| 摘要 |
A prealigner (16) with a first rotating member (14) having a second rotating member (15) mounted therein such that the axis of rotation of the second rotating member (15) is displaced or offset from the axis of rotation of the first rotating member (14). The second rotating member has a substrate holder (52) mounted therein such that the axis of rotation of the substrate holder (52) is displaced or offset from the axis of rotation of the second rotating member (15). When the offset distance between the axes of rotation of the first rotating member (14) and the second rotating member (15) is equal to the offset distance between the axes of rotation of the second rotating member (15) and the chuck (52) then the center of the chuck (52) can be moved to any location within a circle with a radius equal to the sum of the two offset distances. When the two offset distances are not equal, then the center of the chuck (52) can be moved to any location within a zone bounded by an outer circle having a radius equal to the sum of the two offset distances and an inner circle having a radius equal to the absolute value of the difference of the two offset distances.
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