US-12617039-B2 - Scan field and work plane evaluation and orientation for high-speed laser motion systems

US12617039B2US 12617039 B2US12617039 B2US 12617039B2US-12617039-B2

Abstract

System and methods for evaluating build platform flatness and parallelism relative to a focal plane of a high-speed laser in high-speed laser motion systems, wherein the high-speed laser motion systems include the high-speed laser that generates a laser beam, and the build platform having a work plane, comprising positioning a plurality of pin-hole sensors within the focal plane of the high-speed laser, wherein each of the pin-hole sensors is positioned at a predetermined location; directing the laser beam to the predetermined locations of each pin-hole sensor; measuring a spot size of the laser beam at each pin-hole sensor, wherein the spot size at each pin-hole defining structure has a measureable diameter; comparing the measurable diameters obtained at each pin-hole sensor; and adjusting the work plane of the build platform to a position where the measurable diameters of the spot sizes are equal at each pin-hole sensor.

Inventors

Jacob C. Hay
Ajay Krishnan
Ron Aman
Stanley L. Ream

Assignees

EDISON WELDING INSTITUTE, INC.

Dates

Publication Date: 20260505
Application Date: 20230508

Claims (10)

1 . A method for evaluating build platform flatness and parallelism relative to a focal plane of a high-speed laser in high-speed laser motion systems, wherein the high-speed laser motion systems include the high-speed laser that generates a laser beam, and the build platform having a work plane, comprising: (a) positioning a plurality of pin-hole sensors within the focal plane of the high-speed laser, wherein each of the pin-hole sensors is positioned at a predetermined location; (b) directing the laser beam to the predetermined locations of each pin-hole sensor; (c) measuring a spot size of the laser beam at each pin-hole sensor, wherein the spot size at each pin-hole defining structure has a measurable diameter; (d) comparing the measurable diameters obtained at each pin-hole sensor; and (e) adjusting the work plane of the build platform to a position where the measurable diameters of the spot sizes are equal at each pin-hole sensor.
2 . The method of claim 1 , wherein the focal plane of the high-speed laser is ideally parallel to the work plane of the build platform.
3 . The method of claim 1 , further comprising repeatedly redirecting the laser beam to the predetermined locations of each pin-hole sensor, re-measuring the spot size of the laser beam at each pin-hole sensor, and re-adjusting the work plane of the build platform.
4 . The method of claim 1 , further comprising providing feedback to an operator indicating the adjustments necessary for making the work plane of the build platform parallel with the focal plane of the high-speed laser.
5 . The method of claim 1 , further comprising analyzing working parameters of the high-speed laser motion systems, by: (a) measuring the spot size of the laser beam at each pin-hole sensor; (b) comparing the measured spot sizes obtained at each pin-hole sensor; (c) calculating changes in the working parameters due to non-uniformity between the measured spot sizes; and (d) recording the location and profile of the work plane for use during processing.
6 . The method of claim 5 , further comprising providing feedback to an operator indicating the adjustments necessary for making the work plane of the build platform parallel with the focal plane of the high-speed laser.
7 . The method of claim 5 , wherein the high-speed laser motion systems are two-dimensional.
8 . The method of claim 1 , further comprising analyzing orientation of the high-speed laser motion systems, by: (a) measuring the spot size of the laser beam at each pin-hole sensor; (b) comparing the measured spot sizes obtained at each pin-hole sensor; (c) calculating necessary movement of the high-speed laser in the z-axis due to non-uniformity between the measured spot sizes; (d) recording the location and profile of the work plane for use during processing; (e) running a measurement cycle with z-axis compensation; and (f) verifying uniformity in the measured spot sizes between each pin-hole sensor.
9 . The method of claim 8 , further comprising providing feedback to an operator indicating the adjustments necessary for making the work plane of the build platform parallel with the focal plane of the high-speed laser.
10 . The method of claim 8 , wherein the high-speed laser motion systems are three-dimensional.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/339,850 filed on May 9, 2022 and entitled “Scan Field and Work Plane Evaluation and Orientation for High-Speed Laser Systems”, the disclosure of which is hereby incorporated by reference herein in its entirety and made part of the present U.S. utility patent application for all purposes. BACKGROUND The disclosed technology relates in general to laser systems having high speed motion capability and more specifically to systems, devices, and methods for characterizing, analyzing, and verifying proper functioning and performance of lasers used in laser processing systems having high speed motion capability. Laser processing typically includes using a laser beam to modify a work piece in a predetermined manner. Laser processing ranges from high-intensity laser ablation processes to significantly lower intensity processes such as heat treating, in which melting is avoided. Nearly all laser processing techniques involve forming the laser beam into a specific size and shape at a particular location or working distance from the laser system. Precise identification of the location where a laser system will create a focal spot or image having the desired characteristics is an important aspect of creating an efficient and optimized laser process. Laser processing techniques include laser beam welding (LBW), which is a fusion welding process used to join materials in various configurations. Laser beam welding systems typically include a laser light source, a laser light delivery system, an optical arrangement for delivering laser the light to a work piece, and frequently a motion system for moving either the laser or the work piece. LBW systems may include fiber-delivered beams or open beam paths, fixed optical systems or galvanometer systems that allow for rapid deflection of the laser beam. Mechanical motion systems may include high-speed systems or low-speed systems depending on intended application. For the LBW process, laser light is focused using optical arrangements that include a collimation lens or mirror that stops the divergence of the laser light from the light source and delivers the light to a focusing lens or mirror (or other optic). The focusing lens or mirror then directs the high-intensity, focused laser light to the work piece that is to be welded. The high-intensity laser light is then used to melt the material of the work piece and fuse two or more parts or components together. The use of laser processing systems, particularly LBW systems, in manufacturing has become common and such systems can be found in many manufacturing facilities worldwide. The functional success of all laser processing systems depends on predetermined, stable, and repeatable laser beam characteristics including focal spot shape, distribution, and location. Accordingly, there is an ongoing need for accurate, easy to use, and affordable systems, devices, and methods for analyzing the quality and dynamic accuracy of laser focal spots or images formed by laser processing systems having motion capability. SUMMARY The following provides a summary of certain example implementations of the disclosed technology. This summary is not an extensive overview and is not intended to identify key or critical aspects or elements of the disclosed technology or to delineate its scope. However, it is to be understood that the use of indefinite articles in the language used to describe and claim the disclosed technology is not intended in any way to limit the described technology. Rather the use of “a” or “an” should be interpreted to mean “at least one” or “one or more”. One implementation of the disclosed technology provides a method for evaluating build platform flatness and parallelism relative to a focal plane of a high-speed laser in high-speed laser motion systems, wherein the high-speed laser motion systems include the high-speed laser that generates a laser beam, and the build platform having a work plane, comprising positioning a plurality of pin-hole sensors within the focal plane of the high-speed laser, wherein each of the pin-hole sensors is positioned at a predetermined location; directing the laser beam to the predetermined locations of each pin-hole sensor; measuring a spot size of the laser beam at each pin-hole sensor, wherein the spot size at each pin-hole defining structure has a measureable diameter; comparing the measurable diameters obtained at each pin-hole sensor; and adjusting the work plane of the build platform to a position where the measurable diameters of the spot sizes are equal or substantially equal at each pin-hole sensor. The focal plane of the high-speed laser is ideally parallel to the work plane of the build platform. The method may further comprise repeatedly redirecting the laser beam to the predetermined locations of each pin-hole sensor, re-measuring the spot size of lase