US 12,138,712 B2
Method and device for checking a focus position of a laser beam in relation to a workpiece
Ralf Bartmuss, Dietingen (DE)
Assigned to TRUMPF LASER GMBH, Schramberg (DE)
Filed by TRUMPF Laser GmbH, Schramberg (DE)
Filed on Jan. 6, 2021, as Appl. No. 17/142,257.
Application 17/142,257 is a continuation of application No. PCT/EP2019/068003, filed on Jul. 4, 2019.
Claims priority of application No. 10 2018 211 166.9 (DE), filed on Jul. 6, 2018.
Prior Publication US 2021/0121989 A1, Apr. 29, 2021
Int. Cl. B23K 26/70 (2014.01); B23K 26/06 (2014.01); B23K 26/0622 (2014.01); B23K 26/082 (2014.01); B23K 26/21 (2014.01)
CPC B23K 26/705 (2015.10) [B23K 26/0622 (2015.10); B23K 26/0643 (2013.01); B23K 26/0648 (2013.01); B23K 26/21 (2015.10); B23K 26/082 (2015.10)] 14 Claims
OG exemplary drawing
 
1. A method for checking a focus position of a laser beam in relation to a workpiece for welding processing of the workpiece, the method comprising:
focusing and directing the laser beam at a plurality of positions along a trajectory on the workpiece,
detecting radiation generated during an interaction of the laser beam with the workpiece at a respective position of the plurality of positions,
determining a plurality of signal values, each respective signal value corresponding to the detected radiation at the respective position of the plurality of positions,
checking the focus position at at least a first position of the plurality of positions by comparing the signal value at the first position with a reference value, wherein the reference value is formed from the signal values at the plurality of positions along the trajectory on the workpiece, and
based on the comparing, either adapting the focus position at the first position to a nominal focus position or reworking the workpiece.