# US 11,305,483 B2 · Techniques for application of light in additive fabrication and related systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,305,483 B2 - Document ID: US11305483B2 - Status: Granted - Kind: B2 - Application number: 16/163,403 - Filed: 2018-10-17 - Published: 2019-05-23 - Granted: 2022-04-19 - Earliest claimed: 2017-10-20 - Assignees: Formlabs, Inc. - Applicants: Formlabs, Inc. - Inventors: Andrew M. Goldman - Web page: https://patentgrep.com/patent/US11305483B2 ## CPC - B29C 64/135: the energy source being concentrated, e.g. scanning lasers or focused light sources - B29C 64/236: for motion in a direction within the plane of a layer - B29C 64/245: Platforms or substrates (support structures intended to be sacrificed after manufacture B29C64/40) - B29C 64/268: using laser beams; using electron beams [EB] - B29C 64/277: using multiple radiation means, e.g. micromirrors or multiple light-emitting diodes [LED] - B29C 64/393: for controlling or regulating additive manufacturing processes - B29C 64/218: Rollers - 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 - 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) - 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 ## Abstract Techniques for illuminating a photocurable material within a build area of an additive fabrication device are described. According to some aspects, a light source is provided that can be moved alongside a build area, allowing light to be directed to any desired position within the build area by moving the light source. This configuration may also allow the distance from the light source to the build area to be substantially the same for each position across the build area by moving the light source whilst maintaining a fixed distance from the light source to the build volume. The described approach may allow for fabrication of larger parts in an additive fabrication device by expanding or eliminating the practical upper limit on the area of the build volume that can be imposed by use of a laser light source in such a device. ## Claims ### Claim 1 An additive fabrication device configured to form layers of solid material on a build platform, each layer of material being formed so as to contact a container in addition to the surface of the build platform and/or a previously formed layer of material, the additive fabrication device comprising: a container having an interior bottom surface extending in a first direction and a second direction, perpendicular to the first direction, wherein the interior bottom surface of the container is formed, at least in part, from a suspended film; and a movable stage configured to move in the first direction, the movable stage being arranged beneath the container and comprising: a plurality of light sources offset from one another along the second direction and operable to direct light through the interior bottom surface of the container; and a plurality of leveling elements configured to contact the suspended film while the movable stage moves in the first direction, the plurality of leveling elements including leveling elements arranged on either side of the plurality of light sources along the first direction that apply an upward force on the suspended film to produce a flat region of the suspended film between the leveling elements arranged on either side of the plurality of light sources as the movable stage moves in the first direction. ### Claim 2 (depends on 1) The additive fabrication device of claim 1, wherein the plurality of leveling elements includes one or more rollers. ### Claim 3 (depends on 2) The additive fabrication device of claim 2, wherein the one or more rollers are mechanically coupled to the moveable stage. ### Claim 4 (depends on 1) The additive fabrication device of claim 1, further comprising at least one lens coupled to the moveable stage and arranged between one or more of the plurality of light sources and the container. ### Claim 5 (depends on 1) The additive fabrication device of claim 1, wherein the plurality of light sources comprise a plurality of light sources of a first size and a plurality of light sources of a second size, different from the first size. ### Claim 6 (depends on 5) The additive fabrication device of claim 5, wherein the plurality of light sources of the first size is offset from the plurality of light sources of the second size along the first direction. ### Claim 7 (depends on 1) The additive fabrication device of claim 1, wherein the plurality of light sources comprise: a first group of light sources offset from one another along the second direction; and a second group of light sources offset from one another along the second direction and offset from the first group of light sources along the first direction. ### Claim 8 (depends on 7) The additive fabrication device of claim 7, wherein each of the light sources of the second group of light sources are offset from all of the light sources of the first group of light sources in both the first and the second direction. ### Claim 9 (depends on 1) The additive fabrication device of claim 1, wherein the movable stage extends over the entire extent of the container along the second direction. ### Claim 10 (depends on 1) The additive fabrication device of claim 1, wherein the plurality of light sources comprise a plurality of LEDs. ### Claim 11 A method of additive fabrication, the method comprising: moving, within an additive fabrication device, a movable stage beneath a container having an interior bottom surface extending in a first direction and a second direction, perpendicular to the first direction, wherein the interior bottom surface of the container is formed, at least in part, from a suspended film, the container holding a liquid photopolymer, and the movable stage configured to move in the first direction, the movable stage being arranged beneath the container and comprising a plurality of light sources offset from one another along the second direction and operable to direct light through the interior bottom surface of the container, and a plurality of leveling elements configured to contact the suspended film while the movable stage moves in the first direction, the plurality of leveling elements including leveling elements arranged on either side of the plurality of light sources along the first direction that apply an upward force on the suspended film to produce a flat region of the suspended film between the leveling elements arranged on either side of the plurality of light sources as the movable stage moves in the first direction; and directing actinic radiation from at least some of the plurality of light sources through the flat region of the suspended film to the liquid photopolymer held by the container, thereby forming a layer of solid material that contacts the interior bottom surface in addition to the surface of a build platform and/or to a previously formed layer of material. ### Claim 12 (depends on 11) The method of claim 11, wherein the additive fabrication device comprises at least one lens coupled to the moveable stage, the at least one lens being arranged between one or more of the plurality of light sources and the container. ### Claim 13 (depends on 11) The method of claim 11, wherein the plurality of light sources comprise a plurality of light sources of a first size and a plurality of light sources of a second size, different from the first size. ### Claim 14 (depends on 13) The method of claim 13, wherein the plurality of light sources of the first size is offset from the plurality of light sources of the second size along the first direction. ### Claim 15 (depends on 11) The method of claim 11, wherein the plurality of light sources comprise: a first group of light sources offset from one another along the second direction; and a second group of light sources offset from one another along the second direction and offset from the first group of light sources along the first direction. ### Claim 16 (depends on 15) The method of claim 15, wherein each of the light sources of the second group of light sources are offset from all of the light sources of the first group of light sources in both the first and the second direction. ### Claim 17 (depends on 11) The method of claim 11, wherein the movable stage extends over the entire extent of the container along the second direction. ### Claim 18 (depends on 11) The method of claim 11, wherein the plurality of light sources comprise a plurality of LEDs.