US 12,265,207 B2
Dynamic focus for laser processing head
Danny Chan, Kleinmachnow (DE)
Assigned to II-VI DELAWARE, INC., Wilmington, DE (US)
Filed by II-VI Delaware, Inc., Wilmington, DE (US)
Filed on Mar. 4, 2021, as Appl. No. 17/192,327.
Prior Publication US 2022/0283416 A1, Sep. 8, 2022
Int. Cl. G02B 3/04 (2006.01); B23K 26/06 (2014.01); B23K 26/70 (2014.01); G02B 19/00 (2006.01)
CPC G02B 19/0014 (2013.01) [B23K 26/0665 (2013.01); B23K 26/703 (2015.10); G02B 3/04 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A laser processing head configured to transmit a laser beam along an optical axis of the laser processing head and to focus the laser beam at a focal point, the laser processing head comprising:
an input configured to receive the laser beam from a laser source;
a first lens element mounted in a first fixed position in the laser processing head and configured to receive and image the laser beam directly from the input, the first lens element having a first focal length along the optical axis;
a second lens element configured to receive and image the laser beam directly from the first lens element, the second lens element having a second focal length along the optical axis, the second focal length being positive;
an actuator configured to move the second lens element a variable lens distance along the optical axis; and
a third lens element mounted in a second fixed position in the laser processing head and configured to receive the laser beam directly from the second lens element and image the laser beam to the focal point, the third lens element having a third focal length along the optical axis, the third focal length being positive and being greater than the second focal length by at least a factor of two, wherein:
the focal point is configured to vary over a variable focal distance along the optical axis as a function of the variable lens distance, and
the actuator is configured to move the second lens element along the optical axis relative to the first lens element mounted in the first fixed position and relative to the third lens element mounted in the second fixed position.