| 主权项 |
1. A movable stage system configured to support an object, wherein the stage system comprises:
a short stroke part configured to support the object; a long stroke part configured to support the short stroke part, wherein said short stroke part is movable over a first range of movement with respect to the long stroke part, and wherein said long stroke part is movable over a second range of movement with respect to a base support arranged to support the long stroke part, wherein said second range of movement is substantially larger than the first range of movement, a shield element arranged between the short stroke part and the long stroke part, and configured to shield the short stroke part for pressure variations in a space between the long stroke part and the short stroke part, which pressure variations are caused by movements and/or deformations of the long stroke part, and a position control system to control a position related quantity of the shielding element, wherein said position control system is configured to maintain a substantially constant distance between the shielding element and the short stroke part, wherein the position control system comprises a sensor to determine a position related quantity of the shielding element with respect to the short stroke part, a controller to provide a control signal on the basis of the determined position related quantity and at least one actuator to actuate the shielding element on the basis of the control signal, and wherein the actuator is arranged between the shielding element and the long stroke part or between the shielding element and the base support. |
