Abstract: A drive apparatus includes: an electromechanical transducer element wherein mechanical displacement will occur when a voltage is applied thereto, a drive member that is moved by the electromechanical transducer element, a moving member that engages with the drive member so as to be able to make a slipping displacement relative to the same, regulating members for limiting the movement of the moving member by coming into contact with the moving member, a drive circuit for applying a cyclical drive voltage to the electromechanical transducer element, a detecting circuit for detecting the impedance of the electromechanical transducer element, and an evaluating means for determining that the moving member is in contact with one of the regulating members when the value detected by the detecting circuit is not less than a prescribed value.

Abstract: In order to provide a driving device that is capable of eliminating sticking of a movable member due to nonuse, the driving device includes a drive shaft that reciprocates in axial directions with expansion and contraction of an electromechanical transducer element, a movable member that frictionally engages with the drive shaft, and a drive circuit that inputs drive voltage into the electromechanical transducer element, the drive circuit outputting drive operation pattern voltage having a frequency (fd1?) lower than a resonance frequency (fr) of the electromechanical transducer element and lower than a frequency (fd1) that maximizes moving velocity of the movable member and sticking elimination pattern voltage having a frequency lower than the frequency (fd1?) of the drive operation pattern voltage and in vicinity of a frequency (fd2) that maximizes thrust acting on the movable member.

Abstract: There is provided optical devices capable of performing aberration corrections with high accuracy for light rays having plural wavelengths with a simple structure without involving a cost increase. An optical device 1 includes an actuator 8 for driving an optical member 40 in the direction of an optical axis and a guide member 46 for guiding the optical member 40 being driven. The optical member 40 includes plural functional portions 42 and 44 having different functions, and the optical axes of the respective functional portions 42 and 44 of the optical member 40 are brought into coincidence with a light ray through the guiding of the guide member 46.

Abstract: In order to provide a driving device that is capable of eliminating sticking of a movable member due to nonuse, the driving device includes a drive shaft that reciprocates in axial directions with expansion and contraction of an electromechanical transducer element, a movable member that frictionally engages with the drive shaft, and a drive circuit that inputs drive voltage into the electromechanical transducer element, the drive circuit outputting drive operation pattern voltage having a frequency (fd1?) lower than a resonance frequency (fr) of the electromechanical transducer element and lower than a frequency (fd1) that maximizes moving velocity of the movable member and sticking elimination pattern voltage having a frequency lower than the frequency (fd1?) of the drive operation pattern voltage and in vicinity of a frequency (fd2) that maximizes thrust acting on the movable member.

Abstract: 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.

Abstract: There is provided optical devices capable of performing aberration corrections with high accuracy for light rays having plural wavelengths with a simple structure without involving a cost increase. An optical device 1 includes an actuator 8 for driving an optical member 40 in the direction of an optical axis and a guide member 46 for guiding the optical member 40 being driven. The optical member 40 includes plural functional portions 42 and 44 having different functions, and the optical axes of the respective functional portions 42 and 44 of the optical member 40 are brought into coincidence with a light ray through the guiding of the guide member 46.

Abstract: 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.

Abstract: There is provided an actuator utilizing a piezoelectric transducer that is structured in small size by feeding the electrical power to the internal surface to the piezoelectric transducer formed in the cylindrical shape. The electrodes are formed to both front and rear surfaces of a sheet type piezoelectric element and this element is wound in the cylindrical shape. The cylindrical material is normalized under the predetermined temperature and a voltage is applied across the electrodes for the polarization purpose. An electrode terminal having the contactors is inserted to the internal surface of the piezoelectric transducer formed in the cylindrical shape and the contactors are placed in contact with the electrodes exposed at the internal surface of the cylindrical shape for the purpose of power feeding.

Abstract: A drive apparatus having a drive pulse generation device that generates drive pulses. An electromechanical transducer has a first end and a second end. The electromechanical transducer expands and contracts in response to pulses supplied from the drive pulse generation device. A support member is secured to the first end of the electromechanical transducer in the expansion/contraction direction thereof. A first friction member secured to the second end of the electromechanical transducer in the extension/contraction direction thereof. A second friction member frictionally coupled to the first friction member. A load detection device detects the magnitude of a drive load. A drive control device carries out drive control on the basis of the detection results of the load detection device.

Abstract: A drive unit 20, comprising a moving body 24 and a friction drive member 26 fixedly attached at each end of a piezoelectric element 22 in the layer direction, is disposed between a pair of fixed friction members 14 having a plurality of divided contact parts 15 divided by notches 14s formed at equal spacing along the movement path of the friction drive member 26. The divided contact parts 15 are arrayed so as to be slightly inserted into the movement path of the friction drive member 26, and become elastically deformed when in contact with the friction drive member 26 so as to exert a force on friction drive member 26 in reaction thereto. This exerted force remains uniform regardless of the relative position of the friction drive member 26.

Abstract: A drive device using a piezoelectric transducer for correcting a shift of a position of a drive system based on a change in an environmental state such as environmental temperature, in which a drive member coupled to the piezoelectric transducer is driven by causing displacements having different speeds by applying drive pulses of saw tooth waves to the piezoelectric transducer thereby moving a slider block frictionally coupled to the drive member, an amount of a shift of a position of the slider block based on the change in the environmental temperature is previously stored to a memory, when a change in temperature is detected by a temperature sensor, the amount of the shift of the position of the slider block is calculated in accordance with the change in temperature and the shift of the position of the slider block is corrected by driving the piezoelectric transducer in a direction of correcting the shift amount by driving a fine adjustment circuit.

Abstract: A drive device using an electromechanical transducer having inconsiderable loss of drive energy and excellent drive efficiency even with variation in load in which an elastic member is arranged between a driven member frictionally coupled to a drive member and a frictional member fitted to an opening of the driven member whereby drive force is transmitted from the drive member to the driven member with no loss of energy, a frictional force between the drive member and the driven member is periodically changed, an average frictional force is increased when a shift between a phase of variation in a drive velocity and a phase of variation in the frictional force is null, when the shift between the phases is 180.degree.

Abstract: A drive device for driving an optical element suitable to be attached to a camera shake correction device. The drive device employs items molded from a synthetic resin in which the elastic deformation of the synthetic resin allows the oscillation of a piezoelectric element to be adequately converted to drive power. The drive device includes an electromechanical conversion element, a baseplate equipped with a securing area secured to one end of the electromechanical conversion element, and a drive member that is securely linked to the other end of the electromechanical conversion element and displaced together with the electromechanical conversion element. The device further includes a transport member constructed from a rigid synthetic resin material with a Rockwell hardness of about 120 or more and which is frictionally linked to the drive member.

Abstract: A drive device which repeats charging and discharging at different velocities by applying drive pulses to a piezoelectric transducer, causes vibrations with different velocities in the piezoelectric transducer to cause contraction and expansion displacements in a driving member fixedly coupled with the piezoelectric transducer for moving a member frictionally coupled to the driving member. In order to provide stable driving force, stable driving velocity and precise movement, a piezoelectric transducer constituted by stacking a plurality of unit elements is divided into a plurality of blocks having different numbers of lamination layers for driving. A change in impedance by the division is compensated by a compensation circuit, or a plurality of driving circuits corresponding to the impedance are provided and a block and a driving circuit of the piezoelectric transducer are selected in accordance with the driving velocity and moving distance for driving.