Konica Minolta Opto, Inc.

Minolta Company, Ltd.

Murata Manufacturing Co., Ltd.

Tomoyuki Yuasa

Ryuichi Yoshida

Junichi Tanii

Toshio Nishimura

Masanaga Nishikawa

Takayuki Hoshino

Satoshi Shinke

Haruyuki Nakano

Tadashi Yoda

Taketo Namikawa

Taketo Nakamura

Provided is a driving device having an electromechanical transducer, a driving member, a moving member and a driving circuit. The driving circuit outputs a driving voltage at a frequency lower than that where the driving speed of the moving member is at maximum, and changes the drive frequency of the driving voltage so that the drive frequency has a negative correlative relationship with the ambient temperature. The change rate of the drive frequency to a change of the ambient temperature in the negative correlative relationship is larger than a change rate of a frequency where the driving speed of the moving member is at maximum to an increase of the ambient temperature, and the change rate permits the driving speed of the moving member to increase when the ambient temperature increases.

Driving device

An electromechanical conversion element having high connection reliability and an actuator equipped with the electromechanical conversion element. The electromechanical conversion element includes: a displacement part capable of expanding and contracting by application of voltage and having electrode forming faces and an adhesion face which are disposed adjacent to each other; and external electrodes on the electrode forming faces, in which lead electrodes for applying voltage to the displacement part are bonded to bonding regions provided in the external electrodes, and a driven member capable of being driven by the expansion and contraction of the displacement part is bonded to the adhesion face by an adhesive. The electromechanical conversion element further includes bleed flow blocking parts on the electrode forming faces at points closer to the adhesion face than ends of the bonding regions located on the same side as the adhesion face.

Electromechanical conversion element and actuator

A vibratory driving device () comprising an electromechanical transducer () which causes mechanical displacement according to an applied voltage, a driving shaft () which is held so as to be displaced in its axial direction by the electromechanical transducer and which is provided on its surface with two resistive bodies () extending in the axial direction and connected to the electromechanical transducer at one end, a movable member () which slidably engages on the driving shaft so as to contact with the two resistive bodies to connect electrically the contacted points of the resistive bodies each other, a driving circuit () which applies a periodical driving voltage to the electromechanical transducer, and a measuring circuit () which measures electric resistance between the two resistive bodies can determine a position of the movable member and has a simplified wiring () with low risk of disconnection.

Vibratory driving device

A drive unit being characterized in that a movable object can be prevented from being tilted when the movable object is stopped using a restricting member. The drive unit comprises a piezoelectric element; a rod provided at an end of the piezoelectric element; a movable object, which is frictionally engaged with the rod and the movable range of which is restricted using the restricting members; and drive pulse generating means for applying drive signals to the piezoelectric element, wherein the drive pulse generating means apply a first wave drive signal for vibrating the rod so that the movable object moves toward the restricting member when the movable object is moved to a position where the movable object is close to the restricting member, and temporarily apply a second wave drive signal for vibrating the rod so that the movable object is moved in a direction of movement away from the restricting member after the movable object is made contact with the restricting member, and then stop the application of the drive signal.

Drive unit

A piezoelectric element expands and contracts when a pulse voltage is applied. A fixing body is fixed to one end of the piezoelectric element in an expansion-contraction direction. A driving shaft is fixed to the other end of the piezoelectric element in the expansion-contraction direction. A movable body is supported to the driving shaft slidably. When a pulse voltage is applied to the piezoelectric element, the piezoelectric element contracts and expands. Accordingly, the driving shaft oscillates, and the movable body slides along the driving shaft. A material of the driving shaft is fiber reinforced resin complex. A synthetic resin material composing the fiber reinforced resin complex is liquid crystal polymer or polyphenylene sulfide.

A driving device of the disclosure has an electromechanical transducer that extends and contracts upon application of voltage thereto and a support member that slidably supports a movable body and is displaced with the electromechanical transducer to which the support member is connected. The disclosed device includes a drive circuit that applies the voltage to the electromechanical transducer is such that the voltage which increases or decreases from a first voltage to a last voltage in a stepped manner and in which at least three values sequentially circulate. A period of time for which the first voltage is applied is changeable. By this method, the movable body is moved with respect to the support member by making a difference between an extension velocity and a contraction velocity.

Driving device and driving method

To provide a driving device, utilizing an electromechanical conversion element, having a driving pulse generating means capable of generating a sawtooth waveform driving voltage with a simple circuit configuration. The driving device includes: an electromechanical conversion element which is connected to the driving pulse generating means and extends and contracts, and one end of which in an extension/contraction direction is fixed; a rod, one end of which is fixed to the other end in an extension/contraction direction of the electromechanical conversion element; and a moving body, frictionally coupled to the periphery of the rod, moving along the rod corresponding to the vibration of the rod due to the extension/contraction of the electromechanical conversion element. In this device, four voltage values increasing sequentially in steps are applied cyclically to the electromechanical conversion element, and by the resulting sawtooth vibration displacement caused in the rod, the moving body is driven in one direction along the rod. Further, four voltage values decreasing sequentially in steps are applied cyclically, and by the resulting sawtooth vibration displacement caused in the rod, the moving body is driven in a direction opposite the one direction along the rod.

Device and method utilizing electromechanical conversion element

In a drive apparatus having a vibration-generator including a plurality of electromechanical conversion elements, a plurality of weights located between each of the electromechanical conversion elements, and a rod fixed to one end of an electromechanical conversion element, a mass and a spring constant of each component included in the vibration-generator are determined, so that a relationship of integral multiple is satisfied. Thus, highly efficient driving with taking advantage of the resonance frequencies can be realized, and thus the energy consumption can be saved.

An actuator using a piezoelectric element. The actuator includes: the piezoelectric element, which is capacitive; an inductor; and a resistor. The piezoelectric element, the inductor and the resistor are serially arranged so as to define a serial circuit. When a suitable voltage is supplied to the serial circuit, a saw-tooth waveform voltage is applied to the piezoelectric element so that the piezoelectric element extends at a speed and compresses at a different speed repeatedly.

Drive mechanism and drive method employing circuit for generating saw-tooth waveform voltage

An actuator using a piezoelectric element and an operating method thereof. The actuator includes: the piezoelectric element; a drive rod fixed to the piezoelectric element; a moving unit engaging with the drive rod by a frictional force; and a driver for applying a voltage to the piezoelectric element. The voltage repeats a cycle of a first value which is one of a maximum value and a minimum value, a second value which is intermediate between the maximum value and the minimum value, and a third value which is the other of the maximum value and the minimum value so as to drive the driving unit with respect to the drive rod.

Drive mechanism employing electromechanical transducer and drive method therefor

An actuator using vibration caused by a piezoelectric element. The actuator includes: an driving rod bonded to one of the piezoelectric element; a engaging member for engaging frictionally with the driving rod; and a control circuit for applying the piezoelectric element with a driving voltage. The control circuit is provided with a drive circuit which generates a first set of the driving voltage for driving the engaging member, and with a friction reducing circuit which generates a second set of the driving voltage for reducing a frictional force exerting between the driving rod and the engaging member.

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Sakai, Japan

Tomoyuki Yuasa