Piezoelectric actuator for optical alignment screws
AssigneeNew Focus, Inc.
InventorsFrancis S. Luecke, Alexander Tuganov
Life of this patent
Estimating the term…
Abstract
A piezoelectric actuator for rotating a shaft associated with an optical mount positioning system in which the actuator moves in first direction at a slow enough velocity to maintain engagement between the actuator and shaft to drive the shaft in the desired direction, and the actuator moves in a second direction at a sufficiently high acceleration and velocity to cause the actuator to lose engagement with the shaft and slip, thereby achieving motion of the shaft in only the desired direction.
Claims9
A piezoelectric driven actuator for rotation of a shaft positioned for rotational movement within a hole in a mount element, comprising:
- a. an actuator frame;
- b. said frame including a first, movable, jaw having a portion for engagement with the shaft to be driven, said frame further including a second jaw element having a portion for engagement with the shaft to be driven;
- c. actuator frame restraint means engaging said frame and the mount element to prevent rotation of said frame relative to the shaft;
- d. said first and second jaws being positioned in spaced opposing relationship to clamp the shaft there between;
- e. a piezoelectric actuator mounted in said frame for parallel movement of said first jaw element relative to said second jaw element;
- f. drive means, responsive to a control signal, for generating and applying an electrical drive signal to said piezoelectric actuator;
- g. said electrical drive signal having a first portion for effecting a first dimensional change of said piezoelectric actuator and a second portion for effecting a second dimensional change of said piezoelectric actuator to produce reciprocating movement of said first jaw element relative to said second jaw movement;
- and,
- h. said drive means further including acceleration and velocity control means for controlling said first dimensional change to provide a lower acceleration and velocity which maintains non-slipping engagement between said first and second jaws and the shaft and for controlling said second dimensional change to provide a higher acceleration and velocity which causes said first and second jaws to slip on the shaft due to the inertia of the threaded shaft for rotational motion of the shaft in a first direction.
A piezoelectric actuator comprising:
- a. a frame having first and second opposed jaw means for engagement with an output shaft;
- b. said frame having a resilient flexure portion intermediate said first and second jaw means to accommodate longitudinal displacement of said first jaw means relative to said second jaw means;
- c. jaw spring means in engagement with said first and second jaw means to bias said first and second jaw means towards each other.
- d. an elongate piezoelectric element having a first end portion affixed to said frame at a first point in rigid relationship with said first jaw means, and a second end portion affixed to said frame at a second point in rigid relationship with said second jaw element;
- and,
- e. said resilient flexure portion intermediate said first and second points of connection to said piezoelectric element accommodating longitudinal motion of said first jaw means relative to said second jaw means upon a change in longitudinal dimension of said piezoelectric element caused by an electrical signal applied to said piezoelectric element.
Dependencies are inferred from the claim text.