JP2016137654A - Three-dimensional shaping device, shaping method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform high-quality shaping without forming irregularity not included in a shape represented by object data.SOLUTION: A three-dimensional shaping device 100, 200 comprises: droplet discharge parts Nt; a support part 11 to support a structure formed from droplets; a scan part 52 capable of relative displacement of the droplet discharge parts Nt relatively to the support part 11; and control parts 210, 70. A method comprises: discharging droplets from the droplet discharge parts Nt on the basis of the same reference signal so as to form a model (S10); measuring the height in the discharge directions of the droplets in a plurality of sites of the model corresponding to each droplet discharge part Nt (S20); determining a proportion of the droplets to be reduced for each droplet discharge part Nt on the basis of a result of the measurement (S32); determining a reduction pattern PF defining reduction positions at which to reduce the discharge amount for each droplet discharge part Nt on the basis of the proportion of the droplets to be reduced (S34); and discharging the droplets from the droplet discharge parts Nt on the basis of object data Do, which represents a shape of an object, and the reduction pattern PF so as to shape the object (S40).SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for modeling a three-dimensional object.

  Conventionally, a three-dimensional object is formed by repeating the process of discharging and curing droplets at successive positions on a flat surface to form a plate-like member and then forming a plate-like member thereon. There exists a technique to perform (Patent Document 1).

Japanese Patent No. 4888257 JP 2013-67121 A

  However, irregularities that are not included in the shape represented by the object data may be formed due to variations in the amount of each droplet or deformation of the material during the curing process.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

(1) According to one aspect of the present invention, there is provided a three-dimensional modeling apparatus that models an object by discharging droplets. The three-dimensional modeling apparatus includes: a plurality of droplet discharge units that can discharge droplets; a support unit that supports a structure constituted by the droplets; A scanning unit capable of relatively moving the plurality of droplet ejection units in a first direction intersecting with the ejection direction, and in a second direction intersecting with the droplet ejection direction and the first direction; A control unit that controls the droplet discharge unit, the support unit, and the scanning unit. The control unit is configured to cause the scanning unit to perform scanning in the first and second directions, from the plurality of droplet discharge units toward the support unit based on the same reference signal. A model forming unit that forms a model by discharging a droplet; and a measuring unit that measures heights of the droplets in the discharge direction at a plurality of portions of the model corresponding to each of the plurality of droplet discharge units; A ratio determining unit that determines a ratio of droplets to be reduced for each of the plurality of droplet discharge units based on the measurement result; and a plurality of liquids based on the ratio of the droplets to be reduced A pattern determining unit that determines a reduction pattern for determining a reduction position for reducing the discharge amount for each of the droplet discharge units; and causing the scanning unit to scan in the first and second directions while changing the shape of the object. The object data to represent and the previous And reducing the pattern, based on, by ejecting droplets from the plurality of droplet ejecting sections, and a molding unit for molding an object.
With such an aspect, it is possible to perform modeling with a low possibility of forming irregularities not included in the shape represented by the object data.

  In the three-dimensional modeling apparatus of the above aspect, the reduced position is a position where a smaller amount of droplets than the amount of droplets ejected based on the reference signal should be ejected regardless of the object data. It can be. According to such an aspect, it is possible to perform high-quality modeling by canceling the variation in the amount of droplets discharged from each droplet discharge unit due to the difference in the amount of specified droplets.

  In the three-dimensional modeling apparatus of the above aspect, the reduction position may be a position where the droplet is not ejected from the droplet ejecting unit regardless of the object data. By adopting such an aspect, it is possible to perform high-quality modeling by canceling the variation in the amount of droplets ejected from each droplet ejection unit by not ejecting the designated droplets.

(2) In the three-dimensional modeling apparatus of the above aspect, the reduction pattern may include a plurality of two-dimensional patterns. Each of the plurality of two-dimensional patterns is a two-dimensional pattern in which one direction corresponds to each of the plurality of droplet discharge units, and is different from each other as the reduction position for each of the plurality of droplet discharge units. It can be set as the aspect which has determined the position. The modeling unit discharges droplets from the plurality of droplet discharge units based on cross-sectional data generated from the object data and representing a cross-sectional shape of the object and one of the plurality of two-dimensional patterns. Thus, the first processing for forming the plate-like structure having the shape of the cross section is applied to each of the plurality of two-dimensional patterns in order, and the plurality of cross sections of the object are perpendicular to the cross section. It can be set as the aspect which performs the process which overlaps and forms the said several plate-shaped structure by repeating about the different cross section arranged in a direction. With such an aspect, the amount of droplets is reduced at different positions in the plane. For this reason, it is possible to form an object having a shape that accurately reflects object data while reducing the occurrence of unevenness due to the adjustment of the height of each part in the formation of the object.

(3) In the three-dimensional modeling apparatus according to the above aspect, the first process includes: scanning the plurality of droplet discharge units in the first direction while discharging droplets from the plurality of droplet discharge units. By repeating the process; and the process of scanning the plurality of droplet discharge units in the second direction without discharging the droplets from the plurality of droplet discharge units, they are arranged in the first direction. For the region where the droplets are newly supplied while supplying the droplets on the gaps between the lines to which the droplets have already been supplied, every one or several lines that are newly arranged in the first direction. It can be set as the aspect which is a process which supplies a droplet on top and forms the said plate-shaped structure. With such an aspect, it is possible to disperse the locations where each droplet discharge unit discharges droplets. For this reason, it is possible to reduce the occurrence of unevenness on the object due to variations in the performance of each droplet discharge section.

(4) In the three-dimensional modeling apparatus of the above aspect, the first process includes: scanning the plurality of droplet discharge units in the first direction while discharging droplets from the plurality of droplet discharge units. By repeating the process; and the process of scanning the plurality of droplet discharge units in the second direction without discharging the droplets from the plurality of droplet discharge units, the first direction is extended. It is possible to adopt an aspect in which the plate-like structure is formed by supplying the droplets in a shared manner by different droplet discharge units on the line. According to such an aspect, compared to an aspect in which one droplet ejection unit ejects droplets in one line extending in the first direction, the variation in performance of each droplet ejection unit is in the first direction. Difficult to be reflected in one extended line. For this reason, it is possible to reduce the occurrence of unevenness on the object due to variations in the performance of each droplet discharge section.

(5) According to another aspect of the present invention, there is provided a method for modeling an object by discharging droplets. The method includes: (a) forming a model by ejecting droplets from a plurality of droplet ejection units based on the same reference signal; and (b) each of the plurality of droplet ejection units. A step of measuring the height of the droplet in the discharge direction at a plurality of corresponding parts of the model; and (c) a liquid to be reduced for each of the plurality of droplet discharge units based on the measurement result. (D) determining a reduction pattern for determining a reduction position at which the discharge amount should be reduced for each of the plurality of droplet discharge units, based on the ratio of the droplets to be reduced; And (e) ejecting droplets from the plurality of droplet ejection units based on the object data representing the shape of the object and the reduction pattern, and shaping the object.
Even in such an aspect, it is possible to perform modeling with a low possibility of forming irregularities not included in the object data.

  A plurality of constituent elements of each aspect of the present invention described above are not indispensable, and some or all of the effects described in the present specification are to be solved to solve part or all of the above-described problems. In order to achieve the above, it is possible to appropriately change, delete, replace with another new component, and partially delete the limited contents of some of the plurality of components. In order to solve part or all of the above-described problems or to achieve part or all of the effects described in this specification, technical features included in one embodiment of the present invention described above. A part or all of the technical features included in the other aspects of the present invention described above may be combined to form an independent form of the present invention.

  The present invention can be realized in various forms other than the apparatus. For example, it can be realized in the form of a three-dimensional modeling method, a three-dimensional modeling apparatus control method, a computer program for realizing the control method, a non-temporary recording medium on which the computer program is recorded, or the like.

It is explanatory drawing which shows schematic structure of the three-dimensional modeling apparatus as 1st Embodiment of this invention. 4 is a diagram illustrating an example of an original drive signal supplied to a piezo element of a head unit 50. It is a flowchart explaining the process of modeling of the three-dimensional object in this embodiment. It is the graph which showed the height of each field when the height of the highest field among the upper surfaces of model Pt0 was made into 100%. It is a graph which shows the ratio of the quantity of the droplet which each nozzle after adjustment should discharge. It is a figure showing the reduction pattern PF which determines the reduction position which should reduce discharge amount rather than the droplet discharged based on the signal given about each nozzle. It is a figure which shows the voxel which each nozzle prints in the scan of the X direction of step S44, and a Y direction. It is a figure which shows how the two-dimensional pattern Pdi is applied when a droplet is discharged from each nozzle and the plate-like structure Ps is formed in the scanning of the X direction and Y direction of step S44. It is explanatory drawing which shows schematic structure of the three-dimensional modeling apparatus in 2nd Embodiment.

A. First embodiment:
FIG. 1 is an explanatory diagram showing a schematic configuration of a three-dimensional modeling apparatus as a first embodiment of the present invention. The three-dimensional modeling apparatus 100 includes a modeling unit 10, a powder supply unit 20, a flattening mechanism 30, a powder recovery unit 40, a head unit 50, a curing energy application unit 60, a control unit 70, and a measurement. Instrument 80. A computer 200 is connected to the control unit 70. The three-dimensional modeling apparatus 100 and the computer 200 can be combined and understood as a “three-dimensional modeling apparatus” in a broad sense.

  FIG. 1 shows an X direction, a Y direction, and a Z direction orthogonal to each other. The Z direction is a direction along the vertical direction, and the X direction is a direction along the horizontal direction. The Y direction is a direction perpendicular to the Z direction and the X direction.

  The modeling unit 10 includes a container 10c whose upper surface is open, and is a structure for modeling a three-dimensional object inside the container 10c. The modeling unit 10 moves the modeling stage 11 having a flat upper surface along the XY direction, the frame 12 surrounding the modeling stage 11 and standing in the Z direction, and the modeling stage 11 along the Z direction. And an actuator 13. A container 10c is constituted by the modeling stage 11 constituting the bottom surface and the frame body 12 constituting the side surface. When the control unit 70 controls the operation of the actuator 13, the modeling stage 11 can move in the Z direction within the frame 12. The material constituting the three-dimensional object is supplied to the container 10c. In the first embodiment, a photocurable liquid (hereinafter referred to as “curing liquid”) and powder are used as the material of the three-dimensional object.

  The powder supply unit 20 is an apparatus that supplies powder as a material constituting a three-dimensional object into a container 10 c constituted by the modeling stage 11 and the frame body 12. The powder supply unit 20 is configured by, for example, a hopper or a dispenser.

  The flattening mechanism 30 moves the upper surface of the powder in the container 10 c in the horizontal direction (XY direction), thereby flattening the upper surface of the powder in the container 10 c and forming a powder layer on the modeling stage 11. . The flattening mechanism 30 is configured by, for example, a squeegee (a spatula) or a roller. The powder pushed out from the upper surface of the powder in the container 10c by the flattening mechanism 30 is discharged into a powder recovery unit 40 provided adjacent to the container 10c.

  The curable liquid for constituting the three-dimensional object is a mixture of a liquid resin material and a polymerization initiator. The liquid resin material is mainly composed of a monomer and an oligomer to which the monomer is bonded. As the monomer for the resin material, a monomer having a relatively low molecular weight is selected. The number of monomers contained in one oligomer of the resin material is adjusted to about several molecules. Since the monomer and oligomer are adjusted in this way, the viscosity of the curable liquid is low enough to be ejected as droplets from the head unit 50.

  The polymerization initiator becomes an excited state when irradiated with ultraviolet light, and acts on the monomer or oligomer to start polymerization. When the curing liquid is irradiated with ultraviolet light and the polymerization initiator is excited, the monomers of the resin material are polymerized to grow into oligomers, and the oligomers are also polymerized in some places. As a result, the curable liquid quickly cures to become a solid.

  A different type of polymerization initiator from that contained in the curable liquid is attached to the surface of the powder as a material constituting the three-dimensional object. The polymerization initiator attached to the surface of the powder has the property of initiating polymerization by acting on the monomer or oligomer of the curable liquid when in contact with the curable liquid. Therefore, when the curable liquid is supplied to the powder in the container 10c, the curable liquid penetrates into the interior of the powder, and the curable liquid comes into contact with the polymerization initiator on the surface of the powder to be cured. As a result, in the portion where the curable liquid is discharged, the powders are bonded by the cured curable liquid. In addition, when using the powder by which the polymerization initiator adhered to the surface, it is also possible to use the hardening liquid which does not contain a polymerization initiator.

  The head unit 50 of the present embodiment is a so-called piezo drive type droplet discharge head. The head unit 50 is supplied with the above-described curable liquid from a tank 51 connected to the head unit 50. The control unit 70 can adjust the amount of the curable liquid ejected from one nozzle provided in the head unit 50 by controlling the waveform of the voltage of the signal applied to the piezo element.

  FIG. 2 is a diagram illustrating an example of the original drive signal supplied to the piezo element of the head unit 50. 2 shows two original drive signals COMA and COMB. In the upper part of FIG. 2, the horizontal axis represents time. In the upper part of FIG. 2, the vertical axis represents voltage. The original drive signal COMA has a pulse P11 and a pulse P12. The original drive signal COMB has a pulse P21 and a pulse P22.

  When only the pulse P11 is supplied to the piezo element, a 5 ng droplet is ejected from the nozzle. When only the pulse P12 is supplied to the piezo element, a 7.5 ng droplet is ejected from the nozzle. When only the pulse P21 is supplied to the piezo element, the meniscus on the liquid level in the nozzle oscillates, but no droplet is ejected from the nozzle. When only the pulse P22 is supplied to the piezo element, an 8 ng droplet is ejected from the nozzle.

  The original drive signals COMA and COMB can be supplied to one piezo element. More specifically, the pulses P11 and P21 before the original drive signals COMA and COMB can be selectively supplied to one piezo element. Then, the subsequent pulses P12 and P22 of the original drive signals COMA and COMB can be selectively supplied to one piezo element. The selection of the preceding pulse and the selection of the subsequent pulse are independent and are not limited to each other.

  The lower part of FIG. 2 is a table showing selection of pulses supplied to the piezo elements. Selection of the pulse supplied to the piezo element is determined by a combination of ON / OFF of selection signals S0 and S1 of the original drive signal COMA and ON / OFF of selection signals S0 and S1 of the original drive signal COMB. The selection signal ON is indicated by hatching. In the present embodiment, the control unit 70 includes a drive signal (see the uppermost stage) for supplying only the pulse P21 to the piezo element, a drive signal (see the second stage) for supplying only the pulse P22 to the piezo element, and a pulse P11. , 12 is supplied to each piezo element, and a drive signal is supplied to each piezo element (see the third stage) and a drive signal is supplied to the piezo element (see the fourth stage). Can do. These drive signals are represented by information of 00, 01, 10, and 11, respectively. With these four types of drive signals, droplets of 0 (not ejected), 8 ng, 12.5 ng, and 13 ng can be ejected from the nozzle. The drive signal (11) for discharging a 13 ng droplet is referred to as a “reference signal” in the present specification. In this embodiment, when ejecting a droplet in forming an object, in principle, a droplet based on a reference signal is used. When coloring an object, 8 ng droplets and 12.5 ng droplets are used for the colored curable liquid, in addition to 13 ng droplets according to the reference signal.

  The curable liquid supplied to the head unit 50 in FIG. 1 may be cyan, magenta, or yellow, and may not be colored. The head unit 50 includes a nozzle row of nozzles Nc that discharges droplets of a curable liquid colored cyan, a nozzle row of nozzles Nm that discharges droplets of a curable liquid colored magenta, And a nozzle row of nozzles Ny for discharging droplets of the curable liquid colored with a color and a nozzle row of nozzles Nt for discharging liquid droplets of colorless curable liquid. The numbers of nozzles Nc, Nm, Ny are equal to each other. The number of nozzles Nt is equal to the total number of nozzles Nc, Nm, and Ny.

  The nozzles of each nozzle row are arranged along the Y direction. The nozzle rows Nc, Nm, Ny, Nt are arranged side by side in the X direction. Of the three-dimensional object, a portion formed by combining powder with one or more colored curable liquids has a color corresponding to the color of the one or more curable liquids used. Of the three-dimensional object, a portion formed by combining powder with a colorless curable liquid is colorless or has a powder color.

  The head unit 50 is movable in the X direction and the Y direction with respect to the container 10c (modeling stage 11) by the scanning unit 52. The movement of the head unit 50 by the scanning unit 52 is also referred to as “scanning”. When the modeling stage 11 in the modeling unit 10 moves in the Z direction, the head unit 50 is relatively movable in the Z direction with respect to the container 10c and the three-dimensional object in the container 10c.

  The curing energy applying unit 60 is an apparatus for applying energy for curing the curable liquid to the curable liquid discharged from the head unit 50. In the present embodiment, the curing energy applying unit 60 is the light emitting device 61. The light emitting device 61 emits ultraviolet rays as curing energy for curing the curable liquid.

  The curing energy applying unit 60 is fixed to the head unit 50 at a position aligned with the head unit 50 in the X direction. When the head unit 50 is moved by the scanning unit 52, the curing energy application unit 60 (light emitting device 61) also moves together with the head unit 50.

  The measuring device 80 is a sensor that can measure the position (height) in the Z direction of an object placed on the modeling stage 11. In the present embodiment, the measuring device 80 is fixed to the head unit 50 on the side opposite to the curing energy applying unit 60 across the head unit 50 in the X direction. By the scanning unit 52, the measuring device 80 can also move in the X direction and the Y direction with respect to the modeling stage 11. The CPU 210 of the computer 200 can measure the height in the Z direction of the object at each position on the modeling stage 11 using the measuring device 80 via the control unit 70.

  The control unit 70 controls the actuator 13, the powder supply unit 20, the flattening mechanism 30, the head unit 50, the curing energy application unit 60, and the measuring device 80 in accordance with instructions from the CPU 210 of the computer 200. To do. The control unit 70 can model a three-dimensional object in the container 10 c by controlling each unit of the three-dimensional modeling apparatus 100. The control unit 70 includes a CPU, a memory, and a ROM. The CPU implements a function of printing a model and a function of modeling a three-dimensional object, as will be described later, by loading a computer program stored in the ROM into the memory and executing it. Note that these functions of the control unit 70 may be provided on the computer 200 side.

  The computer 200 includes a CPU 210, a memory, and a ROM. The CPU 210 loads a computer program stored in the ROM into the memory and executes it, thereby realizing a function of generating cross-sectional data, which will be described later, and a function of setting a drive signal for the piezo element according to the measurement result. Further, the CPU 210 controls and operates the 3D modeling apparatus 100 via the control unit 70.

  FIG. 3 is a flowchart for explaining processing of modeling a three-dimensional object in the present embodiment. In step S10, the CPU 210 of the computer 200 prints the model. Here, the model has a rectangular parallelepiped shape having planes perpendicular to the X, Y, and Z directions. More specifically, the CPU 210 controls the powder supply unit 20 and the flattening mechanism 30 via the control unit 70 of the three-dimensional modeling apparatus 100 to form a powder layer in the container 10c. Then, the CPU 210 uses the model data stored in the ROM of the computer 200 to drive the piezo element of one nozzle row of the head unit 50 via the control unit 70, and to powder the curable liquid. Discharge to the body layer. As a result, a rectangular parallelepiped model Pt0 is formed on the modeling stage 11 using a curable liquid.

  Here, it is assumed that the nozzle row used for forming the model Pt0 is one of the nozzles Nt that discharge a colorless curable liquid droplet. In forming the model, the same reference signal is supplied to the piezo elements corresponding to the respective nozzles. The reference signal is a drive signal for ejecting 13 ng droplets assuming an ideally formed piezo element and nozzle.

  In the model formation in step S10, a part of so-called pseudo band printing is performed as follows. The control unit 70 causes the head unit 50 to scan in the X direction via the scanning unit 52 and ejects droplets from each nozzle of one nozzle array arranged in the Y direction. At that time, the head unit 50 and the curing energy application unit 60 are scanned so that the head unit 50 first passes through each part on the powder layer, and then the curing energy application unit 60 passes. As a result, the curable liquid discharged from the head unit 50 to the powder layer is then cured by being irradiated with ultraviolet rays by the curing energy applying unit 60.

  Thereafter, the control unit 70 moves the head unit 50 along the X direction to a position before starting scanning in the X direction via the scanning unit 52. Then, the control unit 70 scans the head unit 50 in the Y direction via the scanning unit 52. The magnitude of scanning in the Y direction performed during scanning in the X direction is 1 / n of the pitch of nozzles arranged along the Y direction (n is an integer equal to or greater than 2. Here, n = 4 ). And the control part 70 discharges a droplet from each nozzle, making the head part 50 scan again about a X direction.

  In this way, by repeating the scanning in the X direction and the scanning in the Y direction performed while discharging droplets n times, a rectangular plate shape corresponding to the cross section of one layer in the model. The structure is formed. Thereafter, the CPU 210 drives the actuator 13 via the control unit 70 to lower the modeling stage 11 downward in the Z direction by a stacking pitch corresponding to the modeling resolution in the Z direction (for example, 600 dpi) (see FIG. 1). ). Then, the same process is repeated. That is, the control unit 70 returns the head unit 50 to the initial position, and forms a new plate-like structure on the plate-like structure Ps already formed on the modeling stage 11 (see FIG. 1). As a result, a rectangular parallelepiped model Pt0 is formed on the modeling stage 11.

  In the model Pt0 printed by such printing, a certain range (that is, a nozzle pitch range) in the Y direction is formed by droplets ejected from the same nozzle. In this embodiment, the range corresponds to n (n = 4) droplet discharge positions extending in the X direction. A functional unit of the CPU 210 of the computer 200 that realizes the process of step S10 is shown as a model forming unit 212 in FIG.

  In step S20 of FIG. 3, the CPU 210 uses the measuring device 80 via the control unit 70 to measure the height (position in the Z direction) at each position on the upper surface of the model Pt0 formed in step S10. . More specifically, the measuring unit 80 is scanned in the X direction and the Y direction on the model Pt0 using the scanning unit 52, and the height in the region formed by the same nozzle on the upper surface of the model Pt0 is determined. Then, the measuring device 80 is caused to measure for each such region. And CPU210 calculates the ratio of the height of each other area | region with respect to the height of the highest area | region among the upper surfaces of model Pt0. Each region can be associated with the nozzle that formed the region.

  FIG. 4 is a graph showing the height of each region when the height of the highest region of the upper surface of the model Pt0 is 100%. The horizontal axis of FIG. 4 indicates the positions of 180 nozzles in which each area of n lines (n = 4) is recorded as droplet discharge positions (also referred to as “voxel positions”) 0 to 720. As described above, even when modeling is performed with object data representing an object having a constant height, variations in height occur because of variations in the amount of liquid droplets discharged from each nozzle or during the curing process. This is thought to be due to deformation of the material. A functional unit of the CPU 210 of the computer 200 that realizes the process of step S20 is shown in FIG.

  FIG. 5 is a graph showing the ratio of the amount of droplets to be ejected by each adjusted nozzle. As in FIG. 4, the horizontal axis of FIG. 5 indicates the positions of 180 nozzles in which each area of n lines (n = 4) is recorded as voxel positions (0 to 720). In step S32 of FIG. 3, when the CPU 210 is given the data of the rectangular parallelepiped model having the uniform upper surface for each nozzle, the CPU 210 can form the rectangular parallelepiped having the uniform upper surface. The ratio of droplets to be ejected with the nozzle reduced is determined. That is, the CPU 210 determines the ratio of droplets to be reduced by each nozzle so that an object having an accurate shape according to the model data can be formed for each nozzle. The ratio of the liquid droplets to be discharged by each nozzle is the liquid droplets to be discharged from each nozzle when the discharge amount of the liquid droplets from the nozzles forming the part having the lowest height on the upper surface of the model is 100%. Expressed as a drop fraction. The shape of the graph of FIG. 5 is a shape obtained by inverting the graph of FIG. Note that the functional unit of the CPU 210 of the computer 200 that realizes the process of step S32 is shown as a ratio determination unit 216 in FIG.

  In step S34 in FIG. 3, the CPU 210 determines a reduction position where the discharge amount should be reduced from the droplets discharged based on the reference signal for each nozzle based on the ratio of the droplets to be discharged after reduction. A reduction pattern PF is determined.

  FIG. 6 is a diagram showing a reduction pattern PF for determining a reduction position where the ejection amount should be reduced from the droplets ejected based on a given signal for each nozzle. The reduction pattern PF includes 13 two-dimensional patterns Pd01 to Pd13. In addition, when referring to one of 13 two-dimensional patterns without specifying a target, it is expressed as a two-dimensional pattern Pdi. The position in the vertical direction of the two-dimensional pattern Pdi corresponds to each piezo element of one nozzle row of the head unit 50. More specifically, the vertical position of the two-dimensional pattern Pdi corresponds to a sequence of n voxel lines in the X direction (here, n = 4) recorded by each piezo element in one nozzle row. . In FIG. 6, on the left side of the two-dimensional pattern Pd01, the recording position of the voxel line by each nozzle is indicated by the number of voxels (0 to 720). The position in the vertical direction of the two-dimensional pattern Pdi corresponds to the voxel position in the Y direction of the model formed in step S10 in FIG. It is assumed that the two-dimensional pattern Pdi has data corresponding to 720 voxels in the horizontal direction (X direction).

  In the two-dimensional pattern Pdi of FIG. 6, on the right side of each nozzle position, when each nozzle records an area of 720 droplet ejection positions (voxels), how often ejection is performed based on the reference signal It shows whether or not the droplet discharge process should be performed with a smaller discharge amount than the droplets to be discharged. In FIG. 6, a position represented by white dots is a position (hereinafter, also referred to as “reduction position”) where a droplet discharge process should be performed with a discharge amount reduced compared to a droplet discharged based on the reference signal. is there. A position represented by a black dot is a position where a droplet based on the reference signal should be ejected. In the present embodiment, at the reduction position, a 12.5 ng droplet is ejected instead of a 13 ng droplet based on the reference signal that should be ejected according to the cross-sectional data.

  All of the total amount of droplets at all droplet discharge positions (represented by white or black in the two-dimensional pattern Pdi) included in the row corresponding to one nozzle of the 13 two-dimensional patterns Pd01 to Pd13 The ratio to the total amount of droplets when a 13 ng droplet is ejected by the reference signal to the droplet ejection position is equal to the proportion of droplets to be ejected by the nozzle (see FIG. 5). In this way, by defining a reduction position using a plurality of data (two-dimensional patterns Pd01 to Pd13), the amount of discharge liquid is finely adjusted for each nozzle in accordance with the displacement of the discharge amount (see FIG. 4). be able to. Therefore, by adjusting the droplet discharge amount according to the reduction pattern PF, an object having a shape faithful to the object data can be formed in the formation of the object based on the object data.

  Further, the 13 two-dimensional patterns Pd01 to Pd13 have reduction positions at different positions with respect to one nozzle. For this reason, when 13 two-dimensional patterns Pd01 to Pd13 are overlapped, the reduction positions do not overlap each other. Further, the reduction positions in one two-dimensional pattern Pdi are provided so as not to coincide with each other in adjacent nozzles (not aligned in the vertical direction in FIG. 6). By setting it as such an aspect, it is possible to reduce the possibility of occurrence of irregularities due to liquid volume adjustment on the surface of the object to be shaped instead of adjusting the discharge liquid volume from each nozzle. . In addition, about each nozzle, it is preferable that the reduction position is defined so that the space | interval of a reduction position may become blue noise.

  A functional unit of the CPU 210 of the computer 200 that realizes the process of step S34 is shown as a pattern determination unit 218 in FIG. The processing in steps S10 to S34 is performed for all nozzle rows of the nozzle row Nt that discharges colorless curable liquid droplets. The reduction pattern PF generated for each nozzle row is applied to each nozzle row in step S44 described later.

  In step S40 of FIG. 3, the CPU 210 of the computer 200 controls the three-dimensional modeling apparatus 100 to model a three-dimensional object. First, in step S42, the CPU 210 slices the shape of the three-dimensional object from the three-dimensional data Do representing the shape of the three-dimensional object in a plane perpendicular to the Z direction according to the Z-direction modeling resolution (for example, 600 dpi). Data along the XY directions of a plurality of plate-like structures obtained in this way is generated. This data is called “cross-sectional data”.

  The three-dimensional data Do representing the shape of the three-dimensional object is data representing the shape of the three-dimensional object. The cross-section data Dc has a predetermined modeling resolution (for example, 1200 dpi × 1200 dpi × 1200 dpi) in the X direction, the Y direction, and the Z direction. In the present embodiment, it is assumed that the three-dimensional data Do does not have color information. The cross section data Dc is data representing the shape of a three-dimensional object in a predetermined cross section (XY plane). The cross-section data Dc has a predetermined modeling resolution (for example, 600 dpi × 600 dpi) in the X direction and the Y direction.

  When generating the cross-section data Dc, the CPU 210 determines the resolution of the three-dimensional data Do (for example, 1200 dpi × 1200 dpi × 1200 dpi in each of the XYZ directions) based on the three-dimensional data Do according to the performance of the three-dimensional modeling apparatus 100. The resolution is converted to a resolution (for example, 600 dpi × 600 dpi × 600 dpi in each direction of XYZ). A virtual element of a rectangular parallelepiped or a cube that partitions the inside of the three-dimensional space defined according to the resolution in the X direction, the Y direction, and the Z direction is referred to as “voxel” in this specification.

  In step S42, the cross-sectional data Dc is a two-dimensional data in which gradation values are stored for each element determined according to a predetermined modeling resolution in the X and Y directions (for example, 600 dpi × 600 dpi in each of the XY directions). Represented by raster data. The gradation value stored in each element represents the amount of the curable liquid discharged to the voxel of the XY coordinate corresponding to that element. In this embodiment, in order to facilitate understanding of the technique, the amount of the curable liquid discharged to each voxel is assumed to be constant.

  In step S44 of FIG. 3, the CPU 210 controls the powder supply unit 20 and the flattening mechanism 30 via the control unit 70 of the three-dimensional modeling apparatus 100 to form a powder layer in the container 10c. Then, the CPU 210 drives the head unit 50 via the control unit 70 in accordance with the cross-sectional data Dc generated from the three-dimensional data Do and the two-dimensional pattern Pdi of the reduction pattern PF, and the curable liquid is supplied to the powder layer. To discharge.

  More specifically, the control unit 70 causes the head unit 50 to scan in the X direction via the scanning unit 52, and discharges the curable liquid from each nozzle of each nozzle row according to the cross-sectional data Dc. In the present embodiment, since the three-dimensional data Do has no color information, the curable liquid is ejected from the nozzle Nt that ejects a colorless curable liquid droplet. At that time, the head unit 50 and the curing energy application unit 60 are scanned by the control unit 70 so that the head unit 50 first passes through each part on the powder layer, and then the curing energy application unit 60 passes. The

  When discharging the curable liquid from each nozzle of each nozzle row according to the cross-section data Dc, in principle, the reference signal (11) is supplied to each piezo element connected to the nozzle Nt, and a 13 ng droplet is formed. The liquid is discharged (see the lowermost stage in FIG. 2). However, the drive signal (10) with the pulses P11 and P12 turned ON is supplied to each piezo element at a predetermined timing regardless of the cross-section data Dc, and a 12.5 ng droplet is ejected from the nozzle. Is done. Details of this processing will be described later.

  Thereafter, the control unit 70 moves the head unit 50 along the X direction to a position before starting scanning in the X direction via the scanning unit 52. When the scanning in the X direction is completed, the control unit 70 causes the head unit 50 to scan in the Y direction via the scanning unit 52. And the control part 70 discharges a droplet from each nozzle, making the head part 50 scan again about a X direction. In this way, by repeating the scanning in the X direction and the scanning in the Y direction performed while discharging droplets, the cross-sectional data Dc for one layer is stored in the powder layer in the container 10c. A corresponding plate-like structure Ps is formed (see FIG. 1). The plate-like structure Ps constituted by droplets is supported by the modeling stage 11.

  In step S46, the CPU 210 determines whether or not the plate-like structure Ps is formed according to all the cross-sectional data Dc corresponding to the three-dimensional data Do representing the shape of the three-dimensional object. When the plate-like structure Ps is not formed according to all the cross-sectional data Dc corresponding to the three-dimensional data Do representing the shape of the three-dimensional object (Step S46: No), the process proceeds to Step S48.

  In step S48, the CPU 210 drives the actuator 13 via the control unit 70 to lower the modeling stage 11 downward in the Z direction by a stacking pitch corresponding to the modeling resolution in the Z direction (for example, 600 dpi) ( (See FIG. 1). Thereafter, the process returns to step S44, and the same process is repeated. That is, the control unit 70 forms a new powder layer on the plate-like structure Ps already formed on the modeling stage 11 (see FIG. 1).

  On the other hand, when the plate-like structure Ps is formed according to all the cross-sectional data Dc corresponding to the three-dimensional data Do representing the shape of the three-dimensional object in step S46 of FIG. 3 (step S46: Yes), the CPU 210 The process is terminated. In addition, the function part of CPU210 of the computer 200 which implement | achieves the process of step S42-S48 is shown in FIG. The modeling unit 220 implements the processes of steps S42 to S48 together with the control unit 70 of the three-dimensional modeling apparatus 100.

  FIG. 7 is a diagram illustrating voxels recorded by each nozzle in the scanning in the X direction and the Y direction in step S44. It is assumed that the object to be formed starts from voxel position 0 in the Y direction. In the present embodiment, two or more scans in the X direction (specifically four scans) performed while discharging droplets, and a first scan in the Y direction performed between each scan in the X direction. (In the present embodiment, the scanning amount is 1 / n of the nozzle pitch). Such processing is collectively referred to as “unit processing” or “pass” in this specification. During the unit processing (pass) that is repeatedly performed, the second scanning in the Y direction is performed with a scanning amount larger than the first scanning in the Y direction. A droplet is supplied to each voxel arranged in the X direction and the Y direction continuously by the unit processing (pass) that is repeatedly performed and the second scanning in the Y direction performed during the unit processing.

  In this embodiment, processing for one pass in so-called pseudo band printing is performed in one pass. “Pseudo-band printing” refers to supplying droplets in the order of the direction perpendicular to the one direction on the voxel line between a plurality of voxel lines to which droplets were supplied in one scan in one direction. In this printing method, the process of completing the supply of droplets between successive lines (the process for one pass) is repeated.

  In this embodiment, every time one pass is completed, a scan of 174 voxels in the Y direction is performed as the second scan. As a result, scanning (microfeed) in the Y direction for one voxel (1 / n of the nozzle pitch) as the first scanning n times (n = 4) in one pass and the second after one pass. By scanning in the Y direction as scanning, the head unit 50 moves in the Y direction with respect to the modeling stage 11 by 177 voxels.

  In pass 1 of FIG. 7, in the first scan in the X direction, no. 137 nozzles supply droplets to the voxel at position 0. No. 138 nozzles supply droplets to the voxel at voxel position 4. No. 139 nozzles supply droplets to the voxel at voxel position 8. On the other hand, no. A nozzle having a nozzle number smaller than 137 is not on the target to be formed (is upstream of the target voxel position 0 in the Y direction), and thus does not eject droplets. When the scanning in the X direction is performed once, the first scanning in the Y direction (micro feed) is performed for one voxel (1 / n of the nozzle pitch). Then, a total of n times (n = 4) scanning in the X direction and minute feeding in the Y direction are performed in pass 1.

  In scanning in the X direction, droplets are ejected from nozzles on the object to be formed. However, droplets are supplied in the X-direction scanning to one out of every four voxels arranged in the X direction. After pass 1 is performed, a second scan of 174 voxels is performed in the Y direction.

  In pass 2 of FIG. 7, in the first scanning in the X direction, no. 93 nozzles supply droplets to the voxel at voxel position 1. No. 94 nozzles supply droplets to the voxel at voxel location 5. No. 95 nozzles supply droplets to the voxel at voxel position 9. On the other hand, no. A nozzle having a nozzle number smaller than 93 is not on the target to be formed (is upstream of the target voxel position 0 in the Y direction), and thus does not eject droplets. When scanning in the X direction is performed once, the first scanning (microfeed) in the Y direction is performed for one voxel. Then, a total of n times (n = 4) scanning in the X direction and minute feeding in the Y direction are performed in pass 2.

  In scanning in the X direction, droplets are ejected from nozzles on the object to be formed. However, the droplets are supplied in the scan in the X direction in the pass 2 among the voxels arranged in the X direction and not supplied in the pass 1, and 4 out of the voxels arranged in the X direction. One voxel per unit. As a result, for example, in FIG. One voxel is recorded by four nozzles 137, and in pass 2, No. 1 is recorded. One out of every four voxels is recorded by the 93 nozzles. As a result, two out of four voxels are recorded in pass 1 and pass 2 on the line at voxel position 3. After pass 2 is performed, a second scan of 174 voxels is performed in the Y direction. Thereafter, similarly, scanning in the X direction and scanning in the Y direction are repeated.

  In this embodiment, multipass printing is performed. In “multi-pass printing”, droplets are supplied to a plurality of voxels in a line of voxels arranged in one scanning direction by being shared by different droplet discharge units. For example, in FIG. 7, each voxel on the line at voxel position 3 is No. No. 137 nozzle (pass 1); No. 93 nozzle (pass 2); 49 nozzles (pass 3); 5 nozzles (pass 4) are shared and recorded. By performing such processing, it is possible to reduce the possibility that large irregularities will occur in specific portions in the X direction of the object to be modeled due to variations in the performance of each nozzle and the corresponding piezoelectric element.

  In the present embodiment, the supply of droplets is completed by sharing four voxel lines in a certain region extending in the Y direction by four passes. For example, all the voxel lines from the voxel positions 0 to 176 in the Y direction are recorded by four passes of passes 1 to 4 shown in FIG.

  As described above, in the present embodiment, broad interlace printing is performed. In “interlaced printing”, in one direction of scanning, a new droplet is supplied while supplying a droplet onto the voxel line in the gap between the voxel lines already supplied in the scanning direction. For the region to be printed, this is a printing method in which droplets are newly supplied onto every other or several voxel lines arranged in the scanning direction. For example, in FIG. In the area recorded by the nozzle 137 (the voxel line at voxel positions 0 to 3), and in pass 2, No. The area recorded by the nozzle 137 (not shown in FIG. 7) is separated. The area in between is recorded by other nozzles in other passes.

  By performing such processing, the positions at which the droplets ejected by one nozzle and the corresponding piezo element land can be dispersed in the Y direction. Therefore, it is possible to reduce the possibility of large irregularities occurring in a specific portion in the Y direction of the object to be modeled due to variations in the performance of the nozzle and the piezoelectric element corresponding to the nozzle. Note that “interlaced printing in a broad sense” refers to the conditions of the above-mentioned “interlaced printing”, that is, “scanning in one direction (X direction in the present embodiment) of voxels that have already been supplied with droplets aligned in the scanning direction. While supplying droplets to the voxel line in the gap between the lines, for the region where new droplets are to be supplied, droplets are newly applied to every other voxel line aligned in the scanning direction. The condition “supplying” includes a printing method that is established for voxels arranged in a direction perpendicular to the one direction (Y direction in the present embodiment).

  FIG. 8 shows how the two-dimensional pattern Pdi is applied when droplets are ejected from each nozzle and the plate-like structure Ps is formed in the scanning in the X direction and the Y direction in step S44. FIG.

  In step S44, a plate-like structure Ps having a cross-sectional shape of a three-dimensional object is formed by discharging droplets from the nozzle based on the cross-sectional data Dc and one of the two-dimensional patterns Pdi. .

  In the present embodiment, as shown in FIG. 8, for example, in pass 1, at the position of 0 to 176 voxels in the Y direction, first, about 180 nozzles on the downstream end side (Y direction + side) Droplets are ejected by the 1/4 nozzle. In that case, a pattern in a range of about ¼ from the end of the two-dimensional pattern Pd01 (range of 544 to 720 voxels) is applied to the two-dimensional pattern Pdi that defines the reduction position. When a droplet is ejected from each nozzle, a reduced 12.5 ng droplet is ejected at a reduced position represented by a white square instead of a 13 ng droplet based on the reference signal. When the width of the object to be modeled exceeds the width of the two-dimensional pattern Pdi, the two-dimensional pattern Pdi is repeatedly applied in the X direction.

  Next, in pass 2, droplets are ejected at about 0 to 353 voxels in the Y direction by about 1/2 of the 180 nozzles on the downstream end side. In this case, a pattern in a range of about ½ from the end of the two-dimensional pattern Pd01 (range of 367 to 720 voxels) is applied. When a droplet is ejected from each nozzle, a reduced 12.5 ng droplet is ejected at a reduced position represented by a white square instead of a 13 ng droplet based on the reference signal.

  Further, in pass 3, droplets are ejected by about 3/4 of the 180 nozzles on the downstream end side from 0 to 530 voxels in the Y direction. In this case, a pattern in a range of about 3/4 from the end of the two-dimensional pattern Pd01 (range of 190 to 720 voxels) is applied. When a droplet is ejected from each nozzle, a 12.5 ng droplet is ejected at a reduced position represented by a white square.

  Hereinafter, similarly, a corresponding portion of one two-dimensional pattern Pdi is applied in accordance with the relative position of the nozzle (head unit 50) with respect to the object to be modeled, and a reduction in the discharge amount of droplets is realized. In step S44 of FIG. 2, the plate-like structure Ps is formed while the variation in the discharge amount of droplets from each nozzle is reduced by performing the above processing.

  In step S10 of FIG. 3, one plate-like structure is formed by the same process as the unit process performed in the formation of the plate-like structure performed in step S44, and this is repeated for a plurality of layers. A model Pt0 is formed. In step S34 in FIG. 3, two-dimensional data Pdi (see FIG. 6) is formed for the voxel line to which the droplet is supplied by the unit process. Thus, the following effects are produced by forming the model in correspondence with the unit processing and forming the corresponding two-dimensional data. That is, the discharge amount reduction processing by applying the two-dimensional data Pdi in step S44 in FIG. 2 is easier than a mode in which a model is formed corresponding to the arrangement of nozzles as hardware to form two-dimensional data. .

  After that, when the process of step S44 is performed again through steps S46 and S48 of FIG. 3, the two-dimensional pattern Pd02 is applied, and droplets are ejected. That is, each of the plurality of two-dimensional patterns Pdi is sequentially applied, and the process of step S44 is repeated for a plurality of cross sections of the object that are arranged in a direction perpendicular to the cross section, so that a plurality of plate-like structures Ps is obtained. Are overlaid.

  According to the present embodiment described above, even when there is a variation in the amount of droplets or deformation of the material during the curing process in the droplet ejection unit that ejects droplets, it is not included in the object data. Modeling with a low possibility of forming irregularities can be performed.

  The three-dimensional modeling apparatus 100 and the computer 200 in the present embodiment correspond to the “three-dimensional modeling apparatus” in [Means for Solving the Problems]. The nozzles Nt and the piezo elements corresponding to the respective nozzles correspond to “droplet discharge portions”. The modeling stage 11 corresponds to a “support portion”. The X direction corresponds to the “first direction”. The Y direction corresponds to the “second direction”. The CPU 210 of the computer 200 and the control unit 70 of the 3D modeling apparatus 100 correspond to a “control unit”.

B. Second embodiment:
FIG. 9 is an explanatory diagram illustrating a schematic configuration of the three-dimensional modeling apparatus according to the second embodiment. The three-dimensional modeling apparatus 100 according to the first embodiment models a three-dimensional object by discharging a curable liquid to the powder supplied into the modeling unit 10. On the other hand, the three-dimensional modeling apparatus 100a of the second embodiment models a three-dimensional object using only a curable liquid containing a resin without using powder. In the second embodiment, the data processing such as generation of the cross-sectional data Dc generated by the CPU 210 of the computer 200 and the control unit 70 of the three-dimensional modeling apparatus 100a and the generation of the reduced pattern PF are the same as the processing of the first embodiment. It is processing.

  The three-dimensional modeling apparatus 100a includes a modeling unit 10, a head unit 50, a curing energy applying unit 60, a control unit 70, and a measuring instrument 80. The modeling unit 10 includes a modeling stage 11, a frame body 12, and an actuator 13 as in the first embodiment. However, the frame 12 may be omitted. A tank 51 is connected to the head unit 50. The curing energy applying unit 60 is a light emitting device 61 fixed to the head unit 50 so as to be aligned with the head unit 50 in the X direction.

  The three-dimensional modeling apparatus 100a has a configuration in which the powder supply unit 20, the flattening mechanism 30, and the powder recovery unit 40 are omitted from the three-dimensional modeling apparatus 100 of the first embodiment. Other points of the 3D modeling apparatus 100a are the same as the 3D modeling apparatus 100 of the first embodiment. Even in such a three-dimensional modeling apparatus 100a, a three-dimensional object can be modeled by the same process as the three-dimensional modeling apparatus 100 of the first embodiment, except for the process of forming a powder layer.

  In the second embodiment, it is possible to form a three-dimensional object using a support material. The support material in the present embodiment is a liquid that cures with a curing energy equivalent to the curing energy for curing the curing liquid. After curing, it can be dissolved by exposure to water or a predetermined solution and easily removed. Material. If the support material is discharged toward the outside of the outline of the three-dimensional object, when forming an object with a shape having a larger cross-sectional area in the upper layer than the lower layer, the large area is Can support.

  In the three-dimensional modeling apparatus 100 of the second embodiment, the head unit 50 is provided with nozzles for discharging the curable liquid and the support material, and the head unit 50 includes a tank in which the curable liquid is accommodated. The tank containing the support material is connected. In the present embodiment, the head unit 50 ejects the support material in the same scan as the scan for ejecting the curable liquid. The head unit 50 can also eject the support material in a scan different from the scan for ejecting the curable liquid.

  Also in such an aspect, modeling with a low possibility of forming irregularities not included in the object data can be performed by the processing of FIG. 3 of the first embodiment.

C. Variations:
C1. Modification 1:
In the above embodiment, the nozzles that discharge one color of curable liquid including colorless are one row of nozzles arranged along the Y direction or a set thereof. However, the nozzles that discharge one color of the curable liquid may be arranged in a zigzag manner (zigzag) along the Y direction. That is, the nozzle that discharges one color of the curable liquid may include a plurality of nozzles arranged at different positions in a direction different from the direction of the operation performed while discharging the droplets.

C2. Modification 2:
In the above embodiment, the modeling stage 11 does not move in the X direction and the Y direction, and the head unit 50 including a nozzle and a piezoelectric element as a droplet discharge unit is moved by the scanning unit 52. Further, in the Z direction, the head unit 50 does not move, and the modeling stage 11 as a support unit moves by the actuator 13. However, it is also possible to adopt a mode in which the droplet discharge section moves in three directions that intersect each other. And it can also be set as the aspect which a support part moves about three directions which mutually cross | intersect. Further, it is possible to adopt a mode in which the support portion moves in two directions intersecting each other and the droplet discharge portion moves in one direction intersecting these two directions.

  In the above-described embodiment, the head unit 50 including a nozzle and a piezoelectric element as a droplet discharge unit and the modeling stage 11 as a support unit are moved in X, Y, and Z directions orthogonal to each other. However, the direction in which the droplet discharge unit and the support unit relatively move does not have to be orthogonal. However, it is preferable that the directions intersect each other.

C3. Modification 3:
In the above embodiment, the measuring device 80 is fixed to the head unit 50 including a nozzle and a piezoelectric element as a droplet discharge unit, and is moved by the scanning unit 52 together with the head unit 50. However, the measuring device may be provided separately from the droplet discharge unit. However, it is preferable to be configured to be able to move in the same one or more directions as the one or more movement directions of the droplet discharge unit with respect to the support unit. Moreover, the measuring device may not be provided as a part of the three-dimensional modeling apparatus. However, it is preferable that the model is measured so that information on the height (position in the droplet discharge direction) of each part of the model can be provided to the control unit of the three-dimensional modeling apparatus.

C4. Modification 4:
In the above embodiment, the light emitting device 61 as the curing energy applying unit 60 is provided on one side in the X direction with respect to the head unit 50. However, the light emitting device 61 as the curing energy applying unit 60 can be provided on both sides in the X direction with respect to the head unit 50. In such an embodiment, the measuring device 80 may be provided on the opposite side of the head unit 50 with the curing energy application unit 60 interposed therebetween, and the head unit 50 and the curing energy application unit 60 are independent of each other. It may be provided.

C5. Modification 5:
In the above embodiment, in step S10 of FIGS. 3 and 8, the model is formed by a part of the process performed in the pseudo band printing. However, the model may be formed by other printing methods. However, the model is preferably generated by the same scanning method as the printing method used at least in part in the generation of the plate-like structure performed according to the cross-sectional data.

C6. Modification 6:
In the embodiment, the reduction pattern PF includes 13 two-dimensional patterns Pdi. However, the reduced pattern PF may be configured by a number of two-dimensional patterns Pdi smaller than 13, for example, 12 or 11 two-dimensional patterns Pdi. Further, the reduction pattern PF may be composed of more than 13 two-dimensional patterns Pdi, for example, 14 or 15 two-dimensional patterns Pdi. The reduction pattern PF may be composed of one two-dimensional pattern Pdi. However, it is preferable that the number of two-dimensional patterns larger than the integer value when less than 1% is rounded off is provided for the magnitude (%) of the variation in the height of the upper surface of the model formed by each nozzle. If it is set as such an aspect, the dispersion | variation in the height of the site | part formed by each nozzle can be adjusted in a unit of less than 1%.

C7. Modification 7:
In the above embodiment, a plate-like structure is formed based on the cross-sectional data Dc generated from the three-dimensional data Do and the two-dimensional pattern Pdi of the reduced pattern PF every time in step S44 of FIG. However, when forming a plate-like structure based on the cross-sectional data, it is not always necessary to perform processing in consideration of the two-dimensional pattern of the reduced pattern. That is, in the generation of the plate-like structure every several times, the two-dimensional pattern of the reduction pattern may be considered. In addition, after forming a plate-like structure multiple times in succession, taking into account the two-dimensional pattern of the reduced pattern, multiple times in succession, forming a plate-like structure without taking into consideration the two-dimensional pattern of the reduced pattern May be.

  For example, in the aspect in which the reduced pattern PF is configured with a smaller number of two-dimensional patterns Pdi, the nozzles having the displacement of the ejection amount shown in FIG. 4 are grouped according to the ejection amount, A reduced droplet discharge amount can be assigned to a group. In such an embodiment, it is preferable not to reduce the droplet discharge amount for the group with the least amount of output.

C8. Modification 8:
In the embodiment described above, fewer droplets are ejected at the reduction position than at the non-reduction position. However, it is also possible to adopt a mode in which droplets are not ejected from the droplet ejection unit at the reduction position, regardless of the cross-sectional data of the object data. By adopting such an aspect, it is possible to perform high-quality modeling by canceling the variation in the amount of droplets ejected from each droplet ejection unit by not ejecting the designated droplets.

C9. Modification 9:
In the above-described embodiment, the processes in steps S10 to S34 in FIG. 3 are performed for all nozzle rows of the nozzle Nt that discharges a colorless curable liquid droplet. However, the adjustment process of the droplet discharge amount can be performed for a nozzle that discharges a colored curable liquid droplet. In addition, the adjustment of the discharge amount of the droplets can be performed for some of the nozzles Nt that discharge the colorless curable liquid droplets.

C10. Modification 10:
In the above-described embodiment, the largest droplet ejected from the piezo element and the nozzle as the droplet ejection unit is used in principle, and the next largest droplet is used for adjusting the ejection amount of the droplet. However, a plurality of types of droplets can be discharged from the droplet discharge unit, and the plurality of types of droplets can be used for normal modeling of an object. Then, for one or more types of droplets, it is possible to discharge droplets with a smaller output amount, and the processing of FIG. 3 can be performed.

C11. Modification 11:
In the modeling of the object of the above embodiment, the same processing as one pass of pseudo band printing is performed within one pass, and further, printing that is interlaced printing and multipass printing is performed (see FIG. 7). However, in modeling an object, voxels on one line in the X direction can be recorded with one nozzle without performing multi-pass printing. In modeling an object, interlaced printing without pseudo-band printing can be performed, and pseudo-band printing without interlaced printing can also be performed. That is, in modeling an object, one of pseudo band printing, interlace printing, and multi-pass printing, or a combination of two or more can be applied.

  However, the two-dimensional pattern Pdi of the reduced pattern PF is preferably generated according to a printing process that is adopted as one pass (unit process) in generating a plate-like structure performed according to the cross-sectional data. For example, in the above-described embodiment, in the generation of a plate-like structure performed according to the cross-sectional data, printing (pseudo) that performs scanning in the X direction n times (n = 4) with three minute feeds in one pass. Band printing) is performed (see FIG. 7). Therefore, the two-dimensional pattern Pdi (see FIG. 6) is provided so that n lines (n = 4) of voxels in the X direction correspond to each nozzle. However, in the generation of the plate-like structure performed according to the cross-sectional data, when minute feed is not performed in one pass (n = 1), n two-dimensional patterns Pdi (n = n) for each nozzle. It is preferable that the voxel lines in the X direction in 1) correspond to each other.

  Note that the number n of scans in the X direction with minute feeds in one pass can also be greater than 4 (for example, 2, 3), and can be less than 4 (for example, 5, 6). You can also. The number of repetitions in multipass printing can also be greater than 4 (for example, 2, 3), and can be less than 4 (for example, 5, 6).

C12. Other:
The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Modeling part 10c ... Container 11 ... Modeling stage 12 ... Frame 13 ... Actuator 20 ... Powder supply part 30 ... Flattening mechanism 40 ... Powder collection part 50 ... Head part 51 ... Tank 52 ... Scanning part 60 ... Curing energy Giving unit 61 ... Light emitting device 70 ... Control unit 80 ... Height measuring device 100 ... Three-dimensional modeling device 100a ... Three-dimensional modeling device 200 ... Computer 210 ... CPU
212 ... Model forming unit 214 ... Measuring unit 216 ... Ratio determining unit 218 ... Pattern determining unit 220 ... Modeling unit COMA ... Original drive signal COMB ... Original drive signal Nc ... Nozzle for ejecting cyan droplets Nm ... Magenta droplets Nozzle discharging Nt ... Nozzle discharging colorless droplet Ny ... Nozzle discharging yellow droplet P11, P12, P21, P22 ... Pulse in drive signal PF ... Reduction pattern Ps ... Plate-like structure Pt0 ... Step S10 Model formed by S0, S1 ... selection signal

Claims (9)

A three-dimensional modeling apparatus that models an object by discharging droplets,
A plurality of droplet discharge portions each capable of discharging droplets;
A support for supporting the structure constituted by the droplets;
Relative to the support portion, the plurality of droplet discharge portions in a first direction intersecting with the droplet discharge direction, and in a second direction intersecting with the droplet discharge direction and the first direction. A scanning unit that can be moved automatically,
A control unit for controlling the droplet discharge unit, the support unit, and the scanning unit,
The controller is
By causing the scanning unit to scan in the first and second directions, ejecting the droplets from the plurality of droplet ejection units toward the support unit based on the same reference signal A model forming unit for forming a model;
A measurement unit that measures the height of the droplet in the discharge direction at a plurality of portions of the model corresponding to each of the plurality of droplet discharge units;
Based on the measurement results, for each of the plurality of droplet ejection units, a ratio determination unit that determines a ratio of droplets to be reduced;
A pattern determining unit that determines a reduction pattern that determines a reduction position for reducing the discharge amount for each of the plurality of droplet discharge units, based on the ratio of the droplets to be reduced;
While causing the scanning unit to perform scanning in the first and second directions, droplets are ejected from the plurality of droplet ejection units based on object data representing the shape of an object and the reduction pattern. And a modeling part for modeling an object,
The modeling apparatus is a modeling apparatus in which the reduced position is a position where a smaller amount of droplets than the amount of droplets ejected based on the reference signal should be ejected regardless of the object data. The apparatus of claim 1, comprising:
The reduction pattern includes a plurality of two-dimensional patterns,
Each of the plurality of two-dimensional patterns is
One direction is a two-dimensional pattern corresponding to each of the plurality of droplet discharge portions,
For each of the plurality of droplet discharge units, different positions are defined as the reduction positions,
The modeling part is
By discharging droplets from the plurality of droplet discharge units based on the cross-sectional data generated from the object data and representing the cross-sectional shape of the object, and one of the plurality of two-dimensional patterns, the cross-section Different cross-sections arranged in a direction perpendicular to the cross-section of the object while applying each of the plurality of two-dimensional patterns in order to form a plate-like structure having a shape of About, the modeling apparatus which performs the process which overlaps and forms the said several plate-shaped structure by repeating. The apparatus of claim 2, comprising:
The first process includes
A process of scanning the plurality of droplet discharge sections in the first direction while discharging droplets from the plurality of droplet discharge sections;
A process of scanning the plurality of droplet discharge sections in the second direction without discharging droplets from the plurality of droplet discharge sections;
By repeating the above, a region for newly supplying a droplet while supplying a droplet on the gap line of the line already supplied with the droplet in the first direction is newly added to the first. A modeling apparatus, which is a process for supplying droplets onto every other line or every other line arranged in the direction to form the plate-like structure. The apparatus of claim 2, comprising:
The first process includes
A process of scanning the plurality of droplet discharge sections in the first direction while discharging droplets from the plurality of droplet discharge sections;
A process of scanning the plurality of droplet discharge sections in the second direction without discharging droplets from the plurality of droplet discharge sections;
By repeating
A modeling apparatus, which is a process of forming droplets on a line extending in the first direction by supplying different droplets by supplying different droplets to form the plate-like structure. A method of modeling an object by discharging droplets,
(A) forming a model by discharging droplets from a plurality of droplet discharge units based on the same reference signal;
(B) measuring the height of the droplet in the discharge direction at a plurality of portions of the model corresponding to each of the plurality of droplet discharge units;
(C) determining a ratio of droplets to be reduced for each of the plurality of droplet discharge units based on the measurement result;
(D) determining a reduction pattern for determining a reduction position at which the discharge amount should be reduced for each of the plurality of droplet discharge units, based on the ratio of the droplets to be reduced;
(E) based on object data representing the shape of an object and the reduction pattern, and ejecting droplets from the plurality of droplet ejection units to form an object,
The reduction method is a modeling method in which, regardless of the object data, a position where a smaller amount of droplets than the amount of droplets ejected based on the reference signal should be ejected. The method of claim 5, comprising:
The reduction pattern includes a plurality of two-dimensional patterns,
Each of the plurality of two-dimensional patterns is
One direction is a two-dimensional pattern corresponding to each of the plurality of droplet discharge portions,
For each of the plurality of droplet discharge units, different positions are defined as the reduction positions,
The step (e)
(E1) by discharging droplets from the plurality of droplet discharge units based on cross-sectional data generated from the object data and representing a cross-sectional shape of the object and one of the plurality of two-dimensional patterns Forming a plate-like structure having the cross-sectional shape;
(E2) While applying each of the plurality of two-dimensional patterns in order, by repeating the step (e1) for a plurality of cross-sections of the object that are arranged in a direction perpendicular to the cross-section, A step of forming the plate-like structure on top of each other. The method of claim 6, comprising:
The step (e1)
(E3) scanning the plurality of droplet discharge sections in a first direction while discharging droplets from the plurality of droplet discharge sections;
(E4) After the step (e3), the step of scanning the plurality of droplet discharge portions in a second direction intersecting the first direction without discharging droplets from the plurality of droplet discharge portions. When,
By repeating the above, a region for newly supplying a droplet while supplying a droplet on the gap line of the line already supplied with the droplet in the first direction is newly added to the first. A modeling method, which is a step of forming droplets on one or several lines arranged in the direction of the plate to form the plate-like structure. The method of claim 6, comprising:
The step (e1)
(E3) scanning the plurality of droplet discharge sections in a first direction while discharging droplets from the plurality of droplet discharge sections;
(E4) After the step (e3), the step of scanning the plurality of droplet discharge portions in a second direction intersecting the first direction without discharging droplets from the plurality of droplet discharge portions. When,
By repeating
A modeling method, which is a step of forming droplets on a line extending in the first direction by supplying different droplets and supplying the droplets to form the plate-like structure. A computer program for modeling an object by controlling a 3D modeling apparatus using a computer and discharging droplets,
A function of forming a model by discharging droplets from a plurality of droplet discharge units based on the same reference signal;
A function of measuring the height of the droplet in the discharge direction at a plurality of portions of the model corresponding to each of the plurality of droplet discharge units;
A function of determining a ratio of droplets to be reduced for each of the plurality of droplet discharge units based on the measurement result;
A function for determining a reduction pattern for determining a reduction position where the discharge amount should be reduced for each of the plurality of droplet discharge units, based on the ratio of the droplets to be reduced;
Based on object data representing the shape of an object and the reduction pattern, a function of forming an object by discharging droplets from the plurality of droplet discharge units,
Is a computer program that enables a computer to realize
The computer program, wherein the reduction position is a position where a smaller amount of droplets than the amount of droplets ejected based on the reference signal should be ejected regardless of the object data.

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