Patent ID: 8279408
Filing Date: 2012-10-02
Classification: G03B,G03F

Abstract:
1. A positioning device constructed and arranged to position an object support, the positioning device comprising: first and second side beams having respective first and second sliders mounted thereon; first and second motors configured to move the first and second sliders along each respective side beam; a cross beam mounted proximate first and second ends thereof to the first and second sliders respectively and having a third slider mounted thereto, the cross-beam and the first and second sliders being mounted together; a third motor configured to move the third slider longitudinally along the cross-beam, the third slider being adapted to support the object support; and a fluid bearing arranged in at least one of the first, second and third sliders, the fluid bearing comprising multiple bearing surfaces configured to, in use, exert reaction forces in a same first direction, the first direction being substantially perpendicular to a sliding direction of the at least one slider, wherein two of the multiple bearing surfaces are arranged in different planes that are spaced apart from each other in the first direction.