A planarity teaching station includes one or more proximity sensors arranged to reflect light off a surface to determine a plane in which a substrate is positioned by a robotic arm. The plane of the substrate is then automatically adjusted by changing a Z-axis of a universally tiltable robot base or...http://www.google.de/patents/US6085125?utm_source=gb-gplus-sharePatent US6085125 - Prealigner and planarity teaching station
