High-performance dynamic mount for laser-beam steering mirror and actuating motor therefor

Claim 1

In combination an apparatus for dynamically mounting and actuating an object such as a laser mirror with great precision of motion comprising: at least one piezoelectric shear motor for providing actuating movement along one axis, said shear motor further comprising: (i) a plurality of polarized piezoelectric shear elements arranged in a vertical stack of horizontal layers to provide movement along a horizontal axis in response to applied electrical signals, (ii) each shear element comprising a polarized piezoelectric strip having a first electrode in contact with the top and one end face of the strip and a second electrode in contact with the bottom and other end face of the strip, (iii) adjacent horizontal layers being bonded together so that the bottom surface of the upper layer moves to the same extent as the top surface of the lower layer, the movement of each horizontal layer being a shear movement along a shear plane; and (iv) a base plate for said plurality of piezoelectric shear elements; object-support means to which said object is attached; a motor-mount member for supporting the motor; a suspension plate attached to the motor-mount member and containing at least one suspension assembly formed from a suspension ring holder having a recess and a suspension ring fitting within the recess but spaced from the ring holder; a flexure assembly located within the space separating the suspension ring from the suspension ring holder, the flexure assembly permitting axial, tip and tilt movement of the suspension ring; a support member for affixing the suspension assembly to the object-support means; and a flexible linkage assembly for transmitting movement along a single axis further comprising: (i) shaft means comprising a front, center and rear section each formed with a central axial bore therein; (ii) a flexible joint for providing at least two degrees of rotational freedom between two shafts including a pair of arcuate longitudinal bearings, a trunion block in the shape of a double wedge having a long, arcuate narrow edge at each opposite side thereof, the longitudinal axis of each edge being orthogonal to that of the other edge, the flexible joint being located between the rear end of the first and the front end of the center shaft sections, and between the rear end of the center and front end of the rear sections, the flexible joint formed with a central bore therethrough; (iii) tensioning means running through the bores and attached to the front and rear shaft sections for placing a predetermined amount of tension on the flexible-joint; and (iv) means for stabilizing the flexible linkage in the lateral direction in the area of the flexible-joint.