To compensate for hysteresis in an actuator, a path between a first position and a second position can be selected, and a drive signal can be applied to an actuator element that includes a hysteresis-compensated portion to move an object along the selected path.

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.

A vibration wave actuator has a vibration member including an elastic member and an electro-mechanical energy transducer, and a contact member in contact with the vibration member, and the contact member and the vibration member move relative to each other. The vibration wave actuator includes a detected portion configured to move, together with the contact member, relative to the vibration member, and a detection unit configured to move, together with the vibration member, relative to the contact member to detect displacement information or position information for the detected portion. The vibration member has two projections provided side by side in a direction intersecting with the direction of the relative movement. The contact member contacts the two projections. The detection unit and the detected portion are located between the contact member and the vibration member when viewed from the direction of the relative movement.

A camera module includes a substrate, a sensing chip, a lens module and a piezoelectric plate. The sensing chip is electrically connected with the substrate. The sensing chip includes a sensing region. The sensing chip is covered by the lens module. The sensing chip is arranged between the substrate and the lens module. When an external light beam passes through the lens module and projected on the sensing region, the sensing chip generates an image. The piezoelectric plate is arranged between the substrate and the lens module. When an electric power is provided to the piezoelectric plate, the piezoelectric plate is subjected to deformation, so that the lens group focuses on the sensing region. The present invention also provides a calibration method for the camera module.

A driving assembly is provided, including a transmission element and a first driving source. The transmission element has a first connecting point. The first driving source outputs a first driving force to the transmission element. The first driving source is at least partially fixedly connected to the transmission element at the first connecting point.

An optical element driving mechanism is provided, including a movable portion, a fixed portion, a driving assembly, and an assisting assembly. The movable portion is used for connecting to an optical element having a main axis. The movable portion is movable relative to the fixed portion. The driving assembly is disposed on the movable portion or the fixed portion for driving the movable portion to move relative to the fixed portion. The movable portion is movably connected to the fixed portion through the assisting assembly.

A driving mechanism is provided, including a fixed portion, a movable portion, a driving assembly and a connecting element. The movable portion may move relative to the fixed portion and is used for holding an optical module. The driving assembly moves the movable portion relative to the fixed portion. The connecting element is movably connected to the fixed portion and the movable portion.

The invention relates to a method and an actuator system for determining and applying a voltage to a piezoelectric actuator (PEA) to achieve a given setpoint displacement. The method involves determining a relation d.sub.cal(V) between a PEA displacement measure (d) and voltage (V) and a relation tt.sub.cal(V) between transition time (tt) and voltage and combining the determined relations to calculate a relation d(tt) between the displacement measure and transition time during an initial calibration procedure. This relation is characteristic for the PEA, and by determining a new relation tt.sub.new(V) after repeated biasing of the PEA, a compensated relation d.sub.c(V) can be calculated by substituting tt.sub.new(V) in the calculated d(tt). The compensated relation d.sub.c(V) compensates for piezo creep effects due to the wear and can be used to determine the voltage to be applied directly, or be used in other compensation algorithms.

A controller capable of reducing time required to stop a control target at a target stop position as a final stop position. The controller drives a vibration element including a piezoelectric element by an AC signal to thereby move a contact body in contact with the vibration element relative to the vibration element. The controller controls a pulse duty cycle of a signal converted to the AC signal based on a difference between a target stop position which is a final stop position of the contact body and a current position of the contact body, and an actual speed of the contact body.

A stick-slip piezo motor. At least one voltage source is connected to a piezo motor. The piezo motor has at least one oscillating piezo element and at least one moving friction element connected to the oscillating piezo element. The moving friction element moves in a desired travel direction. A computer is programmed to control the voltage source to deliver voltage to the piezo motor at a predetermined frequency and amplitude to control the speed of the piezo motor. The computer is programmed to hold the frequency constant while varying the amplitude to adjust the speed of the piezo motor. In a preferred embodiment the computer is programmed to hold the frequency constant at an ultrasonic frequency. In another preferred embodiment the computer is programmed to hold the frequency constant at a value of 15 kHz or higher.