A lens drive unit that prevents an actuator from being inclined is provided. In the lens drive unit, when a lens frame is displaced in a direction orthogonal to a direction in which the actuator extends and contracts with respect to a base member by, for example, impact from an outside of the lens drive unit, a drive shaft of the actuator abuts on a first lateral wall and a column, so that the actuator is prevented from being inclined with respect to the base member.

The present invention provides a driving apparatus capable of suppressing the operation noise. A driving apparatus comprises a piezoelectric element expanding and contracting in accordance with a driving signal; a supporting shaft connected to said piezoelectric element; a movable body frictionally engaged with said supporting shaft and capable of moving along said supporting shaft; and a driving portion applying said driving signal including a first driving signal which moves said movable body towards a first direction to said piezoelectric element, wherein said driving portion can repeatedly apply said first driving signal against said piezoelectric element by taking a first time in between, and said first driving signal comprises a main driving waveform group which moves said movable body to said first direction, and a sub driving waveform group which is placed after said main driving waveform group by having a second rest time shorter than said first time in between.

A piezo-electric motor 100 includes an actuation portion including an actuation surface 106 and a piezo stack 102 that is operable in response to the application of a voltage to move the actuation surface along an actuation axis 116 between a retracted position and an extended position. A spring strap 112 partially surrounds the actuation portion and is operable to bias the actuation surface toward the retracted position and a movable portion 108,110 is frictionally engaged with the actuation surface. The voltage is selected such that the movable portion sticks to the actuation surface as the actuation surface moves toward one of the retracted position and the extended position and slips on the actuation surface as the actuation surface moves toward the other of the retracted position and the extended position.

Disclosed is a stick-slip drive comprising a base and a rotor which are in contact with one another via a friction surface and are coupled to one another in such a way that the rotor can perform an inertial motion relative to the base, characterized in that two materials, a noble metal and a ceramic material, are paired up on the friction surface between the base and the rotor.

A one-dimensional large-stroke precise positioning platform includes a housing, a cross ball guiding rail, piezoelectric ceramic and an elastic member. The cross ball guiding rail includes a mover guiding rail and stator guiding rails. A first and second fixing member is movable in a containing chamber provided in the housing. In the longitudinal direction of the mover guiding rail, one end of the piezoelectric ceramic is abutted against the first fixing member, and the other end against the second fixing member. The mover guiding rail is fixed on the second fixing member, and the elastic member is fixed on the first fixing member. In the width direction of the mover guiding rail, the two sides of the elastic member are abutted against the inner side surfaces of the containing chamber, and the first fixing member is connected with the second fixing member by a flexible member.

A piezoelectric actuator includes a piezoelectric element, a connection member of a shaft or weight connected to an element end surface of the piezoelectric element, the other one of the shaft and weight connected to a first end surface constituting an end surface opposing to the element end surface of the piezoelectric element, a wiring portion, and a resin portion. The piezoelectric element forms external electrodes on surfaces thereof, alternately laminates internal electrode layers with piezoelectric layers therebetween, and provides part of the external electrodes on the element end surface. The wiring portion has conductive portions corresponding to the external electrodes. The resin portion fixes the piezoelectric element, the connection member, and the wiring portion so that the element end surface opposes to the connection member with the wiring portion therebetween and that the conductive portions are electrically connected to the external electrodes.

A lens drive unit that offers enhanced reliability in connection between an actuator electrode and an electric wire is provided. In the lens drive unit, an actuator has a weight housed in an holding portion of a base member and is thereby fixed in the base member. Electrodes on a lateral surface of the weight directly contact respective terminal electrodes on an inner lateral surface of the holding portion, so that an electrical connection is established therebetween. The arrangement enhances reliability in connection between the actuator electrodes and the terminal electrodes.

In a linear driving apparatus including a vibration wave motor, a sliding guide method is used as a guiding method for a moving member. The apparatus further includes a driving target body movable in a moving direction, a transmission member configured to engage with the driving target body, abut against the abutment part of the moving member, and transmit the driving force of the vibration wave motor to the driving target body, and a biasing member configured to apply a biasing force between the transmission member and the abutment part. The direction of a frictional contact force that the vibrator receives from the friction member and the direction of a biasing contact force that the abutment part receives from the biasing member are parallel and opposite, and the load center of the distribution load of the biasing contact force exists in the range of the outside shape of the vibrator.

An X-axis movable object holding portion to hold an X-axis movable object is provided at a position facing an X-axis actuator in a base member. A Y-axis movable object holding portion to hold a Y-axis movable object is provided at a position facing a Y-axis actuator in the X-axis movable object. An X-axis stopper mechanism for restricting a movement range of the X-axis movable object is provided in the base member. A Y-axis stopper mechanism for restricting a movement range of the Y-axis movable object is provided in the X-axis movable object.

There is provided a drive controller including a determination part that compares a target stop position of a movable body, which is driven by a piezoelectric actuator driven by a piezoelectric element expanded and contracted in response to an applied voltage, with a real position of the movable body acquired on the basis of a position sensor, and determines whether or not the target stop position matches with the real position, and a drive control part that turns off energization of the piezoelectric actuator when the target stop position matches with the real position while the movable body is being driven by the piezoelectric actuator.