Patent ID: 7504794

Claim:
A planar motor comprising: a movable stage; a common electrode plate including an electrode block in a crisscross arrangement to move on a plane together with the movable stage; a split electrode plate apart from the common electrode plate at a predetermined interval, which is formed of a plurality of pairs of electrode blocks that face the electrode blocks of the common electrode plate; a main base to which the split electrode plate is attached; a plurality of linear actuators attached to the main base; and a transmission mechanism that transmits displacement amounts of output shafts of the plurality of the linear actuators, wherein a differential structure is provided in which electrostatic capacities of two capacitors formed of a pair of the electrode blocks of the split electrode plate, which face the electrode blocks of the common electrode plate are kept unchanged with respect to a movement in an axial direction of the capacitors, and one of the electrostatic capacities is increased while the other is decreased in proportion to a displacement of the movement with respect to the other axial direction; and the plurality of linear actuators are driven to perform one of driving the movable stage in a direction of an X-axis and a Y-axis, and of turning the movable stage so as to output a change in the electrostatic capacity between the split electrode plate and the common electrode plate in accordance with the movement of the movable stage; and wherein the transmission mechanism includes: a bearing attached to an output shaft of the linear actuator having a turning axis vertical to the plane on which the movable stage moves; a bearing guide attached to the movable stage, against which the bearing is pressed; and an elastic member set between the main base and the bearing guide to apply an urging force that presses the bearing against the bearing guide.