# US 12,214,444 B2 · Methods and devices for monitoring a welding process for welding glass workpieces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,444 B2 - Document ID: US12214444B2 - Status: Granted - Kind: B2 - Application number: 17/318,263 - Filed: 2021-05-12 - Published: 2021-08-26 - Granted: 2025-02-04 - Earliest claimed: 2018-11-13 - Assignees: TRUMPF Laser- und Systemtechnik GmbH - Applicants: TRUMPF Laser-und Systemtechnik GmbH - Inventors: Sebastian Hecker; Tim Hesse - Web page: https://patentgrep.com/patent/US12214444B2 ## CPC - B23K 26/324: involving non-metallic parts - B23K 26/032: {using optical means} - B23K 26/0624: {using ultrashort pulses, i.e. pulses of 1 ns or less} - B23K 26/244: Overlap seam welding - B23K 26/26: of rectilinear seams - B23K 26/57: the laser beam entering a face of the workpiece from which it is transmitted through the workpiece material to work on a different workpiece face, e.g. for effecting removal, fusion splicing, modifying or reforming - B23K 31/125: {Weld quality monitoring} - C03B 23/203: Uniting glass sheets (C03B23/24 takes precedence) - G06T 7/001: {using an image reference approach} - G06T 7/73: using feature-based methods - B23K 26/03: Observing, e.g. monitoring, the workpiece - B23K 2101/18: Sheet panels - B23K 2103/54: {Glass} - G06T 2207/30164: Workpiece; Machine component - Y02P 40/57: Improving the yield, e-g- reduction of reject rates - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The present disclosure relates to methods and devices for monitoring a welding process for welding at least one glass workpiece to another workpiece, the workpieces being welded together in a process zone that is exposed to a processing beam, e.g., to a laser beam, such as an ultra-short-pulse laser beam, wherein radiation emitted by the process zone and originating from at least one of the workpieces is detected in a spatially resolved manner. ## Claims ### Claim 1 A method for monitoring a welding process for welding at least one glass workpiece to a further workpiece, the method comprising welding the workpieces together in a process zone that is exposed to a processing beam guided to the process zone through the at least one glass workpiece, which is transparent to the processing beam; and detecting radiation emitted by the process zone and originating from at least one of the workpieces in a spatially resolved manner, wherein the emitted radiation comprises laser processing beam energy reflected or scattered from any one or more of cracks, imperfections, or defects within the at least one glass workpiece. ### Claim 2 (depends on 1) The method of claim 1, wherein the processing beam comprises a laser beam. ### Claim 3 (depends on 1) The method of claim 1, wherein the radiation originating from the workpiece is detected and captured by an image sensor, and further comprising converting the captured radiation into a signal with the image sensor, and preparing the signal for a subsequent evaluation. ### Claim 4 (depends on 2) The method of claim 2, wherein the laser beam comprises an ultrashort pulse laser beam. ### Claim 5 (depends on 1) The method of claim 1, wherein the radiation originating from the workpiece is detected in a spatially resolved manner outside the process zone. ### Claim 6 (depends on 1) The method of claim 1, wherein the radiation originating from the workpiece is further detected in a time-resolved manner. ### Claim 7 (depends on 3) The method of claim 3, wherein the signal is evaluated in terms of one or more of a presence, formation, or a change of one or more cracks, imperfections, or defects. ### Claim 8 (depends on 3) The method of claim 3, wherein two glass workpieces are welded together. ### Claim 9 (depends on 7) The method of claim 7, further comprising providing an error output when predefined tolerance limits of the one or more cracks, imperfections, or defects are exceeded. ### Claim 10 (depends on 3) The method of claim 3, wherein the signal is prepared by one or more of a filtering, noise reduction, smoothing, highlighting of special features, contrast enhancement, or an edge filter. ### Claim 11 (depends on 3) The method of claim 3, wherein the signal is evaluated by a spatial integration across the intensity values of the image pixels and a subsequent synchronization and a following comparison with a previously determined target value and/or by a synchronization of the intensity values with a previously determined target distribution of the intensity values, so as to detect one or more of the presence, formation, emergence, or the change of one or more of cracks, imperfections, or defects. ### Claim 12 (depends on 3) The method of claim 3, further comprising identifying one or more of cracks, imperfections, or defects based on the radiation detected in a spatially resolved manner and originating from at least one of the workpieces; and outputting one or more of the identified cracks, imperfections, or defects in a spatially resolved manner. ### Claim 13 (depends on 3) The method of claim 3, further comprising localizing one or more of cracks, imperfections, or defects relative to the process zone; and outputting the localization of the one or more of the cracks, imperfections, or defects.