# US 11,440,098 B2 · Three-dimensional printing system optimizing contour formation for multiple energy beams > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,098 B2 - Document ID: US11440098B2 - Status: Granted - Kind: B2 - Application number: 16/703,162 - Filed: 2019-12-04 - Published: 2020-07-02 - Granted: 2022-09-13 - Earliest claimed: 2018-12-27 - Assignees: Layerwise NV - Applicants: LayerWise NV - Inventors: Nachiketa Ray; Jan Plas - Web page: https://patentgrep.com/patent/US11440098B2 ## CPC - B29C 64/393: for controlling or regulating additive manufacturing processes - B22F 10/28: Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] - B22F 10/366: Scanning parameters, e.g. hatch distance or scanning strategy - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B29C 64/268: using laser beams; using electron beams [EB] - B29C 64/282: of the same type, e.g. using different energy levels - B22F 10/31: Calibration of process steps or apparatus settings, e.g. before or during manufacturing - B22F 12/50: Means for feeding of material, e.g. heads - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 50/02: for controlling or regulating additive manufacturing processes - Y02P 10/25: Process efficiency - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A system for forming a three-dimensional (3D) article includes a powder dispenser, a fusing apparatus, and a controller. The plurality of energy beams include at least a first beam and a second beam. The controller is configured to operate the powder dispenser to dispense a layer of powder and to operate the fusing apparatus to selectively fuse the layer of powder. Operating the fusing apparatus includes operating the first beam to fuse a first hatch pattern over a first area of the layer of powder and operate at least the second beam to fuse a contour that bounds the hatch pattern. The contour is formed from N scans along the contour. N is an integer that is at least equal to one. N is determined by a lateral alignment uncertainty between at least two of the energy beams. ## Claims ### Claim 1 A method of manufacturing a three-dimensional (3D) article comprising: determining a lateral alignment uncertainty for a system, the system including a powder dispenser for sequentially dispensing individual layers of powder and a fusing apparatus for generating and scanning a plurality of energy beams including a first beam and a second beam to selectively melt the layers of powder, the lateral alignment uncertainty is with respect to at least the first beam and the second beam; determining a number N of overlapping scans for forming a contour that bounds a hatch pattern, N is an integer at least equal to one, the determination is based at least partly upon the lateral alignment uncertainty; operating the powder dispenser to dispense a layer of powder; and operating the fusing apparatus to selectively fuse the powder including: operating at least the first beam to fuse a first hatch pattern over an area of the layer of powder; and operating at least the second beam to fuse a contour using the N overlapping scans to form the contour having a contour width that is equal to N times a melt width of a single scan minus a cumulative overlap of the N overlapping scans. ### Claim 2 (depends on 1) The method of claim 1 wherein the plurality of energy beams includes a third beam, the method further comprises operating the third beam to fuse a second hatch pattern over a second area of the layer of powder. ### Claim 3 (depends on 1) The method of claim 1 wherein N is monotonically related to the lateral alignment uncertainty. ### Claim 4 (depends on 1) The method of claim 1 wherein N is proportional to or increasing with the lateral alignment uncertainty. ### Claim 5 (depends on 1) The method of claim 1 wherein N times the melt width of a single scan is at least equal to the lateral alignment uncertainty. ### Claim 6 A computer-readable storage medium for manufacturing a three-dimensional (3D) article, the computer-readable storage medium being non-transitory and having computer-readable program code portions stored therein that in response to execution by a processor cause a three-dimensional (3D) printing system to: determine a lateral alignment uncertainty for a system, the system including a powder dispenser for sequentially dispensing individual layers of powder and a fusing apparatus for generating and scanning a plurality of energy beams including a first beam and a second beam to selectively melt the layers of powder, the lateral alignment uncertainty is with respect to at least the first beam and the second beam; and determine a number N of overlapping scans for forming a contour that bounds a hatch pattern, N is an integer at least equal to one, the determination is based at least partly upon the lateral alignment uncertainty; operate the powder dispenser to dispense a layer of powder; and operate the fusing apparatus to selectively fuse the powder including: operate at least the first beam to fuse a first hatch pattern over an area of the layer of powder; and operate at least the second beam to fuse a contour using the N overlapping scans to form the contour having a contour width that is equal to N times a melt width of a single scan minus a cumulative overlap of the N overlapping scans. ### Claim 7 (depends on 6) The computer-readable storage medium of claim 6 wherein the plurality of energy beams includes a third beam, execution by the processor further causes three-dimensional (3D) printing system to fuse a second hatch pattern over a second area of the layer of powder. ### Claim 8 (depends on 6) The computer-readable storage medium of claim 6 wherein N is monotonically related to the lateral alignment uncertainty. ### Claim 9 (depends on 6) The computer-readable storage medium of claim 6 wherein N is proportional to or increasing with the lateral alignment uncertainty. ### Claim 10 (depends on 6) The computer-readable storage medium of claim 6 wherein N times the melt width of a single scan is at least equal to the lateral alignment uncertainty.