Three-dimensional molding device and three-dimensional molding method

Abstract

To allow a large-sized molded object to be manufactured while reducing the manufacturing cost of a three-dimensional molding device.SOLUTION: A three-dimensional molding device 1 is equipped with a layer forming mechanism 12 that forms a material layer in a molding space 30, an optical head 11 that irradiates the material layer with light, and a head moving mechanism 13 that moves the optical head 11 in a head moving direction parallel to the material layer. The optical head 11 consists of a light source, a diffraction-type optical modulator with a plurality of linearly arrayed modulation elements, an illumination optical system that guides light from the light source to the optical modulator, and a projection optical system that forms a projected image of the optical modulator on the material layer and changes the direction of the mirror so as to move the projected image in a scanning direction (+X) intersecting with the direction corresponding to the array direction of the plurality of modulation elements and intersecting with a head movement direction (+Y). This allows a large-sized molded object to be manufactured while reducing the manufacturing cost of the three-dimensional molding device 1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for forming a three-dimensional object using modulated light. [Background technology]

[0002] In recent years, SLS (Selective Laser Sintering) type three-dimensional modeling devices have been used, which perform three-dimensional modeling by irradiating a layer of modeling material such as metal powder or resin powder with modulated laser light to bond the modeling material, and repeating the layer formation and the bonding of the modeling material. For example, Patent Document 1 discloses a three-dimensional modeling device that irradiates a planar beam onto a grating light valve, and irradiates the modulated light onto the surface of an object construction area via a beam expander, a galvano scanner that operates in the xy plane, and an Fθ lens in this order.

[0003] Patent document 2 discloses a technology in which a print head module is provided with a dispenser for forming a material layer and an energy source, and while the supply material is being deposited, a beam from the energy source is used to selectively dissolve desired areas of the material layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2021-509094 [Patent Document 2] Special Publication No. 2018-535114 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a three-dimensional modeling device that repeats the formation of a material layer and the irradiation of a light beam, there is a limit to the size of the model when the irradiation position of the light beam is scanned by changing the direction of a reflecting mirror. Of course, measures such as arranging multiple optical heads that emit light beams or increasing the size and output of the optical heads are conceivable, but this would make the three-dimensional modeling device expensive. In addition, in a three-dimensional modeling device, in addition to the irradiation time of the light beam, it is necessary to take the time to form the material layer and the time until the material in the area irradiated by the light beam becomes thermally stable. Therefore, simply increasing the scanning area of ​​the light beam significantly reduces productivity.

[0006] The present invention has been made in consideration of the above problems, and has as its first object to make it possible to produce a large-sized object while suppressing the manufacturing cost of a 3D printing apparatus, and as its second object to further improve the productivity. [Means for solving the problem]

[0007] A first aspect of the present invention is a three-dimensional modeling device that forms a three-dimensional object in a material layer stacked in a modeling space by repeatedly forming a material layer of a powdered or paste-like modeling material and irradiating the material layer with light, the device comprising a layer formation mechanism that forms a material layer in the modeling space, an optical head that irradiates light onto the material layer, and a head movement mechanism that moves the optical head in a head movement direction parallel to the material layer, the optical head comprising a light source, a diffractive optical modulator having a plurality of modulation elements arranged in a line, an illumination optical system that directs light from the light source to the optical modulator, and a projection optical system that forms a projected image of the optical modulator on the material layer and moves the projected image in a scanning direction that intersects with a direction corresponding to the arrangement direction of the plurality of modulation elements and intersects with the head movement direction by changing the orientation of a mirror.

[0008] A second aspect of the present invention is the three-dimensional modeling apparatus of the first aspect, wherein the light modulator is a planar light valve or a diffraction grating light valve.

[0009] A third aspect of the present invention is the three-dimensional modeling apparatus of the first aspect (which may be either the first or second aspect), wherein the optical head moves continuously in the head movement direction.

[0010] A fourth aspect of the present invention is a 3D modeling apparatus according to the first aspect (which may be any one of the first to third aspects), wherein the layer formation mechanism forms a material layer in the direction of head movement, and before the optical head finishes irradiating one material layer with light, the layer formation mechanism starts forming the next material layer.

[0011] A fifth aspect of the present invention is a three-dimensional modeling device that forms a three-dimensional object in a material layer stacked in a modeling space by repeatedly forming a material layer of a powdered or paste-like modeling material and irradiating the material layer with light, and the device comprises a layer formation mechanism that forms a material layer in the modeling space, an optical head that irradiates the material layer with light, and a head moving mechanism that moves the optical head in a head moving direction parallel to the material layer, and the layer formation mechanism forms a material layer in the head moving direction, and before the optical head finishes irradiating one material layer with light, the layer formation mechanism begins forming the next material layer.

[0012] A sixth aspect of the present invention is a 3D printing device according to the fourth or fifth aspect, wherein the time from when the optical head starts irradiating light onto the first material layer to when the layer formation mechanism starts forming the next material layer is variable.

[0013] A seventh aspect of the present invention is a 3D printing apparatus according to aspect 4 or 5 (which may be any one of aspects 4 to 6), wherein the head movement direction of the optical head is reversible, and when the optical head moves in the inverted head movement direction, the layer formation mechanism forms a material layer toward the inverted head movement direction, and before the optical head finishes irradiating light to one material layer while moving in the inverted head movement direction, the layer formation mechanism starts forming a next material layer toward the inverted head movement direction.

[0014] Aspect 8 of the present invention is a 3D modeling method for forming a 3D object in material layers stacked in a modeling space by repeatedly forming a material layer of a powdered or paste-like modeling material and irradiating the material layer with light, the method comprising the steps of: a) lowering the latest material layer by the thickness of one layer; b) starting to irradiate the material layer with light from the optical head while moving the optical head in a head movement direction parallel to the material layer; c) starting to form a next material layer in the head movement direction after step b), after a predetermined delay time has elapsed and before irradiating the material layer with light is terminated; d) terminating the irradiation of light to the material layer; e) terminating the formation of the next material layer; and f) repeating steps a) to e). Effect of the Invention

[0015] According to the first to fourth aspects of the present invention, it is possible to produce a large-sized object while suppressing the manufacturing cost of the three-dimensional printing apparatus. Moreover, according to the fourth to eighth aspects of the present invention, it is possible to further improve the productivity. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a perspective view showing a three-dimensional modeling apparatus. [Diagram 2] FIG. 1 is a diagram illustrating a configuration of a three-dimensional modeling apparatus. [Diagram 3] FIG. 2 is a diagram showing a schematic configuration of an optical head. [Figure 4] FIG. 2 is a diagram showing a simplified structure of an optical modulator. [Diagram 5] FIG. 2 is a simplified diagram showing a projection optical system. [Figure 6] 11 is a diagram for explaining how a multi-spot line beam is irradiated onto a projection surface of a material layer. FIG. [Figure 7] FIG. 2 is a block diagram showing a functional configuration of the three-dimensional printing apparatus. [Figure 8] FIG. 4 is a diagram showing the flow of operations of the three-dimensional printing apparatus. [Figure 9] 13A and 13B are diagrams illustrating another example of irradiation of a light beam onto a projection surface. [Figure 10] FIG. 13 is a diagram showing a three-dimensional printing apparatus according to another example. [Figure 11] FIG. 13 is a diagram showing a three-dimensional printing apparatus according to another example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] FIG. 1 is a perspective view showing a three-dimensional modeling apparatus 1 according to an embodiment of the present invention. The three-dimensional modeling apparatus 1 is an SLS (Selective Laser Sintering) type apparatus that irradiates a powdered or pasty modeling material with modulated laser light and melts and bonds or sinters the modeling material to perform three-dimensional modeling. That is, the three-dimensional modeling apparatus 1 forms a three-dimensional object in the material layers stacked in the modeling space by repeatedly forming a material layer and irradiating the material layer with light. The modeling material is, for example, metal, engineering plastic, ceramics, synthetic resin, etc. The modeling material may include multiple types of materials.

[0018] In the following description, "irradiation of a material layer with light" refers to irradiation of a material layer with a light beam, or more precisely, irradiation of a spatially modulated light beam onto the material layer. The spatially modulated light beam is also called a "multi-spot line beam." As described later, the irradiation position of the light beam scans (moves) on the material layer. Irradiating a desired area of ​​the material layer with light by scanning the light beam may also be expressed simply as "irradiation of a material layer with light." Furthermore, irradiating a desired area of ​​the material layer with light is also called "exposure." The above-mentioned exposure in which light is irradiated only to a required area with a spatially modulated light beam is also called "drawing."

[0019] The three-dimensional modeling apparatus 1 includes an optical head 11, a layer forming mechanism 12, and a head moving mechanism 13. The layer forming mechanism 12 forms a material layer, which is a thin layer of modeling material 91, in the modeling space 30. The optical head 11 irradiates a processing area on the surface of the material layer with modulated light. The head moving mechanism 13 moves the optical head 11 in the Y direction in FIG. 1. FIG. 2 is a simplified diagram showing a cross section of the layer forming mechanism 12 and the optical head 11. In FIG. 2, the parallel diagonal lines indicating the cross section are partially omitted. In the modeling space 30, a plurality of material layers 92 are sequentially formed so as to be stacked, as will be described later.

[0020] Fig. 3 is a diagram showing a schematic configuration of the optical head 11. The optical head 11 includes a laser light source 21, an illumination optical system 22, an optical modulator 23, and a projection optical system 24. Fig. 3 is a simplified diagram, and the arrangement of each component differs from the actual arrangement. The laser light source 21 may be provided outside the optical head 11, and in this case, the light emitted from the laser light source 21 is guided into the optical head 11. The projection optical system 24 has a galvano scanner 44, and scans the irradiation position of light (a multi-spot line beam 8 described later) on the material layer 92 in the horizontal X direction.

[0021] As shown in FIG. 2, the layer forming mechanism 12 includes a modeling unit 31 and a supply unit 32. The modeling unit 31 includes a first cylinder 311 and a first piston 312. The first cylinder 311 is a cylindrical member extending in the vertical direction. The shape of the internal space of the first cylinder 311 in a plan view is, for example, substantially rectangular. The first piston 312 is a substantially flat or columnar member accommodated in the internal space of the first cylinder 311, and the shape in a plan view is substantially the same as that of the internal space of the first cylinder 311. The first piston 312 is movable in the vertical direction in the internal space of the first cylinder 311. In the modeling unit 31, a three-dimensional space surrounded by the inner surface of the first cylinder 311 and the upper surface of the first piston 312 is a modeling space 30 where three-dimensional modeling is performed.

[0022] The supply unit 32 includes a second cylinder 321, a second piston 322, and a layer forming member 323 that is a squeegee. The second cylinder 321 is a cylindrical member that extends in the vertical direction, and is disposed adjacent to the side of the first cylinder 311. The shape of the internal space of the second cylinder 321 in a plan view is, for example, substantially rectangular. The second piston 322 is a substantially plate-like or substantially columnar member that is accommodated in the internal space of the second cylinder 321, and the shape of the internal space in a plan view is substantially the same as that of the internal space of the second cylinder 321. The second piston 322 is movable in the vertical direction in the internal space of the second cylinder 321. In the supply unit 32, a three-dimensional space surrounded by the inner surface of the second cylinder 321 and the upper surface of the second piston 322 is a storage space in which the modeling material 91 to be supplied to the modeling unit 31 is stored. The layer forming member 323 is a rod-shaped (e.g., substantially cylindrical) member extending in the X direction across the upper opening of the second cylinder 321. The layer forming member 323 is movable horizontally in the Y direction along the upper end surface of the second cylinder 321 by a pair of driving mechanisms 324 shown in FIG.

[0023] In the supply unit 32, the second piston 322 rises a predetermined distance, and the modeling material 91 in the second cylinder 321 is lifted upward. At this time, the surface of the modeling material 91 in the modeling space 30 is previously lowered by the first piston 312 by one layer of the material layer 92. In this state, in the three-dimensional modeling device 1, the multi-spot line beam 8 is irradiated from the optical head 11 onto the projection surface 95, which is the surface of the latest material layer 92. That is, the multi-spot line beam 8, which is the projected image of the optical modulator 23 (see FIG. 3), is scanned onto the surface of the modeling material 91 in the modeling space 30. As a result, the modeling material is bonded in a predetermined area of ​​the projection surface 95. As a result, a portion corresponding to one layer of the three-dimensional object 93 is formed.

[0024] As will be described in detail later, in the three-dimensional printing apparatus 1, before the irradiation of one material layer 92 with the multi-spot line beam 8 is completed, the layer forming member 323 starts to move from above the second cylinder 321 to above the first cylinder 311. By moving to the layer forming member 323, the printing material 91 protruding above the upper end surface of the second cylinder 321 is supplied into the printing space 30 of the printing unit 31. The upper surface of the printing material 91 held in the printing space 30 is located at a predetermined height (for example, the same height as the upper end surface of the first cylinder 311). As a result, one material layer 92 is formed in the printing space 30.

[0025] When the scanning of the multi-spot line beam 8 on the processing area, which is the projection surface 95, and the formation of a new material layer 92 are completed, the first piston 312 descends by a distance equivalent to one layer of the material layer 92. As the material layers 92 stacked in the printing space 30 descend, the latest material layer 92 (and the projection surface 95) descends by one layer. Meanwhile, the printing material 91 is pushed up in the supply unit 32. Thereafter, the above-mentioned scanning of the multi-spot line beam 8 and the formation of the material layer 92 are repeated a required number of times. That is, the scanning of the multi-spot line beam 8 and the formation of the new projection surface 95, which are performed partially in parallel, are repeated. As a result, a three-dimensional object 93 is formed in the printing space 30.

[0026] In the 3D printing apparatus 1, the optical head 11, layer forming mechanism 12, and head moving mechanism 13 are controlled by a control unit (see FIG. 7) based on design data (e.g., CAD data) of a 3D object to be produced. The control unit is, for example, a normal computer including a processor, a memory, an input / output unit, and a bus. Note that the configuration of the control unit may be changed in various ways.

[0027] Next, the optical head 11 in Fig. 3 will be described. The laser light source 21 emits a laser light 81 to the illumination optical system 22. The laser light source 21 is, for example, a fiber laser light source. The wavelength of the laser light 81 is, for example, 1.070 µm. The type of the laser light source 21 and the wavelength of the laser light 81 may be variously changed.

[0028] The illumination optical system 22 shapes the cross section of the laser light 81 into a substantially rectangular shaped beam 82 that is long in one direction (hereinafter referred to as the "long axis direction") and guides the shaped beam 82 to the optical modulator 23. In other words, the cross section of the shaped beam 82 is a substantially rectangular shape that is long in the long axis direction and short in the short axis direction perpendicular to the optical axis and the long axis direction. The cross section of the shaped beam 82 is the shape of the shaped beam 82 on a plane perpendicular to the optical axis. The long axis direction and the short axis direction are directions perpendicular to the direction of the optical axis, that is, the traveling direction of the shaped beam 82. In the following description, the light beam (including modulated light) is expressed as "light" or "beam", and the "cross section" of "light" or "beam" means the cross section of the light beam on a plane perpendicular to the optical axis. The cross section of the shaped beam 82 can also be regarded as a straight line extending in the long axis direction. The shape of the shaped beam 82 on the optical modulator 23 is, for example, a substantially rectangular shape with a major axis length of about 27 mm and a minor axis length of about 1 mm.

[0029] The optical modulator 23 converts the shaped beam 82 from the illumination optical system 22 into modulated light 83 that has been one-dimensionally spatially modulated. For example, a PLV (Planar Light Valve) capable of high-speed modulation and capable of withstanding kW-class laser light is used as the optical modulator 23. The PLV is a diffractive two-dimensional spatial light modulator, but in the optical head 11, it is used as a one-dimensional spatial modulator.

[0030] 4 is a diagram showing a simplified structure of optical modulator 23, which is a PLV. Optical modulator 23 includes a plurality of substantially rectangular pixels 231 arranged in a matrix (i.e., arranged two-dimensionally) on a substrate not shown. In optical modulator 23, the surfaces of the plurality of pixels 231 form modulation surface 234. In the example shown in FIG. 4, M pixels 231 are arranged in the vertical direction and N pixels 231 are arranged in the horizontal direction in the figure. The horizontal direction in FIG. 4 corresponds to the long axis direction of shaped beam 82 (see FIG. 3), and the vertical direction in FIG. 4 corresponds to the short axis direction of shaped beam 82.

[0031] Each pixel 231 is a modulation mechanism including a fixed member 232 and a movable member 233. The fixed member 232 is a planar, substantially rectangular member fixed to the substrate, and has a substantially circular opening at its center. The movable member 233 is a substantially circular member provided in the opening of the fixed member 232. A fixed reflecting surface is provided on the upper surface of the fixed member 232 (i.e., the surface on the near side in the direction perpendicular to the paper surface in FIG. 4). A movable reflecting surface is provided on the upper surface of the movable member 233. The movable member 233 is movable in the direction perpendicular to the paper surface in FIG. 4.

[0032] In each pixel 231, the relative position of the fixed member 232 and the movable member 233 in the direction perpendicular to the paper surface in FIG. 4 is changed, so that the reflected light from the pixel 231 is switched between zeroth-order (diffracted) light (i.e., regular reflected light) and non-zeroth-order diffracted light. In other words, in the pixel 231, the movable member 233 moves relative to the fixed member 232, so that light modulation using a diffraction grating is performed. The zeroth-order light emitted from the optical modulator 23 is guided to the printing space 30 by the projection optical system 24 (see FIG. 3). In addition, the non-zeroth-order diffracted light (mainly first-order diffracted light) emitted from the optical modulator 23 is appropriately blocked and does not reach the printing space 30.

[0033] In the optical modulator 23, the diffraction state of reflected light from M pixels 231 (hereinafter also referred to as "pixel column 230") arranged in a vertical line in FIG. 4 is the same. That is, when the reflected light from one pixel 231 is zero-order light, the reflected light from all other pixels 231 (i.e., (M-1) pixels 231) in the pixel column 230 including the pixel 231 is also zero-order light. In addition, when the reflected light from one pixel 231 is non-zero-order diffracted light, the reflected light from all other pixels 231 in the pixel column 230 including the pixel 231 is also non-zero-order diffracted light. That is, in the optical modulator 23, modulation is not performed in the short axis direction of the shaped beam 82, but is performed in the long axis direction. In this way, in the optical modulator 23, M pixels 231 (i.e., M modulation mechanisms) in one pixel column 230 function as one modulation element corresponding to one unit space. The light modulator 23 functions as a one-dimensional spatial light modulator having N modulation elements arranged in a row in the major axis direction of the shaped beam 82. In a preferred example, N is 1000 or more.

[0034] Next, the projection optical system 24 will be described. Fig. 5 is a diagram showing an outline of the projection optical system 24. The projection optical system 24 includes a first projection optical system 241 and a second projection optical system 242. The first projection optical system 241 forms an intermediate image 84 of the optical modulator 23 at a predetermined intermediate position. The second projection optical system 242 scans this intermediate image 84 while projecting it onto the material layer 92, i.e., onto a projection surface 95. In other words, the projection optical system 24 scans while forming a projected image of the optical modulator 23 on the material layer 92. In Fig. 5, the direction perpendicular to the paper surface corresponds to the direction in which the modulation elements of the optical modulator 23 are arranged (hereinafter also referred to as the "long axis direction").

[0035] The first projection optical system 241 has, in order from the optical modulator 23 side, a first lens group 41 and a second lens group 42. The first lens group 41 is at least one lens. The second lens group 42 is also at least one lens. The second projection optical system 242 has, in order from the first projection optical system 241 side, a third lens group 43, a galvano scanner 44, and a fourth lens group 45. The third lens group 43 is at least one lens. The galvano scanner 44 is a scanning mechanism that scans the modulated light in the X direction by changing the orientation of a mirror. In FIG. 5, only the mirror portion of the galvano scanner 44 is shown in a simplified manner. The fourth lens group 45 is at least one lens.

[0036] An intermediate image 84 of the optical modulator 23 is formed by the first projection optical system 241. The first lens group 41 and the second lens group 42 may be composed of only spherical lenses, but when generating one-dimensional modulated light, since modulation in the major axis direction determines the shape of the model, the first projection optical system 241 may include a cylindrical lens or the like to reduce the intermediate image 84 in the minor axis direction.

[0037] The third lens group 43 is preferably a single lens or a laminated lens with suppressed aberration. The fourth lens group 45 is also preferably a single lens or a laminated lens with suppressed aberration. The second projection optical system 242 is preferably composed of only spherical lenses, and is a so-called fθ lens. The second projection optical system 242 may be image-side telecentric or image-side non-telecentric. Furthermore, the second projection optical system 242 may be a non-fθ lens. The second projection optical system 242 forms a projected image of the intermediate image 84 on a projection surface 95 (i.e., powder surface) which is the surface of the material layer 92. The second projection optical system 242 irradiates the intermediate image 84 as a multi-spot line beam 8 on the projection surface 95 which is the processing area. In addition, the galvano scanner 44 scans the projection image on the projection surface 95 in the X direction. In FIG. 5, the manner in which the multi-spot line beam 8 is scanned is simplified by branching the optical path from the galvano scanner 44.

[0038] FIG. 6 is a diagram for explaining how the multi-spot line beam 8 is irradiated on the projection surface 95 of the material layer 92. In FIG. 6, the Y direction corresponds to the long axis direction. That is, the ON (light irradiation) and OFF (light non-irradiation) spots of the multi-spot line beam 8 are lined up in the Y direction. Reference numeral 950 in FIG. 6 indicates the length of the spot row of the multi-spot line beam 8, and drawing is performed in one area 951 with modulated light by moving the multi-spot line beam 8 in the (+X) direction as shown by the arrow 8a by the galvano scanner 44. Hereinafter, the area 951 will be referred to as a "swath."

[0039] When drawing on one swath 951 is completed, the head movement mechanism 13 in Fig. 1 moves the optical head 11 in steps in the (+Y) direction, which is the head movement direction parallel to the material layer 92, and drawing is performed on the adjacent swath 951 in the (+Y) direction. By sequentially drawing on the adjacent swaths 951, drawing on the material layer 92 on the projection surface 95, i.e., exposure of the projection surface 95 by irradiation with modulated light, is completed.

[0040] 7 is a block diagram showing the functional configuration of the three-dimensional printing apparatus 1. The control unit 14 controls the optical head 11, the layer forming mechanism 12, and the head moving mechanism 13. The control unit 14 controls the optical head 11 and the head moving mechanism 13 to irradiate the projection surface 95 with modulated light (multi-spot line beam 8). The control unit 14 controls the layer forming mechanism 12 to form a material layer 92 in the printing space 30. The control unit 14 stores a delay time 71. Under the control of the control unit 14, the layer forming mechanism 12 starts forming the material layer 92 after the delay time 71 has elapsed since the start of irradiation of the modulated light onto the projection surface 95.

[0041] 8 is a diagram showing the flow of operations of the 3D printing apparatus 1. First, the 3D printing apparatus 1 accepts the setting of a delay time (step S11). That is, when an operator inputs a delay time via an input device such as a keyboard or mouse of the control unit 14, the input value is stored as a delay time 71 in the memory of the control unit 14. In this way, the delay time 71 is a changeable value. If it is not necessary to change the delay time 71, step S11 may be omitted.

[0042] In the pre-processing (step S12), for example, the material layer 92 is formed multiple times, the temperature of the material layer 92 is adjusted by a heating unit (not shown), and the like. Next, the first piston 312 is lowered by the thickness of one layer of the material layer 92 (step S13). As a result, the projection surface 95, which is the surface of the top layer, i.e., the latest material layer 92, is positioned at a height suitable for irradiation with the multi-spot line beam 8. Thereafter, irradiation and scanning of the projection surface 95 with the multi-spot line beam 8 is started (step S14). In this way, in the three-dimensional printing apparatus 1, drawing is performed by the multi-spot line beam 8 at a height where the surface of the material layer 92 is lower by one layer of the material layer 92 than immediately after the material layer 92 is formed.

[0043] As described with reference to FIG. 6, drawing is performed by moving the optical head 11 in the (+Y) direction while scanning the multi-spot line beam 8 in the (+X) direction. After the delay time 71 has elapsed from the start of drawing, the supply unit 32 starts forming the next material layer 92 (step S15). That is, before the optical head 11 finishes irradiating the first material layer 92 with light, the layer forming mechanism 12 starts forming the next material layer 92. Specifically, the second piston 322 has pushed the modeling material 91 up above the upper end of the second cylinder 321 in advance, and the layer forming member 323 starts moving in the (+Y) direction so as to follow the movement of the optical head 11, so that the next material layer 92 is formed on the projection surface 95 toward the (+Y) direction. In FIG. 6, the layer forming member 323 is indicated by a two-dot chain line, and the movement of the layer forming member 323 is indicated by an arrow 32a. In the three-dimensional modeling device 1, the irradiation of light and the formation of the material layer 92 are partially performed in parallel. This reduces the time required for modeling and improves the productivity of the modeled objects.

[0044] The delay time 71 is determined in consideration of the time it takes for the modeling material 91 to become thermally stable after it is irradiated with light and melted (or sintered). As a result, after the light irradiation, the thermally stable area is successively covered with the next material layer 92.

[0045] When one cross section (slice) of the object is drawn on the projection surface 95, the irradiation of the light beam is terminated (step S16), and then the formation of the material layer 92 is also terminated (step S17). If the next material layer 92 needs to be irradiated with the light beam (step S18), the process returns to step S13, and the lowering of the material layer 92, the irradiation of the light beam, and the formation of the material layer 92, which is performed partially in parallel with the irradiation of the light beam, are repeated (steps S13 to S17). When the drawing of all slices of the object is completed (step S18), post-processing such as waiting for a predetermined time or removing the object is performed (step S19). Note that step S17 (formation of the material layer 92) after the last step S16 (light irradiation) may not be performed.

[0046] FIG. 9 is a diagram showing another example of irradiation of a light beam onto a projection surface 95 in the three-dimensional modeling apparatus 1. In the example of FIG. 9, the optical head 11 moves continuously in the (+Y) direction. "Continuously" means that the movement of the optical head 11 does not stop during the irradiation of the light beam. Therefore, each swath 951 is inclined toward the (+Y) side with respect to the (+X) direction, as shown by the arrow 8b. This makes it possible to shorten the time required for drawing on the projection surface 95. As in the case of FIG. 6, in FIG. 9, the layer forming member 323 is shown by a two-dot chain line, and the movement of the layer forming member 323 is shown by the arrow 32a.

[0047] 6, assuming that the length 950 of the spot train is 25 mm, the size of the projection surface 95 is 350 mm in the X direction and 1000 mm in the Y direction, the scanning speed of the multi-spot line beam 8 in the X direction is 1000 mm / sec, the time required for the optical head 11 to stop in the Y direction is 0.5 seconds, and the time required for the modeling material 91 to become thermally stable after heating is 3 seconds, the time for one scan in the X direction is 0.35 seconds, and the number of scans in the X direction is 40. Here, if the optical head 11 is repeatedly moved and stopped for each swath 951 as in FIG. 6, the time for drawing on the entire projection surface 95 is approximately 34 seconds (=(0.35 seconds + 0.5 seconds) × 40 times). On the other hand, when the optical head 11 is moved continuously as in Fig. 9, the movement speed of the optical head 11 is 71.4 mm / sec (=25 mm / 0.35 sec), and the time required to perform drawing on the entire projection surface 95 is approximately 14 seconds (=1000 mm / (71.4 mm / sec)). Furthermore, if the delay time 71 is 3 seconds, the time required to process one layer in Fig. 9 is 17 seconds (=14 seconds + 3 seconds).

[0048] It should be noted that the above values ​​are merely examples. For example, even if the scanning speed in the X direction is 5000 mm / sec, the movement speed in the Y direction is 357 mm / sec, which is a feasible speed.

[0049] 10 and 11 are diagrams showing a three-dimensional modeling apparatus 1a according to another example. In the three-dimensional modeling apparatus 1a, drawing is performed on the projection surface 95 when the optical head 11 moves in the (+Y) direction and when it moves in the (-Y) direction. That is, the head movement direction of the optical head 11 during drawing can be reversed, and the head movement direction in the (-Y) direction is the reverse of the head movement direction in the (+Y) direction. In the three-dimensional modeling apparatus 1a, a supply unit similar to the supply unit 32 in FIG. 2 is added to the (+Y) side of the modeling unit 31 of the three-dimensional modeling apparatus 1 in FIG. 2. Hereinafter, the supply unit on the (-Y) side of the modeling unit 31 is referred to as the "first supply unit 32a," and the supply unit on the (+Y) side of the modeling unit 31 is referred to as the "second supply unit 32b." The first supply unit 32a and the second supply unit 32b share the layer forming member 323. In FIG. 10 and FIG. 11, the same components as those in FIG. 2 are denoted by the same reference numerals.

[0050] FIG. 10 shows the optical head 11 moving in the (+Y) direction as indicated by an arrow 11a. FIG. 11 shows the optical head 11 moving in the (-Y) direction as indicated by an arrow 11b. The operation of the three-dimensional modeling device 1a is similar to that of FIG. 8, except that the optical head 11 forms a drawing and a material layer 92 when it moves in the (+Y) direction and the (-Y) direction. That is, the delay time 71 is received and stored in advance (step S11), and when the pre-processing is completed (step S12), the material layer 92 is lowered in the modeling unit 31, and the optical head 11 starts drawing on the projection surface 95 while moving in the (+Y) direction (step S14). When the delay time 71 has elapsed since the start of drawing, the first supply unit 32a starts forming the next material layer 92 (step S15).

[0051] When drawing and formation of the material layer 92 are completed (steps S16 to S18), the material layer 92 is lowered in the modeling unit 31 (step S13), and drawing on the projection surface 95 is started while the optical head 11 is moving in the (-Y) direction as shown in FIG. 11 (step S14). When the delay time 71 has elapsed from the start of drawing, formation of the next material layer 92 is started by the second supply unit 32b (step S15). That is, before the optical head 11 finishes irradiating the first material layer 92 with light while moving in the (-Y) direction, the layer forming mechanism 12 starts forming the next material layer 92 in the (-Y) direction. When drawing and formation of the material layer 92 are completed (steps S16 to S18), the material layer 92 is lowered in the modeling unit 31 (step S13), and drawing and formation of the material layer 92 are performed by the optical head 11 and the first supply unit 32a.

[0052] Since drawing is performed while the optical head 11 moves in the (+Y) and (-Y) directions, the 3D modeling apparatus 1a can perform modeling at even higher speed. To achieve this operation, the 3D modeling apparatus 1a is structured such that the order of the optical head 11 and the layer forming member 323 in the Y direction can be swapped. That is, the layer forming member 323 can pass under the optical head 11.

[0053] As described above, in the 3D printing apparatus 1, 1a (hereinafter, the 3D printing apparatus 1, 1a will be simply referred to as the "3D printing apparatus 1", and the "3D printing apparatus 1" will include the "3D printing apparatus 1a" to the extent that there is no contradiction), by moving the optical head 11 in the Y direction, it is possible to produce a large-sized object while suppressing the manufacturing cost of the 3D printing apparatus 1. Since there is only one optical head 11, the labor required for regular maintenance of the optical head 11 can also be reduced. In addition, since drawing on the projection surface 95 and forming the next material layer 92 are partially performed in parallel, the productivity of the object can be further improved.

[0054] In the 3D printing apparatus 1, management of the preliminary heating of the printing material 91 is important, but since there is sufficient time between the formation of the material layer 92 and drawing on this material layer 92, drawing can be performed stably while suppressing the time consumption for preheating. Furthermore, since the next material layer 92 quickly covers the drawn area after drawing, it is possible to prevent the material after drawing from being subjected to heat from the preliminary heating device, and the shape accuracy of the model can be improved. In particular, since the optical head 11 moves significantly in the 3D printing apparatus 1, it is effective to quickly form the next material layer 92.

[0055] In addition, in the three-dimensional modeling apparatus 1, the delay time 71 from the start of drawing to the start of formation of the next material layer 92 is variable, so that the productivity can be appropriately improved according to the type of modeling material 91.

[0056] The three-dimensional modeling apparatus 1 can be modified in various ways. The three-dimensional modeling apparatus 1 forms a material layer 92 of a powdered or pasty modeling material 91 and repeatedly irradiates the material layer 92 with light, thereby forming a three-dimensional model in the material layer 92 stacked in the modeling space 30. The configuration for irradiating light and the configuration for forming the material layer 92 can be modified in various ways.

[0057] For example, the light source of the optical head 11 is not limited to the laser light source 21. Various other known light sources may be adopted. Various optical systems may be adopted for the illumination optical system 22 as well, as long as they can converge and guide light to the areas of the multiple modulation elements of the optical modulator 23.

[0058] As the diffractive optical modulator 23 having a plurality of linearly arranged modulation elements, a PLV (Planar Light Valve) with high power resistance is preferable. The optical modulator 23 may be a grating light valve (GLV (registered trademark)). As the optical modulator 23, diffractive optical modulators based on various principles can be used as long as they can control the illumination and non-illumination of light at a plurality of positions in the projected image.

[0059] As a scanning mechanism for quickly manipulating the light irradiation position by changing the direction of the mirror, other mechanisms such as a polygon laser scanner may be adopted instead of the galvano scanner 44. In the above-mentioned three-dimensional modeling device 1, the projected image formed at the light irradiation position is scanned in the X direction or approximately in the X direction, but the scanning direction is not limited to these directions. In order to perform two-dimensional drawing by scanning the projected image, the scanning direction may be a direction intersecting the direction of the spot row in the projected image. The spot row is a direction corresponding to the arrangement direction of the multiple modulation elements of the optical modulator 23 in the projected image. On the other hand, since the drawing range needs to be expanded by the movement of the optical head 11, the scanning direction is a direction intersecting the head movement direction. If the direction in which one swath 951 is drawn is called the "primary scanning direction" and the arrangement direction of the swath 951, which is the head movement direction, is called the "secondary scanning direction", the primary scanning direction is a direction intersecting both the spot row direction and the secondary scanning direction.

[0060] The projection optical system 24 forms a projected image of the light modulator 23 on a projection plane 95, but strictly speaking, the light modulator 23 and the projection plane 95 do not need to be optically conjugate. As long as three-dimensional modeling is possible, the projection plane 95 may be slightly shifted from a position conjugate with the light modulator 23. The configuration of the projection optical system 24 may be modified in various ways.

[0061] The first projection optical system 241 forms an intermediate image 84 of the optical modulator 23 at a predetermined intermediate position, but since the optical modulator 23 is a one-dimensional spatial modulator, the "intermediate image" may be interpreted as meaning an image at least in the long axis direction. That is, in the first projection optical system 241, the optical modulator 23 and the intermediate image 84 are in a conjugate positional relationship with respect to the long axis direction. Therefore, the projected image on the projection surface 95 of the optical modulator 23 means a projected image at least in the long axis direction. Of course, the first projection optical system 241 may have the same projection magnification in the long axis direction and the short axis direction. It is also possible for the first projection optical system 241 to be only one lens. The first projection optical system 241 may be one lens group, or three or more lens groups.

[0062] Various known mechanisms can be used as the head moving mechanism 13 that moves the optical head 11 in a head moving direction parallel to the material layer 92. For example, a linear motor, a feed mechanism combining a motor with a ball screw, etc. can be used.

[0063] The layer forming member 323 of the layer forming mechanism 12 is not limited to a squeegee. A roller or a member that spreads the modeling material 91 may be used as the layer forming member. The layer forming mechanism 12 may be a mechanism that does not have the layer forming member 323. As long as a new projection surface 95 can be formed by forming a new material layer 92 of the modeling material 91 on the projection surface 95, various other mechanisms may be used as the layer forming mechanism 12.

[0064] In the three-dimensional modeling apparatus 1, the layer formation mechanism 12 forms a material layer 92 in the head movement direction, and before the optical head 11 finishes irradiating one material layer 92 with light, the layer formation mechanism 12 starts forming the next material layer 92. This operation does not need to be performed for all slices of the model (portions corresponding to one material layer 92 of the model). For example, when the area to be irradiated with light in one slice is small, the time required for irradiating light onto the projection plane 95 corresponding to this slice may be short, so the layer formation mechanism 12 may start forming the next material layer 92 after the light irradiation is completed.

[0065] In the 3D modeling apparatus 1, the delay time 71 from when the optical head 11 starts irradiating one material layer 92 with light until when the layer forming mechanism 12 starts forming the next material layer 92 is variable, but if only one type of modeling material 91 is used, the delay time 71 may be fixed. Note that the delay time 71 does not need to strictly indicate the above time as long as it substantially reflects the time from when the optical head 11 starts irradiating one material layer 92 with light until when the layer forming mechanism 12 starts forming the next material layer 92.

[0066] In the 3D printing device 1a of Figures 10 and 11, the head movement direction of the optical head 11 is reversible, and the layer forming member 323 is shared by the first supply unit 32a and the second supply unit 32b, but the layer forming member 323 may be provided in each of the first supply unit 32a and the second supply unit 32b.

[0067] In the above embodiment, the optical head 11 moves in the head movement direction, and the layer forming mechanism 12 forms the next material layer 92 in the same direction partially in parallel with the movement of the optical head 11. However, when only the purpose of forming a large object while suppressing the manufacturing cost of the three-dimensional printing apparatus 1 is focused on, the movement of the optical head 11 and the formation of the next material layer 92 do not have to be performed in parallel. Also, one modulation spot, not multiple ones, may be formed by the optical head 11, and the irradiation position of the light beam may be scanned in the X direction and gradually moved in the (+Y) direction, so that the next material layer 92 is formed toward the (+Y) direction. In other words, moving the optical head 11 while performing drawing with the multi-spot line beam 8 and performing the irradiation of light and the formation of the material layer 92 partially in parallel may be adopted in the three-dimensional printing apparatus as separate technical matters.

[0068] The configurations in the above-described embodiment and each of the modified examples may be combined as appropriate as long as they are not mutually inconsistent. [Explanation of symbols]

[0069] 1,1a 3D modeling device 11 Optical head 12 Layer formation mechanism 13 Head movement mechanism 21 Laser light source 22 Illumination optical system 23 Optical Modulator 24 Projection optical system 30 Build space 71 Delay Time 91 Modeling materials 92 Material layer 93 Sculptures 230 pixel columns (modulation elements) S13~S18 steps

Claims

1. A three-dimensional modeling device that forms a three-dimensional model in a material layer stacked in a modeling space by repeatedly forming a material layer of a powdered or pasty modeling material and irradiating the material layer with light, comprising: a layer forming mechanism for forming a material layer in the modeling space; an optical head for irradiating the material layer with light; a head moving mechanism for moving the optical head in a head moving direction parallel to the material layer; Equipped with The optical head is A light source; a diffractive optical modulator having a plurality of modulation elements arranged in a line; an illumination optical system that guides light from the light source to the optical modulator; a projection optical system that forms a projected image of the optical modulator on the material layer and moves the projected image in a scanning direction that intersects with a direction corresponding to an arrangement direction of the plurality of modulation elements and intersects with a head moving direction by changing a direction of a mirror; A three-dimensional printing apparatus comprising:

2. The three-dimensional modeling apparatus according to claim 1 , The three-dimensional modeling apparatus, wherein the light modulator is a planar light valve or a diffraction grating light valve.

3. The three-dimensional modeling apparatus according to claim 1 , The three-dimensional modeling apparatus, wherein the optical head moves continuously in the head movement direction.

4. The three-dimensional modeling apparatus according to claim 1 , the layer forming mechanism forms a material layer in the head movement direction; a layer forming mechanism that starts forming a next material layer before the optical head finishes irradiating one material layer with light;

5. A three-dimensional modeling device that forms a three-dimensional model in a material layer stacked in a modeling space by repeatedly forming a material layer of a powdered or pasty modeling material and irradiating the material layer with light, comprising: a layer forming mechanism for forming a material layer in the modeling space; an optical head for irradiating the material layer with light; a head moving mechanism for moving the optical head in a head moving direction parallel to the material layer; Equipped with the layer forming mechanism forms a material layer in the head movement direction; a layer forming mechanism that starts forming a next material layer before the optical head finishes irradiating one material layer with light;

6. The three-dimensional printing apparatus according to claim 4 or 5, A three-dimensional modeling apparatus, characterized in that the time from when the optical head starts irradiating the one material layer with light to when the layer forming mechanism starts forming the next material layer is variable.

7. The three-dimensional printing apparatus according to claim 4 or 5, The head movement direction of the optical head is reversible, When the optical head moves in the reversed head movement direction, the layer forming mechanism forms a material layer toward the reversed head movement direction; A three-dimensional modeling device characterized in that before the optical head finishes irradiating one material layer with light while moving in the inverted head movement direction, the layer formation mechanism begins forming a next material layer in the inverted head movement direction.

8. A three-dimensional modeling method for forming a three-dimensional object in a material layer stacked in a modeling space by repeatedly forming a material layer of a powdered or pasty modeling material and irradiating the material layer with light, comprising: a) lowering the current layer of material by one layer thickness; b) starting irradiation of the material layer with light from the optical head while moving the optical head in a head movement direction parallel to the material layer; c) starting formation of a next material layer in the head movement direction after a preset delay time has elapsed and before the irradiation of the material layer with light is terminated after the step b); d) terminating the irradiation of the material layer with light; e) completing formation of the next layer of material; f) repeating steps a) to e); and A three-dimensional modeling method comprising:

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