US 12,247,867 B2
Device and method for determining a focal position of laser beam
David Blázquez Sánchez, Gaggenau (DE)
Assigned to Precitec GmbH & Co. KG, Gaggenau (DE)
Appl. No. 17/602,323
Filed by Precitec Gmbh & Co. KG, Gaggenau (DE)
PCT Filed Mar. 2, 2020, PCT No. PCT/EP2020/055416
§ 371(c)(1), (2) Date Oct. 8, 2021,
PCT Pub. No. WO2020/207662, PCT Pub. Date Oct. 15, 2020.
Claims priority of application No. 102019109795.9 (DE), filed on Apr. 12, 2019.
Prior Publication US 2022/0196468 A1, Jun. 23, 2022
Int. Cl. B23K 26/70 (2014.01); B23K 26/046 (2014.01); G01J 1/04 (2006.01); G01J 1/42 (2006.01); G02B 26/08 (2006.01)
CPC G01J 1/0411 (2013.01) [B23K 26/046 (2013.01); B23K 26/705 (2015.10); G01J 1/4257 (2013.01); G02B 26/08 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A device for determining a focal position of a machining laser beam of a laser machining head, said device comprising:
an optical decoupling element for decoupling a partial beam from a beam path of said machining laser beam before said machining laser beam is incident on a workpiece to be machined, the decoupling element being inclined with respect to the beam path of said machining laser beam;
a detector for detecting at least one beam parameter of the partial beam;
at least one optical element which has adjustable focal length and is arranged in a beam path of the decoupled partial beam between said optical decoupling element and said detector; and
a control unit configured to set different focal lengths of said optical element,
wherein said at least one optical element having adjustable focal length comprises a first optical element having adjustable focal length and a second optical element having adjustable focal length; and
wherein said control unit is configured to set the focal length of the first optical element independently of the focal length of the second optical element.