Abstract: A long-life ultrasonic motor is provided which increases the output and efficiency and reduces the wear on a moving body. By mounting such an ultrasonic motor on an electronic apparatus, the electronic apparatus is improved in performances including the size-reduction, thickness-reduction, power saving, etc. By configuring a stable self-excited oscillation circuit between first and third electrodes of a piezoelectric element and applying a drive signal to a second electrode through a phase selection circuit for changing the phase of a self-excited oscillation signal, two signals different in phase are supplied to the ultrasonic motor while using the self-excited oscillation circuit.

Abstract: An ultrasonic motor includes an oscillation drive circuit for generating an oscillation wave by self-excited oscillation of an oscillator bonded with a piezoelectric element, and a start/stop signal generating circuit for generating a signal for controlling the starting and stopping of the ultrasonic motor by bringing the oscillation drive circuit into an active state and a stop state, respectively. The oscillation drive circuit includes a power amplifier for amplifying an excitation signal, a capacitive circuit for adjusting a frequency of the excitation signal, and a switching circuit connected to a capacitive element of the capacitive circuit for short-circuiting terminals of the capacitive element based on an output signal of the start/stop signal generating circuit.

Abstract: A sound signal from an audio amplifier is converted to a speed signal by a drive circuit, and a cone sheet which forms a diaphragm is driven by a supersonic wave motor driven by a travelling vibration wave through a link and a leaf spring.

Abstract: A compact ultrasonic motor is made easy to assemble and replace in an electronic apparatus by providing various electronic circuit components on a connector formed integrally with the ultrasonic motor. In one embodiment, a piezoelectric element is in contact with a vibrating body for undergoing vibration along with expansion-and-contraction movement of the piezoelectric element. A moving member is in contact with the vibrating body for undergoing movement in a desired direction in response to vibration of the vibrating body. A support member supports the piezoelectric element, the vibrating body, the moving member, along with a driving circuit for driving the ultrasonic motor and a connector for connecting the piezoelectric element to the driving circuit. The driving circuit is an AC signal generating circuit for supplying an AC signal to the piezoelectric element and a phase adjusting device for adjusting phase characteristics of the AC signal generating circuit.

Abstract: This invention relates to a driving device for a vibration type motor. According to this invention, maximum speed data of the motor is obtained in accordance with the temperature, and the speed is controlled using the data as an upper limit, thereby properly driving the vibration type motor.

Abstract: The present invention relates to a vibration wave motor, and more specifically a vibration wave motor which is configured to prevent abnormal noise from being produced at a start time by setting a voltage to be applied to the motor at a motor driving time at a first voltage lower than a voltage for usual driving and gradually changing the voltage from this condition to a specified voltage for the usual driving for driving the motor.

Abstract: A long-life ultrasonic motor is provided which increases the output and efficiency and reduces the wear on a moving body. By mounting such an ultrasonic motor on an electronic apparatus, the electronic apparatus is improved in performances including the size-reduction, thickness-reduction, power saving, etc. By configuring a stable self-excited oscillation circuit between first and third electrodes of a piezoelectric element and applying a drive signal to a second electrode through a phase selection circuit for changing the phase of a self-excited oscillation signal, two signals different in phase are supplied to the ultrasonic motor while using the self-excited oscillation circuit.

Abstract: An actuator driving circuit includes a drive pulse signal generator, a drive voltage generator for generating a drive voltage for drive pulse signal generation upon receipt of a power supplied from a power source. The drive pulse signal is generated so that the relationship between the frequency of power noise cyclically produced from the drive voltage generator and imposed on the drive voltage and the frequency of the drive pulse signal satisfies the following equation: 4000<|m·f1−n·f2| wherein m: positive integer below a specified value; n: positive integer below a specified value; f1:frequency of power noise; and f2:frequency of the drive pulse signal.

Abstract: In a motor drive apparatus for an ultrasonic motor, a microcomputer checks whether a starter is driven within a predetermined time period from a detection of motor lock, when the motor lock is detected before the detection of a decrease in a battery voltage. The starter drive is stored in its internal memory. The microcomputer checks whether the starter was driven within the predetermined time period, when the battery voltage is restored and the starter drive is completed. The microcomputer drives the ultrasonic motor again if the check result indicates that the starter motor was driven.

Abstract: Power circuit for traveling or standing wave piezo-electric motors comprising a series resonant circuit, a switching element (T1) in parallel with the capacitor C of the resonant circuit and a switching element control (O) ensuring the cyclic closure thereof at a frequency close to the resonant frequency of the resonant circuit. The power circuit includes a transformer (Tr) whose primary constitutes the inductance of the resonant circuit and whose secondary is linked to the piezoelectric exciter, this transformer exhibiting a small magnetic inductance at the primary. An advantage of this power supply is in particular the almost-zero heating of the switching element and low current consumption.

Abstract: In a control device for a vibration wave motor, in the case where the device executes an operation involving a large variation in the load while the motor is controlled at a target speed by the driving frequency using a feedback system, such feedback control is inhibited or the response of the feedback control is restricted in order to avoid the drawback resulting from feedback control at the time of generation of the variation in the load.

Abstract: An ultrasonic motor drive apparatus includes a transformer having a primary coil and a secondary coil which drives a piezoelectric body of an ultrasonic motor. One end and the other end of the primary coil are connected to the drains of MOSFETS. The gates of the MOSFETs are connected to receive switching signals to alternately turn on and off electrical currents which flow in the primary coil. The sources of the MOSFETs are connected to the ground through ferrite beads, respectively. The ferrite bead generates a counter electromotive voltage so that the surge voltage which develops on the drain of the MOSFET at the time of turning off of the MOSFET is suppressed and high frequency oscillations are suppressed.

Abstract: A transducer assembly in accordance with the present invention includes at least one transducer element having a first end and a second end. A first electrode is coupled to the first end and a segmented electrode is coupled to the second end. The segmented electrode is adapted to allow the transducer element to be simultaneously driven by a plurality of electric signals. A generator in accordance with the present invention includes a frequency control loop to generate an electrical signal having a desired level of vibration. A first amplifier having a selected gain receives the electrical signal from the frequency control loop. The first amplifier generates a first output signal to drive the transducer element. A second amplifier having a selected gain receives the electrical signal from the frequency control loop. The second amplifier generates a second output signal to drive the transducer element.

Abstract: An ultrasonic motor driven by a self-oscillation circuit which can be mounted in an electronic device without imposing structural restrictions on the electronic device and can thus be used easily. Among an oscillating member for generating an oscillatory wave, a pressing mechanism for causing a moving body to make pressing contact with the oscillating member, a moving body frictionally driven by the oscillatory wave, and outputting means for transmitting an output from the moving body to the outside, at least one member is made of an insulating material, and when in particular the moving body is provided with outputting means for transmitting an output torque this outputting means is made of an insulating material and no restrictions are imposed on the shapes and the materials of the oscillating member and the moving body, which closely relate to the output performance of the ultrasonic motor.

Abstract: The drive device has a detection circuit (15) to which drive signals are input from a drive circuit (14) that drives a piezoelectric linear actuator (12) and that detects the characteristic of the drive signals regarding a prescribed factor and outputs detected characteristic signals that indicate the characteristic, a characteristic sampling circuit (18) that outputs a standard characteristic signal that indicates the characteristic regarding the prescribed factor when the actuator (12) is in the normal state, and a comparison circuit (16) that outputs a control signal when the difference between the two signals exceeds an allowable range.

Abstract: A control apparatus for driving a vibration wave motor, in which localized fixation between a vibration member and a contact member in contact with the vibration member is peeled off by shifting the frequency of an applied frequency signal from a frequency higher than the resonant frequency to a lower frequency.

Abstract: When a motor is driven by a signal transmitted due to a switch turned on, a count value is added. When the motor is stopped, the count value is subtracted. When the count value is an upper limit value, the motor is continuously driven until the switch is changed to an off state. Subsequently, until the count value comes to a lower limit value, the motor is maintained in a stopped state even if the switch of the motor is changed to an on state. For this reason, generation of heat in the motor can be prevented.

Abstract: The present invention relates to a control device for vibration type actuator and, particularly, to an arrangement for forming a driving signal by using a pulse signal. In the invention, a periodic pulse is formed by integral multiplying of a period of a reference pulse, analog signals of first and second values are formed at each period of the periodic pulse, an analog signal of third value between the first and second values is formed in a short time, the analog signals are input to a low-pass filter so as to convert the signals to pulse signals by comparing the outputs of the low-pass filter with reference valves, and thereby the formed driving signal includes frequencies at higher resolution than that of the reference pulse so that the control device provides a drive with higher precision.

Abstract: In a piezoelectric gyro, an amplifier 42 receives and amplifies a detected signal from detecting electrodes 19 through 26, and a bandpass filter 43 extracts only a detection-side resonant frequency component from the amplified signal. The extracted resonant frequency component is phase-shifted by a phase-shifting circuit 44, and the resultant signal is passed through a limiting resistor 45 to prepare a constant-current drive signal, and the drive signal is inputted to drive electrodes 11 through 18. As a result, the piezoelectric gyro oscillates self-excitedly at the detection-side resonant frequency. The present invention provides a piezoelectric gyro capable of maintaining a high sensitivity with respect to a change in temperature by improving detection sensitivity.

Abstract: A vibration detection piezoelectric element and a driving piezoelectric element are connected to each other without sandwiching an insulation member or a ground electrode therebetween. vibration wave motor accurately detects a vibration state of the motor by arranging a cancel circuit for canceling a driving frequency signal component included in an output from the detection piezoelectric element.