Three-dimensional object printing device and method for controlling the three-dimensional object printing device

Abstract

To provide a three-dimensional object printing apparatus which enables discharge of a liquid and curing of the liquid with an appropriate distance set between nozzles and a workpiece even if interference with the workpiece is inhibited.SOLUTION: A three-dimensional object printing apparatus includes: a first head having a first nozzle face provided with nozzles for injecting a liquid; an energy emitter having an emission face from which energy for curing the liquid injected from the first head is emitted; and a moving mechanism which changes a relative position of the first head and the energy emitter with respect to a three-dimensional workpiece. The moving mechanism includes: a linear motion mechanism that changes the relative position of the first head and the energy emitter with respect to the workpiece along a first axis; a first lifting mechanism that moves the first nozzle face along a second axis intersecting with the first axis; and a second lifting mechanism that moves the emission face along the second axis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a three-dimensional object printing device. [Background technology]

[0002] There are known three-dimensional printing devices that use an inkjet method to print on the surface of a three-dimensional workpiece. For example, Patent Document 1 discloses a device that has a head incorporating a nozzle that ejects ultraviolet-curable ink and a light-emitting unit that emits ultraviolet light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-246855 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-mentioned conventional technology, when attempting to appropriately set the distance between the nozzle and the workpiece in order to improve printing quality for a workpiece having a curved surface or unevenness, there was a problem in that components of the device, such as the light emitting unit, could interfere with the workpiece. [Means for solving the problem]

[0005] In order to solve the above problems, one aspect of the three-dimensional object printing device of the present invention is a three-dimensional object printing device having a first head having a first nozzle surface provided with nozzles that eject liquid, an energy emission unit having an emission surface that emits energy to harden the liquid ejected from the first head, and a movement mechanism that changes the relative position of the first head and the energy emission unit with respect to a three-dimensional workpiece, wherein the movement mechanism includes a linear motion mechanism that changes the relative position of the first head and the energy emission unit with respect to the workpiece along a first axis, a first lifting mechanism that moves the first nozzle surface along a second axis that intersects the first axis, and a second lifting mechanism that moves the emission surface along the second axis. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a perspective view showing an outline of a three-dimensional object printing apparatus 100 according to a first embodiment. [Figure 2] 3 is a diagram illustrating the relationship between the lifting mechanism 230, the liquid discharge unit 300, and the light emitting section 380. FIG. [Figure 3] FIG. 2 is a perspective view showing a schematic configuration of a liquid ejection unit 300. [Figure 4] FIG. 1 is a block diagram showing the electrical configuration of a three-dimensional object printing device 100 according to a first embodiment. [Figure 5] FIG. 3 is a diagram for explaining route information Da in the first embodiment. [Figure 6] FIG. 2 is a flowchart showing the flow of a three-dimensional object printing method according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing an example of the positions of the nozzle surface FD, the emission surface FU, and the workpiece W during execution of a first scan RU1. [Figure 8] FIG. 10 is a diagram showing an example of the positions of the nozzle surface FD and the emission surface FU during execution of a second scan RU2. [Figure 9] FIG. 10 is a diagram showing an example of the positions of the nozzle surface FD and the emission surface FU at the start of the workpiece moving operation WM. [Figure 10] FIG. 10 is a diagram showing an example of the positions of the nozzle surface FD and the emission surface FU at the end of the workpiece moving operation WM. [Figure 11] FIG. 10 is a diagram illustrating a three-dimensional object printing device 100a according to a first modified example. [Figure 12] FIG. 10 is a diagram illustrating a three-dimensional object printing device 100b according to a second modified example. [Figure 13] FIG. 10 is a diagram illustrating a three-dimensional object printing device 100c according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scale of each part are appropriately different from those of the actual parts. Furthermore, since the embodiments described below are preferred examples of the present invention, various technically preferable limitations are applied, but the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited.

[0008] The following description will use the mutually intersecting X-axis, Y-axis, and Z-axis as appropriate. Furthermore, one direction along the X-axis will be referred to as the X1 direction, and the direction opposite the X1 direction will be referred to as the X2 direction. Similarly, opposite directions along the Y-axis will be referred to as the Y1 direction and the Y2 direction. Furthermore, opposite directions along the Z-axis will be referred to as the Z1 direction and the Z2 direction.

[0009] Here, the X-axis, Y-axis, and Z-axis are coordinate axes of a base coordinate system set in a space where a workbench 281 (described later) is installed. Typically, the Z-axis is a vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. Note that the Z-axis does not have to be a vertical axis. Furthermore, the X-axis, Y-axis, and Z-axis are typically perpendicular to each other, but are not limited to this and may not be perpendicular. For example, the X-axis, Y-axis, and Z-axis may intersect each other at an angle between 80° and 100°.

[0010] 1. First embodiment 1-1. Overview of the 3D printing device 1 is a perspective view showing an outline of a three-dimensional object printing apparatus 100 according to the first embodiment. The three-dimensional object printing apparatus 100 is an apparatus that performs printing on the surface of a three-dimensional workpiece W by an inkjet method.

[0011] The workpiece W is a printing medium and has a surface WF to be printed on. In the example shown in FIG. 1, the workpiece W is a rugby ball that is an elongated spheroid about the major axis AX, and the surface WF is a curved surface with a variable curvature. In this embodiment, the workpiece W is positioned so that the major axis AX is parallel to the X axis. Note that the workpiece W is not limited to a rugby ball. For example, the workpiece W may be a product of some kind, and printing on the surface WF is one of a series of processes for manufacturing this product. The shape, size, and other aspects of the workpiece W are not limited to the example shown in FIG. 1 and are arbitrary. For example, the surface of the workpiece W may have a flat surface, a stepped surface, an uneven surface, or a similar surface. For example, the surface WF shown in FIG. 1 is a convex curved surface when viewed in the Z2 direction, but may also be a concave curved surface when viewed in the Z2 direction. Furthermore, the installation orientation of the workpiece W is not limited to the example shown in FIG. 1 and is arbitrary.

[0012] In the example shown in FIG. 1, the three-dimensional object printing apparatus 100 is an inkjet printer that uses an Cartesian robot that moves on two orthogonal axes. Specifically, as shown in FIG. 1, the three-dimensional object printing apparatus 100 has a movement mechanism 200, four liquid ejection units 300, a light emission unit 380, a liquid supply unit 400, a controller 600, and a workpiece support mechanism 900. The four liquid ejection units 300 are liquid ejection units 300_1 to 300_4. In the following description, each of the liquid ejection units 300_1 to 300_4 may be referred to as a liquid ejection unit 300. Below, each part of the three-dimensional object printing apparatus 100 shown in FIG. 1 will be briefly described in order.

[0013] The movement mechanism 200 changes the relative positions of the liquid discharge unit 300 and the light emitting part 380 with respect to the workpiece W. The movement mechanism 200 has a linear motion mechanism 220, a lifting mechanism 230, and a support part 280.

[0014] The linear motion mechanism 220 changes the relative positions of the four liquid discharge units 300 and the light emitter 380 with respect to the workpiece W along the X-axis. The linear motion mechanism 220 includes a rail member 221 and a carriage 222. The rail member 221 is a flat member that allows the carriage 222 to move along the X-axis. Two rails RA are provided along the X-axis on the Z1-direction surface of the rail member 221. The two rails RA extend along the X-axis. The carriage 222 slidably engages with the rails RA. Although not shown, the linear motion mechanism 220 includes a drive mechanism for moving the carriage 222. The drive mechanism includes, for example, a motor that generates a drive force for the movement, a reducer that decelerates and outputs the drive force, and a horizontal encoder 223 that detects the amount of movement. The horizontal encoder 223 is shown in FIG. 4. The X-axis is an example of the "first axis."

[0015] The lifting mechanism 230 moves the four liquid discharge units 300 and the light emitting section 380 along the Z axis. The lifting mechanism 230 has a support plate 231 and five individual lifting mechanisms 235. The five individual lifting mechanisms 235 are individual lifting mechanisms 235_1 to 235_5. In the following description, each of the individual lifting mechanisms 235_1 to 235_5 may be referred to as an individual lifting mechanism 235. Furthermore, elements of the individual lifting mechanism 235 may also be indicated using _x, where x is an integer from 1 to 5.

[0016] The relationship between the lifting mechanism 230, the liquid discharge unit 300, and the light emitting section 380 will be described with reference to FIG.

[0017] Fig. 2 is a diagram illustrating the relationship between the lifting mechanism 230, the liquid discharge unit 300, and the light emitting section 380. The diagram shown in Fig. 2 is a diagram of the vicinity of the lifting mechanism 230 as viewed from the Y1 direction to the Y2 direction.

[0018] The support plate 231 supports the individual lifting mechanism 235 and is fixed to the carriage 222. When the carriage 222 moves along the X axis, the support plate 231 attached to the carriage 222 also moves along the X axis. However, instead of the support plate 231, the lifting mechanism 230 may have a mechanism that uniformly moves the four liquid ejection units 300 and the light emitting section 380 along the Z axis. The Z axis is an example of a "second axis."

[0019] Each individual lifting mechanism 235 moves one of the four liquid discharge units 300 and the light emitter 380 along the Z axis. The individual lifting mechanism 235 is fixed to the support plate 231. The liquid discharge units 300 are attached as end effectors to four of the five individual lifting mechanisms 235 in the Z2 direction, fixed by screws or the like. The light emitter 380 is attached as an end effector to the remaining individual lifting mechanism 235 in the Z2 direction, fixed by screws or the like. Although not shown, each individual lifting mechanism 235 is provided with a drive mechanism that moves the liquid discharge unit 300 or the light emitter 380 relative to the individual lifting mechanism 235. The drive mechanism includes, for example, a motor that generates a drive force for the movement, a reducer that decelerates and outputs the drive force, and a vertical encoder 236 that detects the amount of movement. The vertical encoder 236 is shown in FIG.

[0020] More specifically, the individual lifting mechanism 235_k is equipped with a liquid discharge unit 300_k, where k is an integer from 1 to 4. The individual lifting mechanism 235_5 is equipped with a light emitting section 380. The individual lifting mechanisms 235_1 to 235_5 are arranged in the order of individual lifting mechanisms 235_1, 235_2, 235_3, 235_4, and 235_5 from the X1 direction. It should be noted that, of any two of the individual lifting mechanisms 235_1 to 235_4, one is an example of a “first lifting mechanism,” and the other is an example of a “third lifting mechanism.” The individual lifting mechanism 235_5 is an example of a “second lifting mechanism.”

[0021] Returning to FIG. 1 for the explanation, the support unit 280 supports the linear motion mechanism 220 and the workpiece support mechanism 900. The support unit 280 has a work table 281 and a support pillar 283. The workpiece support mechanism 900 is fixed onto a top plate 282 of the work table 281. The work table 281 is fixed to an installation surface, such as a floor surface, facing the Z1 direction by screws or the like. Note that the installation surface to which the work table 281 is fixed is not limited to the example shown in FIG. 1, and may be, for example, a wall, a surface of a movable cart, or the like. The support pillar 283 is a columnar member that supports the linear motion mechanism 220 and extends in the Z axis.

[0022] The liquid ejection unit 300 ejects ink, an example of a liquid, toward the workpiece W. The light emission unit 380 has an emission surface FU that emits light to cure the ink ejected from the liquid ejection unit 300. More specifically, the light emission unit 380 detects the relative positional relationship of the light emission unit 380 with respect to the workpiece W along the Z axis, and a light source that emits light to cure the ink. Specifically, the sensor included in the light emission unit 380 is a distance sensor such as an optical displacement meter that measures the distance between the light emission unit 380 and a reference surface (not shown) whose position relative to the workpiece W is fixed. Note that this reference surface may be the surface of the workpiece W or the surface of an object other than the workpiece W. The direction of the reference surface is arbitrary, as long as the position and orientation of the reference surface with respect to the surface WF of the workpiece W are known in advance. The light emitting unit 380 is an example of an "energy emitting unit," and the light that hardens the ink is an example of "energy that hardens the liquid."

[0023] In this embodiment, the ink is a curable ink using a curable resin such as an ultraviolet curable ink, but the curable ink is not limited to an ultraviolet curable ink and may be, for example, a heat curable ink, a photocurable ink, a radiation curable ink, an electron beam curable ink, or the like. Furthermore, the ink is not limited to a solution but may be an ink in which a colorant or the like is dispersed as a dispersoid in a dispersion medium. Furthermore, the ink is not limited to an ink containing a colorant. For example, the ink may be an ink containing conductive particles, such as metal particles, as a dispersoid for forming wiring, or a clear ink, or a treatment liquid for surface treatment of the workpiece W. In this embodiment, the three-dimensional object printing apparatus 100 uses four types of ink: an ink containing a cyan colorant, an ink containing a magenta colorant, an ink containing a yellow colorant, and an ink containing a black colorant, and the light emitting unit 380 emits ultraviolet light. Thus, in this embodiment, since four types of ink are used, the three-dimensional object printing apparatus 100 has four liquid ejection units 300. However, the number of liquid ejection units 300 is not limited to four and may be one or more. Furthermore, the types of ink used are not limited to four, and the three-dimensional object printing apparatus 100 may use one type of ink or multiple inks.

[0024] Each of the heads 310_1 to 310_4 of the liquid ejection units 300_1 to 300_4 is supplied with ink containing one of the colors cyan, magenta, yellow, and black. Each of the heads 310_1 to 310_4 may be supplied with any of these four types of ink. However, since the ink that lands spreads over the surface WF of the workpiece W, if the ink of a color that is significantly different from the brightness of the workpiece W spreads over the surface WF, the ink spread becomes noticeable, resulting in a decrease in print quality. In particular, in the case of printing three-dimensional objects, the print medium is often non-absorbent, and since the surface WF is inclined, the ink tends to move after landing, easily causing bleeding. For example, if the workpiece W is white, a color that is significantly different from the brightness of the color of the workpiece W is black. Therefore, it is preferable to supply ink of a color that has a small difference in brightness from the workpiece W to head 310_1, which is far from the light-emitting portion 380, and to supply ink of a color that has a large difference in brightness from the workpiece W to head 310_4, which is close to the light-emitting portion 380.

[0025] Furthermore, in printing using UV-curable ink, there is a technique called the pinning method, in which UV light is irradiated onto the workpiece immediately after it lands to incompletely cure the ink. Because ink fluidity decreases when incompletely cured, the pinning method can be used to prevent the landed ink from spreading across the surface WF of the workpiece W, thereby adjusting the dot size. In the following description, the UV light irradiated immediately after the ink lands to incompletely cure the ink is referred to as "pinning light," and the UV light irradiated to substantially completely cure the ink is referred to as "main curing light." The amount of energy imparted to the ink by the main curing light is greater than the amount of energy imparted by the pinning light. The light emitter 380 includes a light source that emits UV light. The intensity of the UV light emitted from the light emitter 380 may be adjustable depending on the application of the pinning light and the main curing light, or the light source that emits the pinning light and the main curing light may be provided. The amount of energy imparted to the ink can also be adjusted depending on the application of the pinning light and the main curing light by appropriately adjusting the UV light irradiation time. In the following description, the pinning light and the main curing light may be collectively referred to as ultraviolet light. The liquid discharge unit 300 will be described in detail with reference to FIG.

[0026] 3 is a perspective view showing a schematic configuration of a liquid ejection unit 300. The liquid ejection unit 300 has a head 310, a pressure adjustment valve 320, and a sensor 330. These are supported by a support 350 indicated by a two-dot chain line in FIG.

[0027] The head 310 includes multiple piezoelectric elements (not shown), multiple cavities (not shown), and multiple nozzles N. The cavities contain ink. A nozzle N is provided for each cavity and communicates with the cavity. A piezoelectric element is provided for each cavity, and ink is ejected from the nozzle N corresponding to the cavity by changing the pressure in the cavity. This head 310 can be obtained, for example, by bonding multiple substrates, such as silicon substrates, appropriately processed by etching or the like, with an adhesive or the like. Furthermore, heaters that heat ink in the cavities may be used instead of the piezoelectric elements as drive elements for ejecting ink from the nozzles. Here, under ideal conditions, the ink ejection direction from the head 310 is the Z2 direction. Therefore, the direction of movement of the liquid ejection unit 300 by the individual lifting mechanism 235 and the direction of ink ejection from the head 310 are substantially parallel. Note that "substantially parallel" is a concept that includes mechanical errors and errors in ink ejection, and allows for deviation of about ±5°.

[0028] The head 310 has a nozzle surface FD on which a plurality of nozzles N are provided. In the example shown in Fig. 3, the normal direction of the nozzle surface FD is the Z1 direction, and the plurality of nozzles N are divided into a first nozzle row L1 and a second nozzle row L2 that are arranged at intervals in the direction along the X axis. Each of the first nozzle row L1 and the second nozzle row L2 is a collection of a plurality of nozzles N that are linearly arranged in the direction along the Y axis. Here, the elements associated with each nozzle N of the first nozzle row L1 in the head 310 and the elements associated with each nozzle N of the second nozzle row L2 are configured to be approximately symmetrical to each other in the direction along the X axis. Among the liquid discharge units 300_1 to 300_4, the head 310 included in the liquid discharge unit 300 attached to the individual lifting mechanism 235 corresponding to the "first lifting mechanism" is an example of the "first head," and the nozzle surface FD of this head 310 is an example of the "first nozzle surface." Furthermore, the head 310 included in the liquid discharge unit 300 attached to the individual lifting mechanism 235 corresponding to the "third lifting mechanism" is an example of the "second head," and the nozzle surface FD of this head 310 is an example of the "second nozzle surface."

[0029] However, the positions of the multiple nozzles N in the first nozzle row L1 and the multiple nozzles N in the second nozzle row L2 in the direction along the Y axis may or may not match. Also, elements related to each nozzle N of one of the first nozzle row L1 and the second nozzle row L2 may be omitted. Below, a configuration in which the positions of the multiple nozzles N in the first nozzle row L1 and the multiple nozzles N in the second nozzle row L2 in the direction along the Y axis match will be exemplified.

[0030] The pressure adjustment valve 320 is a valve mechanism that opens and closes in response to the pressure of the ink inside the head 310. This opening and closing maintains the ink pressure inside the head 310 at a negative pressure within a predetermined range. This stabilizes the ink meniscus formed in the nozzle N of the head 310. As a result, it is possible to prevent air bubbles from entering the nozzle N and ink from overflowing from the nozzle N.

[0031] In the example shown in FIG. 3, the liquid ejection unit 300 has one head 310 and one pressure adjustment valve 320, but the numbers are not limited to those shown in FIG. 1 and may be two or more.

[0032] The sensor 330 detects the relative positional relationship of the head 310 with respect to the workpiece W on the Z axis. Specifically, the sensor 330 is a distance sensor such as an optical displacement meter that measures the distance to a reference surface (not shown) whose position relative to the workpiece W is fixed. The reference surface may be the surface of the workpiece W or the surface of an object other than the workpiece W. The direction in which the reference surface faces is arbitrary, as long as the position and orientation of the reference surface with respect to the surface WF of the workpiece W are known in advance.

[0033] The support 350 is made of, for example, a metal material or the like, and is substantially rigid. Although the support 350 is shown in Fig. 3 as having a flat box shape, the shape of the support 350 is not particularly limited and is arbitrary. The support 350 is attached to the individual lifting mechanism 235 in the Z2 direction.

[0034] 3, the pressure regulating valve 320 is positioned in the Z1 direction relative to the head 310. The sensor 330 is positioned in the X1 direction relative to the head 310.

[0035] The supply flow path 420 is divided into an upstream flow path 421 and a downstream flow path 422 by the pressure adjustment valve 320. That is, the supply flow path 420 has an upstream flow path 421 that connects the liquid storage section 410 and the pressure adjustment valve 320, and a downstream flow path 422 that connects the pressure adjustment valve 320 and the head 310. In the example shown in FIG. 3, a part of the downstream flow path 422 of the supply flow path 420 is configured with a flow path member 422a. The flow path member 422a has a flow path that distributes ink from the pressure adjustment valve 320 to multiple locations in the head 310. The flow path member 422a is, for example, a laminate of multiple substrates made of a resin material, and each substrate is appropriately provided with grooves or holes for ink flow paths.

[0036] Returning to the explanation of Fig. 1, the liquid supply unit 400 is a mechanism for supplying ink to the head 310. The liquid supply unit 400 has a liquid storage section 410 and a supply flow path 420.

[0037] Liquid storage section 410 is a container that stores ink. Liquid storage section 410 is, for example, a bag-shaped ink pack made of a flexible film.

[0038] 1, the liquid storage unit 410 is fixed to a wall, ceiling, pillar, or the like so that it is always located further in the Z1 direction than the head 310. In other words, the liquid storage unit 410 is located vertically above the movement area of ​​the head 310. Therefore, ink can be supplied from the liquid storage unit 410 to the head 310 with a predetermined pressure without using a mechanism such as a pump.

[0039] The liquid storage unit 410 may be located vertically below the head 310 as long as it can supply ink from the liquid storage unit 410 to the head 310 at a predetermined pressure. In this case, for example, a pump may be used to supply ink from the liquid storage unit 410 to the head 310 at a predetermined pressure.

[0040] The supply flow path 420 is a flow path that supplies ink from the liquid storage section 410 to the head 310. A pressure adjustment valve 320 is provided midway along the supply flow path 420. Therefore, even if the positional relationship between the head 310 and the liquid storage section 410 changes as the movement mechanism 200 operates, fluctuations in the ink pressure inside the head 310 can be reduced.

[0041] The supply flow path 420 is formed, for example, by the internal space of a tube. Here, the tube used for the supply flow path 420 is made of an elastic material such as a rubber material or an elastomer material, and is flexible. By forming the supply flow path 420 using a flexible tube in this way, changes in the relative positional relationship between the liquid storage section 410 and the pressure adjustment valve 320 are permitted. Therefore, even if the position of the head 310 changes while the position and attitude of the liquid storage section 410 remain fixed, ink can be supplied from the liquid storage section 410 to the pressure adjustment valve 320.

[0042] Note that a portion of the supply flow path 420 may be made of a non-flexible material. Also, a portion of the supply flow path 420 may be configured to have a distribution flow path that distributes ink to multiple locations, or may be configured integrally with the head 310 or the pressure adjustment valve 320.

[0043] The controller 600 is a robot controller that controls the driving of the moving mechanism 200 and the workpiece support mechanism 900. Although not shown in FIG. 1, the controller 600 is electrically connected to a control module that controls the discharge operation in the liquid discharge unit 300. A computer is communicably connected to the controller 600 and the control module. The control module corresponds to the control module 500 shown in FIG. 4, which will be described later. The computer corresponds to the computer 700 shown in FIG. 4, which will be described later.

[0044] The workpiece support mechanism 900 supports the workpiece W and changes one or both of the position and posture of the workpiece W. The workpiece support mechanism 900 has a line feed axis mechanism 910 and a rotation axis mechanism 920. The line feed axis mechanism 910 includes a flat member for moving the workpiece W along the Y axis. Two rails RB along the Y axis are provided on the Z1-direction surface of this member. The two rails RB extend along the Y axis. The rotation axis mechanism 920 slidably engages with the rails RB. Furthermore, although not shown in FIG. 1 , the line feed axis mechanism 910 is provided with a drive mechanism for moving the rotation axis mechanism 920 along the Y axis. The drive mechanism includes, for example, a motor that generates a drive force for the movement, a reducer that decelerates and outputs the drive force, and an encoder that detects the amount of movement.

[0045] The rotary shaft mechanism 920 is rotatable about a rotation axis XR along the X-axis. Furthermore, the rotary shaft mechanism 920 has a mounting surface 922. A workpiece W is placed on the mounting surface 922. When the rotary shaft mechanism 920 rotates, the orientation of the mounting surface 922 changes. When the orientation of the mounting surface 922 changes, the posture of the workpiece W placed on the mounting surface 922 changes. Furthermore, although not shown in FIG. 1 , the rotary shaft mechanism 920 is provided with a drive mechanism that moves the rotary shaft mechanism 920 along the Y-axis. The drive mechanism has, for example, a motor that generates a drive force for the movement, a reducer that decelerates and outputs the drive force, and an encoder that detects the amount of movement.

[0046] 1-2. Electrical configuration of the 3D printing device Fig. 4 is a block diagram showing the electrical configuration of the three-dimensional object printing device 100 according to the first embodiment. Fig. 4 shows electrical components among the components of the three-dimensional object printing device 100. Fig. 4 also shows the horizontal encoder 223 and vertical encoders 236_1 to 236_5.

[0047] 4, the three-dimensional object printing apparatus 100 includes the aforementioned movement mechanism 200, liquid discharge unit 300, controller 600, and workpiece support mechanism 900, as well as a control module 500 and a computer 700. Before describing the controller 600 in detail, the control module 500 and the computer 700 will be described below.

[0048] Note that each of the electrical components described below may be divided as appropriate, some may be included in other components, or may be integrated with other components. For example, some or all of the functions of control module 500 or controller 600 may be implemented by a computer 700 connected to controller 600, or may be implemented by another external device such as a PC (personal computer) connected to controller 600 via a network such as a LAN (Local Area Network) or the Internet.

[0049] The controller 600 has a function of controlling the driving of the moving mechanism 200, a function of controlling the driving of the workpiece support mechanism 900, and a function of generating a signal D3 for synchronizing the ink ejection operation of the liquid ejection unit 300 with the operation of the moving mechanism 200. The controller 600 has a memory circuit 610 and a processing circuit 620.

[0050] The storage circuitry 610 stores various programs executed by the processing circuitry 620 and various data processed by the processing circuitry 620. The storage circuitry 610 includes, for example, one or both of semiconductor memories: a volatile memory such as a random access memory (RAM) and a non-volatile memory such as a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), or a programmable read-only memory (PROM). Note that part or all of the storage circuitry 610 may be included in the processing circuitry 620.

[0051] The memory circuit 610 stores path information Da. The path information Da is information indicating the movement path CR along which the head 310 and the light emitting unit 380 should move. The path information Da is expressed, for example, using coordinate values ​​in a base coordinate system. The path information Da is determined based on work information indicating the position and shape of the workpiece W. The workpiece information is obtained by associating information such as CAD (computer-aided design) data indicating the three-dimensional shape of the workpiece W with the aforementioned base coordinate system. The path information Da described above is input from the computer 700 to the memory circuit 610.

[0052] The processing circuit 620 controls the operations of the linear motion mechanism 220, the lifting mechanism 230, the line feed axis mechanism 910, and the rotation axis mechanism 920 based on the path information Da, and generates a signal D3. Specifically, the processing circuit 620 performs calculations to convert the path information Da into operation quantities such as the position and velocity of the linear motion mechanism 220 and the lifting mechanism 230, and calculations to convert the path information Da into operation quantities such as the position and velocity of the line feed axis mechanism 910 and the rotation axis mechanism 920. The processing circuit 620 then outputs control signals Sx and Sz_1 to Sz_5 based on the output signal Dx from the horizontal encoder 223 and the output signals Dz_1 to Dz_5 from the vertical encoders 236_1 to 236_5, so that the operation quantities of the linear motion mechanism 220 and the lifting mechanism 230 correspond to the calculation results described above. The control signal Sx controls the driving of the motor of the linear motion mechanism 220. The control signal Sz_k controls the driving of the motor of the individual lifting mechanism 235_k, where k is an integer from 1 to 5. Hereinafter, each of the output signals Dz_1 to Dz_5 may be referred to as the output signal Dz. Similarly, the processing circuit 620 outputs control signals Sy and Sr based on the output signal Dy output from the encoder included in the line feed axis mechanism 910 and the output signal Dr output from the encoder included in the rotating axis mechanism 920, so that the operating amounts of the line feed axis mechanism 910 and the rotating axis mechanism 920 correspond to the above-mentioned calculation results. The control signal Sy controls the driving of the motor included in the line feed axis mechanism 910. The control signal Sr controls the driving of the motor included in the rotating axis mechanism 920.

[0053] Furthermore, the processing circuit 620 generates a signal D3 based on one or more of the output signals Dx, Dz_1 to Dz_5, Dy, and Dr. For example, the processing circuit 620 generates the signal D3 based on one of the output signals Dx, Dz_1 to Dz_5, Dy, and Dr. For example, the processing circuit 620 generates, as the signal D3, a signal that includes a pulse at the timing when one of the output signals Dx, Dz_1 to Dz_5, Dy, and Dr reaches a predetermined value.

[0054] The processing circuit 620 includes, for example, one or more processors such as a CPU (Central Processing Unit). Note that the processing circuit 620 may include a programmable logic device such as an FPGA (Field-Programmable Gate Array) instead of or in addition to a CPU.

[0055] The control module 500 is a circuit that controls the ejection operation of the head 310 based on a signal D3 output from the controller 600 and print data Img from the computer 700. The control module 500 has a timing signal generation circuit 510, a power supply circuit 520, a control circuit 530, and a drive signal generation circuit 540.

[0056] The timing signal generation circuit 510 generates a timing signal PTS based on the signal D3. The timing signal generation circuit 510 is configured, for example, with a timer that starts generating the timing signal PTS in response to detection of the signal D3. In other words, the signal D3 functions as a trigger signal that determines the start timing of ink ejection by the liquid ejection unit 300.

[0057] The power supply circuit 520 receives power from a commercial power supply (not shown) and generates various predetermined potentials. The generated potentials are supplied appropriately to each section of the three-dimensional object printing device 100. For example, the power supply circuit 520 generates a power supply potential VHV and an offset potential VBS. The offset potential VBS is supplied to the liquid ejection unit 300. The power supply potential VHV is also supplied to the drive signal generation circuit 540.

[0058] The control circuit 530 generates control signals SI_1 to SI_4, a waveform designation signal dCom, a latch signal LAT, a clock signal CLK, and a change signal CNG based on the timing signal PTS. These signals are synchronized with the timing signal PTS. Of these signals, the waveform designation signal dCom is input to the drive signal generation circuit 540, and the other signals are input to the switch circuit 340 of the liquid ejection unit 300. However, the control signal SI_k is a signal supplied to the switch circuit 340 of the liquid ejection unit 300_k, where k is an integer from 1 to 4. In the following description, each of the control signals SI_1 to SI_4 may be referred to as a control signal SI.

[0059] The control signal SI is a digital signal for specifying the operating state of the piezoelectric element of the head 310. Specifically, the control signal SI specifies whether or not to supply a drive signal Com, described below, to the piezoelectric element. This specification, for example, specifies whether or not to eject ink from the nozzle N corresponding to the piezoelectric element, or specifies the amount of ink ejected from that nozzle N. The waveform specification signal dCom is a digital signal for defining the waveform of the drive signal Com. The latch signal LAT and change signal CNG are used in conjunction with the control signal SI to specify the drive timing of the piezoelectric element, and thereby specify the ejection timing of ink from the nozzle N. The clock signal CLK is a reference clock signal synchronized with the timing signal PTS. Of the above signals, the signals input to the switch circuit 340 of the liquid ejection unit 300 will be described in detail later.

[0060] The control circuit 530 includes, for example, one or more processors such as a CPU (Central Processing Unit). Note that the control circuit 530 may include a programmable logic device such as an FPGA (Field-Programmable Gate Array) instead of or in addition to a CPU.

[0061] The drive signal generation circuit 540 is a circuit that generates a drive signal Com for driving each piezoelectric element of the head 310. Specifically, the drive signal generation circuit 540 includes, for example, a DA conversion circuit and an amplifier circuit. In the drive signal generation circuit 540, the DA conversion circuit converts the waveform designation signal dCom from the control circuit 530 from a digital signal to an analog signal, and the amplifier circuit amplifies the analog signal using the power supply potential VHV from the power supply circuit 520 to generate the drive signal Com. Here, of the waveforms included in the drive signal Com, the signal with the waveform actually supplied to the piezoelectric element is the drive pulse PD. The drive pulse PD is supplied from the drive signal generation circuit 540 to the piezoelectric element via the switch circuit 340. The switch circuit 340 switches whether or not to supply at least a portion of the waveform included in the drive signal Com as the drive pulse PD based on a control signal SI.

[0062] The computer 700 has the function of supplying information such as path information Da to the controller 600, the function of supplying information such as print data Img to the control module 500, and the function of controlling the driving of the light emitting unit 380. For example, the computer 700 generates path information Da based on work information indicating the position and shape of the workpiece W, and outputs the generated path information Da to the controller 600. The computer 700 of this embodiment is also electrically connected to the aforementioned sensor 330 and the sensor of the light emitting unit 380, and supplies information for correcting the path information Da to the controller 600 based on signals D2_1 to D2_4 from the sensors 330_1 to 330_4 and a signal D2_5 from the sensor of the light emitting unit 380. The computer 700 can be, for example, a personal computer.

[0063] 1-3. Operation of the three-dimensional object printing device 100 and three-dimensional object printing method FIG. 5 is a diagram illustrating the path information Da in the first embodiment. FIG. 5 shows the movement path CR indicated by the path information Da of the head 310 and the light emitter 380 relative to the workpiece W, viewed from the Z1 direction to the Z2 direction. In the first embodiment, the three-dimensional object printing apparatus 100 executes the first scan RU1, the second scan RU2, the retreat operation RT1, the workpiece movement operation WM, the return operation RT2, the third scan RU3, and the fourth scan RU4, in this order. Thus, the retreat operation RT1, the workpiece movement operation WM, and the return operation RT2 are executed in the period between the second scan RU2 and the third scan RU3. Moving the head 310 and the light emitter 380 from the X2 direction to the X1 direction, followed by moving the head 310 and the light emitter 380 from the X1 direction to the X2 direction, is referred to as a "pass." In this embodiment, one pass is formed by the first scan RU1 and the second scan RU2, and one pass is formed by the third scan RU3 and the fourth scan RU4. In this way, in this embodiment, the three-dimensional object printing device 100 executes two passes, but it may also execute one pass, or three or more passes.

[0064] In FIG. 5, to clearly show the first scan RU1 and the second scan RU2, the trajectories of the first scan RU1 and the second scan RU2 are shown separated on the Y-axis. However, in reality, the start position PS1 of the first scan RU1 approximately coincides with the end position PE2 of the second scan RU2, the end position PE1 of the first scan RU1 approximately coincides with the start position PS2 of the second scan RU2, and the trajectory of the first scan RU1 approximately coincides with the trajectory of the second scan RU2. "Approximately coincident" includes not only perfect coincidence but also cases where the trajectories can be considered coincident considering manufacturing errors. However, the start position PS1 of the first scan RU1 may differ from the end position PE2 of the second scan RU2, the end position PE1 of the first scan RU1 may differ from the start position PS2 of the second scan RU2, or the trajectory of the first scan RU1 may differ from the trajectory of the second scan RU2. Similarly, the third scan RU3 and the fourth scan RU4 are shown separated on the Y-axis. However, in reality, the start position PS3 of the third scan RU3 approximately coincides with the end position PE4 of the fourth scan RU4, the end position PE3 of the third scan RU3 approximately coincides with the start position PS4 of the fourth scan RU4, and the trajectory of the third scan RU3 approximately coincides with the trajectory of the fourth scan RU4. The third scan RU3 and the fourth scan RU4 are similar to the first scan RU1 and the second scan RU2.

[0065] The first scan RU1 and the third scan RU3 are operations that move the relative positions of the head 310 and the light output unit 380 with respect to the workpiece W in the X1 direction. The second scan RU2 and the fourth scan RU4 are operations that move the relative positions of the head 310 and the light output unit 380 with respect to the workpiece W in the X2 direction. In this embodiment, the workpiece support mechanism 900 is not driven during the execution of the first scan RU1, the second scan RU2, the third scan RU3, and the fourth scan RU4. However, the workpiece support mechanism 900 may be driven during the execution of any of the first scan RU1, the second scan RU2, the third scan RU3, and the fourth scan RU4. The X1 direction is an example of a "first direction," and the X2 direction is an example of a "third direction."

[0066] The retraction operation RT1 is an operation for moving the relative positions of the head 310 and the light emitting unit 380 with respect to the workpiece W from the end position PE2 of the second scan RU2 to a retraction position PT1 where the nozzle face FD and the emission surface FU do not overlap with the workpiece W, as viewed along the Z axis. The workpiece movement operation WM is an operation for changing one or both of the position and posture of the workpiece W. Two objects overlapping means that part or all of one object overlaps part or all of the other object. As a result of the change in position or posture of the workpiece W, the positions of the nozzle face FD and the emission surface FU with respect to the workpiece W move from the retraction position PT1 to the retraction position PT2. At the retraction position PT2, the nozzle face FD and the emission surface FU also do not overlap with the workpiece W, as viewed along the Z axis. The return operation RT2 is an operation for moving the relative positions of the head 310 and the light emitting unit 380 with respect to the workpiece W from the retraction position PT2 to the start position PS3 of the third scan RU3.

[0067] FIG. 6 is a flowchart showing the flow of the three-dimensional object printing method according to the first embodiment. As shown in FIG. 6, the three-dimensional object printing apparatus 100 executes the following steps, in this order: step S110 for executing a first scan RU1; step S120 for executing a second scan RU2; step S130 for executing a retraction operation RT1; step S140 for executing a workpiece movement operation WM; step S150 for executing a return operation RT2; step S160 for executing a third scan RU3; and step S170 for executing a fourth scan RU4. The operations shown in FIG. 6 are executed by the computer 700 controlling the movement mechanism 200 and the liquid ejection unit 300 via the controller 600 and the control module 500.

[0068] During execution of the first scan RU1 in step S110, the relative positions of the nozzle surface FD and the emission surface FU change due to the driving of one or more of the individual lifting mechanisms 235_1 to 235_5. The positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W during the first scan RU1 will be described with reference to FIG.

[0069] FIG. 7 is a diagram showing an example of the positions of the nozzle surface FD, emission surface FU, and workpiece W during execution of the first scan RU1. In FIGS. 7 and 8, to avoid complication of the drawings, the heads 310_2 to 310_4 and the nozzle surfaces FD of the heads 310_2 to 310_4 are omitted. During execution of the first scan RU1, the head 310 ejects ink onto the workpiece W in response to a control signal SI. FIG. 7 shows droplets DR ejected from the head 310. Furthermore, during execution of the first scan RU1, the light emission unit 380 emits pinning light UV1 onto the workpiece W.

[0070] In the first scan RU1, the linear motion mechanism 220 is driven to move the heads 310_1 to 310_4 and the light emitting unit 380 in the X1 direction. Simultaneously with the driving of the linear motion mechanism 220, the individual lifting mechanisms 235_1 to 235_4 are driven so that the distance between the nozzle surface FD and the surface WF in the Z2 direction is maintained at d1. The distance between the head 310 and the workpiece W in the Z2 direction is also referred to as the "workpiece gap." Similarly, the individual lifting mechanism 235_5 is driven so that the distance between the emission surface FU and the surface WF in the Z2 direction is maintained at d5. As illustrated in FIG. 7, the distance d1 is shorter than the distance d5. In the following description, the distance between the light emitting unit 380 and the workpiece W in the Z2 direction may also be referred to as the "workpiece gap." The Z2 direction is an example of the "second direction." If the work gap of the head 310 is not properly adjusted, the flight distance of the ink ejected from the head 310 may increase, reducing the accuracy of the position where the ink lands on the workpiece. Furthermore, if the work gap of the light emitting unit 380 is not properly adjusted, the energy emitted from the light emitting unit 380 may attenuate, resulting in insufficient curing of the ink. As described above, the work gap affects print quality.

[0071] Returning to Fig. 6 for the explanation, during execution of the second scan RU2 in step S120, the individual lifting mechanisms 235_1 to 235_4 are not driven, and only the individual lifting mechanism 235_5 is driven. Using Fig. 8, the positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W during the second scan RU2 will be explained.

[0072] FIG. 8 is a diagram showing an example of the positions of the nozzle surface FD and the emission surface FU during execution of the second scan RU2. During execution of the second scan RU2, the head 310 does not eject ink onto the workpiece W. Meanwhile, during execution of the second scan RU2, the light emission unit 380 emits the main curing light UV2 onto the workpiece W. Here, by increasing the intensity of the main curing light UV2 compared to the intensity of the pinning light UV1, it is possible to sufficiently cure the ink that landed on the workpiece during the first scan RU1. Furthermore, by decreasing the movement speed of the linear motion mechanism 220 during the second scan RU2 compared to the first scan RU1, it is possible to lengthen the irradiation time of the main curing light UV2, thereby sufficiently curing the ink that landed on the workpiece during the first scan RU1.

[0073] During the second scan RU2, the head 310 does not eject ink, so the distance e1 between the nozzle faces FD and the face WF in the Z2 direction does not need to be maintained constant. More specifically, during the second scan RU2, the relative positions of the nozzle faces FD of the heads 310 do not change. Furthermore, during the second scan RU2, it is preferable that the position of the nozzle faces FD of the heads 310 in the direction along the Z axis does not change. During the second scan RU2, the linear motion mechanism 220 is driven to move the heads 310_1 to 310_4 and the light emitting unit 380 in the X2 direction. The individual lifting mechanisms 235_1 to 235_4 are driven so that the positions Za of the nozzle faces FD of the heads 310 in the direction along the Z axis are equal. Specifically, the individual lifting mechanisms 235_1 to 235_4 are driven so that the positions Za of the nozzle faces FD of the heads 310 in the direction along the Z axis are equal at the start position PS2 of the second scan RU2, and are stopped from being driven until the second scan RU2 is completed. The individual lifting mechanism 235_5 is driven so that the distance between the emission surface FU and the surface WF in the Z2 direction is maintained at a distance e5. Here, during the second scan RU2, the distance e5 is shorter than the distance e1.

[0074] Returning to Fig. 6, in the retraction operation RT1 in step S130, the linear motion mechanism 220 is driven to move the heads 310_1 to 310_4 and the light emitting part 380 in the X2 direction.

[0075] In the workpiece moving operation WM in step S140, the workpiece support mechanism 900 changes one or both of the position and posture of the workpiece W by driving the line feed axis mechanism 910 and the rotation axis mechanism 920. Furthermore, in the workpiece moving operation WM, in order to shorten the period required to perform the third scan RU3 that is executed after the workpiece moving operation WM, one or more of the nozzle surface FD and the emission surface FU are moved along the Z axis by driving one or more of the individual lifting mechanisms 235_1 to 235_5. The movement of the nozzle surface FD and the emission surface FU in the workpiece moving operation WM will be described using FIGS. 9 and 10.

[0076] 9 is a diagram showing an example of the positions of the nozzle surface FD and the emission surface FU at the start of the workpiece movement operation WM. In this embodiment, at the start of the workpiece movement operation WM, the positions of the nozzle surfaces FD and emission surfaces FU of the head 310 in the direction along the Z axis have not moved since the end of the second scan RU2. Specifically, the position of each nozzle surface FD of the head 310 in the direction along the Z axis is position Za. Meanwhile, the position of the emission surface FU in the direction along the Z axis is a position moved a distance e5 in the Z1 direction from the end position PE2 of the second scan RU2.

[0077] 10 is a diagram showing an example of the positions of the nozzle surface FD and the emission surface FU at the end of the workpiece moving operation WM. By driving the individual lifting mechanisms 235_1 to 235_5, the nozzle surface FD and the emission surface FU of the head 310 move along the Z axis so as to approach the positions of the nozzle surface FD and the emission surface FU of the head 310 in the direction along the Z axis at the start position PS3 of the third scan RU3. Specifically, by driving the individual lifting mechanism 235_1, the head 310_1 moves toward a position moved a distance d1 in the Z1 direction from the start position PS3 of the third scan RU3. Furthermore, by driving the individual lifting mechanism 235_5, the light emitting unit 380 moves toward a position moved a distance d5 in the Z1 direction from the start position PS3.

[0078] Returning to Fig. 6, in the retraction operation RT1 in step S150, the linear motion mechanism 220 is driven to move the heads 310_1 to 310_4 and the light emitting part 380 in the X1 direction.

[0079] During the execution of the third scan RU3 in step S160, the relative positions of the nozzle surface FD and the emission surface FU change due to the driving of one or more of the individual lifting mechanisms 235_1 to 235_5. During the execution of the third scan RU3, the head 310 ejects ink onto the workpiece W in accordance with the control signal SI. Furthermore, during the execution of the third scan RU3, the light output unit 380 outputs pinning light UV1 onto the workpiece W. The positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W during the third scan RU3 is the same as the positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W during the first scan RU1, and is therefore not shown in the figures.

[0080] During the fourth scan RU4 in step S170, the individual lifting mechanisms 235_1 to 235_4 do not operate, and only the individual lifting mechanism 235_5 operates. The relative positions of the nozzle surface FD and the emission surface FU change. During the fourth scan RU4, the head 310 does not eject ink onto the workpiece W. Meanwhile, during the fourth scan RU4, the light emitting section 380 emits the main curing light UV2 onto the workpiece W. The positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W during the fourth scan RU4 is the same as the positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W during the second scan RU2, and is therefore not shown in the figure.

[0081] 1-4. Summary of the first embodiment The three-dimensional object printing apparatus 100 in the first embodiment will be described below using an example in which the individual lifting mechanism 235_1 corresponds to the "first lifting mechanism" and the individual lifting mechanism 235_2 corresponds to the "third lifting mechanism."

[0082] The three-dimensional object printing apparatus 100 in the first embodiment includes a head 310_1 having a nozzle surface FD_1 on which nozzles N that eject ink are provided, a light emitting unit 380 having an emission surface FU that emits light that hardens the ink ejected from the head 310_1, and a movement mechanism 200 that changes the relative positions of the head 310_1 and the light emitting unit 380 with respect to a three-dimensional workpiece W. The movement mechanism 200 includes a linear motion mechanism 220 that changes the relative positions of the head 310_1 and the light emitting unit 380 with respect to the workpiece W along the X axis, an individual lifting mechanism 235_1 that moves the nozzle surface FD_1 along the Z axis that intersects with the X axis, and an individual lifting mechanism 235_5 that moves the emission surface FU along the Z axis. According to the first embodiment, the head 310_1 and the light emitting unit 380 are raised and lowered by separate individual lifting mechanisms 235, allowing printing while adjusting the work gap to an appropriate value according to the shape of the workpiece W. In addition, interference between the workpiece W and the head 310 can be prevented. Furthermore, according to the first embodiment, compared to an embodiment in which the head 310_1 and the light emitting unit 380 are raised and lowered by a single individual lifting mechanism 235, it is possible to design the width of the components that move individually along the Z axis to be narrower in the direction along the X axis. Therefore, even if the workpiece W has unevenness, the head 310 and the light emitting unit 380 can fit between the unevenness, thereby suppressing interference with the workpiece W and enabling ink ejection and ink curing with an appropriate work gap, thereby improving print quality.

[0083] If the operation of moving the relative positions of the head 310_1 and the light emitting unit 380 with respect to the workpiece W in the X1 direction along the X axis is defined as a first scan RU1, then during the execution of the first scan RU1, the head 310_1 ejects ink onto the workpiece W. Also, during the execution of the first scan RU1, the relative positions of the nozzle surface FD_1 and the emission surface FU change due to the driving of at least one of the individual lifting mechanisms 235_1 and 235_5. In this way, the individual lifting mechanism 235_1 and the individual lifting mechanism 235_5 are lifted and lowered individually, so printing can be performed while adjusting the work gap to an appropriate value according to the shape of the work W. It is also possible to prevent interference between the work W and the head 310. Even if the work W has irregularities, the head 310 and the light emitting unit 380 can fit between the irregularities, thereby improving printing quality.

[0084] Furthermore, the light emitting section 380 emits pinning light to the workpiece W during the execution of the first scan RU1. Therefore, in the first scan RU1, immediately after the head 310_1 ejects ink, the pinning light can prevent the ink from spreading over the surface WF.

[0085] Furthermore, during execution of the first scan RU1, the distance d1 between the nozzle surface FD_1 and the workpiece W in the Z2 direction along the Z axis is shorter than the distance d5 between the emission surface FU and the workpiece W in the Z2 direction. In the first scan RU1, by bringing the nozzle surface FD_1 closer to the surface WF of the workpiece W rather than the emission surface FU, the three-dimensional object printing device 100 can improve the accuracy of the ink landing position compared to a configuration in which the distance d1 is longer than the distance d5.

[0086] Furthermore, if the operation of moving the relative positions of the head 310_1 and the light output unit 380 with respect to the workpiece W in the X2 direction, which is the opposite direction to the X1 direction, is defined as the second scan RU2, the second scan RU2 is performed after the first scan RU1. During the second scan RU2, the light output unit 380 outputs the main curing light to the workpiece W. During the second scan RU2, the distance e5 between the output surface FU and the workpiece W in the Z2 direction along the Z axis is shorter than the distance e1 between the nozzle surface FD_1 and the workpiece W in the Z2 direction. In the second scan RU2, by bringing the emission surface FU closer to the surface WF of the workpiece W with priority over the nozzle surface FD_1, it is possible to prevent uncured ink from remaining on the workpiece W compared to a configuration in which the distance e5 is longer than the distance e1. In addition, some of the main curing light emitted to the emission surface FU may be reflected by the surface WF and enter the nozzle N. If the ultraviolet light enters the nozzle N, the ink near the nozzle will be cured, clogging the nozzle N and causing ejection abnormalities. According to this embodiment, the amount of light entering the nozzle N can be reduced compared to a configuration in which the distance e5 is longer than the distance e1, thereby preventing the ink near the nozzle N of the head 310_1 from curing.

[0087] Furthermore, the head 310_1 does not eject ink onto the workpiece W during the execution of the second scan RU2. Since the head 310_1 does not eject ink onto the workpiece W, the head 310_1 can be separated from the workpiece W. By separating the head 310_1 from the workpiece W, the amount of light incident on the nozzle N of the head 310_1 can be reduced, and therefore, hardening of the ink near the nozzle N of the head 310_1 can be reduced.

[0088] Furthermore, the emission intensity of the main curing light emitted by the light emitting section 380 during execution of the second scan RU2 is higher than the emission intensity of the pinning light during execution of the first scan RU1. This can prevent uncured ink from remaining on the workpiece W during the second scan RU2, and can also prevent ink from being cured near the nozzles due to the pinning light during the first scan RU1.

[0089] The three-dimensional object printing apparatus 100 also has a head 310_2 having a nozzle surface FD_2 on which nozzles N that eject ink are provided. The movement mechanism 200 is equipped with an individual lifting mechanism 235_2 that moves the nozzle surface FD_2 along the Z axis. During execution of the first scan RU1, the head 310_2 ejects ink onto the workpiece W. During execution of the first scan RU1, the relative positions of the nozzle surfaces FD_1 and FD_2 change due to the driving of one or both of the individual lifting mechanisms 235_1 and 235_2. During execution of the second scan RU2, the relative positions of the nozzle surfaces FD_1 and FD_2 do not change. In the first scan RU1, head 310_1 and head 310_2 are individually raised and lowered, allowing printing to be performed while adjusting the work gap to an appropriate value according to the shape of the workpiece W. This also prevents interference between the workpiece W and head 310. Furthermore, because ink is not ejected in the second scan RU2, there is no need to operate individual lifting mechanisms 235_1 and 235_2. Therefore, in the second scan RU2, there is no need to drive individual lifting mechanisms 235_1 and 235_2, and power consumption of the three-dimensional object printing apparatus 100 can be reduced compared to a mode in which individual lifting mechanisms 235_1 and 235_2 are driven.

[0090] Furthermore, during the execution of the second scan RU2, the nozzle surfaces FD_1 and FD_2 have substantially the same position Za in the direction along the Z axis. By making the positions Za of the nozzle surfaces FD_1 and FD_2 equal in the direction along the Z axis, and positioning this position Za further in the Z1 direction than the furthest position of the workpiece W in the Z1 direction, it is possible to prevent head 310_1 and head 310_2 from interfering with the workpiece W.

[0091] The three-dimensional object printing apparatus 100 also includes a workpiece support mechanism 900 that supports the workpiece W and changes one or both of the position and the orientation of the workpiece W. By providing the work support mechanism 900, the three-dimensional object printing apparatus 100 can appropriately adjust the positional relationship between the three-dimensional work W and the head 310_1.

[0092] Furthermore, if the operation performed after the second scan RU2 and moving the relative positions of the head 310_1 and the light output unit 380 with respect to the workpiece W in the X1 direction is defined as the third scan RU3, then during the execution of the third scan RU3, the head 310_1 ejects ink onto the workpiece W. In the period between the second scan RU2 and the third scan RU3, the workpiece support mechanism 900 performs a workpiece moving operation WM that changes either or both the position and the posture of the workpiece W. By executing the workpiece moving operation WM, the three-dimensional object printing apparatus 100 can move the workpiece W between multiple passes.

[0093] Furthermore, the workpiece movement operation WM is performed during a part of the period between the second scan RU2 and the third scan RU3. While the workpiece movement operation WM is being performed, the nozzle surface FD_1 and the emission surface FU do not overlap with the workpiece W when viewed in the direction along the Z axis. In this way, the head 310_1 and the light emitting part 380 are retracted to a position where the nozzle surface FD_1 and the emission surface FU do not overlap the workpiece W, so the position of the workpiece W can be adjusted appropriately without considering the possibility that the workpiece W will interfere with the head 310_1 and the light emitting part 380.

[0094] Furthermore, during the execution of the workpiece moving operation WM, one or both of the nozzle surface FD_1 and the emission surface FU are moved along the Z axis by driving one or both of the individual lifting mechanism 235_1 and the individual lifting mechanism 235_2. During the execution of the workpiece movement operation WM, the Z-axis positions of the head 310_1 and the light output unit 380 are adjusted to match the start position PS3 of the third scan RU3, thereby shortening the non-printing time between passes. This reduces the time required for the manufacturing process of products including the workpiece W, improving productivity.

[0095] 2. Variations The above-described embodiments can be modified in various ways. Specific modifications are exemplified below. Two or more embodiments selected from the following examples can be combined as long as they are not mutually contradictory.

[0096] 2-1. First modified example In the first embodiment, the three-dimensional object printing device 100 may have a light blocking plate 390 between the head 310 and the light emitting unit 380 that blocks ultraviolet light.

[0097] FIG. 11 is a diagram illustrating a three-dimensional object printing device 100a in a first modified example. The three-dimensional object printing device 100a differs from the three-dimensional object printing device 100 in that it has a light-emitting unit 380a instead of the light-emitting unit 380. The light-emitting unit 380a differs from the light-emitting unit 380 in that a light-shielding plate 390 is attached to the side surface in the X1 direction. The light-shielding plate 390 is a flat member extending in the YZ plane. The light-shielding plate 390 has a first portion 391 and a second portion 392 in the Z1 direction. The surface of the first portion 391 in the X2 direction is attached to the light-emitting unit 380a. The second portion 392 blocks ultraviolet light emitted from the light-emitting unit 380.

[0098] According to the first modification, the second portion 392 blocks ultraviolet light, thereby reducing the amount of light incident on the nozzles N, and therefore, curing of ink in the vicinity of the nozzles N of the head 310_1 can be suppressed.

[0099] In the first modified example, the light blocking plate 390 is adhered to the side surface of the light emitting portion 380 in the X1 direction, but this is not limiting. For example, the light blocking plate 390 may be adhered to the side surface of the liquid ejection unit 300_4 in the X2 direction.

[0100] 2-2. Second modified example In each of the above-described embodiments, the three-dimensional object printing apparatus 100 has individual lifting mechanisms 235_1 to 235_4 that raise and lower the liquid discharge units 300_1 to 300_4, respectively, and an individual lifting mechanism 235 that raises and lowers the light-emitting unit 380, but the individual lifting mechanism 235 that raises and lowers the light-emitting unit 380 and the individual lifting mechanism 235 that raises and lowers the liquid discharge unit 300_4 closest to the light-emitting unit 380 may be the same.

[0101] 12 is a diagram illustrating a three-dimensional object printing device 100b in a second modified example. The three-dimensional object printing device 100b differs from the three-dimensional object printing device 100 in that it has a lifting mechanism 230b instead of the lifting mechanism 230, and a light emitting unit 380b instead of the light emitting unit 380. The lifting mechanism 230b differs from the lifting mechanism 230 in that it does not have the individual lifting mechanism 235_5, and has an individual lifting mechanism 235_4b instead of the individual lifting mechanism 235_4.

[0102] The light emitting portion 380b is adhered to the side surface of the liquid discharge unit 300_4 in the X2 direction. The individual lifting mechanism 235_4b lifts and lowers the liquid discharge unit 300_4, thereby lifting and lowering the light emitting portion 380b. In the second modified example, of any two of the individual lifting mechanisms 235_1 to 235_3, one is an example of a “first lifting mechanism,” and the other is an example of a “third lifting mechanism.” The individual lifting mechanism 235_4b is an example of a “second lifting mechanism.”

[0103] 2-3.Third modified example In each of the above-described embodiments, the three-dimensional object printing apparatus 100 has one light emitting unit 380 for four heads 310, but it may have one light emitting unit 380 for one head 310.

[0104] 13 is a diagram illustrating a three-dimensional object printing apparatus 100c according to a third modified example. The three-dimensional object printing apparatus 100c differs from the three-dimensional object printing apparatus 100 in that it has four light-emitting units 380, light-emitting units 380_1 to 380_4. For each of m=1 to 3, light-emitting unit 380_m is provided between liquid discharging unit 300_m and liquid discharging unit 300_m+1, and emits pinning light toward ink discharged by head 310_m. Light-emitting unit 380_4 is provided in the X2 direction of liquid discharging unit 300_4, and emits pinning light toward ink discharged by head 310_4, as well as main curing light toward ink discharged by heads 310_1 to 310_4. In this way, the light emitting portion 380_4 emits the main curing light, and the light emitting portions 380_1 to 380_3 emit the pinning light, so that the light emitting portion 380_4 can emit ultraviolet light with higher intensity than the light emitting portions 380_1 to 380_3.

[0105] Light emitters 380_1 to 380_4 also move up and down in the same manner as liquid discharge units 300_1 to 300_4. For example, for each of k values ​​from 1 to 4, an individual lifting mechanism 235_k lifts and lowers light emitter 380_k and liquid discharge unit 300_k. Alternatively, three-dimensional object printing device 100b may have an individual lifting mechanism 235 that lifts and lowers light emitter 380_k, separate from individual lifting mechanism 235_k that lifts and lowers liquid discharge unit 300_k, for each of k values ​​from 1 to 4.

[0106] 2-4.Fourth Modification In each of the above-described embodiments, the three-dimensional object printing apparatus 100 has separate individual lifting mechanisms 235 that lift and lower each liquid discharge unit 300, but one individual lifting mechanism 235 may lift and lower multiple liquid discharge units 300. For example, the three-dimensional object printing apparatus 100 in a fourth modified example has two individual lifting mechanisms 235, liquid discharge units 300_1 to 300_4, and a light output unit 380. One of the two individual lifting mechanisms 235 lifts and lowers liquid discharge units 300_1 and 300_2, and the other individual lifting mechanism 235 lifts and lowers liquid discharge units 300_3, 300_4, and the light output unit 380.

[0107] 2-5. Fifth Modification In the above-described embodiments, while the first scan RU1, the second scan RU2, the third scan RU3, and the fourth scan RU4 are being performed, the linear motion mechanism 220 is driven to change the positions of the head 310 and the light output unit 380 relative to the workpiece W in the direction along the X axis, but this is not limited to this. Specifically, the workpiece support mechanism 900 may be driven to move the workpiece W in the direction along the X axis, thereby changing the positions of the head 310 and the light output unit 380 relative to the workpiece W. In other words, the means for changing the relative positions of the head 310 and the light output unit 380 relative to the workpiece W in the direction along the X axis is not limited.

[0108] 2-6. Sixth Modification In the first scan RU1 of each of the above-described aspects, the distance d1 between the nozzle surface FD and the surface WF in the Z2 direction may be longer than the distance d5 between the emission surface FU and the surface WF in the Z2 direction.

[0109] 2-7. Seventh Variation In the second scan RU2 in each of the above-described embodiments, the distance e5 between the emission surface FU and the surface WF in the Z2 direction may be longer than the distance e1 between the nozzle surface FD and the surface WF in the Z2 direction.

[0110] 2-8. Eighth Variation In each of the above-described embodiments, the three-dimensional object-printing apparatus 100 performs the second scan RU2 after the first scan RU1, but the second scan RU2 does not have to be performed, i.e., the pinning method does not have to be performed. For example, in the first scan RU1, the light emitter 380 emits the main curing light.

[0111] 2-9. 9th Variation During the execution of the workpiece moving operation WM in each of the above-described aspects, the individual lifting mechanism 235_1 and the individual lifting mechanism 235_2 do not need to be driven.

[0112] 2-10. 10th Variation In each of the above-described aspects, when the three-dimensional object printing apparatus 100 executes the workpiece movement operation WM, the nozzle surface FD_1 and the emission surface FU may overlap the workpiece W when viewed in the direction along the Z axis. Specifically, after the second scan RU2 is completed, the three-dimensional object printing apparatus 100 may execute the workpiece movement operation WM after moving the heads 310_1 to 310_4 and the light emission unit 380 in the Z1 direction so as not to interfere with the workpiece W. That is, in the tenth modified example, during execution of the workpiece movement operation WM, the nozzle surface FD_1 and the emission surface FU overlap the workpiece W when viewed in the direction along the Z axis. As a specific example of the tenth modification, the lifting mechanism 230 may have an overall lifting mechanism that uniformly lifts and lowers the individual lifting mechanisms 235_1 to 235_5. Then, after the second scan RU2 is completed, the three-dimensional object printing apparatus 100 may move the individual lifting mechanisms 235_1 to 235_5 uniformly in the Z1 direction using the overall lifting mechanism as the retraction operation RT1, thereby moving the heads 310_1 to 310_4 and the light output unit 380 in the Z1 direction so as not to interfere with the workpiece W.

[0113] 2-11. 11th Variation In each of the above-described embodiments, the three-dimensional object printing apparatus 100 is an inkjet printer that uses an orthogonal robot that moves on two orthogonal axes, but it may also be an inkjet printer that uses an orthogonal robot that moves on three or more orthogonal axes.

[0114] 2-12. 12th Variation The uses of the three-dimensional printing device of the present invention are not limited to printing. For example, a three-dimensional printing device that ejects a solution of color material is used as a manufacturing device for forming color filters for liquid crystal display devices. Also, a three-dimensional printing device that ejects a solution of conductive material is used as a manufacturing device for forming wiring and electrodes on a wiring board. Furthermore, a three-dimensional printing device can also be used as a jet dispenser that applies liquid such as adhesive to a workpiece. [Explanation of symbols]

[0115] 100, 100a, 100b, 100c... Three-dimensional object printing device, 200... Moving mechanism, 220... Linear motion mechanism, 221... Rail member, 222... Carriage, 223... Horizontal encoder, 230, 230b... Lifting mechanism, 231... Support plate, 235, 235_1 to 235_5, 235_4b... Individual lifting mechanism, 236... Vertical encoder, 280... Support part, 281... Work table, 282... Top plate, 283... Support, 300, 300_1 to 300_4... Liquid ejection unit, 310, 310_1 to 310_4... Head, 320... Pressure adjustment valve, 330... Cell sensor, 340...switch circuit, 350...support, 380, 380_1 to 380_4...light emitting portion, 390...light shielding plate, 391...first portion, 392...second portion, 400...liquid supply unit, 410...liquid storage portion, 420...supply flow path, 421...upstream flow path, 422...downstream flow path, 422a...flow path member, 500...control module, 510...timing signal generating circuit, 520...power supply circuit, 530...control circuit, 540...drive signal generating circuit, 600...controller, 610...memory circuit, 620...processing circuit, 700...computer, 90 0...work support mechanism, 910...line feed axis mechanism, 920...rotation axis mechanism, 922...mounting surface, AX...long axis, CLK...clock signal, CNG...change signal, CR...movement path, Com...drive signal, D2_1 to D2_5, D3...signal, DR...droplet, Da...path information, Dr, Dx, Dy, Dz_1...output signal, FD, FD_1 to FD_5...nozzle surface, FU...emission surface, Img...print data, L1...first nozzle row, L2...second nozzle row, LAT...latch signal, N...nozzle, PD...drive pulse, PE1 to PE4...end position, PS1 to PS4... Starting position, PT1, PT2... retraction position, PTS... timing signal, RA, RB... rail, RT1... retraction operation, RT2... return operation, RU1... first scan, RU2... second scan, RU3... third scan, RU4... fourth scan, SI, SI_1, Sr, Sv_k, Sx, Sy, Sz_1 to Sz_5... control signal, UV1... pinning light, UV2... main curing light, VBS... offset potential, VHV... power supply potential, W... workpiece, WF... surface, WM... workpiece movement operation, XR... rotation axis, Y... lift axis, d1, d5, e1, e5... distance, dCom... waveform specification signal.

Claims

1. a first head having a first nozzle surface provided with nozzles that eject liquid; an energy emission unit having an emission surface that emits energy to harden the liquid ejected from the first head; a movement mechanism that changes the relative positions of the first head and the energy output unit with respect to a three-dimensional workpiece; and The moving mechanism includes: a linear motion mechanism that changes the relative positions of the first head and the energy output unit with respect to the workpiece along a first axis; a first lifting mechanism that moves the first nozzle surface along a second axis that intersects with the first axis; a second lifting mechanism that moves the light exit surface along the second axis; Equipped with When an operation of moving the relative positions of the first head and the energy emission unit with respect to the workpiece in a first direction along the first axis is defined as a first scan, During the first scan, the first head ejects liquid onto the workpiece; During the first scan, the energy emission unit emits energy to the workpiece, During the first scan, the first nozzle surface and the emission surface are moved along the second axis in accordance with the shape of the workpiece by driving the first lifting mechanism and the second lifting mechanism, when the first head is discharging liquid onto the workpiece during the first scan, a distance between the first nozzle surface and the workpiece in a second direction along the second axis is shorter than a distance between the exit surface and the workpiece in the second direction, When an operation of moving the relative positions of the first head and the energy emission unit with respect to the workpiece in a third direction opposite to the first direction is defined as a second scan, the second scan is performed after the first scan; During the second scan, the energy emission unit emits energy to the workpiece, when the energy output unit outputs energy to the workpiece during the second scan, a distance between the output surface and the workpiece in the second direction is shorter than a distance between the first nozzle surface and the workpiece in the second direction; Three-dimensional object printing device.

2. During the second scan, the first head does not eject liquid onto the workpiece. The three-dimensional object printing device according to claim 1.

3. an intensity of the energy emitted by the energy emission unit during the second scan is higher than an intensity of the energy emitted by the energy emission unit during the first scan; The three-dimensional object printing device according to claim 1 or 2.

4. the position of the first nozzle face in the second direction does not change during the second scan; The three-dimensional object printing device according to any one of claims 1 to 3.

5. a second head having a second nozzle surface provided with nozzles that eject liquid; The moving mechanism includes: a third lifting mechanism that moves the second nozzle surface along the second axis; During the first scan, the second head ejects liquid onto the workpiece, During the first scan, the first nozzle surface and the second nozzle surface are moved along the second axis in accordance with the shape of the workpiece by driving the first lifting mechanism and the third lifting mechanism, the relative position between the first nozzle surface and the second nozzle surface does not change during the second scan; The three-dimensional object printing device according to claim 1 .

6. during the second scan, the first nozzle surface and the second nozzle surface are positioned substantially equal to each other in a direction along the second axis; The three-dimensional object printing apparatus according to claim 5.

7. a second head having a second nozzle surface provided with nozzles that eject liquid; The moving mechanism includes: a third lifting mechanism that moves the second nozzle surface along the second axis; the second head is located closer to the energy output unit than the first head in the first direction, a difference between the brightness of the liquid ejected from the second head and the brightness of the workpiece is greater than a difference between the brightness of the liquid ejected from the first head and the brightness of the workpiece; The three-dimensional object printing device according to any one of claims 1 to 4.

8. a workpiece support mechanism that supports the workpiece and changes one or both of the position and the posture of the workpiece; The three-dimensional object printing device according to claim 1 .

9. When an operation that is executed after the second scan and moves the relative positions of the first head and the energy output unit with respect to the workpiece in the first direction is defined as a third scan, During the execution of the third scan, the first head ejects liquid onto the workpiece, During a period between the second scan and the third scan, the workpiece support mechanism performs a workpiece moving operation that changes one or both of the position and the attitude of the workpiece. The three-dimensional object printing apparatus according to claim 8.

10. the workpiece moving operation is performed during a part of a period between the second scan and the third scan, During the workpiece moving operation, the first nozzle surface and the emission surface do not overlap with the workpiece when viewed in a direction along the second axis. The three-dimensional object printing apparatus according to claim 9.

11. During the execution of the workpiece moving operation, one or both of the first nozzle surface and the emission surface are moved along the second axis by driving one or both of the first lifting mechanism and the second lifting mechanism. The three-dimensional object printing device according to claim 9 or 10.

12. a light-shielding portion that is provided between the first head and the energy output portion in the first direction and that blocks the energy irradiated from the energy output portion; The three-dimensional object printing device according to any one of claims 1 to 11.

13. the light-shielding portion is provided on the energy output portion, The three-dimensional object printing apparatus according to claim 12.

14. the light blocking section is provided in a liquid ejection unit having the first head; The three-dimensional object printing apparatus according to claim 12.

15. a liquid storage section that stores the liquid ejected from the first head; the liquid storage section is located above a movement area of ​​the first head in the second direction; The three-dimensional object printing device according to any one of claims 1 to 14.

16. a first head having a first nozzle surface provided with nozzles that eject liquid; an energy emission unit having an emission surface that emits energy to harden the liquid ejected from the first head; a movement mechanism that changes the relative positions of the first head and the energy output unit with respect to a three-dimensional workpiece, The moving mechanism includes: a linear motion mechanism that changes the relative positions of the first head and the energy output unit with respect to the workpiece along a first axis; a first lifting mechanism that moves the first nozzle surface along a second axis that intersects with the first axis; a second lifting mechanism that moves the light exit surface along the second axis, A control method for a three-dimensional object printing device, comprising: a first scanning operation that moves the relative positions of the first head and the energy emission unit with respect to the workpiece in a first direction along the first axis; During the first scan, the first head ejects liquid onto the workpiece; During the first scan, the energy emission unit emits energy to the workpiece, During the first scan, the first nozzle surface and the emission surface are moved along the second axis in accordance with the shape of the workpiece by driving the first lifting mechanism and the second lifting mechanism, when the first head is discharging liquid onto the workpiece during the first scan, a distance between the first nozzle surface and the workpiece in a second direction along the second axis is shorter than a distance between the exit surface and the workpiece in the second direction, a second scanning operation that moves the relative positions of the first head and the energy emission unit with respect to the workpiece in a third direction that is opposite to the first direction, the second scan is performed after the first scan; During the second scan, the energy emission unit emits energy to the workpiece, when the energy output unit outputs energy to the workpiece during the second scan, a distance between the output surface and the workpiece in the second direction is shorter than a distance between the first nozzle surface and the workpiece in the second direction; A method for controlling a three-dimensional object printing device.

Images