In recent years the use of electromagnetic wave beams, such as laser beams, has been applied to various fields of technology. Besides scanning or marking of objects also machining of tools and medical treatment currently employ electromagnetic waves. Each of these applications requires accurate directing of the beam to a prescribed target. Directing of the beam is usually performed by deflecting devices which include one or more reflecting elements. One method for controlling the movement of the reflecting devices has been suggested in the prior art in US 2002/0181851 A1 which discloses an apparatus for controlled movement of an element. The apparatus comprises a movable member and a fixed member. The movable member includes a magnetic element and the fixed element comprises a magnetically permeable stator element. A magnetic traction force acts across the air gap between the magnetic element and the stator element and thereby urges the movable member towards the fixed member. Furthermore, stator current coils are wound onto portions of the stator. The electromagnetic force generated by current passing through the coils acts on the magnetic element to move the movable member in a controllable manner.
One disadvantage of this known apparatus is that considerable friction forces occur between the movable member and the fixed member. Hence the performance of the apparatus is not satisfactory.
The problem underlying the present invention is thus to provide an apparatus for positioning an optics, in particular at least one optical element, wherein the apparatus provides high performance.