Stereolithography apparatus

Abstract

This invention provides a three-dimensional printing apparatus capable of spraying and curing liquid at an appropriate distance even while suppressing interference with the workpiece. The apparatus comprises: a first head having a first nozzle surface provided with a nozzle for spraying liquid; an energy emission section having an emission surface that emits energy to cure liquid sprayed from the first head; and a moving mechanism that changes the relative position of the first head and the energy emission section relative to a three-dimensional workpiece. In the three-dimensional printing apparatus, the moving mechanism includes: a linear motion mechanism that changes the relative position of the first head and the energy emission section relative to the workpiece along a first axis; a first lifting mechanism that moves the first nozzle surface along a second axis intersecting the first axis; and a second lifting mechanism that moves the emission surface along the second axis.

Description

Technical Field

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

[0002] Three-dimensional printing apparatuses are known to apply printing to the surface of three-dimensional workpieces by inkjet printing. For example, Patent Document 1 discloses an apparatus having a head equipped with a nozzle for ejecting ultraviolet-curable ink and a light-emitting section for emitting ultraviolet light.

[0003] However, the above-mentioned prior art has the following problem: for workpieces with curved surfaces or uneven surfaces, if an attempt is made to properly set the distance between the nozzle and the workpiece in order to improve printing quality, structural components of devices such as the light emission section may sometimes interfere with the workpiece.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2008-246855 Summary of the Invention

[0005] To address the above-mentioned issues, one aspect of the three-dimensional printing apparatus according to the present invention is a three-dimensional printing apparatus comprising: a first head having a first nozzle surface provided with a nozzle for ejecting liquid; an energy emission section having an emission surface for ejecting energy that solidifies the liquid ejected from the first head; and a moving mechanism for changing the relative position of the first head and the energy emission section relative to a three-dimensional workpiece. In the three-dimensional printing apparatus, the moving mechanism comprises: a linear motion mechanism for changing the relative position of the first head and the energy emission section relative to the workpiece along a first axis; a first lifting mechanism for moving the first nozzle surface along a second axis intersecting the first axis; and a second lifting mechanism for moving the emission surface along the second axis. Attached Figure Description

[0006] Figure 1 A perspective view showing the outline of the three-dimensional printing apparatus 100 according to the first embodiment.

[0007] Figure 2 This figure illustrates the relationship between the lifting mechanism 230, the liquid ejection unit 300, and the light emission section 380.

[0008] Figure 3 A perspective view showing the outline structure of the liquid ejection unit 300.

[0009] Figure 4 This is a block diagram illustrating the electrical structure of the three-dimensional printing apparatus 100 according to the first embodiment.

[0010] Figure 5This is a diagram used to illustrate the path information Da in the first embodiment.

[0011] Figure 6 This diagram illustrates a flowchart of the three-dimensional printing method according to the first embodiment.

[0012] Figure 7 This is a diagram illustrating an example of the positions of the nozzle face FD, the ejection face FU, and the workpiece W during the execution of the first scan RU1.

[0013] Figure 8 This is a diagram illustrating an example of the positions of the nozzle face FD and the exit face FU during the execution of the second scan RU2.

[0014] Figure 9 This is a diagram illustrating an example of the positions of the nozzle face FD and the ejection face FU at the start time of the workpiece movement WM.

[0015] Figure 10 This is a diagram illustrating an example of the positions of the nozzle face FD and the ejection face FU at the end time of the workpiece movement WM.

[0016] Figure 11 The figure illustrates the three-dimensional printing apparatus 100a in the first modified example.

[0017] Figure 12 The figure illustrates the stereolithography printing apparatus 100b in the second modified example.

[0018] Figure 13 The figure illustrates the stereolithography printing apparatus 100c in the third variation. Detailed Implementation

[0019] Hereinafter, the methods for implementing the present invention will be described with reference to the accompanying drawings. However, the dimensions and scales of the various parts in the drawings differ appropriately from the actual situation. Furthermore, although the embodiments described below are preferred specific examples of the present invention and are therefore subject to various technically preferred limitations, the scope of the present invention is not limited to these methods unless otherwise specifically limited in the following description.

[0020] 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. Additionally, opposite directions along the Z-axis are referred to as the Z1 and Z2 directions.

[0021] Here, the X-axis, Y-axis, and Z-axis are coordinate axes of a basic coordinate system set in the space where the worktable 281 (described later) is located. Typically, the Z-axis is a vertical axis, with the Z2 direction corresponding 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 between 80° and 100°.

[0022] 1. First Implementation Method

[0023] 1-1. Overview of a 3D printing apparatus

[0024] Figure 1 This is a perspective view showing an outline of the three-dimensional printing apparatus 100 according to the first 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.

[0025] The workpiece W is the printing medium and has a surface WF that becomes the object of printing. Figure 1 In the example shown, the workpiece W is an ellipsoidal rugby ball about its major axis AX, and the surface WF is a curved surface with variable curvature. In this embodiment, the workpiece W is configured such that its major axis AX is parallel to the X-axis. Furthermore, the workpiece W is not limited to a rugby ball. For example, the workpiece W may be an object that becomes certain articles, and printing on the surface WF is one of a series of steps in manufacturing those articles. Here, the shape or size of the workpiece W is not limited to... Figure 1 The example shown is arbitrary. For example, the surface of workpiece W can also have a flat surface, a stepped surface, or a surface with concave and convex shapes. For example, although Figure 1 The illustrated surface WF appears as a convex surface when viewed in the Z2 direction, but it can also appear as a concave surface when viewed in the Z2 direction. Furthermore, the orientation of the workpiece W is not limited to... Figure 1 The example shown is arbitrary.

[0026] exist Figure 1 In the example shown, the stereoscopic printing apparatus 100 is an inkjet printer that uses an orthogonal robotic arm that moves on two orthogonal axes. Specifically, as Figure 1 As shown, the stereolithography printing apparatus 100 includes a moving mechanism 200, four liquid ejection units 300, a light emitting 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, there may be cases where liquid ejection units 300_1 to 300_4 are each referred to as liquid ejection unit 300. Hereinafter, [the description will be based on...]. Figure 1Each part of the three-dimensional printing apparatus 100 shown will be briefly described in turn.

[0027] The moving mechanism 200 changes the relative position of the liquid ejection unit 300 and the light emission unit 380 with respect to the workpiece W. The moving mechanism 200 includes a linear motion mechanism 220, a lifting mechanism 230, and a support unit 280.

[0028] The linear motion mechanism 220 changes the relative positions of the four liquid ejection units 300 and the light emission section 380 with respect to the workpiece W along the X-axis. The linear motion mechanism 220 has a guide rail component 221 and a carriage 222. The guide rail component 221 is a flat component for moving the carriage 222 along the X-axis. Furthermore, two guide rails RA are provided along the X-axis on the Z1 direction surface of the guide rail component 221. The two guide rails RA extend along the X-axis. The carriage 222 engages with the guide rails RA in a slidable manner. Additionally, although not shown, a drive mechanism for moving the carriage 222 is provided on the linear motion mechanism 220. This drive mechanism includes, for example, a motor that generates a driving force for the movement, a reducer that reduces and outputs the driving force, and a horizontal encoder 223 that detects the amount of movement. The horizontal encoder 223... Figure 4 As shown in the image.

[0029] Additionally, the X-axis is an example of the "first axis".

[0030] The lifting mechanism 230 moves the four liquid ejection units 300 and the light emission unit 380 along the Z-axis. The lifting mechanism 230 has a support plate 231 and five independent lifting mechanisms 235. These five independent lifting mechanisms 235 are referred to as independent lifting mechanisms 235_1 to 235_5. In the following description, independent lifting mechanisms 235_1 to 235_5 may sometimes be referred to as independent lifting mechanism 235. Furthermore, the elements of the independent lifting mechanism 235 may sometimes be indicated using _x, where x is an integer from 1 to 5.

[0031] Regarding the relationship between the lifting mechanism 230, the liquid ejection unit 300, and the light emission unit 380, we will use... Figure 2 Let me explain.

[0032] Figure 2 This diagram illustrates the relationship between the lifting mechanism 230, the liquid ejection unit 300, and the light emission section 380. Figure 2 The figure shown is a view of the vicinity of the lifting mechanism 230 when viewed from the Y1 direction towards the Y2 direction.

[0033] The support plate 231 supports the independent lifting mechanism 235 and is fixed to the carriage 222. The carriage 222 moves along the X-axis, causing the support plate 231, mounted on the carriage 222, to also move along the X-axis. However, the lifting mechanism 230 can also replace the support plate 231 and have a mechanism that allows all four liquid ejection units 300 and the light emission section 380 to move along the Z-axis.

[0034] Additionally, the Z-axis is an example of a "second axis".

[0035] An independent lifting mechanism 235 moves any one of the four liquid ejection units 300 and the light emission unit 380 along the Z-axis. The independent lifting mechanism 235 is fixed to a support plate 231. In the Z2 direction of four of the five independent lifting mechanisms 235, the liquid ejection units 300 are mounted as end effectors and are fixed in a fixed state, such as by screws. In the Z2 direction of the remaining independent lifting mechanism 235, the light emission unit 380 is mounted as an end effector and is fixed in a fixed state, such as by screws. Although not shown in the figure, a drive mechanism is provided on the independent lifting mechanism 235 to move either the liquid ejection unit 300 or the light emission unit 380 relative to the independent lifting mechanism 235. This drive mechanism includes, for example, a motor that generates a driving force for the movement, a reducer that reduces and outputs the driving force, and a vertical encoder 236 that detects the amount of movement. The vertical encoder 236... Figure 4 As shown in the image.

[0036] More specifically, a liquid ejection unit 300_k is installed on the independent lifting mechanism 235_k. k is an integer from 1 to 4. A light emission unit 380 is installed on the independent lifting mechanism 235_5. The independent lifting mechanisms 235_1 to 235_5 are arranged sequentially from the X1 direction in the order of independent lifting mechanisms 235_1, 235_2, 235_3, 235_4, and 235_5.

[0037] Furthermore, among any two of the independent 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". Independent lifting mechanism 235_5 is an example of a "second lifting mechanism".

[0038] Return to the instructions Figure 1The support portion 280 supports the direct-acting mechanism 220 and the workpiece support mechanism 900. The support portion 280 includes a worktable 281 and a support column 283. The workpiece support mechanism 900 is fixed to the top plate 282 of the worktable 281. The worktable 281 is fixed to a mounting surface such as a floor surface facing the Z1 direction by screws or the like. Furthermore, the mounting surface on which the worktable 281 is fixed is not limited to... Figure 1 The example shown could be, for example, a surface such as a wall or a movable trolley. The support 283 is a columnar component that supports the linear motion mechanism 220 and extends along the Z-axis.

[0039] The liquid ejection unit 300 ejects ink, an example of a liquid, toward the workpiece W. The light emitting unit 380 has an emitting surface FU that emits light to cure the ink ejected from the liquid ejection unit 300. More specifically, the light emitting unit 380 detects the light source that emits the light to cure the ink and the relative position of the light emitting unit 380 on the Z-axis relative to the workpiece W. Specifically, the sensor included in the light emitting unit 380 is a distance sensor such as an optical displacement meter that measures the distance between itself and a reference surface (not shown) whose relative position is fixed relative to the workpiece W. Furthermore, this reference surface can be the surface of the workpiece W or the surface of an object different from the workpiece W. Moreover, the direction in which this reference surface faces is arbitrary, as long as the position and orientation of the surface WF relative to the workpiece W are known in advance.

[0040] In addition, the light emitting section 380 is an example of an "energy emitting section", and the light that cures the ink is an example of "energy that cures the liquid".

[0041] In this embodiment, the ink is a curable ink that uses a curable resin such as an ultraviolet-curable type. However, the curable ink is not limited to ultraviolet-curable type, and may be any one of thermosetting, photocurable, radiation-curable, and electron beam curable types.

[0042] Furthermore, the ink is not limited to a solution; it can also be an ink in which color materials, etc., are dispersed as a dispersant in a dispersant. Furthermore, the ink is not limited to inks containing color materials; for example, it can be an ink containing conductive particles such as metal particles used to form wiring, etc., as a dispersant; it can also be a transparent ink; and it can also be a treatment liquid used for surface treatment of the workpiece W. In this embodiment, it will be described as follows: the stereolithography printing apparatus 100 uses four types of inks—ink containing blue-green color materials, ink containing magenta color materials, ink containing yellow color materials, and ink containing black color materials—and the light emitting unit 380 emits ultraviolet light. In this way, although in this embodiment, since four types of inks are used, the stereolithography printing apparatus 100 also has four liquid ejection units 300, the number of liquid ejection units 300 is not limited to four; it can be one or more. Furthermore, the types of ink used are not limited to four; the stereolithography printing apparatus 100 can use one type of ink or multiple types of inks.

[0043] In each of the heads 310_1 to 310_4 of the liquid ejection units 300_1 to 300_4, ink containing any one of the following color materials: blue-green, magenta, yellow, and black is supplied. Each of the heads 310_1 to 310_4 may also be supplied with any one of these four types of ink. However, since the ejected ink diffuses on the surface WF of the workpiece W, if ink of a color significantly different from the brightness of the workpiece W diffuses on the surface WF, the ink diffusion will be more noticeable, leading to a decrease in print quality. Especially in the case of three-dimensional printing, the printing medium is mostly non-absorbent, and because it is tilted on the surface WF, the ink tends to move after ejection, thus easily causing bleeding. A color significantly different from the brightness of the workpiece W is, for example, black if the workpiece W is white. Therefore, it is preferable that ink with a smaller color difference relative to the brightness of the workpiece W is supplied in the head 310_1 away from the light emitting section 380, and ink with a larger color difference relative to the brightness of the workpiece W is supplied in the head 310_4 near the light emitting section 380.

[0044] Furthermore, in printing using UV-curable inks, there is a technique called the pinning method, which involves irradiating the ink with UV light immediately after it is sprayed onto the workpiece, thus preventing the ink from fully curing. Since the ink's fluidity decreases in its partially cured state, the pinning method suppresses the diffusion of the sprayed ink on the surface WF of the workpiece W, thereby allowing for adjustment of the dot size. In the following description, the UV light used to irradiate the ink immediately after spraying and to prevent incomplete curing is referred to as "pinning light," and the UV light used to fully cure the ink is referred to as "formal curing light." The energy imparted to the ink by the formal curing light is greater than the energy imparted by the pinning light. The light emitting unit 380 has a light source that emits UV light. The intensity of the UV light emitted from the light emitting unit 380 can be adjusted according to the uses of the pinning light and the formal curing light, and the unit can have both a light source emitting pinning light and a light source emitting formal curing light. Furthermore, the energy imparted to the ink can be adjusted according to the purpose of the pinning and curing light by appropriately adjusting the irradiation time of the ultraviolet light. In the following description, the pinning and curing light will sometimes be collectively referred to as ultraviolet light. Detailed information about the liquid ejection unit 300 will be provided using... Figure 3 Let me explain.

[0045] Figure 3 This is a perspective view showing the schematic structure of the liquid ejection unit 300. The liquid ejection unit 300 includes a head 310, a pressure regulating valve 320, and a sensor 330. These are controlled by... Figure 3 The support body 350 is shown by the double-dotted line in the figure.

[0046] The head 310 has multiple piezoelectric elements (not shown), multiple chambers (not shown), and multiple nozzles N. The chambers hold ink. Each nozzle N is provided for and communicates with a specific chamber. Each piezoelectric element is provided for a specific chamber, and by changing the pressure in that chamber, ink is ejected from the nozzle N corresponding to that chamber. Alternatively, instead of the piezoelectric element, a heater that heats the ink within the chamber can be used as the driving element for ejecting ink from the nozzles. Ideally, the ink ejected from the head 310 is in the Z2 direction. Therefore, the movement direction of the liquid ejection unit 300, implemented by the independent lifting mechanism 235, is substantially parallel to the ejection direction of the ink ejected from the head 310. Furthermore, "substantially parallel" means a deviation of ±5°, including mechanical errors or errors in ink ejection.

[0047] The head 310 has a nozzle face FD on which multiple nozzles N are provided. Figure 3In the example shown, the normal direction of the nozzle surface FD is the Z1 direction, and the plurality of nozzles N are divided into a first nozzle column L1 and a second nozzle column L2 arranged at intervals along the X-axis. The first nozzle column L1 and the second nozzle column L2 are each a set of a plurality of nozzles N arranged in a straight line along the Y-axis. Here, the elements associated with each nozzle N of the first nozzle column L1 and the elements associated with each nozzle N of the second nozzle column L2 in the head 310 have a structure that is approximately symmetrical to each other along the X-axis.

[0048] Furthermore, the head 310 included in the liquid ejection unit 300, which is mounted on the independent lifting mechanism 235 (equivalent to the "first lifting mechanism") among the liquid ejection units 300_1 to 300_4, is an example of a "first head," and the nozzle surface FD of the head 310 is an example of a "first nozzle surface." Additionally, the head 310 included in the liquid ejection unit 300, which is mounted on the independent lifting mechanism 235 (equivalent to the "third lifting mechanism"), is an example of a "second head," and the nozzle surface FD of the head 310 is an example of a "second nozzle surface."

[0049] However, the positions of the plurality of nozzles N in the first nozzle array L1 and the plurality of nozzles N in the second nozzle array L2 along the Y-axis can be either identical or different. Furthermore, elements associated with each nozzle N in either the first nozzle array L1 or the second nozzle array L2 can be omitted. The following example illustrates a structure in which the positions of the plurality of nozzles N in the first nozzle array L1 and the plurality of nozzles N in the second nozzle array L2 are identical along the Y-axis.

[0050] The pressure regulating valve 320 is a valve mechanism that opens and closes according to the pressure of the ink in the head 310. By opening and closing, the pressure of the ink in the head 310 is maintained at a negative pressure within a predetermined range. Therefore, the meniscus of the ink formed in the nozzle N of the head 310 is stabilized.

[0051] Sensor 330 detects the relative position of head 310 on the Z-axis with respect to workpiece W. Specifically, sensor 330 is a distance sensor such as an optical displacement meter that measures the distance between itself and a reference plane (not shown) whose relative position is fixed relative to workpiece W.

[0052] The support 350 is made of, for example, a metallic material and is a solid rigid body. Furthermore, although in Figure 3 The support body 350 is a flat box shape, but the shape of the support body 350 is not particularly limited and can be arbitrary. The support body 350 is installed in the Z2 direction of the independent lifting mechanism 235.

[0053] exist Figure 3 In the example shown, the pressure regulating valve 320 is located in the Z1 direction relative to the head 310. The sensor 330 is located in the X1 direction relative to the head 310.

[0054] 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 head 310. Figure 3 In the example shown, a portion of the downstream flow channel 422 of the supply flow channel 420 is constituted by flow channel component 422a. Flow channel component 422a has flow channels that dispense ink from the pressure regulating valve 320 to multiple portions of the head 310.

[0055] Return to the instructions Figure 1 The liquid supply unit 400 is a mechanism for supplying ink to the head 310. The liquid supply unit 400 has a liquid reservoir 410 and a supply channel 420.

[0056] 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.

[0057] 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 in the Z1 direction relative to the head 310. That is, the liquid reservoir 410 is located above the moving area of ​​the head 310 in the vertical direction. Therefore, even without using a pump or similar mechanism, ink can be supplied from the liquid reservoir 410 to the head 310 by applying a predetermined pressure.

[0058] The supply channel 420 is a channel for supplying ink from the liquid reservoir 410 to the head 310. A pressure regulating valve 320 is provided midway through the supply channel 420. Therefore, even if the positional relationship between the head 310 and the liquid reservoir 410 changes due to the movement of the moving mechanism 200, the pressure fluctuation of the ink in the head 310 can be reduced.

[0059] The controller 600 is a robot controller that controls the drive of the moving mechanism 200 and the workpiece support mechanism 900. Although in Figure 1 Although not illustrated, the controller 600 is electrically connected to a control module that controls the ejection action in the liquid ejection unit 300. A computer is connected to both the controller 600 and the control module in a communicative manner. Furthermore, this control module corresponds to the one described later. Figure 4 The control module 500 shown is equivalent to the computer described later. Figure 4 The computer shown is 700.

[0060] The workpiece support mechanism 900 supports the workpiece W and allows for changes in one or both of the workpiece W's position and orientation. The workpiece support mechanism 900 includes a changing axis mechanism 910 and a rotating axis mechanism 920. The changing axis mechanism 910 includes a flat component for moving the workpiece W along the Y-axis. Two guide rails RB are provided along the Y-axis on the Z1 direction surface of this component. The two guide rails RB extend along the Y-axis.

[0061] The rotary axis mechanism 920 is capable of rotating about a rotation axis XR along the X-axis. Furthermore, the rotary axis mechanism 920 has a mounting surface 922. A workpiece W is mounted on the mounting surface 922. When the rotary axis 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 mounted on the mounting surface 922 changes.

[0062] 1-2. Electrical Structure of the Three-Dimensional Printing Apparatus

[0063] Figure 4 This is a block diagram illustrating the electrical structure of the three-dimensional printing apparatus 100 according to the first embodiment. Figure 4 The electrical structural elements of the three-dimensional printing apparatus 100 are shown in the diagram. Furthermore, in... Figure 4 The image shows a horizontal encoder 223 and vertical encoders 236_1 to 236_5.

[0064] like Figure 4 As shown, the stereolithography printing apparatus 100, in addition to the aforementioned moving mechanism 200, liquid ejection unit 300, controller 600, and workpiece support mechanism 900, also includes a control module 500 and a computer 700. Before describing the controller 600 in detail below, the control module 500 and the computer 700 will be described in turn.

[0065] Furthermore, the various electrical structural elements described below can be appropriately divided, or a portion can be included in other structural elements, or they can be integrated with other structural elements.

[0066] The controller 600 has the functions of controlling the drive of the moving mechanism 200, controlling the drive of the workpiece support mechanism 900, and generating a signal D3 for synchronizing the ink ejection action in the liquid ejection unit 300 with the action of the moving mechanism 200. The controller 600 has a storage circuit 610 and a processing circuit 620.

[0067] The storage circuit 610 stores the various programs executed by the processing circuit 620 and the various data processed by the processing circuit 620.

[0068] The storage circuit 610 stores path information Da. Path information Da represents the movement path CR that the head 310 and the light emitting unit 380 should move. Path information Da is represented, for example, using coordinate values ​​from a base coordinate system. Path information Da 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 base coordinate system described above. The path information Da is input from the computer 700 into the storage circuit 610.

[0069] The processing circuit 620 controls the movements of the linear motion mechanism 220, the lifting mechanism 230, the switching axis mechanism 910, and the rotating axis mechanism 920 based on the path information Da, and generates a signal D3. Specifically, the processing circuit 620 performs the following calculations: converting the path information Da into the position and speed of the linear motion mechanism 220 and the lifting mechanism 230, and converting the path information Da into the position and speed of the switching axis mechanism 910 and the rotating axis mechanism 920. Then, the processing circuit 620 outputs control signals Sx, 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 respective movements of the linear motion mechanism 220 and the lifting mechanism 230 become the aforementioned calculation results. The control signal Sx controls the drive of the motor of the linear motion mechanism 220. The control signal Sz_k controls the drive of the motor in the independent lifting mechanism 235_k. K is an integer from 1 to 5. In the following text, output signals Dz_1 to Dz_5 will sometimes be referred to as output signal Dz.

[0070] Similarly, the processing circuit 620 outputs control signals Sy and Sr based on the output signal Dy from the encoder included in the switching axis mechanism 910 and the output signal Dr from the encoder included in the rotating axis mechanism 920, so that the actuation amounts of the switching axis mechanism 910 and the rotating axis mechanism 920 become the aforementioned calculation results. Control signal Sy controls the drive of the motor included in the switching axis mechanism 910. Control signal Sr controls the drive of the motor included in the rotating axis mechanism 920.

[0071] Furthermore, the processing circuit 620 generates 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 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 signal D3 containing a pulse at a predetermined timing value for, for example, one of the output signals Dx, Dz_1 to Dz_5, Dy, and Dr.

[0072] The control module 500 is a circuit that controls the ejection action of the head 310 based on the signal D3 output from the controller 600 and the printing data Img 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.

[0073] The timing signal generation circuit 510 generates a timing signal PTS based on signal D3. Signal D3 functions as a trigger signal that determines the start timing of ink ejection implemented by the liquid ejection unit 300.

[0074] The power supply circuit 520 receives power from a commercial power supply not shown in the figure and generates various predetermined potentials. The generated potentials are then appropriately supplied to various parts of the stereolithography printing apparatus 100.

[0075] The control circuit 530 generates control signals SI_1 to SI_4, 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. However, the control signal SI_k is the signal supplied to the switching circuit 340 of the liquid ejection unit 300_k. K is an integer from 1 to 4. In the following description, the control signals SI_1 to SI_4 may sometimes be referred to as control signal SI.

[0076] The control signal SI is a digital signal used to specify the operating state of the piezoelectric element in the head 310. Specifically, the control signal SI specifies whether to supply the drive signal Com (described later) to the piezoelectric element. The latch signal LAT and the exchange signal CNG, used in conjunction with the control signal SI, specify the drive timing of the piezoelectric element, thereby specifying the ink ejection timing from the nozzle N. The clock signal CLK is a clock signal that serves as a reference synchronized with the timing signal PTS. The signals input to the switching circuit 340 of the liquid ejection unit 300 will be described in detail later.

[0077] The drive signal generation circuit 540 is a circuit that generates drive signals Com for driving the various piezoelectric elements of the head 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 signal of the waveform contained in the drive signal Com that is actually supplied to the piezoelectric element is the drive pulse PD. The drive pulse PD is supplied to the piezoelectric element from the drive signal generation circuit 540 via the 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.

[0078] The computer 700 has the functions of supplying path information Da and other information to the controller 600, supplying printing data Img and other information to the control module 500, and controlling the drive of the light emitting unit 380. For example, a personal computer can be used as the computer 700.

[0079] 1-3. Operation of the 3D printing apparatus 100 and the 3D printing method

[0080] Figure 5 This is a diagram used to illustrate the path information Da in the first embodiment. Figure 5 The diagram shows the state when observing the movement path CR of the head 310 and the light emitting unit 380 relative to the workpiece W, represented by the path information Da, from the Z1 direction to the Z2 direction. In the first embodiment, the stereolithography printing apparatus 100 executes the first scan RU1, the second scan RU2, the avoidance action RT1, the workpiece movement action WM, the return action RT2, the third scan RU3, and the fourth scan RU4 in this sequence. In this manner, the avoidance action RT1, the workpiece movement action WM, and the return action RT2 are executed during the period between the second scan RU2 and the third scan RU3. The situation where the head 310 and the light emitting unit 380 are moved from the X2 direction to the X1 direction and then continue to be moved from the X1 direction to the X2 direction is called a "cycle". In this embodiment, one cycle is formed by the first scan RU1 and the second scan RU2, and another cycle is formed by the third scan RU3 and the fourth scan RU4. In this way, although the stereolithography printing apparatus 100 performs two cycles in this embodiment, it can also perform one cycle or more than three cycles.

[0081] exist Figure 5 In order 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 displayed separately on the Y-axis. However, in reality, the start position PS1 of the first scan RU1 is approximately the same as the end position PE2 of the second scan RU2, the end position PE1 of the first scan RU1 is approximately the same as the start position PS2 of the second scan RU2, and the trajectory of the first scan RU1 is approximately the same as the trajectory of the second scan RU2. "Approximately the same" means that, besides being completely identical, it also includes cases where manufacturing errors can be considered as identical. However, it is also possible for the start position PS1 of the first scan RU1 to be different from the end position PE2 of the second scan RU2, for the end position PE1 of the first scan RU1 to be different from the start position PS2 of the second scan RU2, and for the trajectory of the first scan RU1 to be different from the trajectory of the second scan RU2. Similarly, the third scan RU3 and the fourth scan RU4 are displayed separately on the Y-axis. However, in reality, the start position PS3 of the third scan RU3 is roughly the same as the end position PE4 of the fourth scan RU4, the end position PE3 of the third scan RU3 is roughly the same as the start position PS4 of the fourth scan RU4, and the trajectory of the third scan RU3 is roughly the same as the trajectory of the fourth scan RU4. This is also true for the third scan RU3 and the fourth scan RU4, as well as the first scan RU1 and the second scan RU2.

[0082] The first scanning RU1 and the third scanning RU3 involve moving the head 310 and the light emitting unit 380 relative to the workpiece W in the X1 direction. The second scanning RU2 and the fourth scanning RU4 involve moving the head 310 and the light emitting unit 380 relative 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 scanning RU1, the second scanning RU2, the third scanning RU3, and the fourth scanning RU4. However, the workpiece support mechanism 900 may be driven during the execution of any one of the first scanning RU1, the second scanning RU2, the third scanning RU3, and the fourth scanning RU4.

[0083] Additionally, X1 is an example of the "first direction", and X2 is an example of the "third direction".

[0084] Furthermore, the avoidance action RT1 is an action that moves the relative position of the head 310 and the light emitting part 380 relative to the workpiece W from the end position PE2 of the second scanning RU2 to the avoidance position PT1. The avoidance position PT1 is a position where, when viewed along the Z-axis, the nozzle surface FD and the emission surface FU do not overlap with the workpiece W. The workpiece movement action WM is an action that changes one or both of the position and orientation of the workpiece W. The meaning of "overlapping two objects" is that part or all of one object overlaps with part or all of another object. The change in the position or orientation of the workpiece W results in the nozzle surface FD and the emission surface FU moving relative to the workpiece W from the avoidance position PT1 to the avoidance position PT2. The avoidance position PT2 is a position where, when viewed along the Z-axis, the nozzle surface FD and the emission surface FU also do not overlap with the workpiece W. The return action RT2 is an action that moves the relative position of the head 310 and the light emitting part 380 relative to the workpiece W from the avoidance position PT2 to the start position PS3 of the third scanning RU3.

[0085] Figure 6 Here, a flowchart illustrates the process of the three-dimensional printing method according to the first embodiment. Figure 6 As shown, the stereoscopic printing apparatus 100 executes the following steps in sequence: step S110 of executing the first scan RU1, step S120 of executing the second scan RU2, step S130 of executing the avoidance action RT1, step S140 of executing the workpiece movement action WM, step S150 of executing the return action RT2, step S160 of executing the third scan RU3, and step S170 of executing the fourth scan RU4. Furthermore, Figure 6 The actions shown are executed by the computer 700 via the controller 600 and the control module 500, which control the moving mechanism 200 and the liquid ejection unit 300.

[0086] During the execution of the first scan RU1 in step S110, the relative position of the nozzle surface FD and the exit surface FU is changed by driving one or more of the independent lifting mechanisms 235_1 to 235_5. Figure 7 The positional relationship between the nozzle surface FD, the ejection surface FU, and the workpiece W in the first scanning RU1 will be explained.

[0087] Figure 7 This diagram illustrates an example of the positions of the nozzle face FD, the ejection face FU, and the workpiece W during the execution of the first scan RU1. Figure 7 as well as Figure 8To avoid complicating the accompanying drawings, the markings for heads 310_2 to 310_4 and the nozzle surfaces FD of heads 310_2 to 310_4 are omitted. During the execution of the first scan RU1, head 310 ejects ink relative to the workpiece W according to the control signal SI. Figure 7 The image shows droplets DR ejected from head 310. Further, during the execution of the first scan RU1, the light emitting section 380 emits pinning light UV1 relative to the workpiece W.

[0088] In the first scanning RU1, the head 310_1 to 310_4 and the light emission section 380 are moved in the X1 direction by the linear motion mechanism 220. Simultaneously with the driving of the linear motion mechanism 220, the independent lifting mechanisms 235_1 to 235_4 are driven to maintain a distance d1 between the nozzle surface FD and the surface WF in the Z2 direction. The distance between the head 310 and the workpiece W in the Z2 direction is also referred to as the "workpiece gap". Similarly, the independent lifting mechanism 235_5 is driven to maintain a distance d5 between the emission surface FU and the surface WF in the Z2 direction. Figure 7 As illustrated, distance d1 is shorter than distance d5. In the following description, the distance between the light emitting section 380 in the Z2 direction and the workpiece W is sometimes referred to as the "workpiece gap." Furthermore, the Z2 direction is an example of a "second direction." Additionally, if the workpiece gap of the head 310 is not properly adjusted, the flight distance of the ink ejected from the head 310 will increase, resulting in a decrease in the accuracy of the ink's position on the workpiece. Moreover, if the workpiece gap of the light emitting section 380 is not properly adjusted, the energy emitted from the light emitting section 380 will attenuate, resulting in insufficient ink curing. As described above, the workpiece gap affects the printing quality.

[0089] Return to the instructions Figure 6 During the execution of the second scan RU2 in step S120, independent lifting mechanisms 235_1 to 235_4 are not driven, while independent lifting mechanism 235_5 is driven. Figure 8 The positional relationship between the nozzle surface FD, the ejection surface FU, and the workpiece W in the second scanning RU2 is explained.

[0090] Figure 8This diagram illustrates an example of the positions of the nozzle surface FD and the emission surface FU during the execution of the second scan RU2. During the execution of the second scan RU2, the head 310 does not eject ink relative to the workpiece W. On the other hand, during the execution of the second scan RU2, the light emission section 380 emits a formal curing light UV2 relative to the workpiece W. Here, by making the intensity of the formal curing light UV2 higher than the intensity of the pinning light UV1, the ink sprayed onto the workpiece during the first scan RU1 can be sufficiently cured. Furthermore, if the moving speed of the linear motion mechanism 220 in the second scan RU2 is lower than that in the first scan RU1, the irradiation time of the formal curing light UV2 can be extended, thereby ensuring that the ink sprayed onto the workpiece during the first scan RU1 is sufficiently cured.

[0091] During the execution of the second scanning RU2, since the head 310 does not eject ink, the distance e1 between the nozzle surface FD and the surface WF in the Z2 direction does not need to be kept constant. More specifically, during the execution of the second scanning RU2, the relative positions of the respective nozzle surfaces FD of the head 310 do not change. Furthermore, it is preferable that the positions of the nozzle surfaces FD of the head 310 along the Z-axis do not change during the execution of the second scanning RU2. In the second scanning RU2, the heads 310_1 to 310_4 and the light emission section 380 are moved in the X2 direction by being driven by the linear motion mechanism 220. The independent lifting mechanisms 235_1 to 235_4 are driven in a manner that makes the positions Za of the respective nozzle surfaces FD of the head 310 equal along the Z-axis. Specifically, the independent lifting mechanisms 235_1 to 235_4 are driven at the starting position PS2 of the second scanning RU2 to ensure that the positions Za of the respective nozzle surfaces FD of the head 310 along the Z-axis are equal, and the driving stops when the execution of the second scanning RU2 ends. The independent lifting mechanism 235_5 is driven to maintain a distance e5 between the exit surface FU and the surface WF in the Z2 direction. Here, during the execution of the second scanning RU2, the distance e5 is shorter than the distance e1.

[0092] Return to the instructions Figure 6 In the avoidance action RT1 in step S130, the direct motion mechanism 220 drives the heads 310_1 to 310_4 and the light emitting part 380 to move in the X2 direction.

[0093] In the workpiece movement action WM in step S140, the workpiece support mechanism 900 is driven by the switching axis mechanism 910 and the rotating axis mechanism 920, thereby changing one or both of the position and orientation of the workpiece W. Further, in the workpiece movement action WM, to shorten the time spent in the execution of the third scan RU3, which is performed after the workpiece movement action WM, one or more of the nozzle surface FD and the ejection surface FU are moved along the Z-axis by the drive of one or more of the independent lifting mechanisms 235_1 to 235_5. Regarding the movement of the nozzle surface FD and the ejection surface FU in the workpiece movement action WM, the following will be used... Figure 9 as well as Figure 10 Let me explain.

[0094] Figure 9 This diagram illustrates an example of the positions of the nozzle surface FD and the ejection surface FU at the start time of the workpiece movement action WM. In this embodiment, it is assumed that at the start time of the workpiece movement action WM, the positions of the respective nozzle surfaces FD and ejection surfaces FU of the head 310 along the Z-axis do not change from the end time of the second scan RU2. Specifically, the position of the respective nozzle surfaces FD of the head 310 along the Z-axis is position Za. On the other hand, the position of the ejection surface FU along the Z-axis is a position that has moved a distance e5 in the Z1 direction from the end position PE2 of the second scan RU2.

[0095] Figure 10 This diagram illustrates an example of the positions of the nozzle surface FD and the emission surface FU at the end time of the workpiece movement WM. Driven by independent lifting mechanisms 235_1 to 235_5, the nozzle surface FD and the emission surface FU are moved along the Z-axis, approaching their respective positions along the Z-axis at the starting position PS3 of the third scan RU3. Specifically, the head 310_1 is moved towards a position d1 units away from the starting position PS3 of the third scan RU3 in the Z1 direction, driven by the independent lifting mechanism 235_1. Furthermore, the light emission unit 380 is moved towards a position d5 units away from the starting position PS3 in the Z1 direction, driven by the independent lifting mechanism 235_5.

[0096] Return to the instructions Figure 6 In the return action RT2 in step S150, the direct motion mechanism 220 drives the heads 310_1 to 310_4 and the light emitting part 380 to move in the X1 direction.

[0097] During the execution of the third scanning RU3 in step S160, the relative position of the nozzle surface FD and the emission surface FU changes due to the driving of one or more of the independent lifting mechanisms 235_1 to 235_5. During the execution of the third scanning RU3, the head 310 ejects ink relative to the workpiece W according to the control signal SI. Furthermore, during the execution of the third scanning RU3, the light emission section 380 emits pinning light UV1 relative to the workpiece W. Since the positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W in the third scanning RU3 is the same as that in the first scanning RU1, it is omitted from the illustration.

[0098] During the execution of the fourth scan RU4 in step S170, the independent lifting mechanisms 235_1 to 235_4 are not driven, but the independent lifting mechanism 235_5 is driven. The relative position of the nozzle surface FD and the emission surface FU changes. During the execution of the fourth scan RU4, the head 310 does not eject ink relative to the workpiece W. On the other hand, during the execution of the fourth scan RU4, the light emission section 380 emits the formal curing UV2 relative to the workpiece W. Since the positional relationship between the nozzle surface FD, the emission surface FU, and the workpiece W in the fourth scan RU4 is the same as that in the second scan RU2, it is omitted from the illustration.

[0099] 1-4. Summary of the First Implementation Method

[0100] Hereinafter, the three-dimensional printing apparatus 100 in the first embodiment will be described using the example of independent lifting mechanism 235_1 being equivalent to "first lifting mechanism" and independent lifting mechanism 235_2 being equivalent to "third lifting mechanism".

[0101] The stereolithography printing apparatus 100 in the first embodiment includes: a head 310_1 having a nozzle surface FD_1 on which a nozzle N for ejecting ink is provided; a light emitting section 380 having an emitting surface FU for emitting light that cures the ink ejected from the head 310_1; and a moving mechanism 200 for changing the relative position of the head 310_1 and the light emitting section 380 relative to the stereolithographic workpiece W. The moving mechanism 200 includes: a linear motion mechanism 220 for changing the relative position of the head 310_1 and the light emitting section 380 relative to the workpiece W along the X-axis; an independent lifting mechanism 235_1 for moving the nozzle surface FD_1 along the Z-axis intersecting the X-axis; and an independent lifting mechanism 235_5 for moving the emitting surface FU along the Z-axis.

[0102] According to the first embodiment, since the head 310_1 and the light emitting unit 380 are raised and lowered via their respective independent lifting mechanisms 235, printing can be performed while adjusting the gap to an appropriate level according to the shape of the workpiece W. Furthermore, interference between the workpiece W and the head 310 can be prevented. Further, according to the first embodiment, compared to a method where the head 310_1 and the light emitting unit 380 are raised and lowered via a single independent lifting mechanism 235, the width of the structural element that moves independently along the Z-axis can be designed to be narrower in the X-axis direction. Therefore, even when the workpiece W has uneven surfaces, the head 310 or the light emitting unit 380 can enter between these uneven surfaces, thus suppressing interference with the workpiece W while maintaining an appropriate gap for ink ejection and curing, thereby improving print quality.

[0103] If the action of moving the relative position of the head 310_1 and the light emission section 380 relative to the workpiece W in the X1 direction along the X-axis is defined as the first scanning RU1, then during the execution of the first scanning RU1, the head 310_1 ejects ink relative to the workpiece W. Furthermore, during the execution of the first scanning RU1, the relative position of the nozzle surface FD_1 and the emission surface FU changes due to the driving of at least one of the independent lifting mechanisms 235_1 and 235_5.

[0104] In this manner, since the independent lifting mechanisms 235_1 and 235_5 are raised and lowered independently, printing can be performed while adjusting the gap to an appropriate level according to the shape of the workpiece W. Furthermore, interference between the workpiece W and the head 310 can be prevented. Moreover, since the head 310 or the light-emitting part 380 can enter the space between the uneven surfaces even when the workpiece W has irregularities, printing quality can be improved.

[0105] Furthermore, during the execution of the first scan RU1, the light emitting unit 380 emits pinning light relative to the workpiece W.

[0106] Therefore, in the first scanning RU1, the ink diffusion on the surface WF can be suppressed by pinning light immediately after the ink is ejected from the head 310_1.

[0107] Furthermore, during the execution of the first scan RU1, the distance d1 between the nozzle surface FD_1 and the workpiece W along the Z2 direction of the Z-axis is shorter than the distance d5 between the exit surface FU and the workpiece W along the Z2 direction.

[0108] In the first scan RU1, by making the nozzle surface FD_1 preferentially approach the surface WF of the workpiece W compared to the ejection surface FU, the stereolithography printing apparatus 100 can improve the accuracy of the ink spraying position compared to the method where the distance d1 is longer than the distance d5.

[0109] Furthermore, if the action of moving the head 310_1 and the light emitting unit 380 relative to the workpiece W in the X2 direction, which is opposite to the X1 direction, is defined as the second scanning RU2, then the second scanning RU2 is executed later than the first scanning RU1. During the execution of the second scanning RU2, the light emitting unit 380 emits solidification light relative to the workpiece W. During the execution of the second scanning RU2, the distance e5 between the emission 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.

[0110] In the second scan RU2, by prioritizing the proximity of the emission surface FU to the surface WF of the workpiece W compared to the nozzle surface FD_1, the residue of uncured ink on the workpiece W can be suppressed compared to a method where the distance e5 is longer than the distance e1. Furthermore, there exists a situation where a portion of the curing light emitted by the emission surface FU is reflected by the surface WF and incident into the nozzle N. If ultraviolet light is incident into the nozzle N, it can cause the ink near the nozzle to cure, thereby clogging the nozzle N and causing ejection abnormalities. According to this embodiment, since the amount of light incident into the nozzle N can be suppressed compared to a method where the distance e5 is longer than the distance e1, the curing of ink near the nozzle N of the head 310_1 can be suppressed.

[0111] Furthermore, during the execution of the second scan RU2, the head 310_1 does not eject ink relative to the workpiece W.

[0112] Since the head 310_1 does not eject ink relative to the workpiece W, it is possible to move the head 310_1 away from the workpiece W. Since moving the head 310_1 away from the workpiece W can suppress the amount of light incident on the nozzle N of the head 310_1, the curing of ink near the nozzle N of the head 310_1 can be suppressed.

[0113] Furthermore, the emission intensity of the formal curing light emitted by the light emission unit 380 during the execution of the second scanning RU2 is higher than the emission intensity of the pinning light during the execution of the first scanning RU1.

[0114] It can suppress the residue of uncured ink on the workpiece W in the second scanning RU2, and suppress the curing of ink near the nozzle caused by pinning light in the first scanning RU1.

[0115] Furthermore, the stereolithography printing apparatus 100 has a head 310_2, which has a nozzle surface FD_2 provided with a nozzle N for ejecting ink. The moving mechanism 200 includes an independent lifting mechanism 235_2, which moves the nozzle surface FD_2 along the Z-axis. During the execution of the first scan RU1, the head 310_2 ejects ink relative to the workpiece W. During the execution of the first scan RU1, the relative position of the nozzle surface FD_1 and the nozzle surface FD_2 changes due to the driving of one or both of the independent lifting mechanisms 235_1 and 235_2. During the execution of the second scan RU2, the relative position of the nozzle surface FD_1 and the nozzle surface FD_2 does not change.

[0116] In the first scanning RU1, by independently raising and lowering the heads 310_1 and 310_2, printing can be performed while adjusting the gap to an appropriate level according to the shape of the workpiece W. Furthermore, interference between the workpiece W and the heads 310 is prevented. Further, since no ink is ejected in the second scanning RU2, it is unnecessary to operate the independent raising mechanisms 235_1 and 235_2. Therefore, in the second scanning RU2, the independent raising mechanisms 235_1 and 235_2 do not need to be driven, thereby reducing the power consumption of the stereolithography printing apparatus 100 compared to driving the independent raising mechanisms 235_1 and 235_2.

[0117] Furthermore, during the execution of the second scan RU2, the positions Za of nozzle face FD_1 and nozzle face FD_2 along the Z-axis are approximately equal.

[0118] By making the positions Za of nozzle surfaces FD_1 and FD_2 along the Z-axis equal, and by placing these positions Za closer to the Z1 direction than the position closest to the Z1 direction of the workpiece W, interference between the head 310_1 and the head 310_2 and the workpiece W can be prevented.

[0119] In addition, the stereolithography printing apparatus 100 includes a workpiece support mechanism 900, which supports the workpiece W and causes one or both of the position and orientation of the workpiece W to change.

[0120] By incorporating the workpiece support mechanism 900, the three-dimensional printing apparatus 100 is able to appropriately adjust the positional relationship between the three-dimensional workpiece W and the head 310_1.

[0121] Furthermore, if the third scan RU3 is defined as the action performed later than the second scan RU2, which moves the head 310_1 and the light emitting unit 380 relative to the workpiece W in the X1 direction, then during the execution of the third scan RU3, the head 310_1 ejects ink relative to the workpiece W. During the period between the second scan RU2 and the third scan RU3, the workpiece support mechanism 900 performs a workpiece movement action WM that changes one or both of the position and orientation of the workpiece W. By performing the workpiece movement action WM, the stereolithography printing apparatus 100 can move the workpiece W between multiple cycles.

[0122] Furthermore, the workpiece movement action WM is performed during a portion of the period between the second scan RU2 and the third scan RU3. During the execution of the workpiece movement action WM, when viewed along the Z-axis, the nozzle surface FD_1 and the exit surface FU do not overlap with the workpiece W.

[0123] In this way, since the head 310_1 and the light emitting part 380 are avoided to a position where the nozzle surface FD_1 and the emission surface FU do not overlap with the workpiece W, the position of the workpiece W can be appropriately adjusted without considering the possibility of interference between the workpiece W and the head 310_1 and the light emitting part 380.

[0124] Furthermore, during the execution of the workpiece movement action WM, one or both of the independent lifting mechanisms 235_1 and 235_2 are driven to move the nozzle surface FD_1 and the ejection surface FU along the Z-axis.

[0125] During the execution of the workpiece movement WM, the Z-axis positions of the head 310_1 and the light emission unit 380 are adjusted in accordance with the starting position PS3 of the third scanning RU3, thereby shortening the non-printing time between cycles. Therefore, the manufacturing time required for products, including the workpiece W, can be reduced, thus improving productivity.

[0126] 2. Variations

[0127] The methods illustrated above can be modified in a variety of ways. Specific modifications will be illustrated below. Two or more methods selected from the following examples can be appropriately combined without contradiction.

[0128] 2-1. First Variation Example

[0129] In the first embodiment, the stereolithography printing apparatus 100 may also have a light shield 390 between the head 310 and the light emitting part 380 to block ultraviolet light.

[0130] Figure 11 This figure illustrates the stereolithography printing apparatus 100a in the first modified example. The stereolithography printing apparatus 100a differs from the stereolithography printing apparatus 100 in that it has a light emitting section 380a instead of a light emitting section 380a. It also differs from the light emitting section 380a in that a light-shielding plate 390 is adhered to its side surface in the X1 direction. The light-shielding plate 390 is a flat component 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 X2 direction surface of the first portion 391 is adhered to the light emitting section 380a. The second portion 392 blocks ultraviolet light emitted from the light emitting section 380.

[0131] According to the first modified example, since the ultraviolet light is blocked by the second part 392, the amount of light incident on the nozzle N can be suppressed, thereby suppressing the curing of the ink near the nozzle N of the head 310_1.

[0132] Furthermore, although in the first modified example the light shield 390 is bonded to the side of the light emitting section 380 in the X1 direction, it is not limited to this. For example, the light shield 390 may also be bonded to the side of the liquid ejection unit 300_4 in the X2 direction.

[0133] 2-2. Second variation

[0134] Although in the various embodiments described above, the stereolithography printing apparatus 100 has independent lifting mechanisms 235_1 to 4 for raising and lowering the liquid ejection units 300_1 to 300_4 respectively, and an independent lifting mechanism 235 for raising and lowering the light emission unit 380, the independent lifting mechanism 235 for raising and lowering the light emission unit 380 and the independent lifting mechanism 235 for raising and lowering the liquid ejection unit 300_4 closest to the light emission unit 380 can be the same.

[0135] Figure 12 This figure illustrates the stereolithography printing apparatus 100b in the second modified example. The stereolithography printing apparatus 100b differs from the stereolithography printing apparatus 100 in that it has a lifting mechanism 230b instead of a lifting mechanism 230, and a light emitting unit 380b instead of a light emitting unit 380. The lifting mechanism 230b differs from the lifting mechanism 230 in that it does not have an independent lifting mechanism 235_5, and instead of an independent lifting mechanism 235_4, it has an independent lifting mechanism 235_4b.

[0136] A light emitting section 380b is adhered to the side of the liquid ejection unit 300_4 in the X2 direction. The independent lifting mechanism 235_4b raises and lowers the liquid ejection unit 300_4, thereby causing the light emitting section 380b to also rise and fall.

[0137] Furthermore, in the second variation, one of any two of the independent lifting mechanisms 235_1 to 235_3 is an example of a "first lifting mechanism," and the other is an example of a "third lifting mechanism." Independent lifting mechanism 235_4b is an example of a "second lifting mechanism."

[0138] 2-3. Third variation example

[0139] Although in the various methods described above, the stereolithography printing apparatus 100 has one light emitting section 380 for each of the four heads 310, it may also have one light emitting section 380 for each of the four heads 310.

[0140] Figure 13 The figure illustrates the stereolithography printing apparatus 100c in the third modified example. The stereolithography printing apparatus 100c differs from the stereolithography printing apparatus 100 in that it has four light emitting units 380, namely light emitting units 380_1 to 380_4. For the cases where m is 1 to 3, the light emitting unit 380_m is disposed between the liquid ejection unit 300_m and the liquid ejection unit 300_m+1, and emits studded light relative to the ink ejected from the head 310_m. Furthermore, the light emitting unit 380_4 is disposed in the X2 direction of the liquid ejection unit 300_4, and emits studded light relative to the ink ejected from the head 310_4, and emits curing light relative to the ink ejected from the heads 310_1 to 310_4. In this way, since the light emitting section 380_4 emits curing light and the light emitting sections 380_1 to 380_3 emit pinning light, the light emitting section 380_4 can emit ultraviolet light with a higher intensity compared to the light emitting sections 380_1 to 380_3.

[0141] The light emitting units 380_1 to 380_4 are also raised and lowered in the same way as the liquid ejection units 300_1 to 300_4. For example, when k is 1 to 4, the independent lifting mechanism 235_k raises and lowers both the light emitting unit 380_k and the liquid ejection unit 300_k. Alternatively, when k is 1 to 4, the stereolithography printing apparatus 100b may have an independent lifting mechanism 235 for raising and lowering the light emitting unit 380_k, different from the independent lifting mechanism 235_k for raising and lowering the liquid ejection unit 300_k.

[0142] 2-4. Fourth variation

[0143] Although in the various embodiments described above, the stereolithography printing apparatus 100 has its own independent lifting mechanism 235 for raising and lowering each liquid ejection unit 300, it is also possible for a single independent lifting mechanism 235 to raise and lower multiple liquid ejection units 300. For example, the stereolithography printing apparatus 100 in the fourth modification has two independent lifting mechanisms 235, liquid ejection units 300_1 to 300_4, and a light emission unit 380. One of the two independent lifting mechanisms 235 raises and lowers liquid ejection units 300_1 and 300_2, while the other independent lifting mechanism 235 raises and lowers liquid ejection units 300_3, 300_4, and the light emission unit 380.

[0144] 2-5. Fifth variation

[0145] Although the positions of the head 310 and the light emitting part 380 relative to the workpiece W along the X-axis are changed by driving the direct-drive mechanism 220 during the execution of the first scan RU1, second scan RU2, third scan RU3, and fourth scan RU4 in the various methods described above, this is not a limitation. Specifically, the workpiece W can also be moved along the X-axis by driving the workpiece support mechanism 900, thereby changing the positions of the head 310 and the light emitting part 380 relative to the workpiece W. In other words, the means by which the relative positions of the head 310 and the light emitting part 380 relative to the workpiece W along the X-axis are changed is not limited.

[0146] 2-6. Sixth Variation

[0147] Alternatively, in the first scan RU1 of each of the above methods, the distance d1 between the nozzle surface FD and the surface WF in the Z2 direction can be longer than the distance d5 between the exit surface FU and the surface WF in the Z2 direction.

[0148] 2-7. Seventh Variation

[0149] Alternatively, in the second scan RU2 of the above-mentioned methods, the distance e5 between the exit surface FU and the surface WF in the Z2 direction can be longer than the distance e1 between the nozzle surface FD and the surface WF in the Z2 direction.

[0150] 2-8. Eighth Variation

[0151] Although in the various methods described above, the stereolithography printing apparatus 100 performs a second scan RU2 after the first scan RU1, it is also possible to omit the second scan RU2, that is, to omit the pinning method. For example, in the first scan RU1, the light emitting unit 380 emits formal curing light.

[0152] 2-9. Ninth Variation

[0153] Alternatively, during the execution of the workpiece movement action WM in the above-mentioned methods, the independent lifting mechanism 235_1 and the independent lifting mechanism 235_2 may not be driven.

[0154] 2-10. Tenth Variation

[0155] In all the above-described methods, the following method can also be adopted: when the stereolithography printing apparatus 100 performs the workpiece movement action WM, the nozzle surface FD_1 and the emission surface FU overlap with the workpiece W when observed along the Z-axis. Specifically, the stereolithography printing apparatus 100 can also perform the workpiece movement action WM after the second scanning RU2 has ended, after the heads 310_1 to 310_4 and the light emission unit 380 have been moved in the Z1 direction, which does not interfere with the workpiece W. That is, in the tenth variation, during the execution of the workpiece movement action WM, the nozzle surface FD_1 and the emission surface FU overlap with the workpiece W when observed along the Z-axis.

[0156] As a specific example of the tenth variation, the lifting mechanism 230 may also have an integral lifting mechanism that allows the individual lifting mechanisms 235_1 to 235_5 to rise and fall uniformly. Furthermore, the stereolithography printing apparatus 100 may also use the integral lifting mechanism to move the individual lifting mechanisms 235_1 to 235_5 uniformly in the Z1 direction as a avoidance action RT1 after the second scanning RU2 is completed, thereby causing the heads 310_1 to 310_4 and the light emission unit 380 to move in the Z1 direction without interfering with the workpiece W.

[0157] Symbol Explanation

[0158] 100, 100a, 100b, 100c… 3D printing apparatus; 200… Moving mechanism; 220… Linear mechanism; 221… Guide rail component; 222… Carriage; 223… Horizontal encoder; 230, 230b… Lifting mechanism; 231… Support plate; 235, 235_1~235_5, 235_4b… Independent lifting mechanism; 236… Vertical encoder; 280… Support part; 281… Workbench; 282… Top plate; 283… Support column; 300, 300_1~300_4… Liquid ejection unit; 310, 310_1~310_4… Head; 320… Pressure regulating valve; 330… Transmission… Sensor; 340… Switching circuit; 350… Support; 380, 380_1~380_4… Light emitting part; 390… Light shield; 391… First part; 392… Second part; 400… Liquid supply unit; 410… Liquid storage part; 420… Supply channel; 421… Upstream channel; 422… Downstream channel; 422a… Channel component; 500… Control module; 510… Timing signal generation circuit; 520… Power supply circuit; 530… Control circuit; 540… Drive signal generation circuit; 600… Controller; 610… Storage circuit; 620… Processing circuit; 700… Computer; 900… Workpiece support Support mechanism; 910… Feeder axis mechanism; 920… Rotary axis mechanism; 922… Setting surface; AX… Long axis; CLK… Clock signal; CNG… Exchange signal; CR… Movement path; Com… Drive signal; D2_1~D2_5, D3… Signals; DR… Droplet; Da… Path information; Dr, Dx, Dy, Dz_1… Output signals; FD, FD_1~FD_5… Nozzle surface; FU… Exit surface; Img… Printing data; L1… First nozzle row; L2… Second nozzle row; LAT… Latch signal; N… Nozzle; PD… Drive pulse; PE1~PE4… End position; PS1~PS4… Start position Position; PT1, PT2…Avoidance position; PTS…Timing signal; RA, RB…Guide rail; RT1…Avoidance action; RT2…Return action; RU1…First scan; RU2…Second scan; RU3…Third scan; RU4…Fourth scan; SI, SI_1, Sr, Sv_k, Sx, Sy, Sz_1~Sz_5…Control signal; UV1…Pinning light; UV2…Formal curing light; VBS…Bias potential; VHV…Power supply potential; W…Workpiece; WF…Surface; WM…Workpiece movement action; XR…Rotation axis; Y…Lifting axis; d1, d5, e1, e5…Distance; dCom…Waveform specification signal.

Claims

1. A three-dimensional printing apparatus, comprising: The first head has a first nozzle face on which a nozzle for ejecting liquid is provided; An energy ejection section having an ejection surface that ejects energy to solidify the liquid ejected from the first head; A moving mechanism that changes the relative position of the first head and the energy emission part with respect to the three-dimensional workpiece. In the three-dimensional printing apparatus, The mobile mechanism has: A direct-acting mechanism that causes the relative positions of the first head and the energy emission section with respect to the workpiece to change along a first axis; A first lifting mechanism moves the first nozzle surface along a second axis that intersects the first axis; The second lifting mechanism moves the exit surface along the second axis. If the action of moving the relative position of the first head and the energy emission part relative to the workpiece in a first direction along the first axis is defined as the first scan, During the execution of the first scan, the first head sprays liquid relative to the workpiece. During the execution of the first scan, the energy emission section emits energy relative to the workpiece. During the execution of the first scan, the first lifting mechanism and the second lifting mechanism drive the first nozzle surface and the ejection surface to move along the second axis according to the shape of the workpiece. Furthermore, during the execution of the first scan, when the first head ejects liquid relative to the workpiece, the distance between the first nozzle surface and the workpiece along the second direction of the second axis is shorter than the distance between the ejection surface and the workpiece along the second direction. If the action of moving the first head and the energy emission part relative to the workpiece in a third direction opposite to the first direction is defined as the second scan, then... The second scan is then performed later than the first scan. During the execution of the second scan, the energy emission section emits energy relative to the workpiece. During the execution of the second scan, when the energy emission section emits energy relative to the workpiece, the distance between the emission surface in the second direction and the workpiece is shorter than the distance between the first nozzle surface in the second direction and the workpiece.

2. The three-dimensional printing apparatus as claimed in claim 1, wherein, During the execution of the second scan, the first head does not eject liquid relative to the workpiece.

3. The three-dimensional printing apparatus as described in claim 1, wherein, During the execution of the second scan, the position of the first nozzle surface in the second direction does not change.

4. The three-dimensional printing apparatus according to any one of claims 1 to 3, wherein, The energy emitted by the energy emission unit during the execution of the second scan is higher than the energy emitted during the execution of the first scan.

5. The three-dimensional printing apparatus according to any one of claims 1 to 3, wherein, It has a second head, which has a second nozzle face provided with a nozzle for ejecting liquid. The moving mechanism includes a third lifting mechanism, which moves the second nozzle surface along the second axis. During the execution of the first scan, the second head sprays liquid relative to the workpiece. During the execution of the first scan, the first nozzle surface and the second nozzle surface are moved along the second axis according to the shape of the workpiece by the drive of the first lifting mechanism and the third lifting mechanism. During the execution of the second scan, the relative position of the first nozzle surface and the second nozzle surface does not change.

6. The three-dimensional printing apparatus as described in claim 5, wherein, During the execution of the second scan, the positions of the first nozzle surface and the second nozzle surface along the second axis are approximately equal.

7. The three-dimensional printing apparatus according to any one of claims 1 to 3, wherein, The device includes a workpiece support mechanism that supports the workpiece and causes changes in one or both of the workpiece's position and orientation.

8. The three-dimensional printing apparatus as claimed in claim 7, wherein, If the action performed later than the second scan, and which moves the relative positions of the first head and the energy emission part relative to the workpiece in the first direction, is defined as the third scan, then... During the execution of the third scan, the first head sprays liquid relative to the workpiece, and during the period between the second scan and the third scan, the workpiece support mechanism performs a workpiece movement that changes one or both of the position and orientation of the workpiece.

9. The three-dimensional printing apparatus as claimed in claim 8, wherein, The workpiece movement is performed during a portion of the period between the second scan and the third scan. During the execution of the workpiece movement, when viewed along the direction of the second axis, the first nozzle surface and the ejection surface do not overlap with the workpiece.

10. The three-dimensional printing apparatus as claimed in claim 8 or 9, wherein, During the execution of the workpiece movement, Driven by one or both of the first lifting mechanism and the second lifting mechanism, one or both of the first nozzle surface and the ejection surface are moved along the second axis.

11. The three-dimensional printing apparatus according to any one of claims 1 to 3, wherein, It has a light-shielding part, which is disposed between the first head and the energy emitting part along the first direction, and blocks the energy emitted from the energy emitting part.

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