# US 12,179,502 B2 · Three-dimensional printing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,179,502 B2 - Document ID: US12179502B2 - Status: Granted - Kind: B2 - Application number: 17/949,330 - Filed: 2022-09-21 - Published: 2023-03-23 - Granted: 2024-12-31 - Earliest claimed: 2021-09-22 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Keigo Sugai; Masaru Kumagai - Web page: https://patentgrep.com/patent/US12179502B2 ## CPC - B41J 3/4073: {Printing on three-dimensional objects not being in sheet or web form, e.g. spherical or cubic objects (B41J3/283, B41J3/286 take precedence; building up a 3D object using individual droplets from jetting heads B29C64/112)} - B41J 2/04551: {using several operating modes} - B41J 2/04573: {Timing; Delays} - B41J 2/04581: {controlling heads based on piezoelectric elements} - B41J 2/04588: {using a specific waveform} - B41J 2/04593: {Dot-size modulation by changing the size of the drop} - B41J 25/308: with print gap adjustment mechanisms - B41J 25/3086: {with print gap adjustment means between the print head and its carriage} - B41J 2/2132: {Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding (methods for local corrections by dot omission, image edge enhancement, or multi-pass mask selection G06K15/102; colour conversion H04N1/40)} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A three-dimensional printing device includes a first head having a first nozzle array that ejects liquid, a second head having a second nozzle array that ejects liquid, and a moving mechanism having a linear motion mechanism that changes relative positions of the heads with respect to a three-dimensional workpiece. The first region of the workpiece is more inclined with respect to the first axis than the second region of the workpiece. A time period when the first nozzle array faces the first region and the second nozzle array faces the second region is a first time period. In the first time period, the first nozzle array ejects the liquid onto the first region in a first ejection cycle. In the first time period, the second nozzle array ejects the liquid onto the second region in a second ejection cycle. The first ejection cycle is shorter than the second ejection cycle. ## Claims ### Claim 1 A three-dimensional printing device comprising: a first head having a first nozzle array that ejects liquid; a second head having a second nozzle array that ejects liquid; a control circuit controlling ejection of ink from the first head and the second head, and a moving mechanism having a linear motion mechanism that changes relative positions of the first head and the second head with respect to a three-dimensional workpiece along a first axis, wherein when the workpiece includes a first region and a second region adjacent to the first region, the first region is more inclined with respect to the first axis than the second region as viewed along a second axis intersecting the first axis, and a time period when the first nozzle array faces the first region and the second nozzle array faces the second region during execution of movement by the linear motion mechanism is a first time period, the control circuit performs control such that the first nozzle array ejects the liquid onto the first region in a first ejection cycle in the first time period, and the second nozzle array ejects the liquid onto the second region in a second ejection cycle in the first time period, the first ejection cycle being shorter than the second ejection cycle. ### Claim 2 (depends on 1) The three-dimensional printing device according to claim 1, wherein when a time period when the first nozzle array faces the second region during the execution of the movement by the linear motion mechanism is a second time period, the first nozzle array ejects the liquid onto the second region in the second ejection cycle in the second time period. ### Claim 3 (depends on 2) The three-dimensional printing device according to claim 2, wherein the moving mechanism includes a linear motion encoder that outputs a pulse signal according to amounts of relative movement of the first head and the second head with respect to the workpiece along the first axis, the first ejection cycle and the second ejection cycle are defined based on the number of pulse signals output by the linear motion encoder, and the number of pulse signals for the first head to eject the liquid in the first ejection cycle is smaller than the number of pulse signals for the first head to eject the liquid in the second ejection cycle. ### Claim 4 (depends on 1) The three-dimensional printing device according to claim 1, wherein the first nozzle array is provided in a first nozzle surface of the first head, the second nozzle array is provided in a second nozzle surface of the second head, and the moving mechanism includes a first elevating mechanism that is moved by the linear motion mechanism to move the first nozzle surface along a third axis intersecting the first axis and the second axis, and a second elevating mechanism that is moved by the linear motion mechanism to move the second nozzle surface along the third axis. ### Claim 5 (depends on 4) The three-dimensional printing device according to claim 4, wherein in the first time period, an amount of the movement of the first nozzle surface by the first elevating mechanism is larger than an amount of the movement of the second nozzle surface by the second elevating mechanism. ### Claim 6 (depends on 4) The three-dimensional printing device according to claim 4, wherein the moving mechanism includes a linear motion encoder that outputs an output signal according to amounts of relative movement of the first head and the second head with respect to the workpiece along the first axis, a first elevation encoder that outputs an output signal according to an operational amount of the first elevating mechanism, and a second elevation encoder that outputs an output signal according to an operational amount of the second elevating mechanism, the first ejection cycle is defined based on the output signal of the linear motion encoder and the output signal of the first elevation encoder in the first time period, and the second ejection cycle is defined based on the output signal of the linear motion encoder and the output signal of the second elevation encoder in the first time period. ### Claim 7 (depends on 4) The three-dimensional printing device according to claim 4, wherein the moving mechanism includes a linear motion encoder that outputs an output signal according to amounts of relative movement of the first head and the second head with respect to the workpiece along the first axis, the first ejection cycle and the second ejection cycle are defined based on the number of pulse signals output by the linear motion encoder, and operations of the first elevating mechanism and the second elevating mechanism are defined based on the number of pulse signals output by the linear motion encoder. ### Claim 8 (depends on 7) The three-dimensional printing device according to claim 7, further comprising an energy emitting unit that emits energy to cure the liquid, wherein the moving mechanism includes a third elevating mechanism that is moved by the linear motion mechanism to move the energy emitting unit along the third axis, and an operation of the third elevating mechanism is defined based on the number of pulse signals output by the linear motion encoder. ### Claim 9 (depends on 4) The three-dimensional printing device according to claim 4, further comprising a controller that controls the first head, the second head, and the moving mechanism, wherein the moving mechanism includes a linear motion encoder that outputs a pulse signal according to amounts of relative movement of the first head and the second head with respect to the workpiece along the first axis, in the first time period, the moving mechanism determines the first ejection cycle and the second ejection cycle based on first correspondence information indicating a correspondence relationship between the number of pulse signals output by the linear motion encoder, the first ejection cycle, and the second ejection cycle, and the number of pulse signals output by the linear motion encoder, in the first time period, the moving mechanism determines a first movement amount of the first nozzle surface and a second movement amount of the second nozzle surface based on second correspondence information indicating a correspondence relationship between the number of pulse signals output by the linear motion encoder, the movement amount of the first nozzle surface, and the movement amount of the second nozzle surface, and the number of pulse signals output by the linear motion encoder, and in the first time period, the moving mechanism performs a process of controlling the first head to cause the first head to eject the liquid in the determined first ejection cycle, a process of controlling the second head to cause the second head to eject the liquid in the determined second ejection cycle, a process of controlling the first elevating mechanism to cause the first elevating mechanism to move the first nozzle surface by the determined first movement amount, and a process of controlling the second elevating mechanism to cause the second elevating mechanism to move the second nozzle surface by the determined second movement amount. ### Claim 10 (depends on 9) The three-dimensional printing device according to claim 9, wherein the controller generates the first correspondence information and the second correspondence information based on workpiece information indicating a position of the workpiece and a shape of the workpiece. ### Claim 11 A three-dimensional printing device comprising: a first head having a first nozzle surface in which a first nozzle array that ejects liquid is provided; a second head having a second nozzle surface in which a second nozzle array that ejects liquid is provided; a control circuit controlling ejection of ink from the first head and the second head, and a moving mechanism having a linear motion mechanism that changes relative positions of the first head and the second head with respect to a three-dimensional workpiece along a first axis, wherein the moving mechanism includes: a first elevating mechanism to move the first nozzle surface along a third axis intersecting the first axis, and a second elevating mechanism to move the second nozzle surface along the third axis, the first elevating mechanism and the second elevating mechanism are moved along the first axis by the linear motion mechanism, and when a predetermined time period during execution of movement by the linear motion mechanism is a first time period, a cycle in which the first nozzle array ejects the liquid is a first ejection cycle in the first time period, and a cycle in which the second nozzle array ejects the liquid is a second ejection cycle in the first time period, an amount of movement of the first nozzle surface along the third axis in the first time period is larger than an amount of movement of the second nozzle surface along the third axis in the first time period, wherein the control circuit performs control such that the first ejection cycle is shorter than the second ejection cycle. ### Claim 12 (depends on 11) The three-dimensional printing device according to claim 11, wherein when a time period after the first time period during the execution of the movement by the linear motion mechanism is a second time period, the first nozzle array ejects the liquid in the second ejection cycle in the second time period. ### Claim 13 (depends on 11) The three-dimensional printing device according to claim 11, wherein when the workpiece includes a first region and a second region adjacent to the first region, and the first region is more inclined with respect to the first axis than the second region as viewed along a second axis intersecting the first axis and the third axis, the first nozzle array faces the first region in the first time period and the second nozzle array faces the second region in the first time period.