Patent ID: 7068891

Claim:
An instrument for positioning an article with at least three degrees of freedom about a selectable pivot point, the instrument comprising: a base stage for linear motion in two perpendicular axes, the perpendicular axes forming a plane; a yaw stage, coupled to the base stage, for rotational motion about a third axis, the third axis being normal to the plane, the yaw stage being capable of engaging a mount for fixing an article thereto, thereby positioning the article at a first location, and the yaw stage further having a pivot point locatable outside a footprint defined by the base stage and the yaw stage; and a control system in communication with the base stage and the yaw stage for directing motion of the base stage and the yaw stage and correspondingly the article, wherein the control system includes means for specifying the first location of the article, means for selecting a pivot point of the yaw stage, means for directing motion of the article about the selected pivot point to a desired location of the article by the rotational motion of the yaw stage about the third axis, means for determining a difference between the first location and the desired location, if any, and means for calibrating further motion directives to the base stage and yaw stage based on the selected pivot point and the difference such that the motion of the article to the desired location includes negligible error.