A device for changing the focus of an optical system in a dental 3D scanner and a dental 3D scanner

摘要

The present invention relates to a device (28) for changing the focus (24) of an optical system in a dental 3D scanner (10): a forward-turning position and a posterior direction to change the position of the focus with respect to a scan object (22). a lens unit 30 having a lens 20, movable between switching positions; a guide unit (34) for guiding movement of the lens unit between a forward turning position and a rearward turning position along a guide axis (48) parallel to the optical axis (46) of the lens; and a drive unit (36) for driving the movement of the lens unit, said drive unit comprising a linear motor (38) having an anchor (40) and a stator (42), said anchor driving parallel to the guide axis movable along a drive shaft 44 of the unit, the stator being attached to the guide unit. The present invention also relates to a dental 3D scanner (10) for scanning a three-dimensional scan object.