Movement guiding mechanism

Abstract

In a movement guiding device, two parallel stationary guides are fixed to a surface plate and plural hydrostatic gas or bearing members are provided for the surface plate and the stationary guides. A Y stage is moved in a Y-axis direction under the influence of these bearing members. Additional hydrostatic gas or air bearing members are provided in relation to the surface plate and the Y stage so as to support an X stage for movement in an X-axis direction orthogonal to the Y-axis direction. Guide of the Y stage in the X-axis direction is made by the stationary guides on the surface plate, while guide thereof in a Z-axis direction perpendicular to an X-Y plane is made by the surface plate. Guide of the X stage in the Y-axis direction is made by the Y stage, while the guide thereof in the Z-axis direction is made by the surface plate, similar to the Y stage. With such structure, any vibration, rolling, or otherwise, of the Y stage is not transmitted to the X stage. Thus, high-precision guide is attainable. Linear motors are used as drive sources for the X and Y stages, so that all movable portions are provided by non-contact structures. Further, suitable brake members are used, which members are operable at a time of an accident of the stage. By this, accidental collision of the stage and/or derailment of the stage from the guide can be prevented.