| 摘要 |
<p>A positioning stage comprises a base, a stage plate slideably supported on said base, at least three linear drive means rotatably engaging both the stage plate, and the base for moving the stage plate upon the surface of the base. With at least three separate drive displacements, motion of the stage plate with respect to the base is provided along the rectilinearly disposed x and y axes and rotation is also provided. The linear drive means include a motor and a capstan driven by the motor and a drivebar frictionally engaging the capstan. Another object of the stage preferably includes a spring loaded mechanism which provides a constant down-load at the end of the drive bar which engages the stage plate via a ball joint. The down load remains constant regardless of the varying extension of the drive bar. A ball joint provides the ability to alter the preload between the cones and the ball of the ball joint dynamically to desired levels. The positioning system includes an interferometer system comprised of an integrated structure providing a plurality of interferometer optical systems on a unitary element. The system includes integrated, parallel, dual axis plane mirror interferometers in the unitary element.</p> |
