| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a flat servo motor controller for accurately positioning if a plurality of platens are disposed and the moving region of a forcer is extended. <P>SOLUTION: The flat servo motor controller has the forcer 3 and the platens. The forcer 3 is provided with two motors 71, 73 in the X direction, two motors 72, 74 in the Y direction, drivers 101, 102 for driving the motors, encoder heads 41-44 for acquiring position signals from the motors and outputting them to the drivers 101, 102, and a switching circuit 8 for switching destinations of output signals from the encoder heads. The platen is provided with a plurality of two-dimensional encoder scales coupled on a surface. When one of the encoder heads 41-44 detects a boundary between the two-dimensional encoder scales, it is switched so as to use an output signal from the encoder head other than it. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
