Patent ID: 7173363
Filing Date: 2007-02-06
Classification: G03F,H02N

Abstract:
1. A piezo actuating system for moving an object, comprising: (a) a plurality of piezo actuators, each of said piezo actuators configured to lengthen or contract in response to a first control signal and to shear in a first direction or in a second direction opposite to said first direction in response to a second control signal; and (b) a control system for controlling said piezo actuators by supplying said first and second control signals, the control system comprising a position controller and a shuffle controller for switching between a linear shear sequence and a shuffle sequence, the shuffle controller configured to output a first and a second shuffle control signal such that the first shuffle control signal operates as the first control signal and the second shuffle control signal is added to an actuator voltage signal to operate as the second control signal, wherein the actuating system achieves the movement of said object by performing said linear shear sequence and said shuffle sequence, said linear shear sequence including engaging said object using at least one of said piezo actuators and moving said object by shearing said at least one piezo actuator in said first direction, and said shuffle sequence including releasing the engagement of at least another one of said piezo actuators with said object, changing a shear state of said at least another one of said piezo actuators by shearing said at least another one of said piezo actuators in said second direction, and engaging the object again using said at least another one of said piezo actuators, wherein said actuating system is configured to provide a smooth transition from shuffle to linear shear sequence when the second shuffle control signal remains substantially constant and unequal to zero at an end of said shuffle sequence.