Abstract:
In a truss type actuator having two piezoelectric devices provided for crossing at right angle and driven by two alternating driving signals having a predetermined phase difference between them for driving a chip member along a predetermined elliptic trail (including a circular trail). The piezoelectric devices are contacted by protrusions having a high rigidity and formed on contacting faces of the chip member and a base member for holding the piezoelectric devices, and fixed by adhesive having a low rigidity and filled around the protrusions. Thereby, one of the piezoelectric device hardly receives a reaction force from another piezoelectric device due to the displacement thereof.
Abstract:
A truss type actuator including two piezoelectric devices drives a chip member provided at a crossing point of the piezoelectric devices for moving along an elliptic or a circular trail. The piezoelectric devices are respectively driven by driving signals having a frequency equal to or near to the resonance frequency of the piezoelectric devices. By utilizing the resonance phenomenon, the displacements of the piezoelectric device can be increased as larger as possible.
Abstract:
The present invention is an actuator using a piezoelectric element as a displacement element, wherein a drive signal voltage and current are reduced, and power consumption is reduced, while output is increased. A structure comprising two displacement units of laminate-type piezoelectric elements 10 and 10′ and elastic elements 25 and 25′ resonated by the piezoelectric elements are arranged so as to mutually intersect, and a tip 20 provided at the intersection point of the elastic members 25 and 25′ describes a circular path or elliptical path, and moves a rotor 40. The oscillation of the piezoelectric elements 10 and 10′ is suppressed by the elastic members 25 and 25′, so as to set the phase of the electromotive force produced by the voltage effect of the piezoelectric elements 10 and 10′ themselves to the opposite of the phase of the drive signal, thereby reducing current consumption. Making the spring constant of the elastic members 25 and 25′ smaller than the spring constant of the piezoelectric elements 10 and 10′ expands the displacement of the elastic members 25 and 25′ greater than the displacement of the piezoelectric elements 10 and 10′.
Abstract:
A driving apparatus that improves the precision of driving control for a driven member by reliably ensuring the desired motion of the tip member. Regulating members, which hold a piezoelectric actuator at positions opposite a rotor R, are located at positions separated from the piezoelectric actuator by a distance L that equals or exceeds the amplitude of the oscillation generated in the piezoelectric actuator.
Abstract:
A truss type actuator including two piezoelectric devices drives a chip member provided at a crossing point of the piezoelectric devices for moving along an elliptic or a circular trail. Only one piezoelectric device is driven for transmitting vibrations thereof to the other non-driven piezoelectric device. By selecting a frequency of driving signals, both of the piezoelectric devices are resonantly vibrated with a phase difference of 90 degrees.
Abstract:
Piezoelectric elements 10 and 10′ are driven so as to satisfy the relationship Nt=X0(1/(1/k2+1/k3)−1/(1/k1+1/k2+1/k3)) when the drive member, tip 20, and driven member, rotor 40, are in a state of intermittent contact, and in a state near the condition of transition from the intermittent contact state to the normal contact state. When the spring constant of the spring 41 is designated k1, the spring constant of the combined piezoelectric elements 10 and 10′ and the tip 20 is designated k2, the spring constant of the rotor 40 is designated k3, the amount of displacement of the piezoelectric elements 10 and 10′ is designated X0, and the compression force of the spring 41 is designated Nt.
Abstract:
An image shooting apparatus capable of accurately connecting split images while avoiding increase in the size of the apparatus is described. The stop positions of an image forming portion 10 is detected on the order equal to the pixel pitch, the shift amounts of the shot split images are obtained from the shift amounts of the stop positions of the image forming portion 10, and for each split image, the address is converted to a normal address based on the shift amount.
Abstract:
An electronic camera is provided with an image pickup unit in a casing at a position opposite to an opening of the casing. The image pickup unit includes an image pickup device and an optical system. The electronic camera is further provided with a rotating mechanism for rotating the image pickup unit, a changer for changing over a photographing possible state and a photographing impossible state, and a controller for controlling the rotating mechanism to rotate the image pickup unit into a target position in response to the changer.
Abstract:
An actuator includes at least two piezoelectric devices arranged for crossing displacing directions thereof at a predetermined angle, a chip member provided at a coupling point of the piezoelectric devices, and a spring for contacting the chip member to a rotor driven by the actuator. The piezoelectric device is driven for moving the chip member trailing an elliptical trail. The rotation velocity or the driving torque of the rotor is controlled by varying at least one of a length of a major axis or a minor axis of the elliptical trail and an inclination angle of the major axis or the minor axis with respect to a normal at a contacting point of the chip member and the rotor.
Abstract:
A method for making calcium phosphate particles, the method including compressively pulverizing a molded body containing, as a principal component, a calcium phosphate material with a plurality of parallel extending needlelike projections. The molded body contains a plurality of void holes oriented in one direction and the pulverizing is carried out by moving the needlelike projections in a direction of protrusion, which is aligned with the one direction. Each needlelike projection has a diameter within a range of 1.0 to 2.0 mm and a number the needlelike projections per unitary surface area is within a range of 5 to 35 per cm2.