3D modeling device

Abstract

A three-dimensional modeling device is used to produce three-dimensional objects. The device includes a beam irradiation unit, a spatial light modulator, a separation optical system, and a scanning unit. The beam irradiation unit irradiates a light beam. The spatial light modulator spatially modulates the light beam irradiated by the beam irradiation unit along at least a first axis. The separation optical system includes at least one lens array having a plurality of lenses arranged along the first axis. The lens array separates the light beam modulated by the spatial light modulator into a plurality of light beams. The scanning unit scans the plurality of light beams from the separation optical system over a modeling material.

Description

Technical Field

[0001] The present application relates to a three-dimensional modeling device. Background Art

[0002] Previously, a three-dimensional modeling device has been proposed that irradiates a modeling material, such as a metal material (powder), with light from a laser light source and scans the light across the modeling material, thereby melting and sintering the modeling material. Furthermore, research is underway into three-dimensional modeling methods that scan the modeling material with linear light to increase modeling speed (e.g., Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-80604 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] However, when linear light strikes the modeling material, the material's temperature varies within the illuminated linear area. This temperature variation causes the molten material to flow based on its temperature distribution and surface tension. This can cause the surface of the modeling material to bulge locally, and the shape of the cooled and integrated modeling material can differ from the intended shape. This leads to a reduction in the accuracy of the three-dimensional object.

[0008] Therefore, an object of the present application is to provide a technology capable of manufacturing a three-dimensional object with higher shape accuracy.

[0009] Technical means to solve problems

[0010] A first aspect of a three-dimensional modeling device is a three-dimensional modeling device for manufacturing a three-dimensional modeled object, which comprises: a beam irradiation unit for irradiating a beam; a spatial light modulator for spatially modulating the beam irradiated by the beam irradiation unit at least along a first axis; a separation optical system comprising at least one lens array, the lens array having a plurality of lenses arranged along the first axis, the separation optical system separating the beam modulated by the spatial light modulator into a plurality of beams through the lens array; and a scanning unit for scanning the plurality of beams from the separation optical system on a modeling material.

[0011] A second aspect of the three-dimensional modeling device is the three-dimensional modeling device of the first aspect, wherein the separation optical system includes an afocal reduction optical system having a plurality of the lens arrays.

[0012] According to a third aspect of the three-dimensional modeling apparatus, in the three-dimensional modeling apparatus according to the first aspect, the separation optical system includes a single lens array.

[0013] The fourth aspect of the three-dimensional modeling device is that in the three-dimensional modeling device of any one of the first to third aspects, when the number of lenses of the lens array is N, wherein N is a natural number greater than 2, the three-dimensional modeling device further comprises: a projection optical system, which magnifies or reduces the light beam modulated by the spatial light modulator on the first axis, and causes the magnified or reduced light beam to be incident on the M lenses of the lens array, wherein M is variable; and a control device, which controls the magnification of the projection optical system, and the lens array separates the light beam irradiated on the M lenses into M light beams.

[0014] According to a fifth aspect of the three-dimensional modeling apparatus, in the three-dimensional modeling apparatus according to the fourth aspect, the control device receives information on the modeling material and sets M to be smaller as the melting point of the modeling material is higher based on the information.

[0015] A sixth aspect of the three-dimensional modeling apparatus is the three-dimensional modeling apparatus of the fourth aspect or the fifth aspect, wherein N is an odd number or an even number, and the control device limits M to the odd number or the even number.

[0016] The seventh aspect of the three-dimensional modeling device is that in the three-dimensional modeling device of the fourth aspect or the fifth aspect, the three-dimensional modeling device further has a moving mechanism, which moves the separation optical system relative to the projection optical system on the first axis, and the control device controls the moving mechanism to adjust the relative positional relationship between the projection optical system and the separation optical system in such a way that the light beam from the projection optical system is incident on the M lenses of the lens array.

[0017] The eighth aspect of the three-dimensional modeling device is that in the three-dimensional modeling device of any one of the fourth to seventh aspects, the projection optical system magnifies or reduces the light beam modulated by the spatial light modulator with a variable magnification on a second axis intersecting with the first axis.

[0018] According to a ninth aspect of the three-dimensional modeling apparatus, in the three-dimensional modeling apparatus according to any one of the fourth to eighth aspects, the light beam irradiation unit includes a light source that emits a light beam with variable intensity.

[0019] The tenth aspect of the three-dimensional modeling device is a three-dimensional modeling device in any one of the fourth to ninth aspects, wherein M includes M1 and M2 which is smaller than M1, and in the scanning path of the M1 light beams performed by the scanning unit, when at least one of the M1 light beams arranged along the first axis is located on an unnecessary line that does not need to be scanned, the control device changes the magnification of the projection optical system, and the projection optical system causes the light beam to be incident on M2 lenses, so that the lens array emits M2 light beams, and the scanning of the unnecessary line is omitted by scanning the M2 light beams performed by the scanning unit.

[0020] An eleventh aspect of the three-dimensional modeling apparatus is the three-dimensional modeling apparatus according to the tenth aspect, wherein the scanning unit scans the M2 light beams at a scanning speed higher than a scanning speed of the M1 light beams.

[0021] The twelfth aspect of the three-dimensional modeling device is the three-dimensional modeling device of the tenth or eleventh aspect, wherein the control device changes the magnification of the projection optical system while interrupting the irradiation of the light beam by the light beam irradiation unit and the scanning by the scanning unit.

[0022] A thirteenth aspect of the three-dimensional modeling device is a three-dimensional modeling device according to any one of the first to twelfth aspects, wherein the lens array of the separation optical system is arranged at a focal point of an optical system immediately preceding the separation optical system.

[0023] The fourteenth aspect of the three-dimensional modeling device is a three-dimensional modeling device according to any one of the first to thirteenth aspects, wherein the three-dimensional modeling device further comprises an aperture portion having a plurality of openings through which the plurality of light beams separated by the lens array pass.

[0024] The fifteenth aspect of the three-dimensional modeling device is a three-dimensional modeling device of any one of the first aspect to the fourteenth aspect, wherein the spatial light modulator includes at least a plurality of groups arranged along the first axis, each of the plurality of groups includes a plurality of spatial modulation elements, and the intensity distribution of the plurality of light beams is respectively controlled by the plurality of groups.

[0025] A sixteenth aspect of the three-dimensional modeling apparatus is the three-dimensional modeling apparatus according to any one of the first to fourteenth aspects, wherein the spatial light modulator has a plurality of spatial modulation elements arranged two-dimensionally.

[0026] The seventeenth aspect of the three-dimensional modeling device is that in the three-dimensional modeling device of the fifteenth aspect, the spatial light modulator modulates the light beam from the light beam irradiation portion in such a manner that the intensity of the light beam incident on the boundaries of the multiple lenses of the lens array of the separation optical system is smaller than the intensity of the light beam incident on the center of each of the multiple lenses.

[0027] In the eighteenth aspect of the three-dimensional modeling device, in the three-dimensional modeling device of any one of the first aspect to the seventeenth aspect, the three-dimensional modeling device also has an imaging rotator, which causes the multiple light beams from the separation optical system to rotate integrally at a variable rotation angle around a rotation axis parallel to the optical axis, the scanning unit includes a galvanometer mirror, and the imaging rotator is arranged at the subsequent stage of the galvanometer mirror.

[0028] In the nineteenth aspect of the three-dimensional modeling device, in the three-dimensional modeling device of any one of the first aspect to the seventeenth aspect, the three-dimensional modeling device also has an imaging rotator, which causes the multiple light beams from the separation optical system to rotate integrally with a variable rotation angle around a rotation axis parallel to the optical axis, the scanning unit includes a galvanometer mirror, and the imaging rotator is arranged in the upstream stage of the galvanometer mirror.

[0029] The twentieth aspect of the three-dimensional modeling device is a three-dimensional modeling device of any one of the first aspect to the nineteenth aspect, wherein the arrangement direction of the multiple light beams on the modeling material is obliquely intersected with the scanning direction of the multiple light beams performed by the scanning unit, and the multiple light beams are respectively located on multiple continuous rows of scanning lines.

[0030] Effects of the Invention

[0031] According to the first aspect of the three-dimensional modeling apparatus, multiple light beam spots are formed on the modeling material. Because these spots are separated from one another, the range within which the molten modeling material can flow is very narrow. This reduces localized swelling of the molten modeling material. In other words, a three-dimensional object can be produced with high shape accuracy.

[0032] According to the second aspect of the three-dimensional modeling apparatus, the strength of the peripheral region of each point on the modeling material can be increased relative to the central region. If the strength were high only in the central region of the point, this could cause splashing of the modeling material or smoke. However, since the strength of the peripheral region of the point can be increased, the intensity distribution of the point can be made uniform, thereby reducing the possibility of splashing of the modeling material or smoke.

[0033] According to the third aspect of the three-dimensional modeling apparatus, the separation optical system can be constructed with a simple structure.

[0034] According to the fourth aspect of the three-dimensional modeling apparatus, M corresponds to the number of light beams. According to the fourth aspect, the number M of light beams separated by the array lens can be adjusted.

[0035] According to the fifth aspect of the 3D modeling apparatus, the power at each point can be increased by reducing the number of beams M. This allows for modeling materials with high melting points. On the other hand, for materials with low melting points, increasing the number of beams M can expand the area that can be melted in a single scan. This improves processing capacity.

[0036] According to the sixth aspect of the three-dimensional modeling apparatus, the projection optical system can be configured with a simple structure. Specifically, the moving mechanism of the seventh aspect is unnecessary.

[0037] According to the seventh aspect of the three-dimensional modeling apparatus, the number of beams M can be either an even number or an odd number.

[0038] According to the eighth aspect of the three-dimensional modeling apparatus, the width of the dot can be adjusted on the second axis, thereby enabling finer adjustment of the power (area-integrated value of intensity) of the dot.

[0039] According to the ninth aspect of the three-dimensional modeling apparatus, the power of a point can be finely adjusted.

[0040] According to the tenth aspect of the three-dimensional modeling apparatus, scanning of unnecessary lines is omitted by changing the number of beams M. This reduces the amount of light not used for three-dimensional modeling, thereby improving efficiency.

[0041] According to the eleventh aspect of the three-dimensional modeling apparatus, when scanning with M2 beams, the area integral of the intensity of each beam (each point) increases compared to scanning with M1 beams. If the scanning speed is constant, the time integral of the amount of heat imparted from each point to each location on the modeling material increases. However, in the tenth aspect, the scanning speed is high for M2 scans. This reduces the variation in heat between rows that occurs as the number of beams M decreases. Furthermore, the high scanning speed improves processing capacity.

[0042] According to the twelfth aspect of the three-dimensional modeling device, when the magnification is changed while irradiating the light beam, unexpected light is irradiated onto the modeling material, but since the magnification is changed while the irradiation of the light beam is stopped, such unexpected light can be avoided from being irradiated onto the modeling material.

[0043] According to the thirteenth aspect of the three-dimensional modeling apparatus, crosstalk of light beams can be reduced.

[0044] According to the fourteenth aspect of the three-dimensional modeling apparatus, light that has passed through the boundaries of the lenses in the lens array may travel in an unintended direction, but such unnecessary light can be shielded by the aperture portion.

[0045] According to the fifteenth aspect of the three-dimensional modeling apparatus, the spatial intensity distribution of the light beam can be adjusted more finely.

[0046] According to the sixteenth aspect of the three-dimensional modeling apparatus, the power density of the light beam can be increased.

[0047] According to the seventeenth aspect of the three-dimensional modeling apparatus, the intensity of the light beam passing through the boundary between the lenses in the lens array can be reduced. This can reduce the light beam that passes through the boundary between the lenses and travels in an unintended direction.

[0048] According to the eighteenth aspect of the three-dimensional modeling apparatus, the arrangement direction and the scanning direction of the plurality of points on the modeling material can be changed.

[0049] According to the nineteenth aspect of the three-dimensional modeling apparatus, the arrangement direction of the plurality of dots on the modeling material can be changed. Meanwhile, the scanning direction does not rotate due to the rotation of the imaging rotator. Thus, the intervals between the plurality of scanning lines corresponding to the plurality of dots can be adjusted.

[0050] According to the twentieth aspect of the three-dimensional modeling apparatus, a plurality of continuous scan lines can be scanned by moving the plurality of points in the scanning direction at once while separating the plurality of points from each other.

[0051] In addition, the objects, features, aspects, and advantages associated with the technology disclosed in this specification will become more apparent from the detailed description and accompanying drawings shown below. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a diagram schematically showing an example of the structure of a three-dimensional modeling device.

[0053] Figure 2 It is a perspective view schematically showing an example of the structure of a spatial light modulator.

[0054] Figure 3 This is a plan view schematically showing an example of the surface state of the modeling material layer.

[0055] Figure 4 This is a diagram schematically showing an example of an optical path in a three-dimensional modeling device.

[0056] Figure 5 This is a flowchart showing an example of processing of the control device.

[0057] Figure 6 It is a diagram schematically showing an example of the intensity distribution of the modulated light beam.

[0058] Figure 7 This is a diagram schematically showing another example of the structure of the separation optical system.

[0059] Figure 8 This is a diagram schematically showing an example of the structure of a light beam irradiation device.

[0060] Figure 9 This is a diagram schematically showing an example of the structure of a light beam irradiation device.

[0061] Figure 10 This is a diagram schematically showing an example of the structure of a light beam irradiation device.

[0062] Figure 11 It is a perspective view schematically showing an example of the structure of a projection optical system.

[0063] Figure 12 This is a functional block diagram showing another example of the internal structure of the control device.

[0064] Figure 13 This is a flowchart showing another example of the processing of the control device.

[0065] Figure 14 It is a graph showing an example of the intensity distribution of the modulated light beam.

[0066] Figure 15 It is a perspective view schematically showing another example of the structure of the projection optical system.

[0067] Figure 16 It is a perspective view schematically showing an example of the configuration of a zoom optical system along the c-axis of a projection optical system.

[0068] Figure 17 It is a graph schematically showing an example of the intensity distribution of the modulated light beam.

[0069] Figure 18 This is a diagram schematically showing an example of an optical path when the number of light beams is 2.

[0070] Figure 19 This is a diagram schematically showing another example of the structure of the light beam irradiation device.

[0071] Figure 20 This is a functional block diagram showing another example of the internal structure of the control device.

[0072] Figure 21 This is a flowchart showing another example of the processing of the control device.

[0073] Figure 22 This is a diagram schematically showing an example of a dot scanning method.

[0074] Figure 23 This is a flowchart showing an example of processing of the control device.

[0075] Figure 24 This is a diagram schematically showing an example of the structure of a light beam irradiation device.

[0076] Figure 25 This is a functional block diagram showing another example of the internal structure of the control device.

[0077] Figure 26 1 is a diagram schematically showing an example of a point when the rotation angle of the imaging rotator is zero degrees.

[0078] Figure 27 This is a diagram schematically showing an example of a point when the rotation angle of the imaging rotator is 45 degrees.

[0079] Figure 28 This is a diagram schematically showing an example of a point when the rotation angle of the imaging rotator is 90 degrees.

[0080] Figure 29 This is a diagram schematically showing another example of the structure of the light beam irradiation device.

[0081] Figure 30 This is a diagram schematically showing an example of a point when the rotation angle of the imaging rotator is 45 degrees.

[0082] Figure 31 is a diagram schematically showing another example of the structure of a spatial light modulator. DETAILED DESCRIPTION

[0083] The following describes the embodiments with reference to the accompanying drawings. In addition, the components described in this embodiment are merely examples and are not intended to limit the scope of the present disclosure to these examples. In the accompanying drawings, the size and number of each part may be exaggerated or simplified as needed for ease of understanding.

[0084] In the following description, even if ordinal numbers such as "first" or "second" are used, these terms are not intended to limit the order or the like caused by these ordinal numbers, but are used only to facilitate understanding of the contents of the embodiments.

[0085] Unless otherwise specified, terms indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) not only strictly indicate such positional relationships but also indicate a state of displacement relative to an angle or distance within a tolerance or substantially equivalent functionality. Unless otherwise specified, terms indicating equality (e.g., "same," "equal," "homogeneous," etc.) not only indicate a state of strict quantitative equality but also indicate a state of difference sufficient to achieve a tolerance or substantially equivalent functionality. Unless otherwise specified, terms indicating shape (e.g., "quadrilateral" or "cylindrical") not only strictly indicate such shapes but also indicate shapes having concave and convex corners or chamfers, for example, within a range that achieves substantially equivalent effects. The terms "including," "having," "having," or "having" one component are not exclusive terms that exclude the presence of other components. The term "at least one of A, B, and C" includes only A, only B, only C, any two of A, B, and C, and all of A, B, and C.

[0086] <First embodiment>

[0087] In the following description, “heating and melting the molding material” includes not only a case where the temperature of the entire heated molding material reaches a melting point or higher, but also a case where a portion of the heated molding material is sintered at a temperature lower than the melting point.

[0088] In the following description, the term "layer" refers to the portion formed by a single step, when a three-dimensional object is formed by repeatedly irradiating a deposited modeling material with a light beam to melt it, thereby accumulating a solidified product in the thickness direction. While the boundaries between layers can sometimes be confirmed by observing a cross-section of the three-dimensional object, such as when the melting is highly uniform, these boundaries may not be clearly detected.

[0089] <About the Structure of the Three-Dimensional Modeling Device>

[0090] Reference Figure 1 , an example of the three-dimensional modeling device 100 is described. Figure 1 This figure schematically illustrates an example of the structure of the three-dimensional modeling apparatus 100. In this embodiment, for convenience, the X-axis, Y-axis, and Z-axis are sometimes described as being orthogonal to each other. Here, the X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction. Furthermore, in this embodiment, the axes of the optical system are sometimes described as being orthogonal to each other: the a-axis, the b-axis, and the c-axis. The a-axis is the optical axis.

[0091] The three-dimensional modeling apparatus 100 repeatedly irradiates a modeling material with a light beam (modulated light beam L33) to melt the modeling material, thereby accumulating a solidified material in the thickness direction to produce a three-dimensional modeled object. The three-dimensional modeling apparatus 100 is also called a three-dimensional layered modeling apparatus.

[0092] Reference Figure 1 The three-dimensional modeling apparatus 100 includes a light beam irradiation device 40 and a control device 20. The light beam irradiation device 40 irradiates the modeling material with a modulated light beam L33. The control device 20 controls the light beam irradiation device 40.

[0093] The control device 20 controls the controlled object by executing programs stored in internal or external storage media (including the storage unit 30 described below). It includes a processing device such as a CPU (Central Processing Unit), a microprocessor, or a microcomputer. Furthermore, some or all of the functions of the control device 20 may be implemented using hardware circuits such as logic circuits that do not require software. The control device 20 is also referred to as a control circuit.

[0094] The three-dimensional modeling apparatus 100 further includes a supply mechanism 16 and a storage unit 30. The storage unit 30 includes volatile or nonvolatile memories such as RAM (Random Access Memory), ROM (Read Only Memory), and flash memory, and storage units such as HDD (Hard Disk Drive).

[0095] The three-dimensional modeling apparatus 100 creates a three-dimensional modeled object in a modeling space SP. Here, the modeling space SP is a three-dimensional space.

[0096] Three-dimensional objects are manufactured into the desired shape using a specified molding material. The molding material is in powder or paste form and can be, for example, metal powder, engineering plastic, ceramic, or synthetic resin. Metal powders can be made of, for example, titanium, aluminum, or stainless steel. Furthermore, the molding material used in three-dimensional modeling can contain multiple materials.

[0097] The modeling material is supplied to a predetermined unit space, for example, by a supply mechanism 16. The modulated light beam L33 is then irradiated onto the modeling material. The temperature of the portion of the modeling material irradiated by the modulated light beam L33 rises, melting the surface or the entirety of that portion of the modeling material. By scanning the modulated light beam L33 across the modeling material, the modeling material is unified into the desired shape.

[0098] The shape of the three-dimensional object is not particularly limited. Furthermore, three-dimensional modeling data representing the desired shape of the three-dimensional object is stored in the storage unit 30 by, for example, the manufacturer. Examples of the three-dimensional modeling data include CAD (Computer Aided Design) data and STL (Stereolithography) data.

[0099] Next, a specific example of the light beam irradiation device 40 for irradiating the modulated light beam L33 onto the molding material will be described in detail. Figure 1 In the example shown in FIG. 4 , the light beam irradiation device 40 includes a light beam irradiation section 10 , a spatial light modulator 14 , a projection optical system 15 , a separation optical system 18 , and a scanning section 19 .

[0100] The beam irradiation unit 10 includes a laser light source 11 and an illumination optical system 12. The laser light source 11 emits laser light L30 toward the illumination optical system 12. The laser light source 11 is, for example, a fiber laser light source. The wavelength of the laser light L30 is, for example, 1064 nm. The cross-sectional shape of the laser light L30, as measured perpendicular to the direction of travel of the laser light L30, is, for example, approximately circular. Furthermore, the cross-sectional dimensions of the laser light L30, as measured perpendicular to the direction of travel of the laser light L30, increase as the laser light L30 travels in the direction of travel.

[0101] The illumination optical system 12 shapes the laser light L30 into a parallel beam (hereinafter also referred to as the parallel beam L31) and guides the parallel beam L31 to the spatial light modulator 14. Ideally, the cross-sectional dimensions of the parallel beam L31 on a plane perpendicular to the direction of travel of the parallel beam L31 are constant even as it travels in the direction of travel. In addition, the parallel beam L31 has a roughly uniform intensity on this perpendicular plane. The parallel beam L31 has, for example, a rectangular shape that is long in one direction (a direction perpendicular to the paper) on this perpendicular plane. Such a parallel beam L31 can also be called a line beam.

[0102] The spatial light modulator 14 modulates the parallel light beam L31 and guides the modulated light beam L32 to the projection optical system 15. The spatial light modulator 14 is, for example, a Linear-PLV (Planar Light Valve), a GLV (Grating Light Valve), or a DMD (Digital Micromirror Device).

[0103] Figure 2 1 is a diagram schematically showing an example of the structure of the spatial light modulator 14. Figure 2In the example, spatial light modulator 14 is a GLV, with substrate 14A and strip-shaped microbridges 14B and 14C arranged in parallel on substrate 14A, alternating in one or more groups. These serve as a pixel of a diffraction grating-type spatial modulator. Microbridge 14B is also called a movable strip, and microbridge 14C is also called a fixed strip. The direction in which microbridges 14B and 14C are arranged is the same as the length direction of parallel light beam L31.

[0104] The part of the microbridge 14B except the end is away from the substrate 14A, and the lower surface opposite to the substrate 14A is composed of a flexible component made of silicon nitride (SiNx) or the like, and the upper surface on the opposite side of the lower surface is composed of a reflective electrode film composed of a single-layer metal film such as aluminum.

[0105] The spatial light modulator 14 is driven and controlled by turning on / off the voltage applied between the microbridge 14B and the substrate 14A. When the voltage applied between the microbridge 14B and the substrate 14A is turned on, an electrostatic attraction force is generated between the microbridge 14B and the substrate 14A by the charge induced by electrostatic induction, and the microbridge 14B bends toward the substrate 14A side. No charge is applied to the microbridge 14C, and the microbridge 14C maintains its original state (shape), so the microbridges 14B and 14C form a diffraction grating. The light irradiated to one pixel of the spatial light modulator 14 is reflected or diffracted, and the propagation direction of the light changes. When the deflection of the microbridge 14B is one-quarter of the wavelength of the light, the intensity of the regular reflection light or the 0th order diffraction light is zero, and the intensity of the 1st order diffraction light is the maximum. On the other hand, if the voltage applied between microbridge 14B and substrate 14A is removed, the aforementioned deflection is eliminated, and microbridge 14B moves away from substrate 14A, reaching the same height as microbridge 14C. This allows spatial light modulator 14 to function as a regular mirror, maximizing the intensity of regular reflected light or zeroth-order diffracted light. Thus, by switching the voltage applied to microbridge 14B between on and off, the spatial light modulator functions as an optical modulator that switches the intensity of regular reflected light or first-order diffracted light on and off.

[0106] Typically, the pixels of a GLV element are composed of, for example, three groups of microbridges 14B and 14C, and the spatial light modulator 14 includes, for example, 1,000 pixels. These 1,000 pixels are arranged along the length of the parallel light beam L31. That is, 1,000 groups consisting of three groups of microbridges 14B and 14C are arranged along the length of the parallel light beam L31. Furthermore, the spatial light modulator 14 is structured such that the 1,000 pixels are divided into five groups of, for example, 200 pixels each, and the parallel light beam L31 is modulated as five groups, emitting a modulated light beam L32. Since each group has 200 pixels, the shape of the light intensity distribution can be freely modified.

[0107] The projection optical system 15 blocks unnecessary light of the modulated light beam L32 from the spatial light modulator 14. For example, the projection optical system 15 blocks high-order diffracted light included in the modulated light beam L32 and allows the zero-order diffracted light to pass therethrough.

[0108] The separation optical system 18 separates the modulated light beam L32 that has passed through the projection optical system 15 into a plurality of modulated light beams L33 (see also Figure 4 For example, the separation optical system 18 separates the modulated light beam L32 for each group of pixels of the spatial light modulator 14. Here, since the spatial light modulator 14 includes five groups of 200 pixels, the separation optical system 18 separates the modulated light beam L32 into five modulated light beams L33. The five modulated light beams L33 are arranged at intervals on a plane perpendicular to the direction of travel. Each modulated light beam L33 has, for example, a rectangular shape on this plane.

[0109] The scanning unit 19 irradiates the modeling material layer 120 with a plurality of modulated light beams L33 . Figure 3 1 is a top view schematically showing an example of the surface of the modeling material layer 120. Figure 3 In the example, a plurality of modulated light beams L33 are irradiated on the surface of the modeling material layer 120. As a result, a plurality of points S3 are formed on the surface of the modeling material layer 120. Point S3 represents the area on the surface of the modeling material layer 120 irradiated by the modulated light beam L33. On the surface of the modeling material layer 120, a plurality of points S3 are arranged at intervals. Hereinafter, the direction in which the points S3 are arranged on the modeling material layer 120 is also referred to as the arrangement direction D2. Figure 3 In the example, the arrangement direction D2 is parallel to the X-axis.

[0110] The scanning unit 19 scans (moves) the plurality of points S3 along a scanning direction D1 (here, the Y axis) that intersects the arrangement direction D2. Figure 1 In the example shown, the scanning unit 19 includes a galvanometer mirror 192. The scanning unit 19 moves multiple points S3 on the modeling material layer 120 in an integrated manner by rotating the galvanometer mirror 192. The scanning method for these points S3 is arbitrary, but raster scanning can be used, for example. This scanning causes the modeling material layer 120 to melt and sinter according to the intensity distribution within the points S3, and is then integrated into the desired shape.

[0111] Next, the supply mechanism 16 for supplying the molding material will be described. Figure 1 As shown in the example, the supply mechanism 16 includes a part cylinder 16A, a feed cylinder 16B, and a scraper 16D. The supply mechanism 16 sequentially stacks modeling material layers 120 within a predetermined unit space. The modeling material layers 120 are made of modeling material.

[0112] The feed cylinder 16B has a lower surface 16Ba inside the feed cylinder 16B. The lower surface 16Ba is movable in the Z-axis direction inside the feed cylinder 16B. The molding material is accommodated above the lower surface 16Ba inside the feed cylinder 16B.

[0113] Meanwhile, the component cylinder 16A has a lower surface 16Aa inside the component cylinder 16A. The lower surface 16Aa is movable in the Z-axis direction inside the component cylinder 16A. A molding space SP is defined above the lower surface 16Aa inside the component cylinder 16A.

[0114] Modeling material is supplied from feed cylinder 16B into component cylinder 16A. Specifically, lower surface 16Aa of component cylinder 16A is lowered a predetermined distance. Meanwhile, lower surface 16Ba of feed cylinder 16B is raised a predetermined distance. Then, scraper 16D is moved from feed cylinder 16B into component cylinder 16A. As a result, a predetermined amount of modeling material is transferred from feed cylinder 16B into component cylinder 16A.

[0115] Next, an example of the control device 20 will be described. The control device 20 controls the light beam irradiation device 40 and the supply mechanism 16. As a specific example, the control device 20 includes a laser control unit 20A, a modulation control unit 20B, a scanning control unit 20C, a data acquisition unit 20D, and an exposure data generation unit 20E.

[0116] The data acquisition unit 20D receives three-dimensional modeling data from, for example, an external device or a storage medium, and stores the three-dimensional modeling data in the storage unit 30 .

[0117] The exposure data generation unit 20E generates exposure data based on the three-dimensional modeling data acquired by the data acquisition unit 20D, and stores the exposure data in the storage unit 30. The exposure data is data representing the state of each spatial modulation element (microbridge 14B) of the spatial light modulator 14, for example, data representing each voltage applied between each microbridge 14B and the substrate 14A. The exposure data can also be said to be data representing the modulation pattern of the spatial light modulator 14. In order to be able to produce a three-dimensional modeled object indicated by the three-dimensional modeling data, the exposure data generation unit 20E determines the intensity of the modulated light beam L33 at each position of each modeling material layer 120, determines the modulation pattern of the spatial light modulator 14 used to irradiate the modulated light beam L33 with this intensity, and generates exposure data representing this modulation pattern.

[0118] The laser control unit 20A controls the laser light source 11 to cause the laser light source 11 to emit the laser light L30 .

[0119] The modulation control unit 20B controls the spatial light modulator 14 based on the exposure data generated by the exposure data generation unit 20E. As a result, the intensity distribution of the light of the modulated light beam L32 becomes an intensity distribution reflecting the shape indicated by the three-dimensional modeling data.

[0120] The scanning control unit 20C controls the scanning unit 19 and the supply mechanism 16. The scanning control unit 20C controls the scanning unit 19 and the supply mechanism 16 to sequentially guide the modulated light beam L33 to predetermined unit spaces. Specifically, the scanning control unit 20C rotates the galvanometer mirror 192 to scan the modulated light beam L33 across the modeling material layer 120.

[0121] Furthermore, the scanning control unit 20C moves the part cylinder 16A, the feed cylinder 16B, and the scraper 16D to sequentially form the modeling material layer 120 in a predetermined unit space.

[0122] <About Light Path>

[0123] Next, refer to Figure 4 , an example of the optical path in the three-dimensional modeling device 100 is described. Figure 4 This diagram schematically illustrates an example of the optical path in the three-dimensional modeling apparatus 100. The following description introduces an orthogonal coordinate system for the optical system. This orthogonal coordinate system consists of mutually orthogonal a-axis, b-axis, and c-axis. The a-axis corresponds to the optical axis. The b-axis extends along the longitudinal direction of the parallel light beam L31, and the c-axis extends along the width direction of the parallel light beam L31.

[0124] like Figure 4 As shown, the illumination optical system 12 converts the laser light L30 emitted from the laser light source 11 into a parallel beam L31 and guides the parallel beam L31 to the spatial light modulator 14. Figure 1 The illumination optical system 12 may include collimating lenses 121 and 122. Collimating lenses 121 and 122 are, for example, cylindrical lenses or Powell lenses. Collimating lens 121 converts laser light L30 into parallel light when viewed along the c-axis, while collimating lens 122 converts laser light L30 into parallel light when viewed along the b-axis. Furthermore, the illumination optical system 12 may consist of a single collimating lens, or other optical elements may be added to the illumination optical system 12.

[0125] The spatial light modulator 14 modulates the parallel light beam L31 from the illumination optical system 12 to adjust the light intensity distribution along the b-axis. The spatial light modulator 14 includes multiple (here, five) modulator groups 141. Each modulator group 141 corresponds to a group. The spatial light modulator 14 modulates the parallel light beam L31 on a group-by-group basis. Therefore, the modulated light beam L32 is composed of a series of partially modulated light beams L321 modulated by each group (modulator group 141) along the b-axis.

[0126] In addition, Figure 4 In the example of FIG, the projection image of the modulated light beam L32 from the spatial light modulator 14 is schematically shown. Figure 4 For convenience, the optical path before and after the spatial light modulator 14 is a straight line, but when the spatial light modulator 14 is a reflective modulator, the optical paths before and after the spatial light modulator 14 are in opposite directions (see also Figure 1 ).

[0127] The projection optical system 15 blocks unnecessary light from the modulated light beam L32 of the spatial light modulator 14. For example, the projection optical system 15 includes a lens 15A, an aperture portion 15B, and a lens 15C. Lens 15A is, for example, a Fourier transform lens, which focuses the 0th-order diffracted light in the modulated light beam L32 from the spatial light modulator 14 on the opening 15b of the aperture portion 15B. The aperture portion 15B is set at the focal position of lens 15A and only allows the 0th-order diffracted light contained in the modulated light beam L32 to pass through. In other words, the higher-order diffracted light (for example, the 1st-order diffracted light) contained in the modulated light beam L32 is focused on the portion of the aperture portion 15B other than the opening 15b and is blocked. Lens 15C is, for example, an inverse Fourier transform lens, which converts the modulated light beam L32 (0th-order diffracted light) that has passed through the aperture portion 15B into parallel light. In addition, other optical elements may be added to the projection optical system 15.

[0128] The separation optical system 18 separates the modulated light beam L32 from the projection optical system 15 into a plurality of modulated light beams L33. Figure 4 In the example of FIG, the separation optical system 18 is an afocal reduction optical system including lens arrays 18A and 18B. The lens array 18A includes a plurality of ( Figure 1 The number of lenses 18a arranged along the b-axis is the same as the number of groups (modulation element groups 141) of the spatial light modulator 14. The multiple lenses 18a can be arranged continuously. In other words, the multiple lenses 18a can be arranged along the b-axis without any gaps between them, forming a single unit.

[0129] The lens array 18B also includes a plurality of (here, five) lenses 18b arranged along the b-axis. The number of lenses 18b arranged along the b-axis is the same as the number of groups (modulation element groups 141) of the spatial light modulator 14. The plurality of lenses 18b may also be arranged continuously. The lens array 18B is arranged at positions where the plurality of lenses 18b are opposite to the plurality of lenses 18a of the lens array 18A in the direction of the optical axis (a-axis). In addition, other optical elements may be added to the separation optical system 18.

[0130] The modulated light beam L32 from the projection optical system 15 is incident on the five lenses 18a of the lens array 18A. Specifically, the modulated light beam L32 is incident on all five lenses 18a. Ideally, the width of the modulated light beam L32 incident on the lens array 18A is equal to the width of the five lenses 18a as a whole. If the width of the modulated light beam L32 from the spatial light modulator 14 does not match the width of the lenses 18a as a whole, the projection optical system 15 can simply enlarge or reduce the width of the modulated light beam L32 so that the width of the modulated light beam L32 matches the width of the five lenses 18a as a whole. This enlargement and reduction can be achieved by appropriately selecting lenses 15A and 15C.

[0131] The modulated beam L32 consists of five partial modulated beams L321 arranged continuously along the b-axis. When the modulated beam L32 enters the lens array 18A, the five partial modulated beams L321 are incident on five lenses 18a, respectively. Each lens 18a focuses the corresponding partial modulated beam L321 at its focal position. This splits the modulated beam L32 into multiple (here, five) modulated beams L33. In other words, each modulated beam L33 is equivalent to a beam obtained by reducing the size of the partial modulated beam L321.

[0132] The separated multiple modulated light beams L33 are incident on the lens 18b of the lens array 18B respectively. Each lens 18b converts the incident modulated light beam L33 into parallel light. Since the focal length of the light source side of the lens array 18B is shorter than the focal length of the image side of the lens array 18A, the width (width along the b-axis) of each modulated light beam L33 emitted from the separation optical system 18 is narrower than the width of the partial modulated light beam L321. Figure 4 In the example of , the projection images of multiple modulated light beams L33 passing through the lens array 18B are schematically shown.

[0133] The lens array 18A can be positioned at the image-side focal position (synthetic focal position) of the optical system (projection optical system 15) immediately preceding the lens array 18A. In other words, the lens array 18A can be positioned at a location where the projection image of the projection optical system 15 is formed. This reduces crosstalk between adjacent partial modulated light beams L321 in the intensity distribution of the modulated light beam L32 at the location where the lens array 18A is positioned.

[0134] Reference Figure 1, multiple modulated light beams L33 from the separation optical system 18 are incident on the galvanometer mirror 192 via the lens 191, and are reflected by the reflection surface of the galvanometer mirror 192. The lens 191 can also be composed of multiple lenses. The multiple modulated light beams L33 reflected by the galvanometer mirror 192 are irradiated onto the surface of the molding material layer 120 via the lens 193. The lens 193 includes, for example, an fθ lens. The lens 193 can also be composed of multiple lenses. By irradiating the multiple modulated light beams L33 onto the molding material layer 120, multiple points S3 are formed on the surface of the molding material layer 120 (also refer to Figure 3 ). In addition, the lens 191, the galvanometer mirror 192 and the lens 193 belong to the scanning unit 19.

[0135] By rotating the galvanometer mirror 192 about a predetermined rotation axis, the plurality of points S3 are moved integrally along the scanning direction D1. Figure 1 In the example shown, only one galvanometer mirror 192 is schematically shown, but two galvanometer mirrors are actually provided. The rotation axes of the galvanometer mirrors 192 intersect with each other, more specifically, are orthogonal. Multiple points S3 can be moved in any scanning direction by independently controlling each galvanometer mirror 192. Here, as an example, by rotating only one of the galvanometer mirrors, multiple points S3 can be moved in the scanning direction D1, and by rotating only the other galvanometer mirror, multiple points S3 can be moved in an orthogonal direction (e.g., arrangement direction D2) that is orthogonal to the scanning direction D1.

[0136] <Regarding the Processing of the Control Device>

[0137] Next, refer to Figure 5 An example of the processing performed by the control device 20 will be described. Figure 5 This is a flowchart showing an example of the processing of the control device 20.

[0138] First, the data acquisition unit 20D receives three-dimensional modeling data from, for example, an external device or a storage medium and stores the three-dimensional modeling data in the storage unit 30 (step ST1 ). The exposure data generation unit 20E generates exposure data based on the three-dimensional modeling data.

[0139] Next, the laser control unit 20A controls the laser light source 11 (step ST2 ). Specifically, the laser control unit 20A emits laser light L30 from the laser light source 11 . The laser light L30 is converted into a parallel beam L31 in the illumination optical system 12 and enters the spatial light modulator 14 .

[0140] The modulation control unit 20B controls the spatial light modulator 14, and the scanning control unit 20C controls the scanning unit 19 (step ST3). Specifically, the modulation control unit 20B controls the spatial light modulator 14 based on the exposure data. Through this control, the spatial light modulator 14 modulates the parallel light beam L31 and emits the modulated light beam L32. The modulated light beam L32 has an intensity distribution that reflects the shape shown by the three-dimensional modeling data. The modulated light beam L32 is incident on the separation optical system 18 via the projection optical system 15. The separation optical system 18 separates the modulated light beam L32 into multiple modulated light beams L33. The scanning unit 19 guides the multiple modulated light beams L33 from the separation optical system 18 to the modeling material layer 120. The scanning control unit 20C controls the scanning unit 19 in parallel with the modulation control performed by the modulation control unit 20B, and moves the point S3 on the modeling material layer 120.

[0141] Here, an example of a scan path is described. Figure 3 In the example shown in FIG, the interval between dots S3 is substantially the same as the width of dot S3. That is, the five dots S3 are initially located at the beginning of the scan lines of the 1st, 3rd, 5th, 7th, and 9th rows, respectively. By moving the five dots S3 in the scanning direction D1, scanning of the scan lines of the 1st, 3rd, 5th, 7th, and 9th rows is completed.

[0142] Next, the scanning unit 19 moves the five dots S3 along the arrangement direction D2 by a distance approximately equal to the width of the dots S3. As a result, the five dots S3 are located on the scan lines of the 2nd, 4th, 6th, 8th, and 10th rows, respectively. Next, the scanning unit 19 scans the five dots S3 along the scanning direction D1. This completes the scanning of the scan lines of the 2nd, 4th, 6th, 8th, and 10th rows. With the above operation, the scanning of the scan lines from the 1st to the 10th rows is complete.

[0143] Next, the scanning unit 19 moves the five points S3 along the arrangement direction D2 so that the leading point S3 is located on the 11th scan line. This positions the five points S3 on the 11th, 13th, 15th, 17th, and 19th scan lines. Subsequently, by similarly moving the five points S3, the entire area of ​​the modeling material layer 120 can be scanned by the points S3. This causes the modeling material layer 120 to melt and sinter at locations corresponding to the three-dimensional modeling data, shaping it into the shape indicated by the three-dimensional modeling data.

[0144] When the three-dimensional modeling apparatus 100 finishes scanning the modeling material layer 120, it stacks the next modeling material layer 120 and performs scanning again. The three-dimensional modeling apparatus 100 manufactures a three-dimensional modeled object by performing this process multiple times.

[0145] As described above, the three-dimensional modeling apparatus 100 can produce a three-dimensional modeled object. Moreover, according to the three-dimensional modeling apparatus 100, a plurality of points S3 are separated from each other on the modeling material layer 120 (refer to Figure 3 ).

[0146] For comparison, consider the case where the five points S3 are continuous with each other. That is, consider the case where the modulated light beam is linearly irradiated onto the modeling material layer 120. Figure 3 In the example, line LS3 represents the linear modulated light beam on the modeling material layer 120. In this case, the modeling material can be melted throughout line LS3. Thus, for example, the modeling material melted at one end of line LS3 can flow to a position closer to the other end. In other words, the melted modeling material flows over a wider area. The more uneven the temperature distribution of the modeling material within line LS3, the larger the area over which the modeling material flows locally, resulting in a larger bulge in the modeling material in that area.

[0147] In contrast, the three-dimensional modeling apparatus 100 separates the points S3 from one another. Since the modeling material melts at each point S3, the range within which the modeling material can flow is narrowed. Consequently, bulging of the modeling material is reduced. Consequently, a three-dimensional object can be produced in a state closer to the desired shape. In other words, a three-dimensional object can be produced with high shape accuracy.

[0148] For further comparison, consider the case of creating a three-dimensional object from a single point S3. In this case, to improve processing capacity, consider increasing the intensity of the light at point S3 while also increasing the movement speed (also known as the scanning speed) of point S3. However, changing the intensity and movement speed at point S3 changes the physical processes of the modeling material (e.g., the degree of melting, evaporation, etc.). Because the intensity range and movement speed range suitable for creating a three-dimensional object are predetermined, the improvement in processing capacity for three-dimensional modeling from a single point S3 is limited.

[0149] In this embodiment, multiple dots S3 can be formed on the modeling material layer 120. This allows multiple rows of areas to be scanned in a single pass, thereby improving processing capacity. In other words, even with a strength and scanning speed appropriate for the modeling material, increasing the number of dots S3 can improve processing capacity.

[0150] Furthermore, in this embodiment, a single laser light source 11 is used, and the separation optical system 18 separates the modulated light beam L32 into a plurality of modulated light beams L33. Therefore, compared to a case where multiple modulated light beams are generated from a plurality of laser light sources 11, the device size and manufacturing cost of the light beam irradiation device 40 can be reduced.

[0151] <Separation Optical System>

[0152] exist Figure 4 In the example shown in FIG. 4 , the separation optical system 18 includes lens arrays 18A and 18B. Figure 6 1 is a diagram schematically showing an example of the intensity distribution of the modulated light beam L32 incident on the separation optical system 18 and the plurality of modulated light beams L33 emitted from the separation optical system 18. Figure 6 In the example of , a separation optical system 18 is also shown. Figure 6 In the example of , the intensity distribution of the modulated light beam L32 incident on the separation optical system 18 has a rectangular shape. That is, the intensity of the modulated light beam L32 is substantially constant regardless of the position on the b-axis.

[0153] On the other hand, the intensity distribution of each modulated light beam L33 emitted from the separation optical system 18 has a concave shape, with the intensity at the center being lower than the intensity at the sides. In other words, the intensity of each modulated light beam L33 is higher at the sides than in the center. This is due to diffraction occurring near the boundaries between lenses 18a of lens array 18A and near the boundaries between lenses 18b of lens array 18B.

[0154] As described above, the separation optical system 18 including the lens arrays 18A and 18B can emit modulated light beams L33 with high intensities on both sides, even if the intensity of the modulated light beam L32 is constant. As a result, even at point S3 on the modeling material layer 120, the intensity is higher in the side regions than in the center region.

[0155] For comparison, consider a case where the intensity distribution of each modulated light beam L33 has a convex shape, with a peak at its center. A Gaussian beam can be used as an example of a light beam with such a convex intensity distribution. The intensity of each modulated light beam L33 peaks at its center and decreases as it moves away from the center. The intensity distribution at point S3 on the modeling material layer 120 is similar.

[0156] In order to provide sufficient heat to the entire area within point S3, the area integral value of the intensity within point S3 needs to be increased. For example, when the scanning speed of point S3 is increased, in order to provide sufficient heat to each position on the molding material layer 120, the area integral value of the intensity at point S3 needs to be increased. In a Gaussian beam, the intensity has a peak in the central region, so when the area integral value is increased, point S3 exhibits an extreme intensity distribution in which the intensity at the center is much higher than the intensity at the periphery. In such a point S3, since heat is concentrated in a tiny area at the center, this tiny area instantly becomes hotter than the peripheral area. As a result, there are problems such as the molding material melted in the center being splashed to the periphery, or the generation of smoke and dust from the condensed molding material after evaporation.

[0157] In contrast, in the above example, because the separation optical system 18 includes lens arrays 18A and 18B, the intensity distribution of each modulated light beam L33 is higher in the areas on either side than in the center. This creates two peaks, eliminating the need to increase the peak value, as is required for a Gaussian beam, in order to increase the area-integrated value of the intensity within the modulated light beam L33 (point S3). This reduces the likelihood of spattering and fume generation.

[0158] Furthermore, since the heat generated near the two peaks in point S3 also moves toward the center of point S3, the temperature distribution of the molding material in point S3 can be made more uniform, and the heat can be effectively utilized.

[0159] <Separation of points>

[0160] Next, refer to Figure 6 , the positions of the two ends of point S3 are described. The two ends of point S3 are defined by the positions where the intensity of the light in point S3 becomes a predetermined ratio of its peak value p. Specifically, the two ends of point S3 are defined by the positions where the intensity is p / e2. e is Napier's constant. That is, Figure 6 In the example shown, the positions where the intensity is p / e2 are both ends of point S3 on the b-axis. Point S3 separation means that the ends of adjacent points S3 are separated from each other.

[0161] <Modulation Component Group>

[0162] In the above example, the group of spatial light modulators 14 (modulation element group 141) is composed of multiple spatial modulation elements (microbridges 14B and microbridges 14C). As a result, each group (modulation element group 141) can finely adjust the intensity distribution of the partially modulated light beam L321. For example, the spatial light modulator 14 can control each partially modulated light beam L321 in such a way that the intensity distribution of each modulated light beam L32 has multiple (for example, three or more) peaks. Therefore, in order to increase the area integral value of the intensity within point S3, it is not necessary to increase the peak value as in the case of a Gaussian beam, and the temperature distribution of the molding material within point S3 can also be made more uniform.

[0163] In addition, as mentioned above, Figure 6In the example, by passing the modulated light beam L32 (a plurality of partially modulated light beams L321) having uniform intensity on the b-axis through the lens arrays 18A and 18B, the intensity in the central region of each of the plurality of modulated light beams L33 is smaller than that in the regions on both sides. Therefore, each modulation element group 141 of the spatial light modulator 14 can also adjust the intensity distribution of the partially modulated light beam L321 in such a manner that the intensity in the regions on both sides of each partially modulated light beam L321 is lower than that in the central region. Thus, by passing the modulated light beam L32 through the lens arrays 18A and 18B, the intensity distribution of each modulated light beam L33 can be made close to a top hat shape (i.e., roughly rectangular). In other words, the spatial light modulator 14 can control each partially modulated light beam L321 in such a manner that the intensity distribution of each modulated light beam L32 has a roughly rectangular shape. Thus, the temperature distribution of the molding material within point S3 can be made more uniform.

[0164] If GLV or PLV is used as the spatial light modulator 14, each spatial modulator element can adjust its intensity in multiple stages, allowing for more precise adjustment of the intensity distribution of the modulated light beam L33. Furthermore, even when the spatial modulator element adjusts its intensity in a binary (ON / OFF) manner, the intensity distribution of the light can be finely adjusted by increasing the number of spatial modulator elements comprising the modulator element group 141. Furthermore, by temporally modulating the ON / OFF switching of the spatial modulator elements, the temporal average intensity value can be adjusted in multiple stages. This type of modulation is similar to pulse width modulation. Thus, it is also possible to simulate multi-stage intensity adjustment.

[0165] Furthermore, for example, when there is no problem with the temperature distribution of the molding material in the point S3 , each group of the spatial light modulator 14 (modulation element group 141 ) may be composed of a single pixel.

[0166] <Other Examples of Separation Optical Systems>

[0167] Figure 7 1 is a diagram schematically showing another example of the structure of the separation optical system 18. Figure 7 In the example of , the separation optical system 18 includes a single lens array 18C. The lens array 18C includes a plurality of (here, 5) lenses 18c arranged along the b-axis. The number of lenses 18c arranged along the b-axis is the same as the number of groups of spatial light modulators 14 (modulation element groups 141). The plurality of lenses 18c can be arranged continuously. In other words, the plurality of lenses 18c can be arranged along the b-axis without being spaced apart and integrated. The focal length of the image side of the lens array 18C is, for example, longer than the focal length of the lens array 18A.

[0168] Each partial modulated beam L321 in the modulated beam L32 is incident on the corresponding lens 18c. Thus, the modulated beam L32 is separated into a plurality of modulated beams L33. The modulated beam L33 has, for example, a rectangular shape in a cross section perpendicular to its traveling direction.

[0169] According to this structure, the intensity distribution (far-field image) of the modulated light beam L33 is like a Sinc function, with a first peak at its center and a second peak smaller than the first peak on both sides away from its center. Therefore, compared with a Gaussian beam without a second peak, the temperature distribution of the molding material in point S3 can be made more uniform, and heat can be effectively utilized. In addition, compared with a Gaussian beam without a second peak, the area integral value of the intensity in point S3 is high. Therefore, in order to increase the area integral value, there is no need to increase the peak value like a Gaussian beam. Therefore, the possibility of sputtering or smoke can also be reduced.

[0170] Figure 7 The separation optical system 18 is composed of a single lens array 18C, so the separation optical system 18 can be more simply constructed. Therefore, the device size and manufacturing cost of the light beam irradiation device 40 can be reduced. On the other hand, according to Figure 6 The separation optical system 18 can make the intensity of the two side regions of the modulated light beam L33 higher and the intensity distribution more uniform. As a result, the temperature distribution of the molding material in the point S3 can be made more uniform.

[0171] <Spatial Light Modulator>

[0172] A phase-type spatial light modulator (PLV) or a phase-type GLV (GLV) can also be used as the spatial light modulator 14. This spatial light modulator 14 can modulate the parallel light beam L31 by using light interference caused by phase differences. This eliminates the need for the aperture 15B to block unwanted light, thus reducing light loss.

[0173] In the above example, the spatial light modulator 14 is a one-dimensional spatial light modulator, but it can also be a two-dimensional spatial light modulator. That is, the spatial modulation elements can be arranged two-dimensionally on the bc plane. This allows the intensity distribution of the modulated light beam L33 to be adjusted two-dimensionally (in the bc plane).

[0174] <Scanning Method>

[0175] exist Figure 3 In the example shown, the interval between the dots S3 is substantially the same as the width of the dots S3. However, the interval between the dots S3 can be adjusted appropriately. For example, the interval between the dots S3 can be adjusted by adjusting the reduction ratio in the separation optical system 18. For example, the interval between the dots S3 can be set to be substantially the same as an integer multiple of the width of the dots S3.

[0176] In addition, since the heat generated at point S3 also moves to its surroundings, the modeling material can also be melted or sintered in this surrounding area. Therefore, by setting the intervals between points S3 to be very narrow, the modeling material layer 120 can also be melted or sintered between the points S3. In this case, the five points S3 correspond to the scanning lines from the 1st to the 5th rows respectively. By moving these five points S3 along the scanning direction D1, the scanning lines from the 1st to the 5th rows can be scanned. Then, after moving the five points S3 by the amount of 5 rows along the arrangement direction D2, the five points S3 are moved again along the scanning direction D1, thereby scanning the scanning lines from the 6th to the 10th rows. Thereafter, by similarly moving the five points S3, the entire area on the modeling material layer 120 can be scanned with the points S3. In this way, the modeling material layer 120 is melted and sintered, and is integrated into the desired shape.

[0177] More generally speaking, the scanning unit 19 can also repeatedly perform the process of scanning N consecutive rows of scan lines and the process of moving N points S3 N rows in a direction intersecting the scanning direction D1 by moving N (N is a natural number greater than 2) points S3 along the scanning direction D1.

[0178] Even in this case, because the points S3 are separated from each other, the temperature of the modeling material between the points S3 is lower than that within the points S3. This reduces the fluidity of the modeling material between the points S3. This prevents the modeling material from mixing in between the scan lines. This reduces localized bulging of the modeling material layer 120, allowing the modeling material layer 120 to be molded into the desired shape with high precision.

[0179] <Second embodiment>

[0180] The three-dimensional modeling apparatus 100 of the second embodiment has the same structure as the three-dimensional modeling apparatus 100 of the first embodiment except for the internal structure of the light beam irradiation device 40. Hereinafter, the light beam irradiation device 40 of the second embodiment is referred to as a light beam irradiation device 40A.

[0181] Figures 8 to 10 : is a diagram schematically showing an example of the structure of the light beam irradiation device 40A. The light beam irradiation device 40A can change the number of beams M of the modulated light beam L33. In other words, the light beam irradiation device 40A can irradiate the modulated light beam L33 to the molding material layer 120 with the variable number of beams M. Figure 8 In the example, the light beam irradiation device 40A emits 5 modulated light beams L33. Figure 9 In the example of FIG. 4 , the light beam irradiation device 40A emits three modulated light beams L33. Figure 10In the example of FIG. 4 , the light beam irradiation device 40A emits one modulated light beam L33 .

[0182] Hereinafter, the maximum value of the number M of the modulated light beams L33 that the light beam irradiation device 40A can emit is referred to as N. Here, as an example, N is 5. The number M of the light beams is equal to or less than N and is variable.

[0183] The light beam irradiation device 40A has the same structure as the light beam irradiation device 40 except for the internal structure of the projection optical system 15. Hereinafter, the projection optical system 15 of the second embodiment is referred to as a projection optical system 150.

[0184] The projection optical system 150 is an enlarging or reducing optical system (also called a zoom optical system) for adjusting the width (width on the b-axis) of the modulated light beam L32. The projection optical system 150 enlarges or reduces the width of the modulated light beam L32 and causes the enlarged or reduced modulated light beam L32 (hereinafter referred to as the modulated light beam L32A) to be incident on all M lenses 18c. In other words, the projection optical system 150 adjusts the width of the modulated light beam L32 so that the modulated light beam L32A is incident on all M lenses 18c. The lens array 18C separates the modulated light beam L32A into M modulated light beams L33. In other words, by adjusting the magnification of the projection optical system 150, the number of modulated light beams L32A incident on the lens 18c can be adjusted, making the number of light beams M variable.

[0185] Hereinafter, the magnification of the b-axis of the projection optical system 150 when the modulated light beam L32A is incident on all the N lenses 18c of the lens array 18C is represented by Db0.

[0186] The projection optical system 150 multiplies the width of the modulated light beam L32 from the spatial light modulator 14 by (M·Db0 / N) and guides the modulated light beam L32A to the separation optical system 18. The projection optical system 150 is an afocal optical system. The magnification (M·Db0 / N) of the projection optical system 150 is controlled by the control device 20.

[0187] refer to Figure 8 When the number of beams M is 5, projection optical system 150 multiplies modulated beam L32 by Db0 on the b-axis and guides modulated beam L32A to separation optical system 18. Modulated beam L32A from projection optical system 150 is incident on all five lenses 18c of lens array 18C. As a result, lens array 18C separates modulated beam L32A into five modulated beams L33. Consequently, five points S3 are formed on modeling material layer 120.

[0188] On the other hand, when the number of beams M is 3, the projection optical system 150 multiplies the modulated beam L32 by (3·Db0 / 5) on the b-axis and guides the modulated beam L32A to the separation optical system 18 (see Figure 9 Because projection optical system 150 adjusts the width of modulated light beam L32 about the optical axis (axis a), modulated light beam L32A is incident on all three lenses 18c arranged in the center of lens array 18C. Consequently, lens array 18C separates modulated light beam L32A into three modulated light beams L33. This forms three points S3 on modeling material layer 120.

[0189] Thus, when the number of beams M is 3, the modulated beam L32A is split into three modulated beams L33. Since each modulated beam L33 corresponds to a group, the intensity distribution of the modulated beam L32A along the b-axis must have an intensity distribution corresponding to the three groups. Therefore, the structure (allocation) of the groups in the spatial light modulator 14 must be modified.

[0190] For example, when the number of beams M is 5, the spatial light modulator 14 modulates the parallel light beam L31 using five groups and emits the modulated light beam L32. Hereinafter, the number of spatial modulation elements (e.g., microbridges 14B and microbridges 14C) in the spatial light modulator 14 is set to 30. In this case, the spatial light modulator 14 modulates the parallel light beam L31 using six spatial modulation elements as a group (modulation element group 141).

[0191] On the other hand, if the number of beams M is 3, the spatial light modulator 14 modulates the parallel light beam L31 in three groups. That is, when the number of beams M is 3, the spatial light modulator 14 modulates the parallel light beam L31 using 10 spatial modulation elements as one group. In short, when the number of beams M is 5, 6 spatial modulation elements are assigned to one group, while when the number of beams M is 3, 10 spatial modulation elements are assigned to one group.

[0192] This allocation of groups is achieved by the exposure data generator 20E. Specifically, when the number of beams M is 5, the exposure data generator 20E generates exposure data so that each group consists of 6 spatial modulation elements. When the number of beams M is 3, the exposure data generator 20E generates exposure data so that each group consists of 10 spatial modulation elements. The modulation control unit 20B controls the spatial light modulator 14 based on this exposure data.

[0193] Thus, the spatial light modulator 14 can modulate the parallel light beam L31 in the number of groups corresponding to the number of beams M as described above. Specifically, when the number of beams M is 5, the spatial light modulator 14 modulates the parallel light beam L31 in 5 groups. In this case, the modulated light beam L32 is composed of 5 partial modulated light beams L321 corresponding to the 5 groups, which are continuous on the b-axis (see Figure 8 The five partially modulated light beams L321 pass through the projection optical system 15 and are incident on the five lenses 18c of the lens array 18C. Each lens 18c reduces the incident partially modulated light beam L321 and guides it as a modulated light beam L33 to the scanning unit 19. In this way, the modeling material layer 120 can be irradiated with five modulated light beams L33 corresponding to the five groups of the spatial light modulator 14.

[0194] On the other hand, when the number of beams M is 3, the spatial light modulator 14 modulates the parallel beam L31 in three groups. In this case, the modulated beam L32 is composed of three partial modulated beams L321 corresponding to the three groups, which are continuous on the b-axis (see Figure 9 The three partially modulated light beams L321 pass through the projection optical system 15 and are incident on the three lenses 18c on the central side of the lens array 18C. Each lens 18c reduces the incident partially modulated light beam L321 and guides it as a modulated light beam L33 to the scanning unit 19. In this way, the modeling material layer 120 is irradiated with the three modulated light beams L33 corresponding to the three groups of spatial light modulators 14.

[0195] When the number of beams M is 1, the projection optical system 150 multiplies the modulated beam L32 by (Db0 / 5) on the b-axis and guides the modulated beam L32A to the separation optical system 18 (see Figure 10 Because projection optical system 150 adjusts the width of modulated light beam L32 about the optical axis (a-axis), modulated light beam L32A is incident on a single central lens 18c in lens array 18C. Lens array 18C reduces this modulated light beam L32A and emits it as a modulated light beam L33. Consequently, a single point S3 is formed on modeling material layer 120.

[0196] Furthermore, when the number of beams M is 1, the spatial light modulator 14 modulates the parallel light beam L31 as a single group. In the above example, since the spatial light modulator 14 includes 30 spatial modulation elements, these 30 spatial modulation elements are grouped together to modulate the parallel light beam L31. In other words, the 30 spatial modulation elements are assigned to each group.

[0197] As described above, the exposure data generator 20E implements this grouping. Specifically, the exposure data generator 20E generates exposure data so that each of the 30 spatial modulation elements forms a group. The modulation control unit 20B controls the spatial light modulator 14 based on this exposure data. Consequently, the spatial light modulator 14 modulates the parallel light beam L31 in groups. The modulated light beam L32 is composed of a single partially modulated light beam L321.

[0198] Figure 11 This is a perspective view schematically showing an example of the configuration of a zoom optical system for the b-axis only in projection optical system 150. Projection optical system 150 includes a first lens group 151, an aperture portion 152, and a second lens group 153. The modulated light beam L32 from the spatial light modulator 14 is incident on the first lens group 151. The first lens group 151 focuses the modulated light beam L32 along the b-axis onto a slit-shaped opening 1521 in the aperture portion 152.

[0199] The first lens group 151 includes, for example, lenses 1511 and 1512. Lens 1511 is a convex lens, and lens 1512 is a concave lens. Figure 11 In the example of , lenses 1511 and 1512 are cylindrical lenses. Figure 11 In the example shown in FIG. 1 , the lens 1511 is located on the spatial light modulator 14 side relative to the lens 1512 .

[0200] The opening 1521 has an elongated shape with the b-axis as its minor axis and the c-axis as its major axis. The modulated light beam L32 from the first lens group 151 passes through this opening 1521. The aperture portion 152 blocks unnecessary light (e.g., high-order diffracted light from the spatial light modulator 14) contained in the modulated light beam L32. The aperture portion 152 also functions as an aperture.

[0201] The second lens group 153 transforms the modulated light beam L32 that has passed through the opening 1521 into a modulated light beam L32A that is parallel to the b-axis. The second lens group 153 includes, for example, lenses 1531 and 1532. Lens 1531 is a concave lens, and lens 1532 is a convex lens. Figure 11 In the example of , lenses 1531 and 1532 are cylindrical lenses. Figure 11 In the example shown in FIG, the lens 1531 is located on the spatial light modulator 14 side relative to the lens 1532.

[0202] The lenses 1511, 1512 of the first lens group 151, the aperture portion 152, and the lenses 1531, 1532 of the second lens group 153 are configured to be movable independently of each other along the optical axis (a-axis). In other words, a moving mechanism 159 (also see FIG. 159 ) is provided to independently move these optical elements. Figures 8 to 10The moving mechanism 159 is composed of, for example, a ball screw mechanism and is controlled by the control device 20.

[0203] The b-axis side of the projection optical system 150 forms a so-called bilaterally telecentric optical system. The magnification ratio is expressed as fb2 / fb1, using the combined focal length fb1 of the first lens group 151 and the combined focal length fb2 of the second lens group 153. The moving mechanism 159 appropriately moves the aforementioned optical elements within the projection optical system 150 so that the b-axis magnification ratio (fb2 / fb1) of the projection optical system 150 matches M / N. This allows the projection optical system 150 to magnify the modulated light beam L32 by a factor of (M / N) on the b-axis and guide the modulated light beam L32A to the separation optical system 18. Furthermore, the positions of the various optical elements of the projection optical system 150 are adjusted so that the spatial light modulator 14 and the aperture unit 152 coincide with the front and rear focal positions of the first lens group 151, respectively, and the aperture unit 152 and the lens array 18C coincide with the front and rear focal positions of the second lens group 153, respectively.

[0204] As described above, in the second embodiment, the number M of modulated light beams L33 can be varied. A greater number M of modulated light beams L33 increases the number of points S3 on the modeling material layer 120. Therefore, by moving multiple points S3 in unison along the scanning direction D1, a larger area can be scanned. Therefore, a greater number M of beams can improve processing capabilities.

[0205] Furthermore, if light losses in the projection optical system 150 are ignored, the power (in watts) of the modulated light beam L32A is equal to the power of the modulated light beam L32. The power of a light beam is equivalent to the area integral of the intensity of that light beam. Furthermore, if light losses in the separation optical system 18 are ignored, the power of each modulated light beam L33 is equal to the value obtained by dividing the power of the modulated light beam L32A by the number of beams M. In other words, the power of the modulated light beam L33 increases as the number of beams M decreases. Thus, the smaller the number of beams M, the greater the amount of heat per unit area imparted to the modeling material layer 120 at point S3. Therefore, even a modeling material with a high melting point can be melted and sintered by reducing the number of beams M.

[0206] As described above, the three-dimensional modeling apparatus 100 can change the power of each modulated light beam L33 by changing the number M of beams of the modulated light beam L33 irradiating the modeling material layer 120 (point S3). For example, the control device 20 sets a lower number M of beams of the modulated light beam L33 for a modeling material with a high melting point. This allows the high-melting-point modeling material to be melted and sintered appropriately. On the other hand, for a modeling material with a low melting point, the number M of beams of the modulated light beam L33 is set higher. This allows a larger area to be scanned in a single scan, thereby improving processing capacity.

[0207] Figure 12 2 is a functional block diagram schematically showing an example of the internal structure of the control device 20. Figure 1 Compared to the control device 20 of FIG. 1 , the control device 20 further includes a projection optical system control unit 20F and a beam number determination unit 20G. The beam number determination unit 20G determines the beam number M (i.e., the number of points S3) of the modulated light beam L33 irradiated on the molding material layer 120. The beam number determination unit 20G determines the beam number M, for example, based on the type of molding material. Information indicating the type of molding material may also be input to the control device 20 by the user operating an input device not shown in the figure. Alternatively, the control device 20 may receive the information from an external device not shown in the figure, or may read the information from an external storage device not shown in the figure. The correspondence between the type of molding material and the beam number M may also be predetermined and stored in the storage unit 30, for example.

[0208] The exposure data generator 20E generates exposure data based on the three-dimensional modeling data and the number of beams M determined by the beam number determination unit 20G. Specifically, the exposure data generator 20E assigns the spatial modulation elements to a group (modulation element group 141) based on the number of beams M determined by the beam number determination unit 20G. The exposure data generator 20E then generates exposure data based on the three-dimensional modeling data so that the spatial light modulator 14 can modulate the parallel light beams L31 in M ​​groups.

[0209] The modulation control unit 20B controls the spatial light modulator 14 based on the exposure data generated by the exposure data generating unit 20E. As a result, the spatial light modulator 14 modulates the parallel light beam L31 in M ​​groups.

[0210] The projection system control unit 20F controls the magnification of the projection system 150 based on the beam number M determined by the beam number determination unit 20G. Specifically, the projection system control unit 20F controls the moving mechanism 159 so that the magnification of the projection system 150 becomes M / N.

[0211] The scanning control unit 20C determines the moving path of the point S3 based on the number of beams M determined by the beam number determination unit 20G. That is, if the number of beams M of the point S3 is different, the moving path of the point S3 used to scan the entire area on the molding material layer 120 is different, so the scanning control unit 20C determines its moving path based on the number of beams M. Specifically, for example, when scanning with one point S3, the scanning unit 19 moves the point S3 along the arrangement direction D2 by one line every time the scanning of one line is completed, and scans the next line. On the other hand, for example, Figure 3 As shown in FIG. 1 , when scanning M (5) dots S3 spaced one row apart, when scanning of the M (5) rows is completed, dot S3 is moved one row in the arrangement direction D2, and scanning of the next M (5) rows is performed. When scanning of the M (5) rows is completed, dot S3 is moved M (5) rows in the arrangement direction D2, and scanning of the next M (5) rows is performed. The scanning is performed in the same manner thereafter.

[0212] <Regarding the Processing of the Control Device>

[0213] Next, refer to Figure 13 An example of the processing performed by the control device 20 will be described. Figure 13 : is a flowchart showing an example of the processing of the control device 20. First, the data acquisition unit 20D receives three-dimensional modeling data from, for example, an external device or a storage medium, and stores the three-dimensional modeling data in the storage unit 30 (step ST11).

[0214] Next, the beam number determination unit 20G determines the number of beams M (step ST12). For example, information indicating the type of modeling material is input to the control device 20, and the beam number determination unit 20G determines the number of beams M based on the type. For example, the higher the melting point of the modeling material, the smaller the beam number M.

[0215] Next, the exposure data generator 20E generates exposure data based on the number of light beams M and the three-dimensional formation data (step ST13). The exposure data generator 20E generates exposure data based on the number of light beams M and the three-dimensional formation data so that the spatial light modulator 14 can operate as a spatial light modulator having M groups.

[0216] Next, the projection optical system control unit 20F controls the magnification of the projection optical system 150 based on the number of beams M determined by the beam number determination unit 20G (step ST14). Specifically, the projection optical system control unit 20F controls the operation of the moving mechanism 159 so that the magnification of the projection optical system 150 becomes M / N, and adjusts the positions of the various optical elements of the projection optical system 150.

[0217] Next, the laser control unit 20A controls the laser light source 11 (step ST15 ). Specifically, the laser control unit 20A emits laser light L30 from the laser light source 11 . The laser light L30 is converted into a parallel beam L31 in the illumination optical system 12 and enters the spatial light modulator 14 .

[0218] Next, the modulation control unit 20B controls the spatial light modulator 14, and the scanning control unit 20C controls the scanning unit 19 (step ST16). Specifically, the modulation control unit 20B controls the spatial light modulator 14 based on the exposure data generated by the exposure data generation unit 20E. As a result, the spatial light modulator 14 modulates the parallel light beam L31 in M ​​groups. The modulated light beam L32 is multiplied M / N on the b-axis by the projection optical system 150 and enters the separation optical system 18 as the modulated light beam L32A. The separation optical system 18 separates the modulated light beam L32A into M modulated light beams L33. Each modulated light beam L33 has an intensity distribution that reflects the shape indicated by the shaping data.

[0219] The M modulated light beams L33 are irradiated onto the modeling material layer 120 via the scanning unit 19. The scanning control unit 20C controls the scanning unit 19 in parallel with the modulation control unit 20B's control of the spatial light modulator 14, and moves the M points S3 on the modeling material layer 120 along a movement path corresponding to the number of light beams M (step ST16). The points S3 thus move on the modeling material layer 120 with intensities reflecting the shapes indicated by the three-dimensional modeling data. This causes the modeling material layer 120 to melt and sinter at locations corresponding to the modeling data, shaping it into the shape indicated by the modeling data.

[0220] The three-dimensional modeling apparatus 100 of the second embodiment also separates the plurality of points S3 from each other on the modeling material layer 120 (see Figure 3 ). Therefore, similarly to the first embodiment, a three-dimensional object can be manufactured with high shape accuracy.

[0221] Furthermore, in the second embodiment, the power at each point S3 can be varied by changing the number of beams M. For example, for a molding material with a high melting point, the power at point S3 can be increased by using a smaller number of beams M. This allows a higher heat level to be applied to the molding material at point S3, allowing the molding material, even at a high melting point, to be melted and sintered.

[0222] On the other hand, for molding materials with a low melting point, by using a larger number of beams M, a larger area can be scanned with one movement in the scanning direction D1, thereby improving the processing capacity.

[0223] In addition, if Figure 13As illustrated, the magnification control (step ST14) of the projection optical system 150 can be performed while the modulated light beam L33 has not yet been irradiated onto the modeling material layer 120. This prevents unnecessary irradiation of the modulated light beam onto the modeling material layer 120 during the magnification control of the projection optical system 150, i.e., during the movement of the optical elements of the projection optical system 150.

[0224] <Other Configurations of the Projection Optical System 150>

[0225] As described above, the power of the modulated light beam L33 increases as the number of beams M of the modulated light beam L33 decreases. In other words, the intensity of light at each position on the b-axis within the modulated light beam L33 increases. Figure 14 is a graph showing an example of the intensity distribution of the modulated light beam L33. Figure 14 In the example, the solid line represents the intensity distribution of the modulated light beam L33 when the number of beams M is 5, the dashed line represents the intensity distribution of the modulated light beam L33 when the number of beams M is 3, and the dot-dash line represents the intensity distribution of the modulated light beam L33 when the number of beams M is 1. Figure 14 As shown, the intensity of modulated light beam L33 increases as the number of beams M decreases. This is because the b-axis magnification (M·Db0 / N) of projection optical system 150 decreases as the number of beams M increases. In other words, the more the projection optical system 150 reduces modulated light beam L32 along the b-axis, the higher the intensity of modulated light beam L32A. Consequently, the intensity of modulated light beam L33, which is separated from modulated light beam L32A, also increases.

[0226] like Figure 14 As shown, the intensity at point S3 changes significantly with changes in the number of beams M, making it difficult to finely adjust the peak intensity at point S3 by changing the number of beams M. Furthermore, if the peak intensity is too high, the central area of ​​point S3 in the modeling material layer 120 will be instantly and rapidly heated, potentially causing sputtering of the modeling material or generating fumes. Therefore, the projection optical system 150 can also adjust the c-axis width of the modulated beam L32A.

[0227] For example, the projection optical system 150 can mitigate a significant increase in the intensity of the modulated light beam L32A accompanying a decrease in the number of beams M by increasing the c-axis width of the modulated light beam L32A. Furthermore, an excessive increase in the peak intensity of the modulated light beam L33 can be avoided.

[0228] Conversely, if the intensity is slightly insufficient, it may be more preferable for the projection optical system 150 to reduce the c-axis width of the modulated light beam L32A rather than reducing the number of beams M. This is because reducing the number of beams M significantly reduces processing capacity. In this case, the projection optical system 15 can increase the intensity of the modulated light beam L33 by reducing the c-axis width of the modulated light beam L32A, thereby eliminating the intensity deficiency.

[0229] Figure 15 1 is a perspective view schematically showing an example of the structure of the projection optical system 150. The projection optical system 150 adjusts the width of the modulated light beam L32 on the b-axis while also adjusting the width of the modulated light beam L32 on the c-axis. Figure 11 Compared to the projection optical system 150 of FIG. 1 , the projection optical system 150 further includes a third lens group 154 ​​as a c-axis magnification or reduction optical system (zoom optical system), an aperture portion 155, and a fourth lens group 156.

[0230] Figure 16 This is a perspective view schematically showing an example of the configuration of a zoom optical system only along the c-axis in the projection optical system 150. The modulated light beam L32 from the spatial light modulator 14 is incident on the third lens group 154. The third lens group 154 ​​focuses the modulated light beam L32 along the c-axis and onto the slit-shaped opening 1551 of the aperture portion 155.

[0231] The third lens group 154 ​​includes, for example, lenses 1541 and 1542. Lens 1541 is a convex lens, and lens 1542 is a concave lens. Figure 15 and Figure 16 In the example of , lenses 1541 and 1542 are cylindrical lenses. Figure 15 and Figure 16 In the example of FIG, the lens 1541 is located on the spatial light modulator 14 side relative to the lens 1542. Figure 15 In the example, lens 1541 is located between the first lens group 151 and the aperture portion 152 , and lens 1542 is located between the aperture portion 152 and the second lens group 153 .

[0232] An opening 1551 is formed in the aperture portion 155. The opening 1551 has a long strip shape with the c-axis as the short axis and the b-axis as the long axis. The modulated light beam L32 from the third lens group 154 ​​passes through the opening 1551. The aperture portion 155 blocks unnecessary light such as high-order diffracted light contained in the modulated light beam L32. The aperture portion 155 can be used as an aperture. Figure 15 In the example shown in FIG, the aperture section 155 is located between the second lens group 153 and the fourth lens group 156. When the spatial light modulator 14 uses a linear PLV, diffracted light appears not only on the long axis but also on the short axis, so the aperture section 155 is required to block the high-order diffracted light. Furthermore, the linear PLV will be described below.

[0233] The fourth lens group 156 shapes the modulated light beam L32 that has passed through the opening 1551 into a modulated light beam L32 that is parallel to the c-axis. The fourth lens group 156 includes, for example, lenses 1561 and 1562. The lens 1561 is a concave lens, and the lens 1562 is a convex lens. Figure 15 and Figure 16 In the example of , lenses 1561 and 1562 are cylindrical lenses. Figure 15 and Figure 16 In the example of , lens 1561 is located on the spatial light modulator 14 side relative to lens 1562. Figure 15 In the example of FIG. 1 , the fourth lens group 156 is located between the aperture portion 155 and the separation optical system 18 .

[0234] The lenses 1541 and 1542 of the third lens group 154, the aperture unit 155, and the lenses 1561 and 1562 of the fourth lens group 156 are configured to be movable independently of one another in the optical axis (a-axis) direction. The moving mechanism 159 also independently moves these optical elements.

[0235] The c-axis side of the projection optical system 150 is also the same as the b-axis, forming a bilaterally telecentric optical system. The magnification ratio is expressed as fc2 / fc1, using the combined focal length fc1 of the third lens group 154 ​​and the combined focal length fc2 of the fourth lens group 156. Furthermore, the positions of the various optical elements of the projection optical system 150 are adjusted so that the spatial light modulator 14 and the aperture unit 155 are aligned with the front and rear focal positions of the third lens group 154, respectively. Furthermore, the aperture unit 155 and the lens array 18C are aligned with the front and rear focal positions of the fourth lens group 156, respectively.

[0236] As described above, the projection optical system 150 can also magnify or reduce the modulated light beam L32 along the c-axis. This allows for more precise adjustment of the intensity of the modulated light beam L33, compared to the significant changes in the intensity of the modulated light beam L33 that occur with changes in the number of beams M. In other words, the moving mechanism 159 has a positional resolution sufficient to adjust the intensity of the modulated light beam L33 by an amount smaller than the change in the intensity of the modulated light beam L33 that occurs with changes in the number of beams M. This can suppress the sputtering of the modeling material or the generation of fumes. Alternatively, it can compensate for insufficient intensity of the modulated light beam L33.

[0237] <Laser light source>

[0238] In the above example, the fine adjustment of the intensity of the modulated light beam L33 is performed by magnification or reduction of the c-axis based on the projection optical system 150. However, it is not necessarily limited to this. Instead of or in combination with the magnification or reduction of the c-axis, a light source capable of emitting laser light L30 with variable intensity may be used as the laser light source 11. The laser control unit 20A controls the intensity of the laser light L30 emitted from the laser light source 11. For example, if it is a semiconductor laser, the intensity can be adjusted by adjusting the current value flowing through the semiconductor laser. Thus, the intensity of the modulated light beam L33 can be adjusted more finely relative to the large changes in the intensity of the modulated light beam L33 accompanying the change in the number of beams M. In other words, the laser light source 11 can adjust the intensity of the laser light L30 with a resolution smaller than the amount of change in the intensity of the modulated light beam L33 accompanying the change in the number of beams M.

[0239] <Aperture section>

[0240] like Figures 8 to 10 As illustrated, an aperture portion 18D may be provided in the separation optical system 18. The aperture portion 18D is provided at the focal position of the image side of the lens array 18C. A plurality of (here, 5) openings 18d arranged along the b-axis are formed in the aperture portion 18D. Each opening 18d is provided at the focal position of the image side of each lens 18c. The plurality of modulated light beams L33 from the lens array 18C pass through the plurality of openings 18d of the aperture portion 18D, respectively. Thus, it is possible to shield the unnecessary light contained in the modulated light beam L33. This unnecessary light includes, for example, light passing through the boundaries between the plurality of lenses 18c of the lens array 18C. At the boundary, it is considered that the actual lens shape is more likely to deviate from the designed shape than the center. In this case, the light passing through the boundary will travel in an undesirable direction. The aperture portion 18D can shield such unnecessary light. Thus, it is possible to reduce the unnecessary light irradiated on the molding material layer 120.

[0241] <Control of Spatial Light Modulator>

[0242] The exposure data generating unit 20E of the control device 20 may generate exposure data for the spatial light modulator 14 so that the intensity at both ends of each partially modulated light beam L321 is smaller than the intensity at the center thereof. The modulation control unit 20B controls the spatial light modulator 14 based on the exposure data, thereby making the intensity at both ends of the partially modulated light beam L321 smaller than the intensity at the center thereof in the modulated light beam L32.

[0243] Figure 17 Schematically shows an example of the intensity distribution of the modulated light beam L32. Figure 17 In the example of , the modulated light beam L32 is composed of 5 partial modulated light beams L321. Figure 17In the example, the intensity distribution of each partially modulated light beam L321 has a top-hat shape, with the intensity at its ends being lower than the intensity at its center. However, based on the three-dimensional modeling data, a partially modulated light beam L321 with nearly zero intensity can exist at any position along the b-axis. In other words, there may be a group that is OFF. In this case, the intensity at the ends of this partially modulated light beam L321 is equal to the intensity at its center, and is nearly zero.

[0244] When the intensity at both ends of each partially modulated light beam L321 decreases, the intensity of light incident on the boundaries between lenses 18c of lens array 18C becomes lower than the intensity of light incident on the center of each lens 18c. Ideally, the intensity of light incident on these boundaries is zero. This reduces or eliminates unwanted light generated by the boundaries between lenses 18c.

[0245] As described above, by sufficiently reducing the intensity of light at the end of the partially modulated light beam L321 , even without providing the aperture portion 18D, it is possible to reduce unnecessary light irradiating the modeling material layer 120 .

[0246] Without the aperture section 18D, the device size and manufacturing costs can be reduced. With the aperture section 18D, unnecessary light can be shielded with greater precision. Of course, the aperture section 18D can also be provided while the spatial light modulator 14 modulates the parallel light beam L31 so that the intensity at the ends of the partially modulated light beam L321 is lower than the intensity at its center.

[0247] <Separation Optical System>

[0248] In the above example, the separation optical system 18 includes the lens array 18C, but may include lens arrays 18A and 18B instead of the lens array 18C. In this case, the aperture portion 18D is provided between the lens arrays 18A and 18B at the focal positions of the lens arrays 18A and 18B.

[0249] <Lens Array Movement Mechanism>

[0250] As described above, the modulated light beam L32A from the projection optical system 150 is incident on all the M lenses 18c (see Figures 8 to 10 ). Thus, the lens array 18C can appropriately separate the modulated light beam L32A into M modulated light beams L33. Furthermore, in order for the modulated light beam L32A to be incident on the M lenses 18c, an odd number of light beams M must be used. Specifically, the projection optical system control unit 20F must limit the number of light beams M to an odd number (e.g., 1, 3, or 5) and control the projection optical system 150 at a magnification (M·Db0 / N) corresponding to the number of light beams M. The reasons for this are explained below.

[0251] Here, consider a case where the projection optical system 150 multiplies the modulated light beam L32 by (2·Db0 / 5) on the b-axis in order to make the number of light beams M 2. Figure 18 The following diagram schematically illustrates an example of an optical path when the number of beams M is 2. In this case, since the spatial light modulator 14 modulates the parallel beam L31 using two groups (modulation element groups 141), the modulated beam L32 is composed of two partial modulated beams L321. The projection optical system 150 multiplies the modulated beam L32 by (2·Db0 / 5) with the optical axis (a-axis) as the center. In this case, as Figure 18 As shown, the modulated light beam L32A is incident on the central lens 18c and half of the lenses 18c on both sides thereof. In this case, the lens array 18C cannot separate the modulated light beam L32A into two.

[0252] As described above, if an even number is adopted as the beam number M, the separation optical system 18 cannot appropriately separate the modulated beam L32A, so in the above example, the beam number M is limited to an odd number.

[0253] However, when the number N of lenses 18c in lens array 18C is an even number (e.g., 4), the number of beams M must be limited to an even number. The reason for this is explained below. Specifically, when the number N is an even number, if lens array 18C is configured so that the optical axis (a-axis) passes through the center of lens array 18C, the optical axis does not pass through the center of lens 18c, but rather through the boundary between two lenses 18c on the central side. Furthermore, since projection optical system 150 adjusts the width of modulated light beam L32A with the optical axis as the center, modulated light beam L32A can only be incident on an even number of lenses 18c. Therefore, the number of beams M must be limited to an even number.

[0254] As described above, when the number N of lenses 18c is an odd number, the number of beams M is limited to an odd number, and when the number N of lenses 18c is an even number, the number of beams M is limited to an even number. In other words, when the optical axis (a-axis) passes through the center of lens 18c, the number of beams M is limited to an odd number, and when the optical axis passes through the boundary between lenses 18c, the number of beams M is limited to an even number.

[0255] However, it is also preferable to arbitrarily select an even number or an odd number as the number of beams M of the modulated light beam L33. Hereinafter, a three-dimensional modeling apparatus 100 that can adopt either an even number or an odd number as the number of beams M of the modulated light beam L33 will be described.

[0256] Figure 19 1 is a diagram schematically showing an example of the structure of the three-dimensional modeling apparatus 100. This three-dimensional modeling apparatus 100 has the same structure as the above-mentioned three-dimensional modeling apparatus 100 except for the presence or absence of the moving mechanism 181. Figure 19 An example of an optical path in the three-dimensional modeling apparatus 100 is also schematically shown. The moving mechanism 181 is a mechanism for moving the separation optical system 18 relative to the projection optical system 150 on the b-axis. Figure 19 In the example shown in FIG, the separation optical system 18 includes a lens array 18C and an aperture unit 18D. The moving mechanism 181 moves the lens array 18C and the aperture unit 18D integrally. The moving mechanism 181 includes a moving mechanism such as a ball screw mechanism or a cylinder mechanism. The moving mechanism 181 is controlled by the control device 20.

[0257] The lens array 18C and the aperture portion 18D may be connected to each other by a connecting member (not shown). The moving mechanism 181 can move the lens array 18C and the aperture portion 18D integrally by moving the connecting member.

[0258] exist Figure 19 In the example, the number N of lenses 18c of the lens array 18C is 5 (an odd number). The moving mechanism 181 adjusts the relative positional relationship between the projection optical system 150 and the separation optical system 18 in such a way that the modulated light beam L32A from the projection optical system 150 is incident on all the M lenses 18c. For example, when the number of light beams M is an odd number that is the same as the number N, the moving mechanism 181 stops the lens array 18C and the aperture portion 18D at the first position described below. The first position is, for example, the position when the optical axis (a-axis) of the projection optical system 150 passes through the center of the lens array 18C on the b-axis (refer to Figures 8 to 10 ). That is, the first position is the position where the optical axis of projection optical system 150 passes through the center of lens 18c in the center of lens array 18C. This allows modulated light beam L32A from projection optical system 150 to be incident on an odd number of lenses 18c. Consequently, separation optical system 18 can separate modulated light beam L32A into an odd number of modulated light beams L33.

[0259] On the other hand, when the number of beams M is an even number different from the number N, the moving mechanism 181 stops the lens array 18C and the aperture portion 18D at the second position described below. The second position is, for example, a position where the first position is offset along the b-axis by half the width of the lens 18c on the b-axis. In the second position, the optical axis (a-axis) of the projection optical system 150 passes through the boundary between the two adjacent lenses 18c (see Figure 19 ). Thus, the modulated light beam L32A from the projection optical system 150 can be incident on the even-numbered lenses 18c. Thus, the separation optical system 18 can separate the modulated light beam L32A into the even-numbered modulated light beams L33.

[0260] Figure 20 2 is a functional block diagram showing an example of the structure of the control device 20. Figure 12Compared to the control device 20 of FIG. 1 , the control device 20 further includes a separation optical system control unit 20H. When the number of beams M determined by the beam number determination unit 20G is an odd number, the separation optical system control unit 20H controls the moving mechanism 181 to stop the separation optical system 18 at the first position. Furthermore, when the number of beams M determined by the beam number determination unit 20G is an even number, the separation optical system control unit 20H controls the moving mechanism 181 to stop the separation optical system 18 at the second position.

[0261] Furthermore, as described above, by providing the moving mechanism 181, either an even number or an odd number can be used as the number of beams M. Conversely, by limiting the number of beams M to an even number or an odd number equal to the number N, the moving mechanism 181 can be omitted. In this case, the light beam irradiation device 40A can be configured with a simple structure.

[0262] <Regarding the Processing of the Control Device>

[0263] Next, refer to Figure 21 An example of the processing performed by the control device 20 will be described. Figure 21 2 is a flowchart showing an example of the processing of the control device 20. First, the data acquisition unit 20D receives three-dimensional modeling data from, for example, an external device or a storage medium, and stores the three-dimensional modeling data in the storage unit 30 (step ST21).

[0264] Next, the beam number determination unit 20G determines the number of beams M (step ST22). For example, information indicating the type of the molding material is input to the control device 20, and the beam number determination unit 20G determines the number of beams M based on the type. For example, the beam number determination unit 20G determines that the number of beams M decreases as the melting point of the molding material increases.

[0265] Next, the exposure data generator 20E generates exposure data based on the number of light beams M and the three-dimensional formation data (step ST23). The exposure data generator 20E generates exposure data based on the number of light beams M and the three-dimensional formation data so that the spatial light modulator 14 can operate as a spatial light modulator having M groups.

[0266] Next, the projection optical system control unit 20F controls the magnification of the projection optical system 150 based on the number of beams M determined by the number of beams determination unit 20G (step ST24). Specifically, the projection optical system control unit 20F controls the movement of the moving mechanism 159 so that the magnification of the b-axis of the projection optical system 150 is M·Db0 / N. The projection optical system control unit 20F can also adjust the magnification of the c-axis in the same manner as described above.

[0267] Next, the separation optical system control unit 20H controls the position of the separation optical system 18 based on the number of beams M determined by the beam number determination unit 20G (step ST25). Specifically, the moving mechanism 181 moves the separation optical system 18 to the first position when the number of beams M is an odd number, and moves the separation optical system 18 to the second position when the number of beams M is an even number.

[0268] Next, the laser control unit 20A controls the laser light source 11 (step ST26 ). Specifically, the laser control unit 20A emits laser light L30 from the laser light source 11 . The laser light L30 is shaped into a parallel beam L31 in the illumination optical system 12 and enters the spatial light modulator 14 .

[0269] Next, the modulation control unit 20B controls the spatial light modulator 14 based on the exposure data to modulate the parallel light beam L31. Furthermore, the scanning control unit 20C controls the scanning unit 19 to move M points S3 on the modeling material layer 120 along a movement path corresponding to the number of beams M (step ST27). Each modulated light beam L33 has an intensity distribution that reflects the shape indicated by the modeling data.

[0270] According to the three-dimensional modeling apparatus 100 , either an even number or an odd number can be used as the number M of beams of the modulated light beam L33 . Therefore, the number M of beams of the modulated light beam L33 can be adjusted more finely.

[0271] <Third embodiment>

[0272] In the second embodiment, the number M of beams of the modulated light beam L33 is determined according to the type of modeling material, and the entire area of ​​the modeling material layer 120 is scanned with the determined number of beams M. However, this is not necessarily limited to this, and the number of beams M may be changed according to the modeling area relative to the modeling material layer 120. The modeling area is the area where the modeling material is melted or sintered.

[0273] Figure 22 An example of a scanning pattern at point S3 is schematically shown. Figure 22 In the example of , rectangle R12 represents an example of the molding area. The molding material in rectangle R12 is scanned by point S3 and melted and sintered. Figure 22 In the example of FIG, in the last movement in the scanning direction D1, a point S3 on the lower side of the paper is located outside the rectangle R12 ( Figure 22 The scanning line on which this point lies is an unnecessary line and does not need to be scanned. In other words, all five points S3 are not required for the final scan; four points S3 are sufficient. In this case, the number of beams M can also be reduced immediately before the final scan.

[0274] Here, as an example, the number of beams M is changed from 5 to 3, and three of the remaining four scanning lines are scanned. Then, the number of beams M is changed from 3 to 1, and the remaining one scanning line is scanned.

[0275] When the number of beams M decreases from 5 to 3, the modulated beams L33 at both ends of the five modulated beams L33 disappear (see also Figure 8 and Figure 9 ). That is, the points S3 at the two ends of the five points S3 in the modeling material layer 120 disappear, leaving only three points S3. Therefore, the amount of movement of the points S3 along the arrangement direction D2 also needs to be corrected. Specifically, due to the decrease in the number of beams M, the first point S3 (the topmost point on the paper) of the five points S3 disappears, leaving the second point S3 at the top. Therefore, the amount of movement in the arrangement direction D2 also needs to be corrected based on the disappearance of the point S3.

[0276] exist Figure 22 In the example, after scanning the last five scan lines, the number of beams M is reduced from 5 to 3, and the scanner 19 moves the three points S3 upward, for example, by one line. This allows the three points S3 to be positioned on the remaining three scan lines. The scanner 19 scans the three scan lines by moving the three points S3 along the scanning direction D1. This reduces the amount of unnecessary light not used for three-dimensional modeling, compared to scanning with five points S3, allowing for more efficient scanning of the three scan lines.

[0277] Next, the number of beams M is reduced from 3 to 1. As a result, the points S3 on both sides disappear (see also Figure 9 and Figure 10 ), a single point S3 remains in the center. The scanning unit 19 moves this single point S3 downward by four lines. This positions point S3 on the last scan line. The scanning unit 19 scans the last scan line by moving the single point S3 along the scanning direction D1. This reduces light loss compared to scanning with five points S3, enabling more efficient scanning of three scan lines.

[0278] As described above, according to the third embodiment, in the scanning path of M1 (e.g., 5) light beams, when at least one of the M1 points S3 is located on an unnecessary line that does not need to be scanned, the number of beams M is reduced from M1 to M2 (e.g., 3 or 1). Specifically, the projection optical system 150 changes the magnification so that the modulated light beam L32 is incident on M2 lenses 18c and M2 modulated light beams L33 are emitted from the lens array 18C. The scanning unit 19 scans the M2 points S3. This omits scanning of the unnecessary lines. This reduces the amount of unnecessary light not used for three-dimensional modeling, thereby improving efficiency.

[0279] <Scanning Speed>

[0280] As the number of beams M decreases, the power (area-integrated value of the intensity) at point S3 increases. Therefore, if the movement speed of point S3 in scanning direction D1 (hereinafter also referred to as scanning speed) is constant, a heat difference occurs between different rows of scan lines. In the above example, the second heat amount imparted to three rows of scan lines by three points S3 is greater than the first heat amount imparted to five rows of scan lines by five points, and the third heat amount imparted to one scan line by one point S3 is greater than the second heat amount.

[0281] Therefore, the scanning control unit 20C may also set the scanning speed after the number of beams M is reduced to be higher than the scanning speed before the number of beams M is reduced. This can reduce the variation in the time integral of the heat between scanning lines caused by the increase in the area integral value of the intensity at point S3. As a more specific example, the scanning control unit 20C sets the scanning speed after the number of beams M is reduced to {(number of beams M before reduction) / (number of beams M after reduction)} times the scanning speed before the number of beams M is reduced. This can avoid the variation in heat between scanning lines associated with the reduction in the number of beams M.

[0282] <Control device>

[0283] Next, the control device 20 that implements the above-described operation will be described. The beam number determination unit 20G determines the number of beams M based on the type of molding material and molding data. As a specific example, the beam number determination unit 20G first determines the number of beams M based on the type of molding material. For example, the higher the melting point of the molding material, the smaller the number of beams M is set.

[0284] If the determined number of beams M is 2 or greater, the beam number determination unit 20G determines whether any scan lines in the 3D modeling data do not require illumination of point S3. For example, if at least one of the M points S3 is outside the modeling area during the final movement along the scanning direction D1, that point S3 is no longer required.

[0285] Therefore, the beam number determination unit 20G sets the beam number M when moving along the last scanning direction D1 to be smaller than the beam number M when moving in other directions. Figure 22 In the example of , after the number of beams M is reduced from 5 to 3 and scanning is performed through three points S3, the number of beams M is reduced from 3 to 1 and scanning is performed through one point S3.

[0286] An example of the processing of the control device 20 is Figure 21 However, in step ST22, the beam number determination unit 20G also determines the beam number M based on the three-dimensional modeling data as described above, and in step ST27, the scanning unit 19 moves the point S3 along a movement path that reflects the decrease in the beam number M during scanning.

[0287] This allows the number of beams M to be changed during scanning to eliminate unnecessary spots S3. This reduces the amount of unnecessary light not used for three-dimensional modeling, enabling efficient three-dimensional modeling.

[0288] Furthermore, the scanning unit 19 sets the scanning speed of point S3 after the number of beams M is reduced to a higher speed than the scanning speed of point S3 before the number of beams M is reduced. This reduces the variation in heat between scan lines caused by the reduction in the number of beams M, and improves processing capacity. More specifically, by setting the scanning speed of point S3 after the number of beams M is reduced to {(number of beams M before reduction) / (number of beams M after reduction)} times the scanning speed of point S3 before the number of beams M is reduced, the variation in heat between scan lines caused by the reduction in the number of beams M can be eliminated.

[0289] In addition, Figure 22 In the example, when scanning five points S3, unnecessary points S3 are generated in the last five rows. However, unnecessary points S3 may also be generated during scanning depending on the 3D modeling data. For example, on the modeling material layer 120, if the first modeling area and the second modeling area are separated from each other in the arrangement direction D2, the separation area between the first and second modeling areas does not require irradiation with points S3. Therefore, if several of the M1 points are located in the first modeling area and the remaining points are located in the separation area, the number of beams M for point S3 can be reduced to eliminate the point S3 in the separation area. Furthermore, when scanning the second modeling area, the number of beams M can be increased again to M1.

[0290] Considering the increase in the number of beams M, the scanning speed can be set as follows. Specifically, the scanning speed at point S3 after the change in the number of beams M is set to {(number of beams M before the change) / (number of beams M after the change)} times the scanning speed at point S3 before the change in the number of beams M. This eliminates the variation in heat between scan lines caused by the reduction in the number of beams M.

[0291] Furthermore, the patterning region may be different for each patterning material layer 120. Furthermore, in a certain patterning material layer 120, the width of the patterning region (the width in the arrangement direction D2) may be less than five scan lines. In such a case, the number of beams M may be appropriately reduced when scanning the patterning material layer 120.

[0292] <Interruption of Irradiation and Scanning>

[0293] Preferably, when the number of beams M is changed, the irradiation and scanning of the light beam L30 are temporarily interrupted. Figure 23 This is a flowchart showing an example of the processing of the control device 20. Figure 23This process is executed during the scanning of point S3 (step ST27). The control device 20 determines whether to change the number of beams M (step ST271). If the number of beams M has not been changed, step ST271 is executed again. If the number of beams M has been changed, the laser control unit 20A causes the laser light source 11 to interrupt the irradiation of the laser beam L30, and the scanning control unit 20C causes the scanning unit 19 to interrupt the movement of point S3 (step ST272).

[0294] Next, the projection optical system control unit 20F controls the magnification of the projection optical system 150 based on the changed number of beams M (step ST273). For example, if the number of beams M decreases from M1 to M2, the projection optical system control unit 20F changes the magnification of the projection optical system 150 from M1 / N to M2 / N. Furthermore, the separation optical system control unit 20H controls the moving mechanism 181 to adjust the position of the separation optical system 18 as needed. Specifically, if the even / odd number of beams M differs before and after the change, the position of the separation optical system 18 needs to be adjusted, and the moving mechanism 181 adjusts the position of the separation optical system 18.

[0295] Next, the laser control unit 20A causes the laser light source 11 to resume irradiation of the laser beam L30 , and the scanning control unit 20C causes the scanning unit 19 to resume movement of the point S3 (step ST274 ).

[0296] This can prevent unnecessary light beams from being irradiated onto the modeling material layer 120 when the magnification of the projection optical system 150 is changed.

[0297] <Fourth embodiment>

[0298] The three-dimensional modeling apparatus 100 of the fourth embodiment has the same structure as the three-dimensional modeling apparatus 100 of the first to third embodiments except for the presence or absence of the imaging rotator. Figure 24 1 is a diagram schematically showing an example of the configuration of the light beam irradiation device 40 of the three-dimensional modeling apparatus 100 according to the fourth embodiment. Hereinafter, the light beam irradiation device 40 according to the fourth embodiment will be referred to as a light beam irradiation device 40B.

[0299] The light beam irradiation device 40B includes a light beam irradiation unit 10, a spatial light modulator 14, a projection optical system 15 (or a projection optical system 150), a separation optical system 18, an imaging rotator 13, and a scanning unit 19. Figure 24 In the example of FIG, the separation optical system 18 includes the lens array 18C, but may include lens arrays 18A and 18B instead of the lens array 18C. Figure 24 In the example shown in FIG. 2 , the separation optical system 18 includes the aperture portion 18D, but the aperture portion 18D may be omitted.

[0300] exist Figure 24 In the example shown, the imaging rotator 13 is disposed after the galvanometer mirror 192. More specifically, it is disposed between the galvanometer mirror 192 and the lens 193. Multiple modulated light beams L33 from the galvanometer mirror 192 are incident on the imaging rotator 13. The imaging rotator 13 rotates the multiple modulated light beams L33 integrally about the optical axis (a-axis). This allows the arrangement direction of the modulated light beams L33 in the bc plane to be rotated. The imaging rotator 13 includes an optical element (e.g., a lobed prism or a three-sided mirror) and a rotation mechanism that rotates the optical element about the rotation axis (a-axis).

[0301] The imaging rotator 13 is controlled by a controller 20 . Figure 25 2 is a functional block diagram schematically showing an example of the internal structure of the control device 20. Figure 1 Compared with the control device 20 of FIG. 1 , the control device 20 further includes a rotator control unit 20J. The rotator control unit 20J controls the imaging rotator 13 to adjust the arrangement direction of the modulated light beam L33.

[0302] By integrally rotating the plurality of modulated light beams L33 using the imaging rotator 13 , the arrangement direction D2 of the points S3 on the modeling material layer 120 can be changed. Figures 26 to 28 It is a diagram schematically showing an example of a plurality of points S3.

[0303] Figure 26 An example of a point S3 when the rotation angle of the imaging rotator 13 is the initial angle (zero degree) is schematically shown. Figure 26 In the example of FIG, when the rotation angle of the imaging rotator 13 is zero degrees, the plurality of points S3 are arranged along the Y-axis direction. That is, the arrangement direction D2 is the Y-axis direction.

[0304] Scanning direction D1 can be set to any direction by operating two galvanometer mirrors 192 in parallel. However, here, only one galvanometer mirror 192 is operated, and multiple points S3 are moved along scanning direction D1. Here, as an example, scanning direction D1 is perpendicular to arrangement direction D2. Hereinafter, scanning direction D1 when the rotation angle is zero degrees is also referred to as scanning direction D10.

[0305] Figure 27 An example of a point S3 when the rotation angle of the imaging rotator 13 is 45 degrees is schematically shown. Figure 27 In the example of FIG, when the rotation angle is 45 degrees, the plurality of points S3 are arranged along the direction inclined 45 degrees on the +X side and the +Y side. Therefore, the arrangement direction D2 is parallel to the direction inclined 45 degrees on the +X side and the +Y side.

[0306] exist Figure 24In the example shown, since imaging rotator 13 is located after galvanometer mirror 192, scanning direction D1 is also rotated by imaging rotator 13. Since scanning direction D1 is orthogonal to arrangement direction D2, scanning direction D1 is parallel to the direction inclined 45 degrees between the +X and -Y sides. Hereinafter, scanning direction D1 when the rotation angle is 45 degrees is also referred to as scanning direction D11.

[0307] Figure 28 The point S3 when the rotation angle of the imaging rotator 13 is 90 degrees is shown. Figure 28 In the example, when the rotation angle is 90 degrees, multiple points S3 are arranged along the X-axis. Therefore, the arrangement direction D2 is the X-axis direction. Scanning direction D1 is orthogonal to the arrangement direction D2 of points S3 and is therefore the Y-axis direction. Hereinafter, scanning direction D1 when the rotation angle is 90 degrees is also referred to as scanning direction D12.

[0308] The controller 20 can change the scanning direction D1 for each stacked modeling material layer 120. For example, the 3D modeling apparatus 100 scans point S3 on a first modeling material layer 120 in scanning direction D10. This causes the first modeling material layer 120 to melt and sinter according to the modeling data. Next, the supply mechanism 16 of the 3D modeling apparatus 100 supplies a second modeling material layer 120 onto the first modeling material layer 120, and the rotator control unit 20J rotates the imaging rotator 13 to a 45-degree angle. The 3D modeling apparatus 100 then scans point S3 on the second modeling material layer 120 in scanning direction D11. This causes the second modeling material layer 120 to melt and sinter according to the modeling data. Next, the supply mechanism 16 supplies a third modeling material layer 120 onto the second modeling material layer 120, and the rotator control unit 20J rotates the imaging rotator 13 to a 90-degree angle. The three-dimensional modeling apparatus 100 then scans point S3 in the scanning direction D12 on the third modeling material layer 120. Furthermore, the scanning direction D1 can be changed not only for each modeling material layer 120 stacked, but also within the same modeling material layer 120. Furthermore, a combination of changing the scanning direction within the same modeling material layer 120 and changing the scanning direction for each modeling material layer 120 is also possible.

[0309] Then, the scanning direction D1 is changed for each modeling material layer 120, and the point S3 is moved on the modeling material layer 120. Note that the scanning direction D1 does not need to be changed for each layer, and may be changed for a plurality of layers.

[0310] For comparison, consider scanning point S3 in multiple layers in the same scanning direction D1. In this case, the modeling deformation of each layer along scanning direction D1 can accumulate. Furthermore, ridges (convex or concave portions) extending along scanning direction D1 may form on the surface of the three-dimensional object, or the strength of the three-dimensional object may be weakened in one direction due to uneven internal stress.

[0311] In contrast, by appropriately changing the scanning direction D1 for each modeling material layer 120 , the occurrence of such a problem can be reduced.

[0312] However, the scanning direction D1 can be changed by driving the two galvanometer mirrors 192 in parallel and adjusting their respective rotational speeds. However, since both galvanometer mirrors 192 need to be driven at all times, the drive mechanism wears out quickly.

[0313] In contrast, in the above example, point S3 is moved along scanning direction D1 by only one of the galvanometer mirrors 192, and scanning direction D1 is changed by the imaging rotator 13. Thus, even when scanning direction D1 is changed for each modeling material layer 120, the drive of the other galvanometer mirror 192 can be stopped during movement in scanning direction D1. This reduces wear on the drive mechanism of the galvanometer mirror 192.

[0314] Figure 29 This is a diagram schematically showing another example of the structure of the light beam irradiation device 40B of the three-dimensional modeling apparatus 100 according to the fourth embodiment. The light beam irradiation device 40B has the same structure as the three-dimensional modeling apparatus 100 except for the position of the imaging rotator 13. Figure 25 The structure of the light beam irradiation device 40B is the same as that of the light beam irradiation device 40B. Figure 29 In the example of , the imaging rotator 13 is provided in the upstream stage of the galvanometer mirror 192 , and as a more specific example, is provided between the separation optical system 18 and the lens 191 .

[0315] Since the imaging rotator 13 rotates the multiple modulated light beams L33 in unison, the arrangement direction of the modulated light beams L33 on the bc plane can be changed. This also changes the arrangement direction D2 of the multiple points S3 on the modeling material layer 120. However, since the imaging rotator 13 is located upstream of the galvanometer mirror 192, the scanning direction D1 does not change even if the imaging rotator 13 rotates.

[0316] Figure 30 : is a diagram schematically showing an example of point S3 when the rotation angle of the imaging rotator 13 is 45 degrees. Figure 30 In the example, the arrangement direction D2 is parallel to the direction inclined at 45 degrees on the +X side and the +Y side, and the scanning direction D1 is the X-axis direction. The scanning direction D1 and the arrangement direction D2 are obliquely intersected. Figure 30 In the example of , five points S3 are formed, and the scanning unit 19 moves the five points S3 in an integrated manner along the scanning direction D1.

[0317] exist Figure 30 In the example, region R1 is a non-modeling region. Therefore, when point S3 is located within region R1, the spatial light modulator 14 is controlled so that the intensity of point S3 is zero. Region R2 on the +X side of region R1 is a modeling region. When point S3 is located within region R2, the spatial light modulator 14 is controlled so that point S3 has an intensity distribution that reflects the three-dimensional modeling data. In addition, a non-modeling region equivalent to region R1 may exist on the +X side of region R2, but Figure 30 Illustration omitted.

[0318] exist Figure 30 In the example of , the scanning lines corresponding to each point S3 are indicated by two-dot chain lines. Figure 30 In the example shown in FIG, the interval between the scan lines is zero. That is, the points S3 are separated from each other, but the scan lines corresponding to each point S3 are continuous in the Y-axis direction. In other words, the imaging rotator 13 adjusts the arrangement direction D2 so that the interval between the scan lines is zero.

[0319] This allows scanning of five consecutive scan lines with a single movement in the scanning direction D1. Each time the scanning unit 19 moves in the scanning direction D1, it moves the five points S3 by five lines in a direction perpendicular to the scanning direction D1 and scans the next five lines. Thereafter, scanning is performed in a similar manner in units of five consecutive lines. This scanning path makes it easier to control the scanning unit 19 because the amount of movement in the orthogonal direction does not need to be changed.

[0320] Furthermore, since the points S3 are separated from each other, the flow range of the molding material can be narrowed, similar to the first embodiment. This reduces the bulge of the molding material, thus enabling the production of three-dimensional objects with high shape accuracy.

[0321] The interval between the scanning lines does not necessarily need to be 0. The interval between the scanning lines can be adjusted by rotating the arrangement direction D2 using the imaging rotator 13 .

[0322] As described above, the three-dimensional modeling apparatus 100 has been described in detail. However, the above description is illustrative in all respects, and the three-dimensional modeling apparatus 100 is not limited thereto. It should be understood that many variations not illustrated are possible without departing from the scope of this disclosure. The various structures described in the above embodiments and variations may be appropriately combined or omitted, as long as they do not conflict with each other.

[0323] For example, in the example above, the scanning unit 19 changes the direction of the modulated light beam L33 to move the point S3 on the modeling material layer 120, but this is not necessarily limited to this. The scanning unit 19 may also include a movement mechanism that moves the supply mechanism 16 on the XY plane. This also enables the point S3 to be moved on the modeling material layer 120.

[0324] In the above example, the moving mechanism 181 moves the separation optical system 18, but the present invention is not limited thereto. The moving mechanism 181 may move the optical system preceding the separation optical system 18 integrally along the b-axis.

[0325] In the second embodiment, the projection optical system 150 includes a b-axis zoom optical system and a c-axis zoom optical system, but the c-axis zoom optical system is not essential. If a c-axis zoom optical system is not provided, the various lenses of the projection optical system 150 can be conventional lenses composed of spherical surfaces rather than cylindrical lenses. Conversely, in the first embodiment, the lenses 15A and 15C of the projection optical system 15 can be conventional lenses or cylindrical lenses. The same applies to the third and fourth embodiments.

[0326] The lens arrays 18A to 18C may be cylindrical lens arrays in the same manner as the separation optical system 18. In this case, a cylindrical lens array for the c-axis may also be provided.

[0327] In the above example, GLV is used as an example of the spatial light modulator 14, but the present invention is not limited thereto, and Linear-PLV may also be used as the spatial light modulator 14. Figure 31 Description of Linear-PLV.

[0328] Figure 31 The linear-PLV 22 is schematically shown as another example of the structure of the spatial light modulator 14. The linear-PLV 22 includes a plurality of substantially rectangular spatial modulation elements 221, which are adjacent to a substrate (not shown) and arranged in a matrix (i.e., two-dimensionally). In the linear-PLV 22, the surfaces of the plurality of spatial modulation elements 221 serve as modulation surfaces. Figure 31 In the example shown, M spatial modulation elements 221 are arranged in the vertical direction and N spatial modulation elements 221 are arranged in the horizontal direction in the figure. Figure 31 The horizontal direction corresponds to the parallel beam L31 (see Figure 4 ) in the direction of the long axis, Figure 31 The longitudinal direction in corresponds to the short-axis direction of the parallel light beam L31.

[0329] Each spatial modulation element 221 includes a fixed member 222 and a movable member 223. The fixed member 222 is a planar, substantially rectangular component fixed to the substrate, and has a substantially circular opening in the center. The movable member 223 is a substantially circular member disposed on the opening of the fixed member 222. Figure 31 A fixed reflective surface is provided on the upper surface of the movable member 223. The movable member 223 can be moved in a direction perpendicular to the paper surface. Figure 31 Move in a direction perpendicular to the paper.

[0330] In each spatial modulation element 221, by changing the relative position between the fixed member 222 and the movable member 223, the reflected light from the spatial modulation element 221 switches between 0th order diffracted light (i.e., regular reflected light) and non-0th order diffracted light. In other words, in the spatial modulation element 221, by moving the movable member 223 relative to the fixed member 222, light modulation using the diffraction grating is performed. The 0th order diffracted light emitted from the light modulator 22 passes through the projection optical system 15 (see Figure 1 ) is guided to the scanning unit 19. In addition, the non-0th order diffracted light (mainly the 1st order diffracted light) emitted from the spatial light modulator 14 is guided in a direction different from the scanning unit 19 by the projection optical system 15 and is shielded.

[0331] In the projection optical system 15, the Figure 31 The reflected light of the M spatial modulation elements 221 arranged in a row in the longitudinal direction is accumulated and irradiated to the scanning unit 19 as a modulated parallel light beam L32. As a result, the power density of the parallel light beam L32 irradiated from the scanning unit 19 to the molding material layer 120 can be increased. In the spatial light modulator 14, a row of M spatial modulation elements 221 (i.e., M spatial modulation elements) can also be regarded as a modulation component corresponding to a unit space. In other words, for example, a group consisting of M spatial modulation elements 221 arranged in the longitudinal direction is equivalent to a pixel. The spatial light modulator 14 is a parallel light beam L31 on the spatial light modulator 14 in the long axis direction (i.e., Figure 31 A spatial light modulator (SLM) with N modulation elements arranged in a row (in the transverse direction) is more effective. By using such a SLM to shape the beam into a cumulative beam per column extending in the longitudinal direction, it is possible to irradiate the modeling material with greater light energy (beam intensity).

[0332] Description of reference numerals:

[0333] 10: Beam irradiation part

[0334] 11: Light source (laser light source)

[0335] 13: Imaging Rotator

[0336] 14: Spatial Light Modulator

[0337] 141: Modulation element group

[0338] 22: Linear-PLV

[0339] 221: Spatial modulation element

[0340] 15: Projection optical system

[0341] 18: Separation optical system

[0342] 181: Mobile mechanism

[0343] 18A~18C:Lens array

[0344] 18a, 18b: Lens

[0345] 18D: Aperture

[0346] 18d: Opening

[0347] 19: Scanning Department

[0348] 192: Galvanometer Mirror

[0349] 20: Controller

[0350] 30: Storage

[0351] 40: Beam irradiation part

[0352] 41a: Fixed component

[0353] 41b: Movable member

[0354] 100: Three-dimensional modeling device

[0355] L30: Beam (Laser)

[0356] L31: Light beam (parallel beam)

[0357] L32, L32A, L33: Light beam (modulated light beam)

[0358] S3: Point

Claims

1. A three-dimensional modeling device for manufacturing a three-dimensional modeling object, wherein: have: The beam irradiation part irradiates the beam; a spatial light modulator for spatially modulating the light beam irradiated by the light beam irradiation portion at least along a first axis; a separation optical system comprising an afocal reduction optical system having a plurality of lens arrays, wherein the lens arrays have a plurality of lenses arranged along the first axis, and wherein the separation optical system separates the light beam modulated by the spatial light modulator into a plurality of light beams through the lens arrays; as well as The scanning unit scans the plurality of light beams from the separation optical system on the modeling material.

2. The three-dimensional modeling device according to claim 1, wherein: When the number of the lenses in the lens array is N, where N is a natural number greater than 2, The three-dimensional modeling device also has: a projection optical system, configured to magnify or reduce the light beam modulated by the spatial light modulator along the first axis, and to cause the magnified or reduced light beam to be incident on the M lenses of the lens array, wherein M is variable; and a control device for controlling the magnification of the projection optical system, The lens array separates the light beams irradiated by the M lenses into M light beams.

3. The three-dimensional modeling device according to claim 2, wherein: The control device receives information about the modeling material and sets M to be smaller as the melting point of the modeling material is higher based on the information.

4. The three-dimensional modeling device according to claim 2 or 3, wherein: N is either an odd number or an even number. The control device limits M to the one of an odd number and an even number.

5. The three-dimensional modeling device according to claim 2 or 3, wherein: The three-dimensional modeling device further includes a moving mechanism that moves the separation optical system relative to the projection optical system on the first axis. The control device controls the moving mechanism to adjust the relative positional relationship between the projection optical system and the separation optical system in such a manner that the light beam from the projection optical system is incident on the M lenses of the lens array.

6. The three-dimensional modeling device according to claim 2 or 3, wherein: The projection optical system magnifies or reduces the light beam modulated by the spatial light modulator at a variable magnification along a second axis intersecting the first axis.

7. The three-dimensional modeling device according to claim 2 or 3, wherein: The light beam irradiation unit includes a light source that emits a light beam with variable intensity.

8. The three-dimensional modeling device according to any one of claims 1 to 3, wherein: The lens array of the separation optical system is provided at a focal point of an optical system immediately preceding the separation optical system.

9. The three-dimensional modeling device according to any one of claims 1 to 3, wherein: The three-dimensional modeling device further includes an aperture portion having a plurality of openings through which the plurality of light beams separated by the lens array pass.

10. The three-dimensional modeling device according to any one of claims 1 to 3, wherein: The spatial light modulator has a plurality of spatial modulation elements arranged two-dimensionally.

11. The three-dimensional modeling device according to any one of claims 1 to 3, wherein: The arrangement direction of the plurality of light beams on the modeling material obliquely intersects with the scanning direction of the plurality of light beams by the scanning unit, and the plurality of light beams are respectively located on a plurality of continuous scanning lines.

12. A three-dimensional modeling device for manufacturing a three-dimensional modeled object, wherein: have: The beam irradiation part irradiates the beam; a spatial light modulator for spatially modulating the light beam irradiated by the light beam irradiation portion at least along a first axis; a separation optical system comprising at least one lens array having a plurality of lenses arranged along the first axis, wherein the separation optical system separates the light beam modulated by the spatial light modulator into a plurality of light beams through the lens array; as well as a scanning unit configured to scan the plurality of light beams from the separation optical system on a modeling material; When the number of the lenses in the lens array is N, where N is a natural number greater than 2, The three-dimensional modeling device also has: a projection optical system, configured to magnify or reduce the light beam modulated by the spatial light modulator along the first axis, and to cause the magnified or reduced light beam to be incident on the M lenses of the lens array, wherein M is variable; and A control device for controlling the magnification of the projection optical system; The lens array separates the light beams irradiated by the M lenses into M light beams; M includes M1 and M2 which is smaller than M1. In the scanning path of M1 light beams performed by the scanning unit, when at least one of the M1 light beams arranged along the first axis is located on an unnecessary line that does not need to be scanned, the control device changes the magnification of the projection optical system, so that the projection optical system allows the light beam to be incident on M2 lenses, and the lens array emits M2 light beams, and the scanning of the unnecessary line is omitted by scanning the M2 light beams performed by the scanning unit.

13. The three-dimensional modeling device according to claim 12, wherein: The scanning unit scans the M2 light beams at a scanning speed higher than the scanning speed of the M1 light beams.

14. The three-dimensional modeling device according to claim 12 or 13, wherein: The control device changes the magnification of the projection optical system in a state where the irradiation of the light beam by the light beam irradiation unit and the scanning by the scanning unit are interrupted.

15. A three-dimensional modeling device for manufacturing a three-dimensional modeled object, wherein: have: The beam irradiation part irradiates the beam; a spatial light modulator for spatially modulating the light beam irradiated by the light beam irradiation portion at least along a first axis; a separation optical system comprising at least one lens array having a plurality of lenses arranged along the first axis, wherein the separation optical system separates the light beam modulated by the spatial light modulator into a plurality of light beams through the lens array; as well as a scanning unit configured to scan the plurality of light beams from the separation optical system on a modeling material; When the number of the lenses in the lens array is N, where N is a natural number greater than 2, The three-dimensional modeling device also has: a projection optical system, configured to magnify or reduce the light beam modulated by the spatial light modulator along the first axis, and to cause the magnified or reduced light beam to be incident on the M lenses of the lens array, wherein M is variable; and A control device controls the magnification of the projection optical system according to the value of M, The lens array separates the light beams irradiated by the M lenses into M light beams; The spatial light modulator comprises at least a plurality of spatial modulation elements arranged along the first axis, The plurality of spatial modulation elements modulate the light beams in M ​​groups, and intensity distributions of the M light beams are respectively controlled by corresponding groups among the M groups.

16. The three-dimensional modeling device according to claim 15, wherein: The spatial light modulator modulates the light beam from the light beam irradiation unit so that the intensity of the light beam incident on the boundaries of the plurality of lenses of the lens array of the separation optical system is smaller than the intensity of the light beam incident on the center of each of the plurality of lenses.

17. A three-dimensional modeling device for manufacturing a three-dimensional modeled object, wherein: have: The beam irradiation part irradiates the beam; a spatial light modulator for spatially modulating the light beam irradiated by the light beam irradiation portion at least along a first axis; a separation optical system comprising at least one lens array having a plurality of lenses arranged along the first axis, wherein the separation optical system separates the light beam modulated by the spatial light modulator into a plurality of light beams through the lens array; a scanning unit configured to scan the plurality of light beams from the separation optical system on a modeling material; as well as An imaging rotator rotates the plurality of light beams from the separation optical system integrally at a variable rotation angle around a rotation axis parallel to the optical axis. The scanning portion includes a galvanometer mirror, The imaging rotator is provided at a subsequent stage of the galvanometer mirror.

18. A three-dimensional modeling device for manufacturing a three-dimensional modeled object, wherein: have: The beam irradiation part irradiates the beam; a spatial light modulator for spatially modulating the light beam irradiated by the light beam irradiation portion at least along a first axis; a separation optical system comprising at least one lens array having a plurality of lenses arranged along the first axis, wherein the separation optical system separates the light beam modulated by the spatial light modulator into a plurality of light beams through the lens array; a scanning unit configured to scan the plurality of light beams from the separation optical system on a modeling material; as well as An imaging rotator rotates the plurality of light beams from the separation optical system integrally at a variable rotation angle around a rotation axis parallel to the optical axis. The scanning portion includes a galvanometer mirror, The imaging rotator is provided at a front stage of the galvanometer mirror.

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