Patent ID: 6838808

Claim:
A stage device, comprising: a guide bar having a longitudinal dimension; a slider that is movable in the longitudinal dimension as guided by the guide bar and that is positionable along the longitudinal dimension of the guide bar; a stage mounted to the slider; and multiple stage-actuators attached to the slider and extending toward a guide surface of the guide bar, the stage-actuators being operable in a coordinated manner to cause motion of the slider, relative to the guide bar, in a stage-movement direction parallel to the longitudinal dimension; each stage-actuator comprising a first piezoelectric element, a second piezoelectric element, and a pressure-application member having a contact surface and being movable by changes in shape of either or both the first and second piezoelectric elements; the first piezoelectric element being configured to expand, when electrically energized, in a manner that moves the pressure-application member toward the guide surface so as to cause the contact surface to contact the guide surface, and to retract, when the first piezoelectric element is electrically de-energized, the pressure-application member away from the guide surface; the second piezoelectric element being configured to exhibit, when electrically energized, a shear deformation that displaces the pressure-application member and contact surface in the stage-movement direction, and not to exhibit, when electrically de-energized, the shear deformation; the first and second piezoelectric elements being independently energizable in a coordinated manner so as to cause the contact surface periodically to contact and not contact the guide surface in a walking manner that urges movement of the slider relative to the guide bar in the stage-movement direction.