Patent ID: 8179621

Claim:
An EUV lithographic projection objective, comprising: a body; an optical element; and at least three Lorentz actuators connected to the body of the EUV lithographic projection objective, the Lorentz actuators being configured to manipulate the optical element with respect to the body of the EUV lithographic projection objective, wherein each Lorentz actuator comprises a first element that is connected to the body of the EUV lithographic projection objective and is fixed in at least one direction relative to the body of the EUV lithographic projection objective and a second element that is connected to the optical element and is movable in the at least one direction relative to the body of the EUV lithographic projection objective, the first and second elements are mechanically decoupled such that the first and second elements are separated from one another by a gap, and each Lorentz actuator is configured to generate a force in one direction, and wherein: two of the Lorentz actuators are arranged in a first plane defined by the respective force directions of those two Lorentz actuators, thereby forming an actuator device that comprises a linking point to the optical element and two links to the body of the EUV lithographic projection objective, and a third of the Lorentz actuators is arranged in a plane different from the first plane, and the actuator device further comprises a gravity compensation device configured to compensate gravity forces that act on the optical element.