# US 11,999,102 B2 · Devices, systems, and methods for monitoring a powder layer in additive manufacturing processes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,102 B2 - Document ID: US11999102B2 - Status: Granted - Kind: B2 - Application number: 18/077,381 - Filed: 2022-12-08 - Published: 2023-04-06 - Granted: 2024-06-04 - Earliest claimed: 2019-07-26 - Assignees: Arcam AB - Applicants: Arcam AB - Inventors: Björn Löfving; Kristofer Karlsson - Web page: https://patentgrep.com/patent/US11999102B2 ## CPC - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B22F 10/00: Additive manufacturing of workpieces or articles from metallic powder (apparatus or devices therefor B22F12/00) - B22F 10/28: Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] - B22F 10/37: of powder bed aspects, e.g. density - B22F 10/85: for controlling or regulating additive manufacturing processes - B22F 12/60: Planarisation devices; Compression devices - B22F 12/67: Blades - B22F 12/90: Means for process control, e.g. cameras or sensors - B29C 64/393: for controlling or regulating additive manufacturing processes - B33Y 10/00: Processes of additive manufacturing - G06V 10/25: Determination of region of interest [ROI] or a volume of interest [VOI] - B22F 10/10: Formation of a green body - B22F 10/32: of the atmosphere, e.g. composition or pressure in a building chamber - B22F 10/368: Temperature or temperature gradient, e.g. temperature of the melt pool - B22F 10/38: to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures - B22F 12/52: Hoppers - B22F 12/55: Two or more means for feeding material - B22F 2203/03: for feed-back - B22F 2203/11: temperature, temperature profile - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - 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 - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Devices, systems, and methods for monitoring a powder layer in additive manufacturing are disclosed. A method of monitoring a powder layer includes receiving image data corresponding the powder layer supported by a powder bed within a build chamber from imaging devices, determining leading and trailing regions of interest located adjacent to a leading end and a trailing end of the moving powder distributor, respectively, the leading and trailing regions of interest moving according to movement of the moving powder distributor, selecting at least one point located in the leading region of interest from the image data, determining first characteristics of the point, when the point is located within the trailing region of interest, determining second characteristics of the point, and comparing the first characteristics to the second characteristics. ## Claims ### Claim 1 An additive manufacturing system, the additive manufacturing system comprising: a build chamber comprising a powder distributor and a powder bed, the powder bed supporting a powder layer thereon, the powder distributor movable over the powder bed to distribute the powder layer; an imaging device positioned adjacent to the build chamber such that a field of view of the imaging device encompasses the powder bed; and a control component communicatively coupled to the imaging device, the control component configured to receive image data from the imaging device, determine a leading region of interest adjacent to a leading end of the powder distributor and a trailing region of interest adjacent to a trailing end of the powder distributor in the image data, select at least one point on the powder bed that is within the leading region of interest, determine one or more first characteristics of the at least one point, determine one or more second characteristics of the at least one point when the powder distributor moves such that the at least one point is located within the trailing region of interest, and compare the one or more first characteristics with the one or more second characteristics to monitor the powder layer. ### Claim 2 (depends on 1) The additive manufacturing system of claim 1, wherein the imaging device is an area scan camera. ### Claim 3 (depends on 2) The additive manufacturing system of claim 2, wherein the area scan camera comprises a monochrome sensor. ### Claim 4 (depends on 2) The additive manufacturing system of claim 2, wherein the area scan camera comprises a color sensor and a Bayer filter. ### Claim 5 (depends on 1) The additive manufacturing system of claim 1, wherein the imaging device detects radiation reflected off the powder layer and the image data comprises a radiation map. ### Claim 6 (depends on 1) The additive manufacturing system of claim 1, wherein the control component is further configured to determine one or more defects of the powder layer based on the comparing. ### Claim 7 An additive manufacturing system, the additive manufacturing system comprising: a build chamber comprising a powder distributor and a powder bed, the powder bed supporting a powder layer thereon, the powder distributor movable over the powder bed to distribute the powder layer; a dynamic optical element positioned adjacent to the build chamber; a plurality of imaging devices positioned adjacent to the build chamber and optically coupled to the dynamic optical element such that a field of view of a first imaging device of the plurality of imaging devices is directed towards a leading region of interest located adjacent to a leading end of the powder distributor and such that a field of view of a second imaging device of the plurality of imaging devices is directed towards a trailing region of interest located adjacent to a trailing end of the powder distributor; and a control component communicatively coupled to each of the plurality of imaging devices, the control component configured to receive image data from the plurality of imaging devices, select at least one point on the powder bed that is located within the leading region of interest, determine one or more first characteristics of the at least one point, determine one or more second characteristics of the at least one point when the powder distributor moves such that the at least one point is located within the trailing region of interest, and compare the one or more first characteristics with the one or more second characteristics to monitor the powder layer. ### Claim 8 (depends on 7) The additive manufacturing system of claim 7, wherein at least one of the plurality of imaging devices is a hyperspectral line scan camera. ### Claim 9 (depends on 7) The additive manufacturing system of claim 7, wherein the dynamic optical element comprises at least one of a rotating mirror, a MEMS mirror, a lens, and a prism. ### Claim 10 (depends on 7) The additive manufacturing system of claim 7, wherein the plurality of imaging devices detect radiation reflected off the powder layer and the image data comprises a radiation map. ### Claim 11 (depends on 7) The additive manufacturing system of claim 7, wherein the control component is further configured to determine one or more defects of the powder layer based on the comparing.