Stereoscopic object printing apparatus and stereoscopic object printing method

Abstract

A three-dimensional object printing apparatus and a three-dimensional object printing method that reduce clogging of nozzles of a liquid ejection head while improving print quality in the presence of a mechanism that hardens or cures ink. The three-dimensional object printing apparatus executes a first step of ejecting liquid from the liquid ejection head toward a workpiece in execution of a first scan in which a relative position of the liquid ejection head and an energy emission portion with respect to the workpiece is changed along a first path, and a second step of irradiating energy from the energy emission portion toward the liquid on the workpiece in execution of a second scan in which the relative position of the liquid ejection head and the energy emission portion with respect to the workpiece is changed along a second path, the first step satisfying a relationship of L1 < L2 when a distance between the workpiece and a nozzle surface of the liquid ejection head in a normal direction of the nozzle surface is set as L1 and a distance between the workpiece and an emission surface of the energy emission portion in a normal direction of the emission surface is set as L2, and the second step satisfying a relationship of L1 > L2.

Description

Technical Field

[0001] This invention relates to a three-dimensional printing apparatus and a three-dimensional printing method. Background Technology

[0002] A three-dimensional printing apparatus is known for printing on the surface of a three-dimensional object by inkjet printing. For example, the system described in Patent Document 1 has a robot and a printhead disposed on the robot, and sprays ink droplets from the printhead onto the curved surface of the vehicle.

[0003] Patent document 1 describes a technique for hardening freshly applied ink by having a hardening head, which is positioned adjacent to the printing head, track the printing head in the same way.

[0004] In the apparatus described in Patent Document 1, the print head and the curing head are arranged adjacent to each other. Thus, in an apparatus where the relative positional relationship between the print head and the curing head is fixed, there is a possibility that when the print head is positioned in a desired position and orientation, the curing head cannot be positioned in the desired position and orientation. In other words, there is a possibility that neither the print head nor the curing head can be positioned in the desired position and orientation. Therefore, for example, when the print head is positioned in the desired position and orientation to ensure print quality, the curing head may not be in the desired position and orientation, making it difficult to effectively perform the curing of the ink by the curing head.

[0005] Patent Document 1: Japanese Patent Publication No. 2015-520011 Summary of the Invention

[0006] To address the above-mentioned issues, one aspect of the three-dimensional printing apparatus according to the present invention includes: a liquid ejector head having a nozzle surface provided with a nozzle for ejecting liquid; an energy ejection section having an ejection surface for ejecting energy that hardens or solidifies the liquid from the liquid ejector head; and a moving mechanism that changes the relative position and orientation of the liquid ejector head and the energy ejection section relative to a three-dimensional workpiece. The three-dimensional printing apparatus performs a first step and a second step, wherein the first step is that the moving mechanism changes the relative position of the liquid ejector head and the energy ejection section relative to the workpiece in the first... In the execution of the scan, the step of the liquid nozzle spraying liquid onto the workpiece, the second step is, in the execution of the second scan in which the moving mechanism changes the relative position of the liquid nozzle and the energy ejection part relative to the workpiece, the step of the energy ejection part irradiating energy onto the liquid on the workpiece, when the distance between the workpiece and the nozzle surface in the normal direction of the nozzle surface is set as L1, and the distance between the workpiece and the ejection surface in the normal direction of the ejection surface is set as L2, the first step satisfies the relationship L1 < L2, and the second step satisfies the relationship L1 > L2.

[0007] One aspect of the three-dimensional printing method of the present invention is a method of printing on a workpiece using a device and a moving mechanism that changes the relative position and posture of the device relative to a three-dimensional workpiece. The device includes: a liquid ejector head having a nozzle surface with a nozzle for ejecting liquid; and an energy ejector having an ejection surface that ejects energy to harden or solidify the liquid from the liquid ejector head. In the three-dimensional printing method, a first reference point indicating a position within the device, a second reference point indicating a position within the device different from the first reference point, a first path for the first reference point to move, and a second path for the second reference point to move are set. A first step is performed where, while the liquid ejector head ejects liquid onto the workpiece, the moving mechanism changes the relative position of the first reference point relative to the workpiece along the first path. A second step is performed where, while the energy ejector irradiates energy onto the liquid on the workpiece, the moving mechanism changes the relative position of the second reference point relative to the workpiece along the second path.

[0008] Another aspect of the three-dimensional printing method of the present invention is a method for printing on a three-dimensional workpiece using a liquid ejector head and an energy ejector, wherein the liquid ejector head has a nozzle surface provided with a nozzle for ejecting liquid, and the energy ejector has an ejection surface for ejecting energy to harden or solidify the liquid from the liquid ejector head. In the three-dimensional printing method, a first step and a second step are performed. The first step is that, during the execution of a first scan in which the relative positions of the liquid ejector head and the energy ejector relative to the workpiece change along a first path, the liquid ejector head is used to print on a three-dimensional workpiece. The first step involves spraying liquid from the liquid ejector head onto the workpiece. The second step involves irradiating energy onto the liquid on the workpiece from the energy ejector head during the execution of a second scan in which the relative positions of the liquid ejector head and the energy ejector relative to the workpiece change along a second path. When the distance between the workpiece and the nozzle surface in the normal direction of the nozzle surface is set to L1 and the distance between the workpiece and the ejector surface in the normal direction of the ejector surface is set to L2, the first step satisfies the relationship L1 < L2, and the second step satisfies the relationship L1 > L2. Attached Figure Description

[0009] Figure 1 A perspective view showing the outline of the three-dimensional printing apparatus according to the embodiment.

[0010] Figure 2 This is a block diagram illustrating the electrical structure of the three-dimensional printing apparatus according to the embodiment.

[0011] Figure 3 This is a perspective view showing the outline structure of the liquid ejection unit in the embodiment.

[0012] Figure 4 This is a flowchart illustrating the process of the three-dimensional printing method according to the embodiments.

[0013] Figure 5 This diagram is used to illustrate the setting of reference points and paths in the implementation method.

[0014] Figure 6 This is a schematic diagram used to illustrate the first step of the implementation method.

[0015] Figure 7 This is a schematic diagram used to illustrate the second step in the implementation method. Detailed Implementation

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the dimensions or proportions of the parts in the drawings differ appropriately from actual dimensions, and some parts are shown schematically for ease of understanding. Furthermore, unless otherwise stated in the following description, the scope of the present invention is not limited to these embodiments.

[0017] The following explanation uses intersecting X, Y, and Z axes appropriately. Furthermore, a direction along the X-axis is referred to as the X1 direction, and the opposite direction is referred to as the X2 direction. Similarly, opposite directions along the Y-axis are referred to as the Y1 and Y2 directions. Furthermore, opposite directions along the Z-axis are referred to as the Z1 and Z2 directions.

[0018] Here, the X-axis, Y-axis, and Z-axis are the coordinate axes of a reference coordinate system established in the space containing the workpiece W (described later) and the base 210. Typically, the Z-axis is a vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z-axis may not be a vertical axis. Furthermore, although the X-axis, Y-axis, and Z-axis are typically orthogonal to each other, this is not a limitation, and there are cases where they are not orthogonal. For example, the X-axis, Y-axis, and Z-axis may intersect each other at an angle within the range of 80° to 100°.

[0019] 1. First Implementation Method

[0020] 1-1. Overview of a 3D printing apparatus

[0021] Figure 1 This is a perspective view showing an outline of the three-dimensional printing apparatus 100 according to the embodiment. The three-dimensional printing apparatus 100 is an apparatus that performs printing on the surface of a three-dimensional workpiece W by inkjet printing.

[0022] The workpiece W has a surface WF that becomes the object of printing. Figure 1 In the example shown, surface WF is a convex curved surface with multiple parts having different curvatures. Alternatively, the printing object can be any surface other than surface WF among the multiple surfaces of the workpiece W. Furthermore, the size, shape, or orientation of the workpiece W is not limited to... Figure 1 The example shown is arbitrary.

[0023] exist Figure 1 In the example shown, the stereoscopic printing apparatus 100 is an inkjet printer using a vertical multi-joint robot. Specifically, as Figure 1 As shown, the 3D printing apparatus 100 includes a robot 200, a liquid ejection unit 300, a liquid supply unit 400, and a controller 600. Hereinafter, we will first describe... Figure 1The various parts of the three-dimensional printing apparatus 100 shown will be briefly described.

[0024] Robot 200 is a moving mechanism that changes the position and orientation of the liquid ejection unit 300 relative to the workpiece W. Figure 1 In the example shown, robot 200 is a so-called six-axis vertical joint robot. Specifically, robot 200 has a base 210 and an arm 220.

[0025] The base 210 is a platform that supports the arm 220. Figure 1 In the example shown, the base 210 is fixed to a mounting surface such as a floor surface facing the Z1 direction by means of screws or the like. Furthermore, the mounting surface of the base 210 can be a surface facing any direction, and is not limited to any particular direction. Figure 1 The example shown can also be a surface such as a wall, ceiling, or movable cart.

[0026] Arm 220 is a six-axis robotic arm having a base end mounted on base 210 and a tip end that allows for three-dimensional changes in position and orientation relative to the base end. Specifically, arm 220 has arms 221, 222, 223, 224, 225, and 226, which are connected in this order.

[0027] Arm 221 is connected to base 210 via joint 230_1, allowing it to rotate about a first rotation axis O1. Arm 222 is connected to arm 221 via joint 230_2, allowing it to rotate about a second rotation axis O2. Arm 223 is connected to arm 222 via joint 230_3, allowing it to rotate about a third rotation axis O3. Arm 224 is connected to arm 223 via joint 230_4, allowing it to rotate about a fourth rotation axis O4. Arm 225 is connected to arm 224 via joint 230_5, allowing it to rotate about a fifth rotation axis O5. Arm 226 is connected to arm 225 via joint 230_6, allowing it to rotate about a sixth rotation axis O6. In the following text, joints 230_1 to 230_6 may be referred to as joint 230.

[0028] Joint 230 is an example of a "movable part". Figure 1 The example shown illustrates the case where the number N of joints 230 is six. Figure 1 In the example shown, joints 230_1 to 230_6 are mechanisms that connect one of two adjacent arms to the other in a rotatable manner. Although in Figure 1Although not shown in the diagram, drive mechanisms are provided on joints 230_1 to 230_6 respectively, for rotating one of two adjacent arms relative to the other. These drive mechanisms include, for example, a motor that generates a driving force for the rotation, a reducer that decelerates and outputs the driving force, and a rotary encoder that detects the amount of motion, such as the angle of rotation. Furthermore, the assembly of these drive mechanisms corresponds to the following... Figure 2 The arm drive mechanism 240 is shown. Furthermore, the encoder corresponds to the one described later. Figure 2 The encoder 241 is shown in the figure.

[0029] The first rotation axis O1 is perpendicular to a mounting surface (not shown) of the fixed base 210. The second rotation axis O2 is perpendicular to the first rotation axis O1. The third rotation axis O3 is parallel to the second rotation axis O2. The fourth rotation axis O4 is perpendicular to the third rotation axis O3. The fifth rotation axis O5 is perpendicular to the fourth rotation axis O4. The sixth rotation axis O6 is perpendicular to the fifth rotation axis O5.

[0030] Furthermore, for these rotation axes, "perpendicular" includes not only the case where the angle between the two rotation axes is strictly 90°, but also the case where the angle between the two rotation axes deviates from 90° within a range of approximately ±5°. Similarly, "parallel" includes not only the case where the two rotation axes are strictly parallel, but also the case where one of the two rotation axes is tilted relative to the other within a range of approximately ±5°.

[0031] At the top of the arm 220, namely the arm 226, a liquid ejection unit 300 is installed as an end effector.

[0032] The liquid ejection unit 300 is a device having a liquid ejection head 310 and an energy ejection section 330. The liquid ejection head 310 ejects ink, an example of a liquid, toward the workpiece W, and the energy ejection section 330 ejects energy to harden or solidify the ink ejected from the liquid ejection head 310 onto the workpiece W. In this embodiment, in addition to the liquid ejection head 310 and the energy ejection section 330, the liquid ejection unit 300 has a pressure regulating valve 320 for regulating the pressure of the ink supplied to the liquid ejection head 310. Since they are fixed together on the arm 226, their relative positions and orientations are fixed.

[0033] The ink is not particularly limited, and examples include aqueous inks that dissolve color materials such as dyes or pigments in aqueous solvents, UV-curable inks that use curable resins, and solvent-based inks that dissolve color materials such as dyes or pigments in organic solvents. Among these, curable inks are preferred. The curable ink is not particularly limited; for example, it can be any of the following: thermosetting, photocurable, radiation-curable, and electron wire-curable types, but photocurable types such as UV-curable are preferred. Furthermore, the ink is not limited to a solution and can also be an ink in which color materials are dispersed as a dispersion medium. Moreover, the ink is not limited to inks containing color materials and can also be an ink containing conductive particles such as metal particles used to form wiring as a dispersion medium.

[0034] Although Figure 1 Although not shown in the figure, the liquid ejector head 310 includes a piezoelectric element, a chamber for collecting ink, and a nozzle communicating with the chamber. Here, the piezoelectric element is provided for each chamber, and by changing the pressure in that chamber, ink is ejected from the nozzle corresponding to that chamber. Such a liquid ejector head 310 is obtained, for example, by bonding together multiple substrates, such as a silicon substrate, appropriately processed by etching or the like, using an adhesive or the like. Furthermore, the piezoelectric element corresponds to the [described later]... Figure 2 The piezoelectric element 311 is shown. Alternatively, a heater that heats the ink within the chamber can be used instead of the piezoelectric element as a drive element for ejecting ink from the nozzle.

[0035] The pressure regulating valve 320 is a valve mechanism that opens and closes according to the pressure of the ink within the liquid nozzle 310. Through this opening and closing, the pressure of the ink within the liquid nozzle 310 is maintained at a negative pressure within a predetermined range. Therefore, the meniscus of the ink formed on the nozzle N of the liquid nozzle 310 is stabilized. As a result, air bubbles are prevented from entering the nozzle N, or ink overflows from the nozzle N.

[0036] In addition, although Figure 1 In the example shown, the liquid ejection unit 300 has one liquid ejection head 310 and one pressure regulating valve 320, but this number is not limited to one. Figure 1 The example shown can also include more than two. Furthermore, the position of the pressure regulating valve 320 is not limited to arm 226; it can be, for example, other arms, or a position fixed relative to the base 210.

[0037] The energy emission section 330 emits energy such as light, heat, electron beams, or radiation, depending on the type of ink. For example, in the case of an ultraviolet-curing ink, the energy is ultraviolet light. The energy emission section 330 has a structure corresponding to the type of energy. For example, in the case of ultraviolet light, the energy emission section 330 includes a light source such as a light-emitting diode (LED) that emits ultraviolet light. In addition, the energy emission section 330 may also include optical components such as lenses for adjusting the direction or range of energy emission.

[0038] Here, the energy ejection unit 330 is preferably capable of adjusting the intensity of the ejected energy. In this case, by reducing the energy intensity during the printing operation described later, nozzle clogging can be reduced, and by increasing the energy intensity during the curing operation described later, the time required for ink curing or hardening can be shortened.

[0039] The liquid supply unit 400 is a mechanism for supplying ink to the liquid ejector head 310. The liquid supply unit 400 has a liquid reservoir 410 and a supply channel 420.

[0040] The liquid storage section 410 is a container for storing ink. The liquid storage section 410 is, for example, a bag-shaped ink packet formed of a flexible film.

[0041] exist Figure 1 In the example shown, the liquid reservoir 410 is fixed to a wall, ceiling, or column in a manner that always positions it further in the Z1 direction than the liquid nozzle 310. That is, the liquid reservoir 410 is located higher in the vertical direction than the moving area of ​​the liquid nozzle 310. Therefore, even without using a pump or similar mechanism, ink can be supplied from the liquid reservoir 410 to the liquid nozzle 310 at a predetermined pressure.

[0042] Furthermore, the location of the liquid reservoir 410 can be such that ink can be supplied from the liquid reservoir 410 to the liquid nozzle 310 at a predetermined pressure, or it can be located further below the liquid nozzle 310 in the vertical direction. In this case, for example, ink can be supplied from the liquid reservoir 410 to the liquid nozzle 310 at a predetermined pressure using a pump.

[0043] The supply channel 420 is a channel for supplying ink from the liquid reservoir 410 to the liquid nozzle 310. A pressure regulating valve 320 is provided midway through the supply channel 420. Therefore, even if the positional relationship between the liquid nozzle 310 and the liquid reservoir 410 changes, the pressure fluctuation of the ink in the liquid nozzle 310 can be reduced.

[0044] The supply channel 420 is formed by, for example, the internal space of a tube. Here, the tube for the supply channel 420 is made of an elastic material such as rubber or an elastomer, and is flexible. Thus, by using a flexible tube to form the supply channel 420, changes in the relative positional relationship between the liquid reservoir 410 and the pressure regulating valve 320 are allowed. Therefore, even if the position or orientation of the liquid nozzle 310 changes while maintaining a fixed position and posture of the liquid reservoir 410, ink can still be supplied from the liquid reservoir 410 to the pressure regulating valve 320.

[0045] Alternatively, a portion of the supply channel 420 may be made of a non-flexible component. Furthermore, a portion of the supply channel 420 may be a structure with a dispensing channel that distributes ink to multiple locations, or it may be integrally formed with the liquid nozzle 310 or the pressure regulating valve 320.

[0046] Controller 600 is a robot controller that controls the drive of robot 200. Although in Figure 1 Although not shown in the diagram, a control module that controls the ejection action of the liquid ejection unit 300 is electrically connected to the controller 600. A computer is connected to the controller 600 and the control module in a communicative manner. Furthermore, this control module corresponds to the one described later. Figure 2 The control module 500 is shown. This computer is equivalent to the one described later. Figure 2 The computer shown is 700.

[0047] 1-2. Electrical Structure of the Three-Dimensional Printing Apparatus

[0048] Figure 2 This is a block diagram illustrating the electrical structure of the three-dimensional printing apparatus 100 according to the first embodiment. Figure 2 The diagram shows the electrical structural elements within the structural elements of the three-dimensional printing apparatus 100. Furthermore, in... Figure 2 The image shows an arm drive mechanism 240 including encoders 241_1 to 241_6. The arm drive mechanism 240 is an assembly of the aforementioned drive mechanisms that actuate joints 230_1 to 230_6. Encoders 241_1 to 241_6 are arranged in a manner corresponding to joints 230_1 to 230_6, and the rotation angle and other actuation quantities of encoders 241_1 to 241_6 are measured. Furthermore, in the following text, each encoder 241_1 to 241_6 is sometimes referred to as encoder 241.

[0049] like Figure 2As shown, the stereolithography printing apparatus 100, in addition to the robot 200, liquid ejection unit 300, and controller 600 described above, also includes a control module 500 and a computer 700. Furthermore, the electrical structural elements described below can be appropriately separated, partially incorporated into other structural elements, or integrally formed with other structural elements. For example, part or all of the function of the control module 500 or controller 600 can be implemented by the computer 700 connected to the controller 600, or by other external devices such as a PC (personal computer) connected to the controller 600 via a network such as a LAN (Local Area Network) or the Internet.

[0050] The controller 600 has the function of controlling the drive of the robot 200 and generating a signal D3 to synchronize the spraying action of the liquid nozzle 310 with the action of the robot 200. The controller 600 has a storage circuit 610 and a processing circuit 620.

[0051] The storage circuit 610 stores various programs executed by the processing circuit 620 and various data processed by the processing circuit 620. The storage circuit 610 may include, for example, a semiconductor memory comprising one or both of the following: volatile memory such as RAM (Random Access Memory) and non-volatile memory such as ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), or PROM (Programmable Read-Only Memory). Alternatively, part or all of the storage circuit 610 may be included in the processing circuit 620.

[0052] The storage circuit 610 stores reference point information Da and path information Db. The reference point information Da is information related to the respective positions of the liquid ejector head 310 and the energy ejection section 330. Specifically, the reference point information Da is information related to the first reference point TCP1 and the second reference point TCP2, which are set as tool center points (described later).

[0053] The path information Db represents the path that the liquid ejector head 310 and the energy ejection unit 330 should move. Specifically, the path information Db includes information representing the path that the first reference point TCP1 (described later), i.e., the first path RU_1 (described later), should move, and information representing the path that the second reference point TCP2 (described later), i.e., the second path RU_2 (described later). The first path RU_1 and the second path RU_2 may be the same or different. The path information Db is represented, for example, using coordinate values ​​from a reference coordinate system. The path information Db is determined based on workpiece information representing the position and shape of the workpiece W. This workpiece information is obtained by establishing a correspondence between information such as CAD (computer-aided design) data representing the three-dimensional shape of the workpiece W and the aforementioned reference coordinate system. The path information Db is input from the computer 700 into the storage circuit 610.

[0054] The processing circuit 620 controls the movement of joints 230_1 to 230_6 based on path information Db and generates signal D3. Specifically, the processing circuit 620 performs inverse kinematics calculation, converting the path information Db into motion quantities such as rotation angle and rotation speed of each joint 230_1 to 230_6. Then, the processing circuit 620 outputs control signals Sk_1 to Sk_6 based on the outputs D1_1 to D1_6 of the encoders 241_1 to 241_6 included in the arm drive mechanism 240 of the robot 200, in a manner that makes the actual rotation angle and rotation speed of each joint 230_1 to 230_6 the above calculation result. The control signals Sk_1 to Sk_6 correspond to joints 230_1 to 230_6 and control the drive of the motors installed on the corresponding joints 230. Additionally, outputs D1_1 to D1_6 correspond to encoders 241_1 to 241_6. In the following text, each output D1_1 to D1_6 may be referred to as output D1.

[0055] Furthermore, the processing circuit 620 generates a signal D3 based on the output D1 from at least one of the encoders 241_1 to 241_6. For example, the processing circuit 620 generates a trigger signal as signal D3 that includes a timing pulse of the output D1 from one of the encoders 241_1 to 241_6 becoming a predetermined value.

[0056] The processing circuit 620 described above includes, for example, one or more processors such as CPUs (Central Processing Units). Alternatively, the processing circuit 620 can replace a CPU, or, in addition to a CPU, include programmable logic devices such as FPGAs (field-programmable gate arrays).

[0057] The control module 500 is a circuit that controls the spraying action of the liquid nozzle 310 based on the signal D3 output from the controller 600 and the printing data from the computer 700. The control module 500 includes a timing signal generation circuit 510, a power supply circuit 520, a control circuit 530, and a drive signal generation circuit 540.

[0058] The timing signal generation circuit 510 generates a timing signal PTS based on signal D3. The timing signal generation circuit 510 is, for example, composed of a timer that starts generating the timing signal PTS upon detection of signal D3.

[0059] The power supply circuit 520 receives power from a commercial power supply not shown and generates various predetermined potentials. These potentials are appropriately supplied to various parts of the stereolithography apparatus 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. Furthermore, the power supply potential VHV is supplied to the drive signal generation circuit 540.

[0060] The control circuit 530 generates a control signal SI, a waveform specification signal dCom, a latch signal LAT, a clock signal CLK, and a switching signal CNG based on the timing signal PTS. These signals are synchronized with the timing signal PTS. The waveform specification signal dCom is input to the drive signal generation circuit 540, while the other signals are input to the switching circuit 340 of the liquid ejection unit 300.

[0061] The control signal SI is a digital signal used to specify the operating state of the piezoelectric element 311 of the liquid ejector head 310. Specifically, the control signal SI specifies whether to supply the drive signal Com (described later) to the piezoelectric element 311. This specification, for example, specifies whether ink is ejected from the nozzle corresponding to the piezoelectric element 311, or specifies the amount of ink ejected from the nozzle. The waveform specification signal dCom is a digital signal used to specify the waveform of the drive signal Com. The latch signal LAT and the exchange signal CNG, together with the control signal SI, are used to specify the drive timing of the piezoelectric element 311, thereby specifying the timing of ink ejection from the nozzle. The clock signal CLK is a clock signal that serves as a reference synchronized with the timing signal PTS. Among the above signals, the signals input to the switching circuit 340 of the liquid ejection unit 300 will be described in detail below.

[0062] The control circuit 530 described above includes, for example, one or more processors such as CPUs (Central Processing Units). Alternatively, the control circuit 530 may replace the CPU, or may include programmable logic devices such as FPGAs (field-programmable gate arrays) in addition to the CPU.

[0063] The drive signal generation circuit 540 is a circuit that generates drive signals Com for driving the piezoelectric elements 311 of the liquid nozzle 310. Specifically, the drive signal generation circuit 540 includes, for example, a DA conversion circuit and an amplification circuit. In the drive signal generation circuit 540, the DA conversion circuit converts the waveform specification signal dCom from the control circuit 530 from a digital signal to an analog signal, and the amplification circuit amplifies the analog signal using the power supply potential VHV from the power supply circuit 520, thereby generating the drive signal Com. Here, the waveform contained in the drive signal Com that is actually supplied to the piezoelectric element 311 is the drive pulse PD. The drive pulse PD is supplied from the drive signal generation circuit 540 to the piezoelectric element 311 via a switching circuit 340. The switching circuit 340 switches whether to supply at least a portion of the waveform contained in the drive signal Com as the drive pulse PD based on the control signal SI.

[0064] The computer 700 has the functions of supplying reference point information Da and path information Db to the controller 600, and supplying printing data to the control module 500. In addition, the computer 700 in this embodiment is electrically connected to the energy emission unit 330 described above, and outputs a signal D2 to control the drive of the energy emission unit 330 based on the signal from the controller 600 or the control module 500.

[0065] 1-3. Liquid ejection unit

[0066] Figure 3 This is a perspective view showing the outline structure of the liquid ejection unit 300 in the first embodiment.

[0067] The following explanation uses intersecting a-axis, b-axis, and c-axis appropriately. Furthermore, a direction along the a-axis is called the a1 direction, and the direction opposite to the a1 direction is called the a2 direction. Similarly, opposite directions along the b-axis are called the b1 and b2 directions. Furthermore, opposite directions along the c-axis are called the c1 and c2 directions.

[0068] Here, the a-axis, b-axis, and c-axis are the coordinate axes of the tool coordinate system set in the liquid ejection unit 300, and their relative positions and postures with the X-axis, Y-axis, and Z-axis change due to the actions of the robot 200. Figure 3 In the example shown, the c-axis is an axis parallel to the sixth rotation axis O6 mentioned above. Furthermore, while the a-axis, b-axis, and c-axis are typically orthogonal to each other, this is not a limitation; for example, they can intersect at an angle between 80° and 100°.

[0069] As described above, the liquid ejection unit 300 includes a liquid ejection head 310, a pressure regulating valve 320, and an energy ejection section 330. These are composed of… Figure 3 The support body 350 is shown by the double-dotted line in the figure.

[0070] The support 350 is made of, for example, a metallic material and is a solid rigid body. Furthermore, although in Figure 3 In the middle, the support body 350 is a flat box shape, but the shape of the support body 350 is not particularly limited and can be any shape.

[0071] The support 350 is mounted on the top of the arm 220, i.e., the arm 226. Therefore, the liquid nozzle 310, the pressure regulating valve 320, and the energy ejection part 330 are each fixed on the arm 226.

[0072] exist Figure 3 In the example shown, the pressure regulating valve 320 is located in the c1 direction relative to the liquid nozzle 310. The energy ejection section 330 is located in the a2 direction relative to the liquid nozzle 310.

[0073] The supply channel 420 is divided into an upstream channel 421 and a downstream channel 422 by a pressure regulating valve 320. That is, the supply channel 420 has an upstream channel 421 that connects the liquid reservoir 410 to the pressure regulating valve 320, and a downstream channel 422 that connects the pressure regulating valve 320 to the liquid nozzle 310. Figure 3 In the example shown, a portion of the downstream flow channel 422 of the supply flow channel 420 is constituted by a flow channel component 422a. The flow channel component 422a has flow channels that dispense ink from the pressure regulating valve 320 to multiple locations of the liquid ejector head 310. The flow channel component 422a is, for example, a laminate of multiple substrates made of a resin material, and grooves or holes for ink flow channels are suitably provided on each substrate.

[0074] The liquid ejector head 310 has a nozzle face F1 and a plurality of nozzles N opening on the nozzle face F1. Figure 3 In the example shown, the normal direction of the nozzle surface F1 is the c2 direction. The plurality of nozzles N are divided into a first nozzle column La and a second nozzle column Lb, which are spaced apart from each other along the a-axis. The first nozzle column La and the second nozzle column Lb are examples of "nozzle columns" and are collections of a plurality of nozzles N arranged in a straight line along the b-axis. Here, the elements associated with each nozzle N in the first nozzle column La and the elements associated with each nozzle N in the second nozzle column Lb in the liquid ejector head 310 are structurally approximately symmetrical with each other along the a-axis.

[0075] However, the positions of the multiple nozzles N in the first nozzle column La and the multiple nozzles N in the second nozzle column Lb along the b-axis can be either identical or different. Furthermore, elements associated with each nozzle N in either the first nozzle column La or the second nozzle column Lb can be omitted. The following example illustrates a structure where the multiple nozzles N in the first nozzle column La and the multiple nozzles N in the second nozzle column Lb are identical in position along the b-axis.

[0076] The energy emission section 330 has an emission surface F2 that emits energy such as ultraviolet rays. Figure 3 In the example shown, the normal direction of the injection surface F2 is the c2 direction, and the injection surface F2 is disposed on the same plane as the nozzle surface F1 described above. Alternatively, the normal direction of the injection surface F2 may be different from the normal direction of the nozzle surface F1. Furthermore, the injection surface F2 may be located either on the same plane as the nozzle surface F1, or, for example, relative to the nozzle surface F1, in the c1 or c2 direction.

[0077] The 3D printing apparatus 100 can set a first reference point TCP1 and a second reference point TCP2, representing different positions within the liquid ejection unit 300, as tool center points, and selectively executes a printing action that drives the robot 200 by moving the first reference point TCP1 along a predetermined path, and a hardening action that drives the robot 200 by moving the second reference point TCP2 along a predetermined path. Furthermore, in the printing action, a tool coordinate system with the first reference point TCP1 as the origin is used. In the hardening action, a tool coordinate system with the second reference point TCP2 as the origin is used.

[0078] The first reference point TCP1 is the point representing the position of the liquid ejector head 310. Figure 3 In the example shown, the first reference point TCP1 is the center point of the nozzle surface F1. Furthermore, the second reference point TCP2 is a point indicating the position of the energy ejection section 330. Figure 3 In the example shown, the second reference point TCP2 is the center point of the injection surface F2. Furthermore, the first reference point TCP1 is not limited to the center of the nozzle surface F1, but only to a position closer to the nozzle surface F1 than the injection surface F2 within the liquid ejection unit 300. Similarly, the second reference point TCP2 is not limited to the center of the injection surface F2, but only to a position closer to the injection surface F2 than the nozzle surface F1 within the liquid ejection unit 300.

[0079] 1-4. Operation of the 3D printing apparatus and 3D printing method

[0080] Figure 4 This is a flowchart illustrating the process of the three-dimensional printing method according to the embodiment. This three-dimensional printing method is implemented using the three-dimensional printing apparatus 100 described above. Figure 4 As shown, the stereoscopic printing apparatus 100 sequentially executes step S110 of setting reference points and paths, step S120 of spraying ink from the liquid nozzle 310 onto the surface WF, and step S130 of hardening the ink sprayed in step S120.

[0081] Figure 5 This diagram illustrates the setting of reference points and paths in the implementation method. In step S110 described above, first reference point TCP1 and second reference point TCP2 are set. This setting is performed, for example, by moving a portion of the liquid ejection unit 300, which should be set as one of these reference points, to a known position in the reference coordinate system. The other reference point is set based on the positional relationship between these reference points. Thus, by setting the first reference point TCP1 and the second reference point TCP2, the aforementioned reference point information Da is generated.

[0082] Next, based on workpiece information representing the position and shape of workpiece W, a first path RU_1 is set as the path that the first reference point TCP1 should move in the first scan. Although in Figure 5 Although not illustrated, the second path RU_2, described later, is similarly set based on workpiece information representing the position and shape of workpiece W, serving as the path through which the second reference point TCP2 should move in the second scan. Thus, by setting the first path RU_1 and the second path RU_2, the aforementioned path information Db is generated. Furthermore, the first path RU_1 and the second path RU_2 can be either identical or different. However, from the viewpoint of simplifying the structure of the liquid ejection unit 300 while appropriately implementing printing and hardening, it is preferable that these paths are parallel or substantially parallel to each other; furthermore, it is preferable that they are consistent or substantially consistent when viewed in the normal direction of the surface WF.

[0083] Figure 6 This is a schematic diagram illustrating step S120, which is an example of the first step in the implementation. In step S120, printing is performed by spraying ink toward the surface WF of the workpiece W while moving along the first path RU_1 from the first reference point TCP1. Here, the movement of the robot 200 along the first path RU_1 is an example of a first scan. At this time, the liquid nozzle 310 is located further forward in the direction of movement than the energy ejection unit 330. That is, the a1 direction in the tool coordinate system is towards the first path RU_1.

[0084] Here, the distance between the first path RU_1 and the surface WF is fixed or approximately fixed, and the angle between the normal of the nozzle surface F1 of the liquid ejector head 310 and the surface WF is fixed or approximately fixed. Therefore, when the distance between the first reference point TCP1 in the normal direction of the nozzle surface F1 and the surface WF is set as distance L1, distance L1 spans the entire domain of the first path RU_1 and is fixed. Therefore, the ink spraying error from the liquid ejector head 310 to the surface WF can be reduced. Furthermore, in Figure 6 In the example shown, the normal to nozzle surface F1 is orthogonal or approximately orthogonal to surface WF. Therefore, it is easier to improve print quality compared to the case where the normal to nozzle surface F1 is inclined relative to surface WF.

[0085] In contrast, when the distance between the second reference point TCP2 in the normal direction of the ejection surface F2 and the surface WF is set as distance L2, distance L2 changes with the curvature of surface WF in step S120. Furthermore, since surface WF is a convex curved surface, and as described above, the normal of the nozzle surface F1 of the liquid ejection head 310 is orthogonal or approximately orthogonal to surface WF, distance L2 is greater than distance L1 in step S120.

[0086] In step S120, energy is not emitted from the energy emission section 330, or the intensity of the energy from the energy emission section 330 is such that the ink on the surface WF is not completely cured but rather pinned. Therefore, compared to the case in step S120 where energy is emitted from the energy emission section 330 to the same degree as in step S130, nozzle N clogging is prevented or reduced. Furthermore, when the above-described pinning process is performed, ink deviation from the desired position on the surface WF can be prevented or reduced.

[0087] Preferably, the energy per unit area of ​​the irradiated surface WF in step S120 is less than that in step S130. In this case, nozzle N clogging can be reduced compared to the case where the energy is equal to or greater than that in step S130.

[0088] Figure 7 This is a schematic diagram illustrating step S130, which is an example of the second step in the embodiment. In step S130, while moving along the second path RU_2 from the second reference point TCP2, the energy ejector 330 ejects energy toward the ink sprayed onto the surface WF in step S120, thereby hardening or curing the ink. Here, the movement of the robot 200 along the second path RU_2 is an example of a second scan. At this time, similar to step S120 described above, the liquid ejector head 310 is located further forward in the direction of movement than the energy ejector 330.

[0089] Here, in step S130, ink is not ejected from the liquid ejection head 310. Therefore, the energy emitted from the energy ejection unit 330 does not affect the ejection of ink from the liquid ejection head 310. Furthermore, the second scan is performed after the first scan, and the two are not performed simultaneously. In addition, the robot 200 is capable of performing actions different from the first and second scans. Such different actions also include returning the position of the liquid ejection unit 300 to its initial position in the first scan.

[0090] Furthermore, the distance between the second path RU_2 and the surface WF is fixed or approximately fixed, and the angle between the normal of the emission surface F2 of the energy emission section 330 and the surface WF is fixed or approximately fixed. Therefore, when the distance between the second reference point TCP2 in the normal direction of the emission surface F2 and the surface WF is set as distance L2, distance L2 spans the entire domain of the second path RU_2 and is fixed. Therefore, uneven energy irradiation from the energy emission section 330 to the surface WF can be reduced. Furthermore, in Figure 6 In the example shown, the normal to the ejection surface F2 is orthogonal or approximately orthogonal to the surface WF. Therefore, compared to the case where the normal to the ejection surface F2 is inclined relative to the surface WF, it is easier to reduce the energy reflected on the surface WF and reaching the vicinity of the nozzle N.

[0091] In contrast, when the distance between the first reference point TCP1 in the normal direction of the nozzle surface F1 and the surface WF is set as distance L1, distance L1 changes with the curvature of the surface WF in step S130. Furthermore, since the surface WF is a convex curved surface, and as described above, the normal of the emission surface F2 of the energy emission section 330 is orthogonal or approximately orthogonal to the surface WF, distance L1 is greater than distance L2 in step S130. In other words, distance L2 is less than distance L1 in step S130. Therefore, even if energy is emitted from the energy emission section 330, it is difficult for the energy reflected on the surface WF to reach the vicinity of the nozzle N.

[0092] In step S130, the intensity of the energy from the energy emission section 330 is sufficient to completely harden the ink on the surface WF. Therefore, it is possible to prevent or reduce ink peeling on the surface WF after step S130. Here, the energy per unit area irradiated on the surface WF in step S130 is greater than that in step S120.

[0093] From the viewpoint of improving production efficiency, it is preferable that the moving speed of the second reference point TCP2 along the second path RU_2 in step S130 is faster than the moving speed of the first reference point TCP1 along the first path RU_1 in step S120. Such a moving speed is achieved by increasing the intensity of the energy emitted from the energy emission unit 330.

[0094] As described above, the three-dimensional printing apparatus 100 includes a liquid ejector head 310, an energy ejector unit 330, and a robot 200 as an example of a "moving mechanism". Here, the liquid ejector head 310 has a nozzle surface F1 provided with a nozzle N for ejecting ink, an example of a "liquid". The energy ejector unit 330 has an ejection surface F2 for ejecting energy that hardens or cures the ink. The robot 200 changes the relative position and orientation of the liquid ejector head 310 and the energy ejector unit 330 relative to the three-dimensional workpiece W. Furthermore, "hardening" includes the case where a hardening resin, such as a thermosetting resin or a photosetting resin, hardens through a reaction such as polymerization. "Cure" includes the case where a solid derived from a solute is obtained by removing the solvent from a solution, or a solid derived from a dispersed substance is obtained by removing the dispersing solvent from a dispersion.

[0095] In particular, as described above, the stereolithography printing apparatus 100 performs step S120 as an example of a "first step" and step S130 as an example of a "second step". In step S120, during the execution of a first scan in which the relative positions of the liquid ejector head 310 and the energy ejector unit 330 relative to the workpiece W change along a first path RU_1, the liquid ejector head 310 ejects ink onto the workpiece W. In step S130, during the execution of a second scan in which the relative positions of the liquid ejector head 310 and the energy ejector unit 330 relative to the workpiece W change along a second path RU_2, the energy ejector unit 330 irradiates energy onto the ink on the workpiece W.

[0096] Here, when the distance between the first reference point TCP1 in the normal direction of nozzle surface F1 and surface WF is set as L1, and the distance between the second reference point TCP2 in the normal direction of ejection surface F2 and surface WF is set as L2, step S120 satisfies the relationship L1 < L2. In contrast, step S130 satisfies the relationship L1 > L2.

[0097] Furthermore, L1 is not limited to the distance between the first reference point TCP1 and the surface WF; the distance between the workpiece W in the normal direction of the nozzle surface F1 and the nozzle surface F1 can also be set as L1. Similarly, L2 is not limited to the distance between the second reference point TCP2 and the surface WF; the distance between the workpiece W in the normal direction of the injection surface F2 and the injection surface F2 can also be set as L2. In this case, step S120 satisfies the relationship L1 < L2. In contrast, step S130 satisfies the relationship L1 > L2.

[0098] In the above-described 3D printing apparatus 100, by satisfying the relationship L1 < L2 in step S120, the ink flight distance can be shortened, thereby reducing the ink spraying error from the liquid ejector head 310 to the workpiece W. Furthermore, by satisfying the relationship L1 > L2 in step S130, compared to satisfying the relationship L1 < L2, energy attenuation can be suppressed, thereby effectively hardening or curing the ink on the workpiece W. As a result, a high-quality image is obtained by hardening or curing the ink sprayed onto the workpiece W at the desired location.

[0099] Here, since steps S130 and S120 are performed separately, in step S120, it is not necessary to eject energy from the energy ejection unit 330, or the energy ejected from the energy ejection unit 330 needs to be less than that in step S130. Therefore, in step S120, it is possible to prevent or reduce the hardening or curing of ink near the nozzle N caused by energy from the energy ejection unit 330.

[0100] Furthermore, in step S130, since the relationship L1 > L2 is satisfied, even if energy is ejected from the energy ejection section 330, the energy can be prevented from reaching the vicinity of the nozzle N, or the energy reaching the vicinity of the nozzle N from the energy ejection section 330 can be reduced compared to the case where the relationship L1 < L2 is satisfied. Therefore, even if an amount of energy sufficient to harden the ink on the workpiece W is ejected from the energy ejection section 330, the hardening or curing of the ink near the nozzle N caused by the energy from the energy ejection section 330 can be prevented or reduced.

[0101] Here, as described above, since ink is ejected from the liquid ejector head 310 to the workpiece W in step S120, it is not necessary to eject ink from the liquid ejector head 310 to the workpiece W in step S130. Therefore, the liquid ejector head 310 does not eject ink to the workpiece W in step S130.

[0102] Furthermore, as described above, in step S120, it is preferable that the energy injection section 330 irradiates the ink on the workpiece W with energy. In this case, the ink sprayed onto the workpiece W can be semi-hardened or semi-cured by the energy from the energy injection section 330. As a result, it is possible to prevent the ink on the workpiece W from unintentionally moving between the spraying in step S120 and the energy irradiation in step S130. In addition, in this case, in step S120, it is sufficient to harden or cure the ink on the surface WF to a degree that prevents unintentional movement of the ink on the workpiece W; it is not necessary to completely harden and cure the ink on the workpiece W. Therefore, in step S120, the energy emitted from the energy injection section 330 can be reduced. As a result, in step S120, it is possible to prevent or reduce the clogging of the nozzle N caused by the energy from the energy injection section 330.

[0103] Preferably, in step S130, the amount of energy per unit area on the ink irradiated by the energy injection section 330 onto the workpiece W is greater than the amount of energy per unit area on the ink irradiated by the energy injection section 330 onto the workpiece W in step S120. In this case, it is possible to prevent or reduce nozzle N clogging caused by the energy from the energy injection section 330 in step S120, while in step S130, the ink on the workpiece W is completely hardened or cured by the energy from the energy injection section 330.

[0104] Furthermore, preferably, the time per unit area for the energy from the energy injection section 330 to irradiate the ink on the workpiece W in step S130 is longer than the time per unit area for the energy from the energy injection section 330 to irradiate the ink on the workpiece W in step S120. In this case, the ink on the workpiece can be easily hardened or cured completely by the energy from the energy injection section in step S130.

[0105] Furthermore, preferably, the intensity of the energy irradiated onto the ink on the workpiece W from the energy injection section 330 in step S130 is higher than the intensity of the energy irradiated onto the ink on the workpiece W from the energy injection section 330 in step S120. In this case, the ink on the workpiece can be easily hardened or cured completely by the energy from the energy injection section in step S130.

[0106] Furthermore, as described above, the relative positions of the liquid nozzle 310 and the energy ejector 330 are fixed, and the robot 200 moves both the liquid nozzle 310 and the energy ejector 330 simultaneously. Therefore, compared to the structure that moves the workpiece W, setting the reference point and path for the drive control of the robot 200 in steps S120 and S130 is easier. Moreover, in the structure that moves the workpiece W, there is a situation where the workpiece W vibrates during movement, resulting in an error from the ideal movement path. This error is more significant when the size of the workpiece W is relatively large compared to the robot 200, or when the rigidity of the workpiece W is low. Therefore, by not moving the workpiece during printing and moving both the liquid nozzle 310 and the energy ejector 330 simultaneously using the robot 200, the error from the ideal movement path caused by the vibration of the workpiece W can be reduced.

[0107] Furthermore, both the nozzle surface F1 and the injection surface F2 are positioned opposite the workpiece W in both steps S120 and S130. Therefore, compared to a structure where neither the nozzle surface F1 nor the injection surface F2 is positioned opposite the workpiece W in steps S120 or S130, the time required for switching between the two steps can be shortened. Moreover, with both the nozzle surface F1 and the injection surface F2 positioned opposite the workpiece W in step S120, the efficiency of the operation can be improved when photoneedling curing is performed in step S120. This is because ink can be ejected from the nozzle provided on the nozzle surface F1 onto the workpiece W simultaneously, and energy can be applied from the injection surface F2 to the ink on the workpiece W.

[0108] Furthermore, preferably, the direction in which the robot 200 changes the relative position of the liquid ejector head 310 relative to the workpiece W is the same in steps S120 and S130. That is, preferably, the directions of the first path RU_1 and the second path RU_2 are the same. In this case, compared with the case where the direction in which the liquid ejector head 310 changes the relative position of the liquid ejector head 310 relative to the workpiece W is different in steps S120 and S130, the deviation in the time length from the ink spraying off the workpiece W to the energy irradiation can be reduced, resulting in improved printing quality.

[0109] As described above, the stereolithography printing apparatus 100 includes, for example, a liquid ejection unit 300 comprising a liquid ejection head 310 and an energy ejection section 330, and sets a first reference point TCP1, a second reference point TCP2, a first path RU_1, and a second path RU_2. The first reference point TCP1 represents a position within the liquid ejection unit 300. The second reference point TCP2 represents a position within the liquid ejection unit 300 that differs from the first reference point TCP1. The first path RU_1 is the path that the first reference point TCP1 should move along. The second path RU_2 is the path that the second reference point TCP2 should move along.

[0110] In step S120, while the liquid ejector head 310 ejects ink onto the workpiece W, the robot 200 changes the relative position of the first reference point TCP1 relative to the workpiece W along the first path RU_1. In step S130, while the energy ejector 330 irradiates energy onto the ink on the workpiece W, the robot 200 changes the relative position of the second reference point TCP2 relative to the workpiece W along the second path RU_2.

[0111] Thus, by using the first reference point TCP1 and the second reference point TCP2, it is relatively easy to set the first path RU_1 and the second path RU_2 corresponding to each step. Here, the first reference point TCP1 is the point indicating the position of the liquid ejector head 310, and more specifically, the point that is closer to the nozzle surface F1 than the ejection surface F2. The second reference point TCP2 is the point indicating the position of the energy ejection section 330, and more specifically, the point that is closer to the ejection surface F2 than the nozzle surface F1.

[0112] Furthermore, as described above, it is preferable that the first path RU_1 is set such that the distance L1 between the workpiece W in the normal direction of the nozzle surface F1 and the first reference point TCP1 is fixed. In this case, the ink spraying error from the liquid ejector head 310 to the workpiece W can be reduced.

[0113] Furthermore, as described above, it is preferable that the second path RU_2 is set such that the distance L2 between the workpiece W in the normal direction of the injection surface F2 and the second reference point TCP2 is fixed. In this case, uneven irradiation of ink onto the workpiece W by energy from the energy injection section 330 can be reduced.

[0114] 2. Variations

[0115] The methods illustrated above can be modified in a variety of ways. Specific methods applicable to the above methods are illustrated below. Furthermore, two or more methods arbitrarily selected from the following examples can be appropriately combined without contradiction.

[0116] 2-1. Variation Example 1

[0117] While the above description illustrates the structure of a six-axis vertical multi-axis robot as a motion mechanism, it is not limited to this structure. The motion mechanism only needs to enable three-dimensional changes in the relative position and orientation of the liquid nozzle relative to the workpiece. Therefore, the motion mechanism can be, for example, a vertical multi-axis robot other than a six-axis robot, or a horizontal multi-axis robot. Furthermore, the movable part of the robotic arm is not limited to a rotating mechanism; it can also be, for example, a telescopic mechanism.

[0118] 2-2. Variation Example 2

[0119] While the above description illustrates a structure using screws or similar methods for fixing the liquid nozzle relative to the top of the robotic arm, it is not limited to this structure. For example, the liquid nozzle can be held by a gripping mechanism such as a handle mounted on the top of the robotic arm, thereby fixing the liquid nozzle relative to the top of the robotic arm.

[0120] 2-3. Variation Example 3

[0121] Furthermore, although the above-described method exemplifies a moving mechanism that moves the liquid nozzle, it is not limited to this structure. For example, it could also be a structure where the position of the liquid nozzle is fixed, the moving mechanism moves the workpiece, and the relative position and posture of the workpiece with respect to the liquid nozzle undergo three-dimensional changes. In this case, the workpiece could be held, for example, by a gripping mechanism such as a handle mounted on the top of a robotic arm.

[0122] 2-4. Variation Example 4

[0123] Although the above-described method illustrates a structure for printing using one type of ink, it is not limited to that structure. The invention can also be applied to structures that use two or more types of ink for printing.

[0124] 2-5. Variation Example 5

[0125] The application of the three-dimensional printing apparatus of the present invention is not limited to printing. For example, the three-dimensional printing apparatus that sprays a solution of color material can be used as a manufacturing apparatus for color filters in liquid crystal display devices. Furthermore, the three-dimensional printing apparatus that sprays a solution of conductive material can be used as a manufacturing apparatus for wiring and electrodes in wiring substrates. Additionally, the three-dimensional printing apparatus can also be used as a spray dispenser for applying liquids such as adhesives to workpieces.

[0126] Symbol Explanation

[0127] 100…3D printing apparatus; 200…robot (moving mechanism); 300…liquid ejection unit (equipment); 310…liquid ejection head; 330…energy ejection section; F1…nozzle surface; F2…ejection surface; L1…distance; L2…distance; N…nozzle; RU_1…first path; RU_2…second path; S120…step (first step); S130…step (second step); TCP1…first reference point; TCP2…second reference point; W…workpiece.

Claims

1. A three-dimensional printing apparatus, characterized in that, have: A liquid ejector head having a nozzle face with a nozzle for ejecting liquid; An energy ejection section having an ejection surface that ejects energy to harden or solidify the liquid from the liquid ejection head; A moving mechanism that changes the relative position and orientation of the liquid ejector head and the energy ejector unit relative to the three-dimensional workpiece. The stereolithography printing apparatus performs the first step and the second step. The first step is the step of the liquid nozzle spraying liquid onto the workpiece during the execution of a first scan in which the moving mechanism changes the relative position of the liquid nozzle and the energy ejection part relative to the workpiece. The second step is, during the execution of the second scan in which the moving mechanism changes the relative position of the liquid ejector head and the energy ejector relative to the workpiece, the energy ejector irradiates energy onto the liquid on the workpiece. When the distance between the workpiece and the nozzle surface in the normal direction of the nozzle surface is set to L1, and the distance between the workpiece and the injection surface in the normal direction of the injection surface is set to L2, The first step satisfies the relationship L1 < L2. The second step satisfies the relationship L1 > L2. The relative positions of the liquid ejector head and the energy ejector are fixed. The moving mechanism causes both the liquid nozzle and the energy ejection section to move simultaneously. Both the nozzle surface and the injection surface are positioned opposite the workpiece in both the first and second steps. L1 is fixed in the first step, and changes in the second step as the curvature of the workpiece surface changes. L2 is fixed in the second step, but changes with the curvature of the workpiece surface in the first step. In the second step, the liquid nozzle does not spray liquid onto the workpiece. In the first step, the energy ejection section irradiates energy onto the liquid on the workpiece.

2. The three-dimensional printing apparatus as described in claim 1, characterized in that, The energy ejection section in the first step prevents a portion of the liquid on the workpiece from hardening and solidifying.

3. The three-dimensional printing apparatus as described in claim 1, characterized in that, In the second step, the amount of energy per unit area irradiated onto the liquid on the workpiece from the energy emission section is greater than the amount of energy per unit area irradiated onto the liquid on the workpiece from the energy emission section in the first step.

4. The three-dimensional printing apparatus as described in claim 3, characterized in that, In the second step, the time per unit area of ​​energy irradiated from the energy emission section onto the liquid on the workpiece is longer than the time per unit area of ​​energy irradiated from the energy emission section onto the liquid on the workpiece in the first step.

5. The three-dimensional printing apparatus as described in claim 3, characterized in that, The intensity of the energy irradiated onto the liquid on the workpiece from the energy emission section in the second step is higher than the intensity of the energy irradiated onto the liquid on the workpiece from the energy emission section in the first step.

6. The three-dimensional printing apparatus as described in claim 1, characterized in that, The moving mechanism is a six-axis vertical joint robot. The liquid ejector and the energy ejector are mounted on top of the six-axis vertical joint robot.

7. The three-dimensional printing apparatus according to any one of claims 1 to 5, characterized in that, The direction in which the relative position of the liquid nozzle is changed relative to the workpiece via the moving mechanism is the same in both the first and second steps.

8. A method for printing three-dimensional objects, characterized in that, It is a method for printing on a workpiece using a device and a moving mechanism that changes the relative position and orientation of the device with respect to the three-dimensional workpiece, wherein, The device includes: A liquid ejector head having a nozzle face with a nozzle for ejecting liquid; An energy ejection section having an ejection surface that ejects energy to harden or solidify the liquid from the liquid nozzle. In the aforementioned three-dimensional printing method, A first reference point representing a position within the device, a second reference point representing a position within the device different from the first reference point, a first path for the first reference point to move, and a second path for the second reference point to move are defined. The first step involves, simultaneously, the moving mechanism changing the relative position of the first reference point with respect to the workpiece along the first path while the liquid nozzle sprays liquid onto the workpiece. The second step involves, simultaneously, while the energy ejection section irradiates energy onto the liquid on the workpiece, the moving mechanism causes the relative position of the second reference point with respect to the workpiece to change along the second path. When the distance between the first reference point in the normal direction of the nozzle surface and the surface of the workpiece is set to L1, and the distance between the second reference point in the normal direction of the injection surface and the surface of the workpiece is set to L2, The first step satisfies the relationship L1 < L2. The second step satisfies the relationship L1 > L2. The relative positions of the liquid ejector head and the energy ejector are fixed. The moving mechanism causes both the liquid nozzle and the energy ejection section to move simultaneously. Both the nozzle surface and the injection surface are positioned opposite the workpiece in both the first and second steps. L1 is fixed in the first step, and changes in the second step as the curvature of the workpiece surface changes. L2 is fixed in the second step, but changes with the curvature of the workpiece surface in the first step. In the second step, the liquid nozzle does not spray liquid onto the workpiece. In the first step, the energy ejection section irradiates energy onto the liquid on the workpiece.

9. The method for printing three-dimensional objects as described in claim 8, characterized in that, The first reference point is a point indicating the position of the liquid ejection head. The second reference point is a point that indicates the position of the energy emission section.

10. The method for printing three-dimensional objects as described in claim 8, characterized in that, The first reference point is a point that is closer to the nozzle surface compared to the injection surface. The second reference point is a point that is closer to the ejection surface than the nozzle surface.

11. The method for printing three-dimensional objects as described in any one of claims 8 to 10, characterized in that, The first path is set such that the distance between the workpiece and the first reference point in the normal direction of the nozzle surface is fixed.

12. The method for printing three-dimensional objects as described in any one of claims 8 to 10, characterized in that, The second path is set such that the distance between the workpiece and the second reference point in the normal direction of the injection surface is fixed.

13. A method for printing three-dimensional objects, characterized in that, It is a method for printing on three-dimensional workpieces using a liquid ejection head and an energy ejection section, wherein, The liquid ejector head has a nozzle surface with a nozzle for ejecting liquid, and the energy ejection section has an ejection surface for ejecting energy that hardens or solidifies the liquid from the liquid ejector head. In the three-dimensional printing method, the first step and the second step are performed. The first step is the step of spraying liquid from the liquid nozzle onto the workpiece during the execution of a first scan that changes the relative position of the liquid nozzle and the energy ejection section relative to the workpiece along a first path. The second step involves irradiating energy onto the liquid on the workpiece from the energy ejector during the execution of a second scan, in which the relative positions of the liquid ejector head and the energy ejector unit with respect to the workpiece change along a second path. When the distance between the workpiece and the nozzle surface in the normal direction of the nozzle surface is set to L1, and the distance between the workpiece and the injection surface in the normal direction of the injection surface is set to L2, The first step satisfies the relationship L1 < L2. The second step satisfies the relationship L1 > L2. The relative positions of the liquid ejector head and the energy ejector are fixed. Both the liquid ejector head and the energy ejector section move simultaneously. Both the nozzle surface and the injection surface are positioned opposite the workpiece in both the first and second steps. L1 is fixed in the first step, and changes in the second step as the curvature of the workpiece surface changes. L2 is fixed in the second step, but changes with the curvature of the workpiece surface in the first step. In the second step, the liquid nozzle does not spray liquid onto the workpiece. In the first step, the energy ejection section irradiates energy onto the liquid on the workpiece.

Images