A technique for automatically compensating for differences in orientation of a workpiece, such as a rectangular substrate, a substrate cassette, a loadlock for accessing a vacuum chamber, and a substrate support on a robot mechanism. Sensors on the substrate support detect the position of a front edge...http://www.google.de/patents/US5537311?utm_source=gb-gplus-sharePatent US5537311 - Apparatus for aligning substrates for loading and unloading using a robot mechanism
