MEASURING MODULE WITH ADJUSTABLE PATHWAY DIFFERENCE AND FOCUSING DEVICE FOR LASER PROCESSING DEVICES

Abstract

Measuring module (10) for a laser processing device (1) comprising the following: a housing (11) having a connection port (12) for optically coupling the measuring module (10) with a distance detection device and a coupling port (14) for optically coupling the measuring module (10) with a laser processing module (30) of the laser processing device (1); wherein a first optical path (P1) and a second optical path (P2) are defined for the laser light within the housing (11) for laser light that is received and output through the connection port (12), wherein the first optical path (P1) is defined from the connection port (12) to an optical reference reflector (16) of the measuring module (10), wherein the optical reference reflector (16) reflects the laser light back to the connection port (12), and wherein the second optical path (P2) is defined from the connection port (12) to the coupling port (14) and back to the connection port (12); and wherein the measuring module (10) further comprises an optical path length control system (20), that is configured to set an optical path length difference between an optical path length of the first optical path (P1) and an optical path length of the second optical path (P2); where the first optical path (P1) has a fixed, predefined optical path length; and wherein the second optical path (P2) has a variable optical path length which is adjustable by the optical path length control system (20); wherein the measuring module (10) further comprises a focusing device (18) which is arranged in the second optical path (P2) between the connecting port (12) and the optical path length control system (20) and is configured to focus the laser light transmitted through the second optical path (P2).

Claims

[1] Measuring module (10) for a laser processing device (1) comprising the following: a housing (11) having a connection port (12) for optically coupling the measuring module (10) with a distance detection device and a coupling port (14) for optically coupling the measuring module (10) with a laser processing module (30) of the laser processing device (1); wherein a first optical path (P1) and a second optical path (P2) are defined for the laser light within the housing (11) for laser light that is received and output through the connection port (12), wherein the first optical path (P1) is defined from the connection port (12) to an optical reference reflector (16) of the measuring module (10), wherein the optical reference reflector (16) reflects the laser light back to the connection port (12), and wherein the second optical path (P2) is defined from the connection port (12) to the coupling port (14) and back to the connection port (12); and wherein the measuring module (10) further comprises an optical path length control system (20), that is configured to set an optical path length difference between an optical path length of the first optical path (P1) and an optical path length of the second optical path (P2); where the first optical path (P1) has a fixed, predefined optical path length; and wherein the second optical path (P2) has a variable optical path length which is adjustable by the optical path length control system (20); wherein the measuring module (10) further comprises a focusing device (18) which is arranged in the second optical path (P2) between the connecting port (12) and the optical path length control system (20) and is configured to focus the laser light transmitted through the second optical path (P2). [2] Measuring module according to claim 1, wherein the focusing device (18) has a variable focal length and preferably comprises one or more static lenses and one or more movable lenses, corresponding galvanometer motors for adjusting the position of each of the movable lenses and a corresponding control unit for adjusting the focal length of the focusing device (18). [3] Measuring module according to claim 1 or 2, wherein the focusing device (18) has a fixed focal length and preferably comprises one or more static lenses and is preferably free of movable lenses. [4] Measuring module according to one of the preceding claims, wherein the optical path length control system (20) comprises a plurality of reflection elements (22a, 22b, 22c, 22d, 22e, 22f) for reflecting the laser light along the second optical path (P2), wherein the plurality of reflection elements (22a, 22b, 22c, 22d, 22e, 22f) comprises at least two movable reflection elements (22b, 22d, 22f), wherein the optical path length of the second optical path (P2) is adjustable, in particular continuously adjustable, by setting a position of the at least two movable reflection elements (22b, 22d, 22f). [5] Measuring module according to claim 4, wherein the optical path length control system (20) comprises at least one pair of reflection elements (22a, 22b, 22c, 22d, 22e, 22f) for reflecting the laser light along the second optical path (P2), wherein an extension of the second optical path (P2) between reflection elements (22a, 22b; 22c, 22d; 22e, 22f) of each of the at least one pair of reflection elements is adjustable, in particular continuously adjustable, by setting a relative position, in particular a separation distance, between the reflection elements (22a, 22b; 22c, 22d; 22e, 22f) of each of the at least one pair of reflection elements, wherein each pair of reflection elements (22a, 22b; 22c, 22d; 22e, 22f) preferably has a movable The reflection element (22b, 22d, 22f) is movable in a direction corresponding to the second optical path (P2);wherein all movable reflective elements (22b, 22d, 22f) are more preferably movable together in the same direction.; [6] Measuring module according to claim 4 or 5, wherein the optical path length control system (20) is configured to simultaneously and / or uniformly move two or more, preferably all, of the movable reflection elements (22b, 22d, 22f), wherein all movable reflection elements (22b, 22d, 22f) are preferably movable together in the same direction. [7] Measuring module according to one of the preceding claims, wherein the optical path length control system (20) comprises at least one pair of inclined reflection elements (24a, 24b) for multiple reflections of the laser light along the second optical path (P2) on reflective surfaces thereof, wherein the reflective surfaces of each of the reflection elements of each of the at least one pair of inclined reflection elements are facing each other and are angled relative to each other, wherein an extension of the second optical path (P2) between inclined reflection elements (24a, 24b) of each of the at least one pair of mutually inclined reflection elements is adjustable by setting a relative position between the inclined reflection elements (24a, 24b), preferably by moving both of the inclined reflection elements (24a, 24b). [8] Measuring module according to one of the preceding claims, wherein the optical path length control system (20) comprises at least one pair of refractive elements (26a, 26b) for transmitting the laser light along the second optical path (P2), wherein an extension of the second optical path (P2) by refractive elements (26a, 26b) of each of the at least one pair of refractive elements (26a, 26b) is adjustable by setting a relative position of the refractive elements (26a, 26b), preferably by moving both of the refractive elements (26a, 26b) relative to each other. [9] Measuring module according to one of the preceding claims, further comprising a distance detection device (40), in particular a detection device which includes or is connectable to an interference sensor, which is optically coupled to the connection port (12) and is configured to detect a distance based on interference of the laser light received by the distance detection device (40) from the first optical path (P1) with the laser light received by the distance detection device (40) from the second optical path (P2). [10] Measuring module according to one of the preceding claims, further comprising a monitoring port (62) and an optical element (64) configured to reflect a first part of the laser light propagating along the second optical path (P2) and to transmit a second part of the laser light propagating along the second optical path (P2) such that the first or second part is extracted from the second optical path (P2) and directed to the monitoring port (62). [11] Interferometer system comprising a distance sensing device (40), a coupling port (14) and a measuring module (10) according to any of the preceding claims; wherein the measuring module (10) defines a first optical path (P1) corresponding to a reference arm of the interferometer system and a second optical path (P2) corresponding to an object arm of the interferometer system, wherein the measuring module (10) comprises an optical reflector (16) arranged in the first optical path (P1) for reflecting back laser light received along the first optical path (P1); wherein the measuring module (10) further comprises an optical path length control system (20) configured to set an optical path length of the second optical path (P2); wherein the coupling port (14) is configured for optical coupling of the second optical path (P2) with a laser processing module; and wherein the distance sensing device (40) is configured to perform distance measurements based on interference of laser light transmitted along the first optical path (P1) with laser light transmitted along the second optical path (P2). [12] Laser processing device (1) comprising the following: a laser processing module (30) for laser processing of a workpiece (P) on a work area (37) using a work beam (W); and a measuring module (10) according to one of claims 1 to 10, wherein the measuring module (10) is optically coupled to the laser processing module (30) via the coupling connection (14) of the measuring module (10) in order to receive and output laser light from and to the laser processing module (30) in the form of a measuring beam (M); wherein the laser processing module (30) comprises the following: an optical element (32) for reflecting one of the working beam (W) and the measuring beam (M) and for transmitting the other of the working beam (W) and the measuring beam (M) thereby; and a deflection unit (34) for deflecting the working beam (W) and the measuring beam (M) to and from the workpiece (P) and / or the working field (37); wherein a working beam path and a measuring beam path are defined in the laser processing module (30) for the working beam (W) and the measuring beam (M), respectively, wherein the working beam path is defined such that the working beam (W) is reflected / transmitted by the optical element (32) in the direction of the deflection unit (34) and is deflected by the deflection unit (34) to the workpiece (P) and / or the working field (37), wherein the measuring beam (M) propagates in the measuring module (10) along the second optical path (P2) of the measuring module (10), wherein the measuring beam path is defined such that the measuring beam (M) extends from the coupling port (14) of the measuring module (10) to the optical element (32) and to the deflection unit (34) and propagates back to the coupling connection (14), is transmitted / reflected through the optical element (32) to and from the deflection unit (34), is deflected by the deflection unit (34) to and from the workpiece (P) and / or the working field (37) and is reflected back at the workpiece (P) and / or the working field (37). [13] Laser processing device (1) according to claim 12, further comprising the distance sensing device (40) according to claim 9, wherein the distance sensing device (40) is configured to determine variations in a distance between the workpiece (P) and / or the working area (37) and the deflection unit (34) and / or to determine the distance (D) based on interference of the measuring beam with laser light propagating in the measuring module (10) along the first optical path (P1) thereof. [14] Laser processing device (1) according to one of claims 12 to 13, wherein the laser processing module (30) comprises a working beam focusing device (36) for focusing the working beam (W), wherein the working beam focusing device (36) has a variable focal length and is preferably arranged in the working beam path between the optical element (32) and a source or an input (38) of the working beam (W). [15] Laser processing device (1) according to one of claims 12 to 14, wherein the focusing device (18) of the measuring module (10) is configured to focus the measuring beam (M) onto the working field (37) and / or onto the workpiece (P), in particular in a position corresponding to a focus of the working beam (W).