APPARATUS FOR VARYING A FOCAL POINT OF AN OPTICAL SYSTEM IN A DENTAL 3D-SCANNER AND DENTAL 3D-SCANNER

摘要

The present invention relates to an apparatus (28) for varying a focal point (24) of an optical system in a dental 3D-scanner (10), comprising: a lens unit (30) with a lens (20) being movable between a front reversal position and a rear reversal position to vary a position of a focal point with respect to a scan object (22): a guide unit (34) for guiding a movement of the lens unit between the front reversal position and the rear reversal position along a guide axis (48) being parallel to an optical axis (46) of the lens; and a drive unit (36) for driving the movement of the lens unit, said drive unit including a linear motor (38) with an anchor (40) and a stator (42), said anchor being movable along a drive axis (44) of the drive unit that is parallel to the guide axis, said stator being affixed to the guide unit. The present invention further relates to a dental 3D-scanner (10) for scanning a three-dimensional scan object.