the mirror portion, and a piezoelectric actuator support portion supporting a piezoelectric actuator comprising a piezoelectric film. The scanning mirror system further comprises a transmission arm extending between the flexure arm and the piezoelectric actuator support portion to transmit motion of the piezoelectric film to the flexure arm, the transmission arm separated at least partially from the piezoelectric actuator support portion by a first gap. The scanning mirror system further comprises an anchor portion separated at least partially from the piezoelectric actuator support portion by a second gap, the anchor portion configured to anchor the scanning mirror system to another structure.

A vibration type drive device capable of maintaining stable drive performance and controllability includes a vibration type actuator comprising a vibrator and a contact body, and a drive control device. The drive control device applies two-phase alternating current voltages to the energy conversion element of the vibrator by a drive portion, converts a control amount of feedback control based on the relative position/speed into a phase difference between the two-phase alternating current voltages, and outputs the phase difference to the drive portion by using, for the relative movement, a phase difference of a first or second quadrant in a coordinate system (in a first direction) and a phase difference of a third or fourth quadrant (in a second direction), with θ representing the phase difference, SIN θ corresponding to the vertical axis, and COS θ corresponding to the horizontal axis in the coordinate system.

A vibration drive device that is capable of preventing instability when the speed control is switched between frequency control and pulse width control includes a controller that controls driving of a vibration actuator by applying an alternating voltage to an electromechanical energy conversion element. A switching pulse is generated by switching a DC voltage. A maximum duty ratio of the switching pulse is determined based on a driving condition of the vibration actuator. The driving of the vibration actuator is controlled by switching between frequency control and pulse width control. A gain for frequency control and a gain for pulse width control are set according to the maximum duty ratio so as to prevent electric power or electric current from exceeding an electric power limit or an electric current limit set in advance.