Light shaping device and method for manufacturing a three-dimensional shaped object

Abstract

The present application provides a light shaping device capable of properly ensuring exposure accuracy even in the case of large-scale shaping objects. The projector of the exposure mechanism is configured to be tilted with respect to a second direction orthogonal to a first direction in a posture in which the center positions of two adjacent pixels are offset from each other by a prescribed drawing pitch in the first direction, to be freely movable in the second direction, and to be capable of switching between an on state and an off state of exposure light each time the distance corresponding to the drawing pitch is moved in the second direction, to sequentially expose a prescribed drawing region of a photocurable material in each of a plurality of strip regions each extending in the second direction and having a prescribed drawing width in the first direction, to form a connection portion of two adjacent strip regions among the plurality of strip regions in the case of obtaining a three-dimensional shaped object by layering a plurality of layers of the photocurable material while exposing each layer, and to make the in-plane positions of the connection portion different from each other in at least two layers among the plurality of layers.

Description

Technical Field

[0001] This invention relates to a light modeling device and a method for manufacturing three-dimensional objects. Background Technology

[0002] From the perspective of being able to directly model and process complex three-dimensional shapes, the three-dimensional modeling method is a processing method with great advantages. Compared with the existing methods of obtaining three-dimensional solid objects based on cutting processing, it has a very high degree of freedom, and its advantages have attracted much attention in recent years.

[0003] As an existing example of three-dimensional modeling methods, the three-dimensional light modeling method, known as the free surface method, is widely known. It utilizes a scanning exposure system using a laser beam and an electroluminescence mirror. Additionally, the back-exposed method, known as the confined surface method, is also widely known. This method involves creating a layer by passing the material through glass from the bottom side of a container containing photocurable material, using DMD-based batch exposure. The model is then lifted to the required thickness, and material is filled underneath. This process of repeated exposure and lifting is used to create the model (see, for example, Patent Document 1).

[0004] However, in recent years, as a three-dimensional light modeling method, the method of applying a photocurable resin to a flat surface and exposing it from above by laser scanning has become popular. For example, it is known to obtain a three-dimensional model by repeatedly performing the following steps: a paste-like material called a slurry, which is made by mixing ceramic powder or the like into a photocurable monomer resin (liquid), is thinly applied to a modeling table, and the desired area is exposed from above by laser scanning to cure the resin (for example, see Patent Document 2).

[0005] Furthermore, a method for high-speed exposure (drawing) by moving the DMD projector along, for example, the column direction (row-column direction) of the mirror arrangement direction while performing flow exposure on the pattern is well known. However, in this method, the projection pixel size in the row direction is the smallest unit of drawing, which may not be suitable for high-precision drawing. In view of this, as an improvement to this exposure method, a method of performing exposure by tilting the DMD mirror relative to the direction of movement to make the smallest unit of drawing finer is also known (for example, see Patent Document 3).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-124631

[0009] Patent Document 2: Patent No. 6438919

[0010] Patent Document 3: Patent No. 3938714 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] As the advantages of 3D light modeling become widely recognized, the demand for larger and more large-area models is increasing. With the increasing size of the models, the time required for modeling also increases. Therefore, from a productivity perspective, there is a natural need for a method to improve the efficiency of modeling processes.

[0013] In addition, when creating large or extensive sculptures, it is necessary to maintain stable exposure accuracy during the creation process.

[0014] The present invention was made in view of the above-mentioned problems, and its object is to provide a light modeling device that can appropriately ensure exposure accuracy even when the modeled object is large-scale.

[0015] Technical solutions to the problem

[0016] To address the aforementioned problems, the present invention provides a light modeling apparatus for obtaining a three-dimensional model, characterized in that it comprises: an exposure mechanism for exposing a photocurable material according to an exposure pattern pre-made based on three-dimensional shape data; and a control mechanism for controlling the operation of the light modeling apparatus. The exposure mechanism includes a projector having a plurality of pixels arranged in a two-dimensional configuration. The projector is capable of individually switching the on and off states of the exposure light for each of the plurality of pixels. The projector is configured to move freely in a second direction at an angle relative to a second direction orthogonal to the first direction, with the center positions of two adjacent pixels offset from each other by a predetermined drawing distance in a first direction. Furthermore, each movement in the second direction by a distance equivalent to the drawing distance enables the switching of the exposure light. The control mechanism is configured to switch between an on state and an off state, wherein the projector is alternately and repeatedly moved back and forth in the second direction with a stepping motion in the first direction, while the on state and off state of the exposure light in each pixel are individually switched based on the exposure pattern. Each of the plurality of strip regions extending in the second direction and having a predetermined drawing width in the first direction is sequentially exposed to a predetermined drawing area of ​​the photocurable material. When the three-dimensional model is obtained by exposing each of the plurality of layers of the photocurable material by stacking multiple layers, a connection portion is formed between two adjacent strip regions in the plurality of strip regions, and the in-plane position of the connection portion is different from each other in at least two of the plurality of layers.

[0017] The second aspect of the present invention, in the light modeling apparatus of the first aspect, is characterized in that, when obtaining the three-dimensional model by exposing each of the plurality of layers of the photocurable material by stacking multiple layers of the photocurable material using the exposure mechanism, the control mechanism makes the in-plane position of the connecting portion different from that of the other layers in each of the plurality of layers.

[0018] The third aspect of the present invention, in the light modeling apparatus of the second aspect, is characterized in that, when the drawing width is L and the number of stacked layers of the plurality of layers is N, the in-plane position of the connecting portion when the projector exposes each of the plurality of layers deviates from the in-plane position of the connecting portion in the first exposed layer of the plurality of layers in the first direction by an integer multiple of L / N.

[0019] The fourth aspect of the present invention, in any one of the first to third aspects of the light modeling apparatus, is characterized in that the light modeling apparatus further includes: a modeling table; an ejection mechanism capable of ejecting a slurry as the photocurable material onto the modeling table; and a sweeping mechanism for sweeping the slurry ejected onto the modeling table to form a slurry film of a predetermined thickness, wherein the control mechanism stacks a plurality of slurry films as a plurality of layers by repeatedly ejecting the slurry from the ejection mechanism and sweeping the ejected slurry using the sweeping mechanism.

[0020] A fifth aspect of the present invention provides a light modeling apparatus for obtaining a three-dimensional model, characterized in that it comprises: a modeling stage; an exposure mechanism for exposing a photocurable material according to an exposure pattern pre-made based on three-dimensional shape data; an ejection mechanism for ejecting a slurry, which is the photocurable material, onto the modeling stage; a sweeping mechanism for sweeping the slurry ejected onto the modeling stage to form a slurry film of a predetermined thickness; and a control mechanism for controlling the operation of the light modeling apparatus, wherein the exposure mechanism has a projector having a plurality of pixels arranged in a two-dimensional manner, and the projector is capable of individually switching the on and off states of the exposure light for each of the plurality of pixels, the projector being configured as follows: The control mechanism is configured to allow the projector to move freely in a second direction, with the center positions of two adjacent pixels in a plurality of pixels offset from each other by a predetermined drawing spacing in a first direction. This allows the projector to move freely in a second direction, with each movement in the second direction equal to the drawing spacing, thereby switching the on and off states of the exposure light. The control mechanism is configured to allow the projector to alternately and repeatedly move back and forth in the second direction with steps in the first direction, while simultaneously switching the on and off states of the exposure light in each pixel based on the exposure pattern. This applies to pixels extending in the second direction and in the first direction... Each of a plurality of strip regions having a predetermined drawing width is sequentially exposed to a predetermined drawing area of ​​the photocurable material. While obtaining the three-dimensional model by exposing each of the plurality of layers using the exposure mechanism while stacking multiple layers of the photocurable material, the plurality of slurry films are stacked as multiple layers by repeatedly ejecting the slurry from the ejection mechanism and sweeping the ejected slurry using the sweeping mechanism, forming a connection between adjacent strip regions within the plurality of strip regions. At least the ejection mechanism and the sweeping mechanism are controlled so that, when forming each of the plurality of slurry films, the slurry film... In addition to the first region that would normally require the application of the slurry for shaping the three-dimensional object, the system also includes a second region located within a predetermined range closer to the sweeping start position of the sweeping mechanism than the first region, and a third region between the first and second regions. Furthermore, the center of gravity of the slurry film in the horizontal plane is made approximately the same as or close to the center of gravity of the modeling platform in the horizontal plane. When the exposure mechanism exposes the first region according to the exposure pattern, it also exposes the second region. When forming the mth layer (m is an integer greater than or equal to 2) of the plurality of slurry films, the ejection mechanism ejects the slurry onto the second region of the (m-1)th layer of the slurry film.

[0021] The sixth aspect of the present invention discloses a method for manufacturing a three-dimensional model, characterized in that the manufacturing method includes an exposure step, wherein a photocurable material is exposed according to an exposure pattern pre-made based on three-dimensional shape data by means of a projector having a plurality of pixels arranged in a two-dimensional shape and capable of individually switching the on and off states of the exposure light for each of the plurality of pixels; wherein the projector, in a posture inclined relative to a second direction orthogonal to the first direction such that the center positions of two adjacent pixels among the plurality of pixels are offset from each other in a first direction by a predetermined drawing interval, is alternately and repeatedly moved back and forth in the second direction by stepping in the first direction. While the projector moves a distance equivalent to the drawing spacing each time, the on and off states of the exposure light in each pixel are switched individually based on the exposure pattern. Each of the plurality of strip regions extending in the second direction and having a predetermined drawing width in the first direction is sequentially exposed to a predetermined drawing area of ​​the photocurable material. When the three-dimensional model is obtained by exposing each of the plurality of layers of the photocurable material using the exposure process while stacking the plurality of layers, a connection portion is formed between two adjacent strip regions in the plurality of strip regions, and the in-plane position of the connection portion is different from each other in at least two of the plurality of layers.

[0022] Invention Effects

[0023] According to the first to sixth embodiments of the present invention, the influence of the presence of the connecting portion on the shaping accuracy can be appropriately suppressed, and a shaped object with excellent dimensional accuracy can be obtained.

[0024] Furthermore, according to the fifth method, even when the weight of the object being shaped is large, the bias load on the shaping table can be appropriately suppressed, thereby appropriately suppressing the decrease in shaping accuracy (exposure accuracy) caused by the bias load. In addition, even when the planar dimensions of the object being shaped are small, the bias load on the shaping table can be appropriately suppressed, and a paste film of the required size can be formed by spraying paste with the required minimum spray volume. Attached Figure Description

[0025] Figure 1 This is a perspective view showing the general structure of the light-emitting device 1.

[0026] Figure 2 This is a functional block diagram of the main parts of the light modeling device 1.

[0027] Figure 3This is a side view showing the configuration of the main structural components in the light modeling device 1.

[0028] Figure 4 This is a flowchart showing a series of actions of the light-forming device 1.

[0029] Figure 5 This is a flowchart showing a series of actions of the light-forming device 1.

[0030] Figure 6 This is a flowchart showing a series of actions of the light-forming device 1.

[0031] Figure 7 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0032] Figure 8 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0033] Figure 9 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0034] Figure 10 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0035] Figure 11 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0036] Figure 12 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0037] Figure 13 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0038] Figure 14 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0039] Figure 15 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0040] Figure 16 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0041] Figure 17 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0042] Figure 18 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0043] Figure 19 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0044] Figure 20 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0045] Figure 21 This is a side view schematically showing the state of the light-forming device 1 during its shaping process.

[0046] Figure 22 This is a schematic diagram of tilted exposure performed by projector 21 in the light modeling device 1.

[0047] Figure 23 This is a diagram used to illustrate the pixel configuration and tilt of the projector 21.

[0048] Figure 24 This is a diagram used to illustrate the pixel configuration and tilt of the projector 21.

[0049] Figure 25 This is a diagram illustrating an example of the change in the exposure pattern when the projector 21 is moved while the depiction area DA is exposed according to a prescribed depiction pattern with a width L.

[0050] Figure 26 This diagram illustrates the exposure method used to eliminate the effects of the connecting parts.

[0051] Figure 27 This diagram illustrates the exposure method used to eliminate the effects of the connecting parts.

[0052] Figure 28 This is a side view schematically showing the process of forming a slurry spraying area simultaneously in the light modeling device 1.

[0053] Figure 29 This is a side view schematically showing the process of forming a slurry spraying area simultaneously in the light modeling device 1.

[0054] Figure 30 This is a side view schematically showing the process of forming a slurry spraying area simultaneously in the light modeling device 1.

[0055] Figure 31 This is a side view schematically showing the process of forming a slurry spraying area simultaneously in the light modeling device 1.

[0056] Figure 32 This is a side view showing the situation during the modeling process when the planar dimensions of the model are smaller than the planar dimensions of the modeling platform 11.

[0057] Figure 33 This is an overview diagram of a device that uses the free surface method to create three-dimensional shapes. Detailed Implementation

[0058] The laser scanning method used in the free-surface method allows for minute reduction of the exposure spot diameter and precise control of the pointing position on the depicted surface at the 1-micron level, making it an excellent exposure method for high-precision depiction. However, in the case of laser scanning exposure methods, much like writing in one stroke, it essentially involves scanning and exposing the outline and the area to be painted with a single point of laser light sequentially. Therefore, the exposure time for each depicted area is roughly proportional to the area being painted. For example, there are cases where, when depicting a 20cm square area with a laser beam diameter of 30μm, exposing each surface (layer) takes tens of minutes.

[0059] On the other hand, in batch exposure based on DMD projector projection used in the confined liquid surface method, although it depends on the energy level, the exposure time per unit area is theoretically very short. In this DMD batch exposure method, if the projection is reduced using an optical system, it is possible to expose based on micro-pixels at the 1μm level. However, the area depicted in a single exposure is very small, thus requiring step-and-repeat exposures, which significantly reduces modeling productivity. Therefore, projection exposures are typically performed using pixel sizes such as 50μm to achieve a balance with productivity. Thus, this pixel size must be the smallest unit of depiction. Of course, when exposing large areas, step-and-repeat exposures are also performed sequentially; therefore, when fine detailing is desired, the exposure time increases in this method.

[0060] Furthermore, the exposure method disclosed in Patent Document 3 was previously used only in apparatuses that expose a single surface, such as those used for exposing printed circuit boards. In the exposure of printed circuit boards, it is typically necessary to depict large areas, such as 500 mm square, with high precision at the micrometer level. Therefore, this exposure method usually involves reciprocating exposure. That is, while at the end of each movement, the DMD projector is deflected at a predetermined interval in a direction perpendicular to the exposure direction, and exposure (unit exposure) is repeatedly performed on a forward and return path based on a predetermined width of the DMD projector, thereby exposing the entire target area.

[0061] In this case, strictly speaking, the exposure state of the connecting portion of adjacent unit exposure areas differs from that of other portions. However, this is hardly a substantial problem when exposing a single side of a printed circuit board. However, if the above exposure method is applied to three-dimensional modeling, exposure is not limited to a single side; it typically occurs when dozens or hundreds of layers of paste film are sequentially stacked.

[0062] Furthermore, Patent Document 2 discloses a method for obtaining a large-scale object in the height direction. In this method, a freely movable coating station (auxiliary station) is provided on the side of the molding table. A photocurable material is sprayed onto the coating station, and then the material is spread onto the molding table by sweeping with a scraper. In this case, the position of the coating station is, in principle, limited to the side of the molding table. Therefore, the object is usually shaped at the end of the molding table that is close to the coating station.

[0063] <Summary of the Device>

[0064] Figure 1 This is a perspective view showing the schematic structure of the light modeling device 1 of this embodiment. Figure 2 This is a functional block diagram of the main parts of the light modeling device 1. Figure 3 This is a side view showing the configuration of the main structural components of the light modeling device 1.

[0065] The light modeling apparatus 1 of this embodiment is generally as follows: a paste-like material, called a slurry, which is made by mixing ceramic powder (e.g., alumina) with a photocurable monomer resin (liquid), is thinly applied to a modeling table. Light from a laser, LED, or the like is irradiated over the obtained slurry film to expose the desired area, thereby curing the resin. This process is repeated on sequentially stacked slurry films to obtain a three-dimensional model (layer). It should be noted that, hereinafter, the exposure based on pattern data for exposure performed in the light modeling apparatus 1 is referred to as drawing.

[0066] The light modeling device 1 mainly includes a modeling table 11, an auxiliary table 12, an exposure unit 20, a coating unit 30, a slurry ejection pump 40, and a controller C. Figure 2 It should be noted that, in Figure 1 The document includes a right-handed xyz coordinate system (the same coordinate system will be used below) that sets the direction from the auxiliary platform 12 toward the modeling platform 11 as the positive y-axis and the vertical upward direction as the positive z-axis.

[0067] The modeling platform 11 is a platform on which modeling is performed, and which appears rectangular when viewed from above. As indicated by arrow AR1, the modeling platform 11 can move freely up and down in the z-axis direction. This lifting action is achieved through the z-axis lifting mechanism 11M. Figure 2 ) to achieve. Specifically, such as Figure 3 As shown, it mainly moves between the initial position 11a (height h1), the ejection exposure position 11b (height h2), and the coating position 11c (height h3).

[0068] In general, the molding platform 11 rises from its initial position 11a during the application of the slurry and subsequent exposure, and descends by the required amount each time the model is formed (each time the formation of each layer is completed).

[0069] In order to create large objects, the shaping platform 11 preferably has a shaping area of ​​at least 600mm × 600mm, and more preferably a shaping area of ​​at least 650mm × 650mm.

[0070] Additionally, the molding table 11 has a plurality of adsorption grooves (grooves) 11g on its upper surface. The plurality of adsorption grooves 11g are used to fix a film (e.g., a protective film) laid on the upper surface of the molding table 11 during molding. The plurality of adsorption grooves 11g are provided throughout the molding area. More specifically, the plurality of adsorption grooves 11g are used in conjunction with an air adsorption and blowing mechanism 11AR (… Figure 2 The membrane is connected and, under the control of the controller C (an example of the control mechanism of the present invention), a negative pressure is applied to the plurality of adsorption tanks 11g by the air adsorption blowing mechanism 11AR while the membrane is laid, so that the membrane is vacuum adsorbed.

[0071] It should be noted that during transport after the molded object is completed, the vacuum adsorption is released under the control of the controller C. Instead, air is supplied to the adsorption tank 11g from the air adsorption blowing mechanism 11AR. As a result, the molded object and the film are slightly lifted from the molding table 11, making it easy to hold the film and transport it together with the molded object using the film clamp 52 described later.

[0072] The auxiliary platform 12 is a rectangular platform used in the preparation of the membrane and the handling of the completed molded object, which is viewed from above. The auxiliary platform 12 has approximately the same planar dimensions as the molding platform 11. The auxiliary platform 12 is mounted and supported on a fixing part (support member) 12F, and, as... Figure 3 As shown, the auxiliary platform 12 is set at the same height h1 as the initial position 11a of the modeling platform 11. As indicated by arrow AR2, the auxiliary platform 12 is configured to move freely forward and backward along the y-axis direction, together with the fixing part 12F. Specifically, it moves forward and backward between the normal position 12a and the adjacent position 12b, which is the position aligned and adjacent to the modeling platform 11 located at the initial position 11a on the positive side in the y-axis direction. This forward and backward movement is achieved by the y-axis moving mechanism 12M provided in the fixing part 12F. Figure 2 This is achieved through [the mechanism]. The y-axis moving mechanism 12M has an actuator.

[0073] In addition, the auxiliary platform 12 is also provided with a plurality of adsorption grooves (grooves) 12g on its upper surface. The plurality of adsorption grooves 12g are used to temporarily fix the film laid on the upper surface of the molding platform 11 during molding before laying. More specifically, the plurality of adsorption grooves 12g are connected to the air adsorption and blowing mechanism 11AR via the fixing part 12F. Figure 2 With the membrane laid on, a negative pressure is applied to a plurality of adsorption tanks 12g by an air adsorption blowing mechanism 11AR, thereby vacuum adsorbing the membrane. The membrane temporarily laid on the auxiliary stage 12 is transported to the molding stage 11 via the adsorption pad unit 51 described later.

[0074] Furthermore, the auxiliary platform 12 is configured to be freely detachable from the fixed part 12F in its normal position 12a. That is, it has the mobility to be separated from and transported by the y-axis moving mechanism 12M and the air adsorption blowing mechanism 11AR. In the light modeling apparatus 1 of this embodiment, by utilizing the mobility of the auxiliary platform 12, after completion, the modeling object transferred to the auxiliary platform 12 can be transported together with the auxiliary platform 12.

[0075] For example, such as Figure 3 As shown, the air adsorption and blowing mechanism 11AR includes a vacuum pump (an example of the adsorption mechanism of the present invention) PP1, a compressed air pump (an example of the air supply mechanism of the present invention) PP2, and switching valves VLV1 and VLV2. Switching valves VLV1 and VLV2 operate as switching devices that switch between adsorption based on vacuum pump PP1 and air blowing based on compressed air pump PP2 in the molding stage 11 and auxiliary stage 12, respectively. Controller C controls vacuum pump PP1, compressed air pump PP2, and switching valves VLV1 and VLV2, and switches between vacuum adsorption and air levitation of the membrane.

[0076] Multiple adsorption tanks 11g are dispersed in multiple independent regions zn. Switching valves VLV1 and VLV2 are also configured to switch between adsorption based on vacuum pump PP1 and air blowing based on compressed air pump PP2 for each region zn. During handling, the appropriate region zn's adsorption tank 11g is selectively used according to the size and position of the object. It should be noted that... Figure 1 In this example, although the rectangular adsorption tanks 11g and 12g are arranged in two dimensions, this is only an example. It is also possible to set multiple adsorption tanks 11g and 12g in other arrangements such as stripes.

[0077] The exposure unit (an example of an exposure mechanism) 20 is a light source including one or more projectors 21 that emit light. The projectors 21 include light-emitting elements such as lasers and LEDs. As indicated by arrow AR3, the exposure unit 20 is configured to move freely forward and backward in the y-axis direction. This forward and backward movement is achieved by... Figure 1The diagram in the image is omitted, showing a pair of 20M linear motors (left and right). Figure 2 This was achieved.

[0078] Projector 21 is a component that exposes (projects) a pattern onto the paste coating film formed on the modeling table 11. For example, exposure based on projector 21 is performed using DMD projection. That is, the projector 21 projects a projected (exposed) pattern (data) while moving stepwise or continuously in the y-axis direction. After the movement in one direction ends, the projector 21 moves a predetermined distance in the x-axis direction, and then performs exposure again while moving in the opposite direction in the y-axis direction. In other words, in this embodiment, exposure is performed in strips in each area of ​​a predetermined width. The above operation is repeated until the exposure of the entire modeling object area in each layer is completed.

[0079] More specifically, the projector 21 is configured to be slightly tilted relative to the y-axis direction and moves in this tilted posture. Therefore, the method performed in the light modeling apparatus 1 of this embodiment is specifically referred to as the tilt exposure method. A detailed description of the tilt exposure method will be provided later.

[0080] The projector 21 is configured such that its lower end is located at a height of a predetermined projector movement distance (Proj_WD) above the ejection exposure position 11b of the modeling platform 11 along the z-axis.

[0081] It should be noted that, in Figure 1 In the light modeling device 1 shown, four projectors 21 (21a to 21d) are arranged at equal intervals in the x-axis direction and are exposed synchronously.

[0082] The movement of the projector 21 along the y-axis is achieved by moving the entire exposure unit 20. On the other hand, the movement along the x-axis, as indicated by arrow AR4, is achieved by the x-axis movement mechanism 21M. Figure 2 This is achieved by the x-axis moving mechanism 21M, which has an actuator.

[0083] The coating unit 30 is a unit that integrates the coating device (an example of the sweeping mechanism of the present invention) 31, the slurry ejection pump (an example of the ejection mechanism of the present invention) 40, and the screw 42. As shown by arrow AR6, the coating unit 30 is configured to move freely forward and backward in the y-axis direction. This forward and backward movement is achieved by... Figure 1 The diagram omits the pair of 30M linear motors arranged on the left and right sides. Figure 2 This is achieved through [the following]. Preferably, the guide rail of the linear motor 30M is shared with the linear motor 20M used to move the exposure unit 20.

[0084] The coater 31 is a scraper-shaped component that sweeps and applies slurry sprayed onto the molding table 11. The coater 31 is disposed within the coater unit 30, extending along its length in the x-axis direction, and its x-axis dimension is approximately the same as that of the molding table 11. While maintaining a predetermined distance from the molding table 11, the coater 31 moves in the y-axis direction due to the movement of the coater unit 30, causing the slurry sprayed onto the molding table 11 to spread along the y-axis direction and form a slurry film.

[0085] After use, the applicator 31 is cleaned by the cleaning unit (cleaner) 32. The cleaning unit 32 is configured, as shown by arrow AR7, to move up and down between a usage height 32a, a standby height 32b during shaping, and a standby height 32c, located below one end of the applicator 31. Furthermore, the cleaning unit 32 is configured to move freely along the x-axis direction at the usage height 32a, as shown by arrow AR8. The cleaning unit 32 may include a scraper, a brush, or other structures.

[0086] After using the coater 31, the cleaning unit 32, positioned at the operating height 32a, moves along the x-axis while in contact with the coater 31, thereby removing the slurry adhering to (residual) the coater 31. Thus, the coater 31 is cleaned.

[0087] Subsequently, while the slurry is repeatedly applied, the cleaning unit 32 remains in standby height 32b during the molding process. After all the coating is completed, it remains in standby height 32c until the next use.

[0088] The movement of the cleaning unit 32 in the z-axis direction, as indicated by arrow AR7, is achieved through the z-axis lifting mechanism 32M1. Figure 2 This is achieved through the x-axis movement of the cleaning unit 32, indicated by arrow AR8. Figure 2 This is achieved by the x-axis moving mechanism 32M2, which has an actuator.

[0089] The slurry ejection pump 40 is a pump that internally stores slurry for molding and ejects the slurry onto the molding table 11 during molding. The slurry ejection pump 40 is configured to move along the y-axis via the movement of the coater unit 30, and also via the x-axis movement mechanism 40M. Figure 2 It moves along the x-axis as indicated by arrow AR9. The x-axis moving mechanism 40M has an actuator.

[0090] A screw 42 responsible for ejecting the slurry is provided in the slurry ejection pump 40. The screw 42 is rotated by a screw drive motor 42M. As the screw 42 rotates inside the slurry ejection pump 40, the slurry is ejected from the lower end of the slurry ejection pump 40. The amount of slurry ejected from the slurry ejection pump 40 varies according to the rotational speed of the screw 42. It should be noted that the distance between the lower end of the slurry ejection pump 40 and the ejection exposure position 11b of the molding table 11, i.e., the ejection height h4, can be appropriately set considering the material of the slurry.

[0091] Furthermore, the light-forming device 1 has an adsorption pad unit (adsorption carrier) 51 and a membrane clamp 52 as structures responsible for moving the membrane. The adsorption pad unit 51 is an example of the adsorption and transport mechanism of the present invention, and the membrane clamp 52 is an example of the holding and transport mechanism of the present invention.

[0092] The adsorption pad unit 51 is a film adsorption mechanism used to adsorb the film placed on the auxiliary stage 12 and transfer it to the molding stage 11. Under the control of the controller C, the adsorption pad unit 51 is normally in the standby position 51a. Figure 3 In standby position 51a, located below the standby position of the exposure unit 20, the adsorption pad unit 51 is integrated with the lower part of the exposure unit 20 via a pin (not shown). As the exposure unit 20 moves, it moves in the negative y-axis direction and reaches the adsorption position 51b above the positive y-axis end of the auxiliary stage 12 at the adjacent position 12b, adsorbing the positive y-axis end of the film on the auxiliary stage 12. By maintaining this adsorption state while moving the exposure unit 20 in the positive y-axis direction, the adsorption pad unit 51 moves to the terminal position 51c, thereby transferring the film to the molding stage 11.

[0093] As indicated by arrow AR5, the adsorption and desorption of the film are achieved by the up-and-down movement of the adsorption pad unit 51. This up-and-down movement is realized by a cylinder 51AS. It should be noted that the driving air is supplied from an interface (not shown) provided in the exposure unit 20.

[0094] The membrane clamps 52 are a pair of membrane holding mechanisms used to transport the completed molded object from the molding table 11 to the auxiliary table 12. Controlled by the controller C, the membrane clamps 52 are typically in the standby position 52a. Figure 3In standby position 52a, located at the two ends of the auxiliary stage 12 in the x-axis direction and below the standby position of the coating unit 30, the film clamp 52 is integrated with the lower part of the coating unit 30 via pins (not shown) during use. Thus, as the coating unit 30 moves in the positive y-axis direction, the two ends of the film, which is suspended in air along with the molded object, are held at the holding positions 52b located at the two ends of the molding stage 11 in the negative y-axis direction. By maintaining this holding state while moving the coating unit 30 in the negative y-axis direction, the film and the molded object placed on its upper surface are transported to the auxiliary stage 12. At this time, the areas zn belonging to the adsorption tanks 11g and 12g, which receive air from the compressed air pump PP2, are switched sequentially according to the movement of the molded object. That is, only the adsorption tanks 11g and 12g required to suspend the moving molded object in air are used sequentially and selectively.

[0095] When transporting the model, the air supply from the adsorption tanks 11g and 12g that are not directly below the membrane or the model can be stopped. This prevents a large amount of air from being blown out of the adsorption tanks 11g and 12g that are not above the membrane or have a low load on the model, thus allowing sufficient air to be blown out from the adsorption tanks 11g and 12g that are directly below the model, which is necessary for it to float. The controller C can determine the air supply area based on the membrane transport distance, or it can detect the position of the membrane and / or the model using sensors and determine the air supply area based on the detection results.

[0096] In addition, the light modeling device 1 also includes a fan filter unit (FFU) 15, etc. The FFU 15 is a mechanism used to maintain the cleanliness inside the light modeling device 1.

[0097] The operation of each part of the light modeling device 1, which has the structure described above, is controlled by the controller C. Figure 2 Control. Controller C can be implemented using a general-purpose or special-purpose computer.

[0098] Preferably, the controller C has a modeling data processing unit C1, which converts the three-dimensional shape data (CAD data) of the modeling object into projection (exposure) pattern data that can be used in each layer of strip exposure by the projector 21. The slice data generated by the modeling data processing unit C1 is used sequentially in the pattern exposure of the projector 21.

[0099] It should be noted that the modeling data processing unit C1 can also be a computer separate from the controller C.

[0100] <The Actions of the Light Modeling Installation>

[0101] Figures 4 to 6 This is a flowchart showing a series of actions of the light modeling device 1 when a model is created in the light modeling device 1. Figures 7 to 21 This is a side view schematically showing the situation during the shaping process of the light shaping device 1.

[0102] First, each part or unit moves to its initial position (standby position) (step S1). Specifically, the modeling stage 11, auxiliary stage 12, exposure unit 20, and coating unit 30 are positioned in their initial positions.

[0103] Next, as Figure 7 As shown, the operator manually places (loads) the membrane F (also called a protective sheet or simply a sheet) onto the auxiliary stage 12 (step S2). The membrane F is placed to cover the entire auxiliary stage 12. The placed membrane F is vacuum-adsorbed onto the auxiliary stage 12 by applying negative pressure to the plurality of adsorption tanks 12g through the air adsorption blowing mechanism 11AR. Additionally, as... Figure 8 As shown, the auxiliary stage 12 on which the membrane F is placed moves from the normal position 12a to the adjacent position 12b.

[0104] When the film F is set, the adsorption pad unit 51 is integrated with the exposure unit 20 by pin fitting (step S3). At this time, air is supplied from the exposure unit 20 side to the cylinder 51AS through the connector connection.

[0105] Next, the exposure unit 20 moves in the negative y-axis direction, and the adsorption pad unit 51 moves to the adsorption position 51b (step S4). For example... Figure 9 As shown, the adsorption pad unit 51 is driven by the cylinder AS to descend and adsorb the membrane F (step S5). Along with this adsorption, the vacuum adsorption of the membrane F relative to the auxiliary stage 12 is released.

[0106] Exposure unit 20 moves in the positive y-axis direction with the film F adsorbed by adsorption pad unit 51 (step S6). Thus, as... Figure 10 As shown, the film F is transported onto the molding stage 11. The exposure unit 20 stops when the adsorption pad unit 51 moves to the terminal position 51c and the film F covers the entire molding stage 11.

[0107] Simultaneously with this stop, the air adsorption blowing mechanism 11AR applies negative pressure to the plurality of adsorption tanks 11g, thereby vacuum adsorbing the membrane F onto the molding stage 11 (step S7). On the other hand, the adsorption based on the adsorption pad unit 51 is released (step S8).

[0108] Next, the exposure unit 20 is moved to the standby position, the pin engagement is released, and the adsorption pad unit 51 is separated from the exposure unit 20 (step S9). Simultaneously, as... Figure 11As shown, the auxiliary stage 12 located at the adjacent position 12b moves to the normal position 12a (step S10). It should be noted that the operator can also place the membrane F directly on the molding stage 11.

[0109] Next, in the modeling data processing unit C1, strip data is generated from the three-dimensional shape data (CAD data) of the modeling object (step S11), and projection (exposure) pattern data is generated based on the strip data (step S12). Here, strip data refers to a portion of the three-dimensional shape data corresponding to the area exposed by the projector 21 through a single movement in the y-axis direction.

[0110] The generated projection (exposure) pattern data is transmitted to projector 21 (step S13). During the transmission (not in step S14), the slurry coating process is performed in parallel.

[0111] Specifically, after the auxiliary stage 12 moves to the normal position 12a (step S10), the molding stage 11 on which the film F is attached rises to the ejection exposure position 11b at a height h2 (step S15).

[0112] Next, the slurry ejection pump 40 moves to the designated slurry ejection position by moving the coating unit 30 in the positive y-axis direction. While the slurry ejection position can be appropriately set according to the size and area of ​​the object being modeled, it is generally... Figure 12 The setting is located inside the molding table 11 in the y-axis direction. At this slurry ejection position, the slurry ejection pump 40, with the lower nozzle 44 in the open state, moves in the x-axis direction while rotating the screw 42 at the required speed, thereby ejecting a predetermined amount of slurry linearly onto the molding table 11 (step S16).

[0113] It should be noted that the group of spray start point and spray end point is not limited to one group; multiple groups can be set at appropriate intervals Δp along the y-axis. This spraying method of slurry is called multi-line spraying. The spraying operation continues until all the required amount of slurry has been sprayed (step S17). It should be noted that in the case of multi-line spraying, the distance between the lower end of the slurry spraying pump 40 and the lower end of the coater 31 is appropriately set to avoid the top of the coater 31 contacting the sprayed slurry.

[0114] At the end of the slurry spraying (yes in step S17), the nozzle 44 is closed by a gate or the like, and then the coater unit 30 moves to the coating start position (step S18). Following the movement of the coater unit 30, the molding stage 11 rises from the spraying exposure position 11b to the coating position 11c (step S19). At this time, the distance between the coating position 11c and the lower end of the coater 31 is the coating height h5 corresponding to the thickness of the desired slurry film SLF. It should be noted that the coating start position is usually set so that the coater 31 is located further to the positive side of the y-axis direction than the slurry spraying range.

[0115] When the molding platform 11 reaches the coating position 11c, the coater unit 30 moves in the negative y-direction. Thus, as... Figure 13 As shown, the slurry sprayed onto the molding table 11 is swept by the coating device 31 to form a slurry film SLF of a specified thickness (step S20).

[0116] When the coating unit 31 moves a specified distance in the y-axis direction and forms a slurry film SLF in the specified range of the molding table 11, the coating unit 30 moves further in the negative y-axis direction and returns to the standby position (coating cleaning position) (no in steps S21 and S22).

[0117] When the coater unit 30 reaches the standby position (coater cleaning position) (yes in step S22), the cleaning unit 32, which had been in standby at the standby height 32c, resumes operation. Figure 14 The unit rises to the cleaning position (using height 32a) (step S23). The cleaning unit 32 reciprocates in the x-axis direction, thereby scraping off the slurry adhering (residual) to the coater 31 (step S24). That is, the coater 31 is cleaned.

[0118] After cleaning is completed, the cleaning unit 32 retracts to the initial position along the x-axis (step S25), and retracts to the standby height 32b when shaping (step S26).

[0119] On the other hand, after the formation of the slurry film SLF based on the coater 31 is completed and the coater unit 30 moves to the cleaning position (yes in step S22), pattern exposure based on the projector 21 is performed in parallel with the cleaning of the coater 31.

[0120] Specifically, first, the molding stage 11 with the slurry film SLF formed is moved from the coating position 11c to the ejection exposure position 11b (step S28). Next, the exposure unit 20 is positioned at the exposure start position (step S29). More specifically, the exposure unit 20 is moved in the negative y-axis direction, and the position of the projector 21 in the x-axis direction is adjusted.

[0121] When the projector 21 is positioned at the designated exposure start position, based on the pre-transmitted exposure pattern data, a combination of continuous reciprocating movement of the exposure unit 20 in the y-axis direction and stepping movement of the projector 21 in the x-axis direction is used, such as... Figure 15 As shown, the slurry film SLF is exposed in strip units using the exposure light EL emitted from the projector 21 (step S30).

[0122] More specifically, if at the point where the exposure of a strip is completed by a single movement of the exposure unit 20 in the y-axis direction, there are still strips remaining that are to be exposed (drawn) (no in step S31), then the creation of strip data to be the next strip (step S11), the generation of exposure pattern data (step S12), and the transmission of exposure pattern data (steps S13 and S14) are performed. Afterwards, the projector 21 moves stepwise along the x-axis direction, and the exposure unit 20 moves in the y-axis direction in the opposite direction to the most recent drawing, thereby performing exposure based on the newly generated exposure pattern data.

[0123] When the drawing of all the strips is finished (Yes in step S31), the exposure unit 20 retracts to the standby position (step S32). At this time, the projector 21 also moves to the initial position. It should be noted that, normally, at the moment when the drawing of all the strips is finished, the cleaning of the coater 31 (step S24) has been completed, and the cleaning unit 32 moves to the modeling standby height 32b (Yes in step S27).

[0124] If it is then necessary to depict other layers (slurry film SLF) (not in step S33), the process after step S11 is repeated. That is, the formation of the slurry film SLF and pattern exposure are repeated. It should be noted that the slurry film SLF formed in this case is the most recently exposed slurry film SLF. Figure 16 This shows the state of a model (a laminate of paste film SLF, LB) completed by exposing all layers, with the unexposed portions embedded.

[0125] When the object is completed (yes in step S33), the object is removed to remove the unexposed parts, such as... Figure 17 As shown, the modeling platform 11 is lowered to the initial position 11a (step S34). In addition, the cleaning unit 32, which has been located at the modeling standby height 32b so far, is also lowered to the standby height 32c (step S35).

[0126] Furthermore, the film clamp 52, located in the standby position 52a, is integrated with the coater unit 30 via pin engagement (step S36). Next, the coater unit 30 moves in the positive y-axis direction, positioning the film clamp 52 at the holding positions 52b on both ends of the molding table 11 in the negative y-axis direction (step S37). The film clamp 52 holds the end of the film F laid under the molded object in the molding table 11 at this position (step S38).

[0127] On the other hand, in parallel with this holding, the auxiliary platform 12, which is in standby position 12a, is moved to the adjacent position 12b (step S39). As a result, the molding platform 11, on which the model and the film F are placed, is aligned with the auxiliary platform 12. In this state, the vacuum adsorption of the film F relative to the molding platform 11, generated by the negative pressure applied by the air adsorption blowing mechanism 11AR, is released. Instead, the air adsorption blowing mechanism 11AR sequentially and selectively supplies air to the adsorption tanks 11g and even the adsorption tanks 12g in the areas required to make the model float (step S40).

[0128] Figure 18 The air supply process is illustrated. First, the air adsorption and blowing mechanism 11AR, under the control of the controller C, supplies air to the adsorption tank 11g in the area corresponding to the position of the molded object. When the air supply begins, the back side of the membrane F, which has been in contact with the molding table 11 so far, experiences an upward force due to the air, and all or part of the membrane F floats slightly along with the molded object. Thus, all or part of the membrane F and the molded object are no longer in contact with the molding table 11, making it easier to handle by applying a horizontal force. It should be noted that... Figure 18 In the example, the blowing of air from the adsorption tank 12g of the auxiliary platform 12, before the model has arrived, is stopped.

[0129] When this non-contact state is achieved, the coating unit 30 moves, and the film clamp 52 moves toward the standby position 52a in the negative y-axis direction. Since the film clamp 52 holds the film F that is floating due to air, the film F and the molded object on it move from the molding table 11 to the auxiliary table 12 along with the movement of the film clamp 52 (step S41).

[0130] Figure 19 and Figure 20 The scenario of this movement is illustrated. For example... Figure 19 As shown, when transporting the molded object placed on the membrane F, the controller C controls the air adsorption and blowing mechanism 11AR to supply air from the adsorption tanks 11g and 12g in the area corresponding to the position of the molded object, and stops supplying air from the adsorption tanks 11g and 12g that are offset from that area. Thus, as... Figure 20 As shown, the model and part or all of the membrane F are transported together in a state of floating from the modeling platform 11 and the auxiliary platform 12.

[0131] When the movement of the membrane F and the modeling object toward the auxiliary stage 12 ends, the membrane clamp 52 releases its grip on the membrane F (step S42). Next, the coating unit 30, which is integrated with the membrane clamp 52, is moved along the y-axis and returned to the standby position (step S43), and the connection between the membrane clamp 52 and the coating unit 30 is released (step S44).

[0132] Furthermore, the auxiliary platform 12, which holds the mold and the film F, returns from the adjacent position 12b to the normal position 12a. In this normal position 12a, the auxiliary platform 12 can be freely attached to and detached from the fixing part 12F, such as... Figure 21 As shown, the operator removes the auxiliary platform 12 from the fixed part and moves the model along with the auxiliary platform 12 to the pre-prepared transport platform CV, and then transports it to the outside of the light modeling device 1 (step S45). This allows for transport without direct contact with the model, thus reducing the possibility of breakage and enabling stable transport.

[0133] The above describes the steps for creating and removing a model in the light modeling apparatus 1 of this embodiment. A key feature of the light modeling apparatus 1 of this embodiment is that it allows for easy and reliable removal of large models, even when they are being created.

[0134] Specifically, air can be supplied to a plurality of vacuum adsorption tanks provided on the surface of the molding platform 11 for molding. Furthermore, an auxiliary platform 12 is provided separately from the molding platform 11 as an outlet for the molded object, and air can be supplied to the auxiliary platform 12 in the same manner as to the molding platform 11. Therefore, even large, large-area molded objects can be levitated by air, thus preventing them from contacting the molding platform 11 and the auxiliary platform 12. This facilitates the horizontal transport (transfer) of the molded object by holding the membrane laid beneath it.

[0135] Furthermore, the auxiliary platform 12 is configured to be freely detachable from the fixed part 12F. In other words, the auxiliary platform 12 itself is movable. Therefore, the model transferred from the modeling platform 11 can be transported to the outside together with the auxiliary platform 12. As a result, it is possible to transport without contacting the model, thus enabling stable transport that reduces the possibility of breakage.

[0136] <Details about tilted exposure>

[0137] Figure 22 This is a schematic diagram of tilted exposure performed by projector 21 in the light modeling device 1 of this embodiment.

[0138] first, Figure 22This illustrates the situation where exposure corresponding to the depicted pattern PT is performed at the position of the projector 21 under the control of the controller C.

[0139] As described above, in the light modeling apparatus 1 of this embodiment, a pattern is projected by projecting a projection (exposure) pattern (data) while the projector 21, which is arranged at a slight tilt relative to the y-axis, is moved stepwise or continuously along the y-axis. In fact, four projectors 21 (21a to 21d) are arranged at equal intervals along the x-axis in the exposure unit 20, and these four projectors 21a to 21d are configured to perform exposures simultaneously. Figure 22 The operation of some of the projectors 21a and 21b is shown. Specifically, the four projectors 21 move in the following manner: alternatingly moving in a step Mx in the positive x-axis direction, moving My1 in the negative y-axis direction and My2 in the positive y-axis direction between the end of the depiction area DA in the positive y-axis direction and the end in the negative y-axis direction, and projecting (depicting) according to the projection (exposure) pattern during the movement My1 and My2.

[0140] Figure 23 and Figure 24 This diagram illustrates the pixel configuration and tilt angle of the projector 21. The projector 21 has a structure in which a plurality of pixels PXL are arranged two-dimensionally (e.g., in a rectangular shape), and the on / off state of the exposure light for each pixel PXL can be individually switched under control based on the controller C and corresponding to the exposure pattern data. It should be noted that... Figure 23 The image clearly shows pixel PXL1, which is in the on state, and pixel PXL2, which is in the off state.

[0141] The projector 21 is tilted relative to the direction of movement, i.e., the y-axis direction. Specifically, the projector 21 is tilted on the exposure unit 20 such that, when the desired drawing pitch is set to Re (μm), the center positions PXLc of adjacent pixels PXL in the arrangement of pixels PXL in the y-axis direction (the up and down direction in the figure) are offset from each other by the drawing pitch Re in the x-axis direction. By giving this tilt, the drawing pitch Re can also be obtained in the x-axis direction.

[0142] Furthermore, along the y-axis direction (scanning direction) where the projector 21 moves My1 and My2, the exposure pattern is switched for exposure whenever the projector 21 moves a distance Re. That is, by switching the drawing pattern (lamp control) whenever the projector moves a distance Re, the drawing spacing Re can be obtained in the y-axis direction.

[0143] More specifically, such as Figure 24As shown, when the size (pixel pitch) of pixel PXL is set to P (μm), the projected size of this size in the x-axis direction is set to Px (μm), and the projected size in the y-axis direction is set to h (μm), it is preferable that Px:h = n:1 (n is an integer). For example, when the pixel arrangement in the projector 21 is 1920 pixels × 1080 columns, considering the degree of freedom in setting the exposure conditions, it is preferable that n = 24.

[0144] It should be noted that the drawing spacing Re is set to be smaller than the pixel size P. Furthermore, the exposure of each pixel PXL of the projector 21 at a certain position is turned on or off by whether the center position PXLc enters the drawing pattern PT. For example, in Figure 23 The image shows pixel PXL1, which is in the on state, and pixel PXL2, which is in the off state, when the projector 21 performs an exposure corresponding to the drawn pattern PT.

[0145] In addition, in this embodiment, such as Figure 23 As shown, in a projector 21 where pixel PXL is configured as a rectangular shape, the distance in the x-axis direction between positions P1 (negative end in the x-axis direction and positive end in the y-axis direction) and P2 (positive end in the x-axis direction and positive end in the y-axis direction) is called the drawing width L. This drawing width L is the width in the x-axis direction of the strip region extending along the y-axis direction when the projector 21 moves once in the y-axis direction. It should be noted that, strictly speaking, due to the tilt of the projector 21, when the projector 21 moves along the y-axis direction, a rectangular region of width ΔL formed in the x-axis direction at the aforementioned positions P2 and P3 (positive end in the x-axis direction and negative end in the y-axis direction) is also exposed. This region overlaps with the strip region during the next exposure in the y-axis direction (called the connecting portion), typically at most two to three pixels in the x-axis direction.

[0146] Figure 25 This diagram illustrates an example of the change in exposure pattern when the projector 21 moves while exposing the depicted area DA to a predetermined depiction pattern with a width L. The projector 21 performs strip exposures while moving incrementally along the y-axis. Therefore, as... Figure 25As shown, the exposure patterns at any times t = t(n), t(n+1), t(n+2), and t(n+3) are different from each other. However, locally, as the projector 21 moves, the different pixels PXL arranged along the y-axis of the projector 21 successively expose the same position of the depiction area DA. Therefore, as a result, approximately the same amount of exposure light (cumulative light) is applied at any position of the depiction area DA. In the light modeling apparatus 1 of this embodiment, by exposing in this manner, the exposure unit 20 can move at high speed and the depiction area DA can be exposed with high precision.

[0147] <Offset of the connecting part of the strip area>

[0148] like Figure 23 and Figure 25 As shown, when the depicted area DA is exposed with a depiction width L, a connection portion with a width ΔL is formed in adjacent strip areas. In the light modeling apparatus 1 of this embodiment, which obtains a three-dimensional model by repeatedly forming (layering) a paste film and exposing it, this connection portion is formed in each layer.

[0149] Figure 26 and Figure 27 This diagram illustrates the exposure method used to eliminate the influence of the connecting portion. Specifically, Figure 26 This illustrates the exposure method for adjacent upper and lower layers when creating a model using an N-layer paste film. It should be noted that, although in Figure 26 For simplicity, only one depiction pattern PT is shown in the illustration, but the depiction pattern PT can be different in each layer.

[0150] In this embodiment, generally speaking, the in-plane position of the connecting portion when exposing each layer is intentionally deviated from the in-plane position (horizontal position) of the connecting portion of other layers. As an example, such as... Figure 26 As shown, when exposing the depiction area DA (DA1) with a depiction width L by reciprocating the projector 21 as indicated by arrows AR31a and AR31b to the slurry film on the lower side, the depiction area DA (DA2) is set such that the connecting portion JT (JTb) and the connecting portion JT (JTa) of the layer directly below are offset by L / N in the positive x-axis direction, and the depiction area DA2 is exposed with the same depiction width L by reciprocating the projector 21 as indicated by arrows AR32a and AR32b. It should be noted that in this invention, "in-plane position" refers to the position on the surface of the slurry film SLF when viewed from a direction perpendicular to the slurry film SLF.

[0151] When this deviation is made across all layers, such as Figure 27(a) shows a cross-sectional view. In the model of the laminated body LB as a slurry film, the connecting portions JT (JT1, JT2, JT3...) of adjacent strip regions in each layer are offset horizontally in each layer. In this case, the offset of the connecting portion in the slurry film SLF of the kth layer from the bottom (1≤k≤N) relative to the connecting portion of the slurry film of the first layer is (k-1)·(L / N).

[0152] It should be noted that, although in Figure 26 At first glance, it may seem that the depiction area DA does not cover the depiction pattern PT as the layers are stacked, but this is only for illustrative purposes. In reality, the size of the depiction area is determined based on the depiction pattern PT in each layer, and the exposure of each layer is performed by striping the depiction area DA, which is set to cover the depiction pattern PT, while the position of the connecting part JT is offset.

[0153] It should be noted that the methods for misaligning the connecting parts JT (JT1, JT2, JT3...) are not limited to the following. Figure 27 (a) shows a deviation in one direction, for example, as Figure 27 The cross-sectional view shown in (b) can also be positioned approximately evenly in the horizontal direction. In this case, considering the direction of deviation, the deviation of the connecting portion in the k-th slurry film SLF is (-1). k-1 ·(k-1)·(L / N).

[0154] More generally, the deviation of the connecting portion JT in each of the N-layer slurry film from the first direction, based on the position of the connecting portion JT in the first layer, is an integer multiple of L / N and is different from each other.

[0155] Strictly speaking, the exposure state of the connecting portion differs from that of the other portions. In this embodiment, for example, as... Figure 27 (a) or Figure 27 As shown in (b), in the model formed by the laminate LB as a paste film, the in-plane positions of the connecting portions JT in each layer are made different (dispersed) and averaged. Alternatively, in the laminate LB, the in-plane positions of the connecting portions JT in at least two layers can be made different from each other. This allows for the appropriate suppression of the influence of the presence of connecting portions on the modeling accuracy, thereby obtaining a model with excellent dimensional accuracy. For example, even when dozens or hundreds of layers of paste film are repeatedly laminated and exposed, the cumulative effect of the connecting portions on the modeling accuracy (more specifically, the volume change caused by energy changes due to overlapping exposures) can be suppressed, thus preventing it from affecting the modeling accuracy.

[0156] As described above, according to this embodiment, when obtaining a three-dimensional model by repeatedly forming (layering) and exposing a paste film, the projector is tilted during the exposure of each layer, and a plurality of strip regions corresponding to the drawing width of the projector are exposed sequentially. Then, the in-plane position of the connecting portion of adjacent strip regions in at least one layer is deviated from the in-plane position of the connecting portion in at least one other layer. This appropriately suppresses the influence of the presence of connecting portions on the modeling accuracy, thereby obtaining a model with excellent dimensional accuracy.

[0157] It should be noted that, as Figure 27 (c) shows a cross-sectional view in which the positions of the connecting parts JT (JT1, JT2, JT3...) of each layer are the same in the horizontal direction.

[0158] <The slurry is formed simultaneously with the area being sprayed>

[0159] Next, we will describe a method of creating a shape in the light modeling device 1 of this embodiment, which involves simultaneously forming a region where slurry is sprayed out. Figures 28 to 32 This is a side view schematically showing the process of forming a slurry spraying area simultaneously in the light modeling device 1.

[0160] Here, the slurry spraying area refers to the area where slurry SL is sprayed during the formation of each layer when creating a model of a laminate LB that is a slurry film. Furthermore, the simultaneous formation of the slurry spraying area refers to a method in which the slurry spraying area is formed by exposing and curing the slurry while forming the layer directly below it, before forming any layers other than the first layer (bottom layer). It should be noted that, during the formation of the first layer, the area on the upper surface of the molding stage 11 where the film F is adsorbed and fixed, which is the slurry spraying area, is the area where the slurry is sprayed.

[0161] first, Figure 28 The following diagram shows the situation after the formation of the first layer (bottom layer). The formation of the first layer is carried out in the following manner: according to the steps described above, the slurry SL is sprayed from the slurry ejection pump 40 onto the film F adsorbed and fixed on the molding stage 11, and the slurry SL is swept by the coating device 31 to form a slurry film SLF1, and the slurry film SLF1 is exposed using a prescribed exposure pattern.

[0162] However, during the formation of this first layer, a paste film SLF1 is formed in a continuous manner, consisting of the shaping area RE1, which requires the application of paste for shaping the object; the paste spraying area RE2, which is set within a predetermined range further along the positive side of the y-axis direction (near the sweeping start position of the coater 31) than the shaping area RE1; and the boundary area RE3 between the shaping area RE1 and the paste spraying area RE2. Furthermore, the formation range of the paste film SLF1 is set such that the center of gravity of the paste film SLF1 in the horizontal plane is approximately the same as or close to the center of gravity of the shaping table 11 in the horizontal plane.

[0163] The shaping area RE1, which would normally require the application of slurry for shaping the object, becomes the shaping area through photocuring by exposure. On the other hand, in the slurry spraying area RE2, the part that is photocured at the m-th layer (m is an integer greater than or equal to 2) functions as a slurry spraying platform for the (m+1)-th layer.

[0164] Subsequently, during subsequent exposures, the area RE1 where the shape is formed is exposed according to the pattern PT, and the area RE2 where the slurry is sprayed is also exposed.

[0165] then, Figure 29 The process of spraying slurry SL during the formation of the second layer is shown. Additionally, Figure 30 This shows the situation after the second layer is formed.

[0166] The second layer is formed by forming a slurry film SLF2 on top of the previously formed slurry film SLF1 (first layer). At this time, slurry SL is sprayed onto the slurry spraying area RE2 of the first layer. Since the slurry spraying area RE2 is stabilized by exposure curing, it is suitable for spraying slurry SL from the slurry spraying pump 40 and subsequent sweeping by the coating device 31. Similarly to the first layer, the slurry film SLF2 is also formed in a continuous manner with the modeling area RE1, the slurry spraying area RE2, and the boundary area RE3. Because the slurry film SLF2 is formed on top of the slurry film SLF1, the center of gravity of the entire slurry film in the horizontal plane remains approximately the same as or close to the center of gravity of the modeling table 11 in the horizontal plane.

[0167] Subsequently, in subsequent exposures, just as when the first layer was formed, the area RE1 where the shape was formed was exposed according to the pattern PT, and the area RE2 where the slurry was sprayed was also exposed.

[0168] Similarly, when forming subsequent layers, the paste SL is sprayed onto the paste spraying area RE2 of the previously formed paste film SLF. The paste SL is swept by the coating device 31 to form a paste film SLF consisting of the model forming area RE1, the paste spraying area RE2, and the boundary area RE3. The model forming area RE1 and the paste spraying area RE2 corresponding to the drawing pattern PT are exposed.

[0169] In this case, the center of gravity of the entire slurry film in the horizontal plane is always roughly the same as or close to the center of gravity of the molding stage 11 in the horizontal plane. Therefore, even with a large number of layers and a large weight of the molded object, the off-center load applied to the molding stage 11 can be appropriately suppressed. As a result, the decrease in molding accuracy (especially exposure accuracy) caused by this off-center load can be appropriately suppressed.

[0170] Furthermore, since the slurry used to form each layer is sprayed over the slurry region RE2, which was previously formed as part of the slurry film and cured by exposure, stable sweeping is possible.

[0171] Figure 31 This illustrates the process of forming a model of a laminate LB as a slurry film by repeatedly performing the formation and exposure of the slurry film SLF as described above. Figure 31 As shown, the laminate LB is composed of the original laminate portion LB1 which serves as the shape, the laminate portion LB2 which is provided in the slurry spraying area RE2 of each layer, and the laminate portion LB3 which is provided in the uncured boundary area RE3 of the same layer.

[0172] Although the laminate LB is eventually transported out of the device together with the auxiliary table 12 through the above steps, since there is an uncured laminate LB3 between the laminate LB1 and the laminate LB2, it is easy to separate the laminate LB1 from the laminate LB2 and further remove the laminate LB3 after transport.

[0173] Figure 32 This diagram illustrates a scenario during the molding process where the planar dimensions of the shaped object are smaller than the planar dimensions of the molding table 11 (the case of slurry SL being sprayed). In this case, slurry SL is sprayed onto the slurry spraying area RE2 of the previously formed slurry film SLF. By sweeping the slurry SL with the coater 31, a slurry film SLF is formed that continuously comprises the shaped object forming area RE1, the slurry spraying area RE2, and the boundary area RE3. Furthermore, the exposure of the shaped object forming area RE1 and the slurry spraying area RE2 corresponding to the drawing pattern PT is performed exactly the same as in the case described above.

[0174] Furthermore, by making the center of gravity of the entire slurry film formed during the formation of the first layer roughly coincide with or be close to the center of gravity of the molding table 11 in the horizontal plane, the center of gravity of the subsequently formed laminate can be kept roughly coincide with or be close to the center of gravity of the molding table 11 in the horizontal plane, and the same applies to suppressing the application of eccentric load to the molding table 11.

[0175] Furthermore, since the slurry is sprayed out of the area RE2 at a position and size corresponding to the planar size of the object (specifically, near the object forming area RE1 and closer to the center when the planar size of the object is larger), a slurry film SLF including the object forming area RE1 of the required size can be formed by spraying slurry SL with the required minimum amount of slurry.

[0176] In a method as disclosed in Patent Document 1, where slurry is sprayed onto a freely lifting coating table (auxiliary table) located on the side of the molding table, and a slurry film is layered by sweeping the slurry, the aforementioned effect will certainly not be achieved. Assuming that such a coating table is used for... Figure 32 In the case of small-sized molding, when the molding position is set to the center of the molding stage, the slurry is swept from the coating stage to that center. This sweeping requires more slurry than is needed for molding, which is costly. To avoid this, if the molding position is set near the coating stage, molding will occur at the end of the molding stage, resulting in an unbalanced load. This eliminates all the problems described above where molding is performed while the slurry is being sprayed out in area RE2.

[0177] As described above, according to this embodiment, when forming a slurry film by sweeping slurry using a coater, the slurry film includes, in addition to the modeling area where slurry is normally applied for forming the model, a slurry ejection area located within a predetermined range closer to the start position of the coater than the modeling area, and the boundary area between these modeling areas and the slurry ejection area. Furthermore, the center of gravity of the slurry film in the horizontal plane is approximately the same as or close to the center of gravity of the modeling table in the horizontal plane. Moreover, when exposing the modeling area corresponding to the drawn pattern, the slurry ejection area is also exposed. Therefore, even when the model is heavy, the bias load on the modeling table can be appropriately suppressed, thereby appropriately suppressing the decrease in modeling accuracy (exposure accuracy) caused by the bias load. On the other hand, when the planar dimensions of the object are small, since the area where the slurry is sprayed can be formed at a position and size corresponding to the planar dimensions of the object, it is possible to both appropriately suppress the eccentric load on the molding table and form a slurry film including the required size of the object forming area by spraying slurry with the minimum required amount of slurry.

[0178] <Other Implementation Methods>

[0179] In the above embodiments, a slurry in which ceramic powder is mixed into a photocurable resin was used as the photocurable material. Alternatively, a slurry containing only the photocurable resin but not ceramic powder may be used, or a slurry containing other materials such as metal powder may be used instead of ceramic powder.

[0180] In the above embodiment, a plurality of adsorption tanks 11g and 12g are used as the plurality of air supply ports for the molding platform 11 and the auxiliary platform 12. Alternatively, the plurality of air supply ports may be provided separately from the plurality of adsorption tanks 11g and 12g in the grooves or holes of the molding platform 11 and / or the auxiliary platform 12. In this case, a compressed air pump of an air adsorption and blowing mechanism 11AR is connected to the plurality of air supply ports. In addition, a plurality of adsorption holes may be used in the molding platform 11 and / or the auxiliary platform 12 to replace the plurality of adsorption tanks 11g and 12g used for vacuum adsorption (and air supply). Alternatively, if a plurality of air supply ports are provided separately in the auxiliary platform 12, the plurality of adsorption tanks 11g may not be required.

[0181] In the above embodiment, the membrane is adsorbed and fixed to the molding table 11. Alternatively, the membrane can be fixed to the molding table 11 by holding both ends of the membrane with clamps and pulling it downwards.

[0182] In the above embodiment, a transport device (carrier) including an adsorption pad unit 51 and a film clamp 52 is used as the transport mechanism. Alternatively, a transport device including a holding device (holder) with other structures may also be used. Furthermore, the transport device may also have an actuator for film transport. In the above embodiment, the film can be transported to the molding stage 11 while being held by the clamp on the auxiliary stage 12. Alternatively, the film can be transported to the auxiliary stage 12 while being adsorbed by the adsorption pad on the molding stage 11.

[0183] In the above embodiment, the exposure unit 20, which has a projector 21, is used as the exposure mechanism. Alternatively, other light sources such as laser scanning or liquid crystal shutters that utilize current mirrors can also be used.

[0184] In the above embodiment, a light modeling apparatus for obtaining a three-dimensional object was used, which forms the three-dimensional object by applying a slurry and exposing it to light. Alternatively, an exposure unit identical to the exposure unit 20 in the above embodiment can be used, and an apparatus can be used to form the three-dimensional object using the free surface method. Figure 33 This is an overview diagram of a device that uses the free surface method to create three-dimensional shapes. Figure 33 The apparatus shown includes: a housing 101 holding liquid photocurable resin as a photocurable material; a modeling platform 102 for mounting the three-dimensional model LB; and a projector 103, identical to the embodiment described above. Furthermore, as a light modeling apparatus for obtaining a three-dimensional model, an apparatus for forming the three-dimensional model by limiting the liquid surface or other methods can also be used.

Claims

1. A light modeling device for obtaining three-dimensional shapes, characterized in that, include: An exposure mechanism exposes a photocurable material to a pre-made exposure pattern based on three-dimensional shape data; and The control mechanism controls the operation of the light modeling device. The exposure mechanism includes a projector with a plurality of pixels arranged in a two-dimensional manner. The projector is capable of individually switching the on and off states of the exposure light for each of the plurality of pixels. The projector is configured such that, With the center positions of two adjacent pixels in the plurality of pixels offset from each other by a predetermined drawing spacing in a first direction, the image is tilted relative to a second direction orthogonal to the first direction, and moves freely in the second direction. Each time the device moves a distance equivalent to the drawing spacing in the second direction, the on / off state of the exposure light can be switched. The control mechanism is configured such that, By alternating and repeatedly moving the projector in the second direction with steps in the first direction, and individually switching the on and off states of the exposure light in each pixel based on the exposure pattern, the projector sequentially exposes a predetermined depiction area of ​​the photocurable material to each of a plurality of strip regions extending in the second direction and having a predetermined depiction width in the first direction. When the three-dimensional object is obtained by exposing each of the plurality of layers using the exposure mechanism while stacking a plurality of layers of the photocurable material, a connection portion is formed between two adjacent strip regions in the plurality of strip regions, and the position of the connection portion in the surface of the layer when viewed from a direction perpendicular to the first direction and the second direction, i.e., the in-plane position, is different from each other in at least two of the plurality of layers.

2. The light modeling device according to claim 1, characterized in that, In obtaining the three-dimensional model by exposing each of the plurality of layers of the photocurable material using the exposure mechanism while stacking multiple layers of the photocurable material, the control mechanism makes the in-plane position of the connecting portion different from that of the other layers in each of the plurality of layers.

3. The light modeling device according to claim 2, characterized in that, When the depiction width is L and the number of stacks of the plurality of layers is N, the in-plane position of the connecting portion when the projector exposes each of the plurality of layers deviates from the in-plane position of the connecting portion in the first exposed layer of the plurality of layers in the first direction by an integer multiple of L / N.

4. The light modeling apparatus according to any one of claims 1 to 3, characterized in that, The light modeling device also includes: Styling table; The spraying mechanism is capable of spraying a slurry, which is the photocurable material, onto the molding table; and The sweeping mechanism sweeps the slurry sprayed onto the molding table to form a slurry film of a specified thickness. The control mechanism stacks multiple slurry films as multiple layers by repeatedly ejecting the slurry from the ejection mechanism and sweeping the ejected slurry with the sweeping mechanism.

5. A light modeling device for obtaining three-dimensional shapes, characterized in that, include: Styling table; The exposure mechanism exposes the photocurable material according to an exposure pattern pre-made based on three-dimensional shape data; The spraying mechanism is capable of spraying a slurry, which is the photocurable material, onto the molding table; A sweeping mechanism sweeps the slurry sprayed onto the molding table to form a slurry film of a specified thickness; and The control mechanism controls the operation of the light modeling device. The exposure mechanism includes a projector with a plurality of pixels arranged in a two-dimensional manner. The projector is capable of individually switching the on and off states of the exposure light for each of the plurality of pixels. The projector is configured such that, With the center positions of two adjacent pixels in the plurality of pixels offset from each other by a predetermined drawing spacing in a first direction, the image is tilted relative to a second direction orthogonal to the first direction, and moves freely in the second direction. Each time the device moves a distance equivalent to the drawing spacing in the second direction, the on / off state of the exposure light can be switched. The control mechanism is configured such that, By alternating and repeatedly moving the projector in the second direction with steps in the first direction, and individually switching the on and off states of the exposure light in each pixel based on the exposure pattern, the projector sequentially exposes a predetermined depiction area of ​​the photocurable material to each of a plurality of strip regions extending in the second direction and having a predetermined depiction width in the first direction. In obtaining the three-dimensional model by stacking multiple layers of the photocurable material while exposing each of the multiple layers using the exposure mechanism, the multiple slurry films are stacked as multiple layers by repeatedly ejecting the slurry from the ejection mechanism and sweeping the ejected slurry using the sweeping mechanism, and the connection portion between two adjacent strip regions in the multiple strip regions is formed. At least the ejection mechanism and the sweeping mechanism are controlled so that, when forming each of the plurality of slurry films, the slurry film includes, in addition to a first region that would normally require the application of the slurry for shaping the three-dimensional object, a second region located within a predetermined range closer to the sweeping start position of the sweeping mechanism than the first region, and a third region between the first region and the second region. and, The center of gravity of the slurry film in the horizontal plane is aligned with or close to the center of gravity of the molding table in the horizontal plane. When the exposure mechanism exposes the first area according to the exposure pattern, it also exposes the second area simultaneously. When forming the mth layer (m is an integer greater than or equal to 2) of the plurality of said slurry films, the ejection mechanism ejects the slurry onto the second region of the (m-1)th layer of the slurry film.

6. A method for manufacturing a three-dimensional object, characterized in that, The manufacturing method includes an exposure step, in which a photocurable material is exposed according to an exposure pattern pre-made based on three-dimensional shape data using a projector having a plurality of pixels arranged in a two-dimensional shape and capable of individually switching the on and off states of the exposure light for each of the plurality of pixels. In the exposure process, the projector, tilted relative to a second direction orthogonal to the first direction with the center positions of two adjacent pixels offset from each other in a first direction by a predetermined drawing spacing, alternately and repeatedly moves back and forth in the second direction with steps in the first direction. Each time the projector moves a distance equivalent to the drawing spacing, the on and off states of the exposure light in each pixel are individually switched based on the exposure pattern. Exposure is performed sequentially on each of the plurality of strip regions extending in the second direction and having a predetermined drawing width in the first direction, for a predetermined drawing area of ​​the photocurable material. When the three-dimensional model is obtained by exposing each of the plurality of layers using the exposure process while stacking a plurality of layers of the photocurable material, a connection portion is formed between two adjacent strip regions in the plurality of strip regions, and the position of the connection portion in the surface of the layer when viewed from a direction perpendicular to the first direction and the second direction, i.e., the in-plane position, is different from each other in at least two of the plurality of layers.

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