System for relative movement between two plates and positioning device comprising such a movement system

摘要

A system provides for relative movement between two plates that are substantially parallel to a plane defined by a first direction and a second direction. The system includes a first unit that is configured to allow a relative movement between the two plates in a third direction that is orthogonal to the plane. The first unit also independently prevents a relative movement between the two plates in the plane. The system further includes a second unit that is configured to allow one plate to relatively travel with respect to the other plate about the first and second directions.