US 12,066,686 B2
Apparatus for varying a focal point of an optical system in a dental 3D-scanner and dental 3D-scanner
Markus Berner, Bülach (CH); Martin Seib, Heppenheim (DE); and Fabrizio Confalonieri, Heppenheim (DE)
Assigned to DENTSPLY SIRONA INC., York, PA (US)
Appl. No. 17/279,148
Filed by DENTSPLY SIRONA inc., York, PA (US)
PCT Filed Sep. 27, 2019, PCT No. PCT/EP2019/076151
§ 371(c)(1), (2) Date Mar. 24, 2021,
PCT Pub. No. WO2020/064992, PCT Pub. Date Apr. 2, 2020.
Claims priority of application No. 18197051 (EP), filed on Sep. 27, 2018.
Prior Publication US 2021/0389549 A1, Dec. 16, 2021
Int. Cl. G02B 26/08 (2006.01); A61B 5/00 (2006.01); G02B 7/04 (2021.01); G02B 27/64 (2006.01)
CPC G02B 7/04 (2013.01) [A61B 5/0062 (2013.01); A61B 5/0088 (2013.01); G02B 27/646 (2013.01)] 18 Claims
OG exemplary drawing
 
1. Apparatus for varying a focal point of an optical system in a dental 3D-scanner, comprising:
a lens unit with a lens 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;
a guide unit for guiding a movement of the lens unit between the front reversal position and the rear reversal position along a guide axis being parallel to an optical axis of the lens; and
a drive unit for driving the movement of the lens unit, said drive unit including a linear motor with an anchor and a stator, said anchor being movable along a drive axis of the drive unit that is parallel to the guide axis, said stator being affixed to the guide unit
wherein the drive unit includes a coupling arrangement for coupling a movement of the anchor and the lens unit so that a movement of the anchor in a first direction is transferred to a movement of the lens in a second direction opposite to the first direction.