Patent ID: 8035903

Claim:
A positioning unit, comprising a first connecting area configured to connect to an optical element, a second connecting area configured to connect to an object in the vicinity of the optical element, at least two levers, each lever having a lever bearing, a force arm and a load arm, the at least two levers being connected via their respective lever bearings to the second connecting area, a hinged joint, an intermediate element configured to act on the hinged joint, the respective load arm of the at least two levers being connected via the hinged joint and via the intermediate element to the first connecting area, and adjustment devices or actuators arranged on the respective force arms of the levers, wherein: in a first position, the first connecting area and the second connecting area are arranged relative to one another such that the lever bearings of the at least two levers and the hinged joints which are associated with the at least two levers have approximately parallel rotation axes, which lie approximately on one plane in the first position, and the positioning unit is configured to be used in a microlithographic projection exposure installation.