Molding apparatus and molding method

Abstract

The present invention provides a modeling device capable of saving the amount of transparent ink used when forming each layer and capable of suppressing the quality of the surface of a modeled object from deteriorating when planarizing. The modeling device models a modeled object by forming each layer of the modeled object based on a plurality of slice images showing the cross-sectional shape and color matching of the each layer of the modeled object and stacking the each layer, the modeling device comprising: a color ink ejection position decision unit that decides whether to eject each color of ink for coloring to each ejection position constituting a layer based on a slice image corresponding to the layer; a transparent ink ejection position decision unit that decides whether to need to eject transparent ink to each ejection position based on whether to eject each color of ink for coloring to each ejection position decided in the color ink ejection position decision unit; and a layer forming unit that causes a color ink head and a transparent ink head to eject each color of ink and transparent ink to each ejection position as decided in the color ink ejection position decision unit and the transparent ink ejection position decision unit.

Description

TECHNICAL FIELD

[0001] The present application relates to a modeling device and a modeling method. BACKGROUND

[0002] Conventionally, a modeling device (3D printer) that models a modeled object using an inkjet head is known (for example, refer to Patent Literature 1). In such a modeling device, a modeled object is modeled, for example, by a layering modeling method that is a method of modeling a modeled object by layering a plurality of layers of ink formed by an inkjet head.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2015-071282 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In a case where a modeled object is modeled by a layering modeling method, it is necessary to make the layering thickness of one layer as uniform as possible to prevent modeling failure.

[0008] As a method of making the layering thickness of one layer uniform, for example, a method can be cited in which, after a color ink is ejected, a fixed amount of a transparent ink is ejected regardless of the amount of the ejected color ink to make the layering thickness be equal to or more than an expected layering thickness, and the ink exceeding the expected layering thickness is scraped off by a flattening roller.

[0009] However, in a case where this method is employed, the ink scraped off by the flattening roller is discarded, and therefore, if the amount of the scraped ink is large, a cost waste is correspondingly generated. In addition, the more the amount of the scraped ink is, the worse the quality of the surface of the modeled object is.

[0010] Therefore, an object of the present application is to provide a modeling device and a modeling method that can solve the above-described problem.

[0011] MEANS FOR SOLVING THE PROBLEM

[0012] The modeling device of the present application models a modeling object by forming layers at different positions in a predetermined layering direction of the modeling object as ink layers based on a plurality of slice images showing cross-sectional shapes and colorings of the layers of the modeling object, and layering the ink layers, and includes: a color ink ejection position decision unit that decides whether to eject each ink of a plurality of colors of ink for coloring to each ejection position constituting a layer by quantization processing based on a slice image corresponding to the layer; a transparent ink ejection position decision unit that decides whether to need to eject transparent ink as transparent to each ejection position based on whether to eject each color of ink for coloring to each ejection position decided in the color ink ejection position decision unit; a color ink head capable of ejecting each ink of a plurality of colors of ink; a transparent ink head capable of ejecting transparent ink; and a layer forming unit that causes the color ink head and the transparent ink head to eject each color of ink and transparent ink to each ejection position as decided in the color ink ejection position decision unit and the transparent ink ejection position decision unit, thereby forming a layer.

[0013] Also, the color ink ejection position decision unit can further decide a dot size of the ink to be ejected, the transparent ink ejection position decision unit can decide whether to eject transparent ink and a dot size to each ejection position based on whether to eject each ink of a plurality of colors of ink for coloring and the dot size to each ejection position decided in the color ink ejection position decision unit, the color ink head and the transparent ink head can each be capable of ejecting a plurality of dot sizes of ink, and the layer forming unit can cause the color ink head and the transparent ink head to eject each color of ink and transparent ink to each ejection position in a dot size as decided in the color ink ejection position decision unit and the transparent ink ejection position decision unit.

[0014] Thus, it is possible to fill each ejection position with transparent ink in a dot size corresponding to a dot size of ejected color ink.

[0015] Also, when a dot size is represented by a value that is larger the larger the dot size, the transparent ink ejection position decision unit can decide a dot size of transparent ink to be ejected to each ejection position in such a manner that a sum of values of dot sizes of each color of ink for coloring to be ejected to each ejection position decided in the color ink ejection position decision unit and a value of a dot size of transparent ink to be ejected to each ejection position is as close as possible to a prescribed reference value.

[0016] Thus, it is possible to realize uniformization of a thickness of an ink layer formed.

[0017] The modeling method of the present application is for modeling a modeling object by forming layers at different positions in a predetermined layering direction of the modeling object as ink layers based on a plurality of slice images showing cross-sectional shapes and color matching of the layers of the modeling object, and layering the ink layers, in which the following steps are performed: a color ink ejection position decision step of deciding whether to eject each color of ink for coloring from each ejection position constituting a layer by quantization processing based on a slice image corresponding to the layer; a transparent ink ejection position decision step of deciding whether to need to eject transparent ink, i.e., transparent ink, from each ejection position based on whether to eject each color of ink for coloring from the ejection position decided in the color ink ejection position decision step; and a layer formation step of causing a color ink head and a transparent ink head to eject each color of ink and transparent ink from each ejection position in accordance with the decisions in the color ink ejection position decision step and the transparent ink ejection position decision step, thereby forming a layer.

[0018] Also, in the color ink ejection position decision step, a dot size of the ink to be ejected is also decided, in the transparent ink ejection position decision step, whether to eject transparent ink and the dot size from each ejection position are decided based on whether to eject each color of ink for coloring and the dot size of the ink from each ejection position decided in the color ink ejection position decision step, the color ink head and the transparent ink head are able to eject ink of a plurality of dot sizes, and in the layer formation step, the color ink head and the transparent ink head are caused to eject each color of ink and transparent ink of the dot size in accordance with the decisions in the color ink ejection position decision step and the transparent ink ejection position decision step from each ejection position.

[0019] Thus, transparent ink of a dot size corresponding to the dot size of the ejected color ink can be filled in each ejection position.

[0020] Also, when a value of a number whose value is larger as a dot size is larger is used to express the dot size, in the transparent ink ejection position decision step, the dot size of the transparent ink to be ejected from the ejection position is decided in such a manner that the sum of the values of the dot sizes of each color of ink for coloring to be ejected from the ejection position decided in the color ink ejection position decision step and the dot size of the transparent ink to be ejected from the ejection position is as close as possible to a prescribed reference value.

[0021] Thus, uniformization of the thickness of the formed ink layer can be achieved.

[0022] In addition, the modeling apparatus of the present application models a modeling object by forming layers at different positions in a predetermined stacking direction of the modeling object as ink layers based on a plurality of slice images showing cross-sectional shapes and colorings of the layers of the modeling object, and stacking the ink layers, and includes: a color ink ejection position determination unit that determines whether to eject each ink of a plurality of colors of ink for coloring from each ejection position constituting a layer by quantization processing based on a slice image corresponding to the layer; a transparent ink ejection position determination unit that determines whether to eject transparent ink, i.e., transparent ink, from an ejection position corresponding to a pixel based on a density of the pixel for each pixel in a coloring region of the slice image before the color ink ejection position determination unit performs the quantization processing; a color ink head capable of ejecting each ink of the plurality of colors of ink; a transparent ink head capable of ejecting the transparent ink; and a layer forming unit that causes the color ink head and the transparent ink head to eject each color of ink and the transparent ink from each ejection position as determined in the color ink ejection position determination unit and the transparent ink ejection position determination unit, thereby forming the layer.

[0023] The slice image can be an image in which a pixel value is represented by a plurality of gradations for each color of a prescribed color system in each pixel.

[0024] In addition, the slice image can include a plurality of images obtained by dividing each color of a plurality of colors of ink, in which a pixel value is represented by a plurality of gradations in each pixel, respectively.

[0025] By determining whether to eject the transparent ink from each ejection position based on the divided slice image, the determination accuracy of determining whether to eject the transparent ink can be improved compared to a case of determining based on the slice image before division.

[0026] Also, the transparent ink ejection position determination unit, when it is determined that the transparent ink is to be ejected, can determine a dot size of the ink based on the density of the pixel, the transparent ink head can eject the transparent ink in a plurality of dot sizes, and the layer forming unit can cause the transparent ink head to eject the transparent ink in the dot size as determined in the transparent ink ejection position determination unit from each ejection position.

[0027] Thus, the transparent ink can be filled in a more appropriate amount compared to a case in which the dot sizes are uniform.

[0028] The shaping method of the present application is for shaping an object by forming layers at different positions in a predetermined layering direction of the object as ink layers based on a plurality of slice images showing cross-sectional shapes and color matching of the layers, and layering the ink layers, in which the following steps are performed: based on the slice image corresponding to a layer, determining whether to eject each ink of a plurality of colors of ink for color matching from each ejection position constituting the layer by quantization processing; a transparent ink ejection position determining step of determining whether to need to eject transparent ink, i.e., transparent ink, from an ejection position corresponding to a pixel based on the gradation of the pixel for each pixel in a color matching region of the slice image before the quantization processing in the color ink ejection position determining step; and a layer forming step of causing a color ink head and a transparent ink head to eject each color of ink and transparent ink from each ejection position according to the determination in the color ink ejection position determining step and the transparent ink ejection position determining step, thereby forming a layer.

[0029] The slice image can be an image in which pixel values are expressed in a plurality of gradations for each color of a prescribed color matching system in each pixel.

[0030] In addition, the slice image can include a plurality of images in which pixel values are expressed in a plurality of gradations in each pixel for each color of a plurality of colors of ink, obtained by dividing the slice image by each color.

[0031] By determining whether to need to eject transparent ink from each ejection position based on the divided slice image, the determination accuracy of determining whether to need to eject transparent ink can be improved compared to the case of determining based on the slice image before division.

[0032] Also, in the transparent ink ejection position determining step, in the case where it is determined to eject, the dot size of the ink can also be determined based on the gradation of the pixel, the transparent ink head can eject a plurality of dot sizes of ink, and in the layer forming step, the transparent ink head can be caused to eject transparent ink of the dot size according to the determination in the transparent ink ejection position determining step from each ejection position.

[0033] Thus, compared to the case where the dot sizes are uniform, the transparent ink can be filled in a more appropriate amount.

[0034] Effects of the Invention

[0035] The shaping device and shaping method of the present application determine whether to need to eject transparent ink for each ejection position, and eject the transparent ink according to the determination, so the amount of transparent ink used when forming each layer can be saved, and the amount of ink scraped off when planarizing can also be reduced, so the quality of the surface of the object can be suppressed from decreasing. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a drawing showing an example of the structure of the shaping device 100 of the present application.

[0037] Figure 2 is a view showing an example of a molded article 50 molded by the molding apparatus 100.

[0038] Figure 3 is a view showing an example of the structure of the head 110.

[0039] Figure 4 is a view showing an example of the processing flow of the control section 140.

[0040] Figure 5 is a view showing a first specific example of the ink ejection position determination method in the transparent ink ejection position determination section 143.

[0041] Figure 6 is a view showing a second specific example of the ink ejection position determination method in the transparent ink ejection position determination section 143.

[0042] Figure 7 is a view showing a third specific example of the ink ejection position determination method in the transparent ink ejection position determination section 143.

[0043] Figure 8 is a view showing a fourth specific example of the ink ejection position determination method in the transparent ink ejection position determination section 143.

[0044] Figure 9 is a view showing another example of the fourth specific example of the ink ejection position determination method in the transparent ink ejection position determination section 143.

[0045] Figure 10 is a view showing an example of the processing flow of the control section 140.

[0046] Figure 11 is a view showing the ink ejection position determination method in the transparent ink ejection position determination section 143.

[0047] Figure 12 is a view showing another example of the ink ejection position determination method in the transparent ink ejection position determination section 143. DETAILED DESCRIPTION

[0048] Hereinafter, an embodiment of the present application will be described with reference to the accompanying drawings. In addition, in the following description and drawings, the same reference numerals are assigned to the same functional sections, and the description of the functional sections already described will be omitted or will be given within a necessary range.

[0049] In Figure 1An example of the structure of the modeling device 100 of the present application is shown in FIG. 1. The modeling device 100 is a modeling device (3D printer) that models a three-dimensional modeled object 50 by a layering modeling method. The layering modeling method referred to herein is a method in which data (hereinafter referred to as "modeled object data") representing the three-dimensional shape, surface color, and the like of the modeled object 50 is sliced in the thickness of an ink layer along a predetermined layering direction, each layer is sequentially formed into an ink layer based on the sliced image of each layer thus obtained, and the layers are layered, thereby modeling the modeled object 50.

[0050] Figure 2 FIG. 1 is a diagram showing an example of the modeled object 50 modeled by the modeling device 100, and shows the structure of the X-Y cross section of the modeled object 50 that is orthogonal to the layering direction (Z direction). The structure of the Z-X cross section and the Z-Y cross section of the modeled object 50 that are perpendicular to the Y direction and the X direction is the same structure.

[0051] The modeled object 50 has at least an internal region 51 and a colored region 52. The modeling device 100 models the modeled object 50 by sequentially forming ink layers of such a cross-sectional structure and layering the ink layers.

[0052] The internal region 51 is a region that constitutes the inside of the modeled object 50. In the present embodiment, the internal region 51 is formed as a region having the function of a light reflecting region by being formed with white ink. The light reflecting region is a light reflecting region for reflecting light incident from the outside of the modeled object 50 via the colored region 52 or the like. The light reflecting region can also be formed as another region formed around the internal region 51. In this case, the internal region 51 can be formed with ink other than white ink.

[0053] The colored region 52 is a region having a prescribed thickness that is colored with color ink. The modeling device 100 ejects color ink of each color from each inkjet head of the head 110 and causes the color ink to land around the internal region 51, thereby forming the colored region 52 around the internal region 51 in each layer. At this time, by appropriately determining whether to eject color ink of each color to each ejection position (each position at which ink ejected from the inkjet head can land, determined in accordance with the modeling resolution of the modeling device 100) that constitutes the colored region 52, it is possible to express each color in the colored region 52.

[0054] In addition, when the amount of color ink accumulated in each ejection position differs due to the color to be expressed, an ink layer having unevenness is formed, and layering such a layer can result in a decrease in the quality and strength of the modeled object 50. Therefore, in the present application, by the method described later, transparent ink is ejected to the ejection position and the like to which color ink is not ejected, thereby achieving planarization of the layer and suppressing the amount of use of transparent ink.

[0055] Furthermore, areas other than the internal region 51 and the colored region 52 can be formed according to the required quality of the model 50. For example, a transparent region (internal transparent region) can be formed by spraying transparent ink between the internal region 51 and the colored region 52. By forming an internal transparent region, it is possible to prevent ink mixing between the internal region 51 and the colored region 52. Alternatively, a transparent region (external transparent region) can be formed by spraying transparent ink around the colored region 52. By forming an external transparent region, it is possible to protect the outer surface of the model 50.

[0056] The shaping device 100 can shape an object 50 and form a support layer 60 around it as needed. The support layer 60, for example, supports a stacked structure of objects by surrounding the outer periphery of the object 50. When the object 50 alone has a shape that cannot maintain a stable posture, forming the support layer 60 around it can stabilize the posture of the object 50 during shaping. When forming the support layer 60, a known material for easily removable support layers is used to form the support layer 60 together with the object 50, and the support layer 60 is removed after the object 50 is shaped.

[0057] For example, Figure 1 As shown, the styling device 100 includes a head 110, a styling table 120, a scanning drive unit 130, and a control unit 140. However, the styling device 100 may not necessarily be physically integrated. For example, it may be structured such that one or more functional units are extracted as separate devices and information is transmitted and received via wired or wireless communication, thereby performing functions as a single unit.

[0058] In addition, except for the points described below, the shaping device 100 may have the same or identical structure as known shaping devices. Specifically, except for the points described below, the shaping device 100 may have the same or identical features as known shaping devices that shape objects by ejecting droplets of material used as the object 50 using an inkjet head. Furthermore, in addition to the structure shown in the figure, the shaping device 100 may also have various structures necessary for shaping the object 50, for example.

[0059] The head 110 is a portion that ejects a material (modeling material) of the modeling object 50. Specifically, the material of the modeling object 50 is ink, and more specifically, for example, ink that is cured according to a prescribed condition. The head 110 has a plurality of inkjet heads 111 that eject prescribed ink from each inkjet head to each ejection position that constitutes an ink layer, according to control by the control section 140 described later. Each ejection position is determined according to the modeling resolution of the modeling device 100. Furthermore, an ink layer is formed by curing ink that lands on each ejection position according to a prescribed condition. In this example, as ink that is cured according to a prescribed condition, ultraviolet-curable ink (UV ink) that is cured from a liquid state by irradiation of ultraviolet rays is used.

[0060] In addition, the head 110 ejects ink that is used as a material of the support layer 60, in addition to ink that is used as a material of the modeling object 50, as necessary. Thereby, the head 110 forms the support layer 60 around the modeling object 50.

[0061] The structure of the head 110 is described in more detail. Figure 3 An example of the structure of the head 110 is shown. In this example, the head 110 has a plurality of inkjet heads 111, a plurality of ultraviolet light sources 112, and a flattening roller 113. In addition, as the plurality of inkjet heads 111, there are an inkjet head 111s, an inkjet head 111w, an inkjet head 111y, an inkjet head 111m, an inkjet head 111c, an inkjet head 111k, and an inkjet head 111t, as shown in the drawing. These inkjet heads 111 are examples of ejection heads that are arranged in the main scanning direction, for example, in a manner aligned in the position in the sub-scanning direction. In addition, each inkjet head has a nozzle row in which a plurality of nozzles are arranged in a prescribed nozzle row direction, in a surface facing the modeling table 120. In addition, in this example, the nozzle row direction is a direction parallel to the sub-scanning direction.

[0062] The inkjet head 111s is a support material inkjet head that ejects ink that is used as a support material. As the support material, for example, a publicly known material for a support layer can be appropriately used. In addition, inkjet heads other than the inkjet head 111s among the plurality of inkjet heads 111 of the head 110 eject ink that is a material of the modeling object 50. The ink that is a material of the modeling object 50 is ink that constitutes a portion of the modeling object 50 at the time of completion of the modeling object 50.

[0063] The inkjet head 111w is a white ink inkjet head that ejects white (W-color) ink. White ink is an example of ink that is light-reflective, and is used, for example, when a region (light-reflecting region) having a property of reflecting light is to be formed in the modeling object 50. In this example, the white ink is used as a material of the support layer 60. Figure 2 In the example shown, by forming an internal region 51 that constitutes the inside of the modeling object 50 with white ink, the internal region 51 is able to function as a light-reflecting region.

[0064] The inkjet head 111y, the inkjet head 111m, the inkjet head 111c, and the inkjet head 111k are color inkjet heads for use in modeling the colored region 52 of the modeled object 50. More specifically, the inkjet head 111y ejects yellow (Y-color) ink. The inkjet head 111m ejects magenta (M-color) ink. The inkjet head 111c ejects cyan (C-color) ink. In addition, the inkjet head 111k ejects black (K-color) ink. In this example, the CMYK colors are examples of process colors used in full-color expression based on the subtractive color mixing method.

[0065] The inkjet head 111t is a transparent inkjet head for ejecting transparent ink. The transparent ink is, for example, transparent ink of a transparent color that is colorless and transparent (T) with respect to visible light. The transparent ink is used in modeling the colored region 52 of the modeled object 50 and the like.

[0066] Further, for the color inkjet heads and the transparent inkjet head, a head (binary head) that can set only one ejection amount at a normal ejection timing can be used as needed, or a head (multi-value head) that can select and set a plurality of ejection amounts (dot sizes) can be used.

[0067] The plurality of ultraviolet light sources 112 are light sources (UV light sources) for curing ink, which generate ultraviolet light for curing ultraviolet-curable ink. In this example, the plurality of ultraviolet light sources 112 are respectively provided on one end side and the other end side in the main scanning direction of the head unit 110 in a manner in which the arrangement of the ultraviolet light sources 112 is spaced apart by the inkjet heads. As the ultraviolet light sources 112, for example, a UV LED (ultraviolet LED) or the like can be appropriately used. In addition, as the ultraviolet light sources 112, a metal halide lamp, a mercury lamp, or the like is also considered.

[0068] The flattening roller 113 is a flattening unit for flattening an ink layer formed by ink ejected from each inkjet head. The flattening roller 113 contacts the surface of the ink layer in a prescribed scanning cycle (for example, when performing a main scanning operation) to remove a portion of the ink before curing, thereby flattening the ink layer and adjusting the thickness of the ink layer to a predetermined thickness.

[0069] By using the head unit 110 having the above structure, the ink layer constituting the modeled object 50 can be appropriately formed. In addition, by forming the modeled object 50 in a manner in which a plurality of ink layers are overlapped, the modeled object 50 can be appropriately modeled.

[0070] The molding table 120 is a table-shaped member for supporting the molding object 50 in molding, and is provided at a position facing the inkjet head of the head portion 110. The molding object 50 in molding and the support layer 60 are placed on the upper surface of the molding table 120. In this example, the molding table 120 has a structure in which at least the upper surface is movable in the layering direction (Z direction in the drawing), and at least the upper surface of the molding table 120 is moved according to the progress of molding of the molding object 50 by driving of the scanning drive portion 130. The layering direction is a direction in which ink layers are layered in the layering molding method. In this example, the layering direction is a direction orthogonal to the main scanning direction (Y direction in the drawing) and the sub scanning direction (X direction in the drawing) that are set in advance in the molding apparatus 100.

[0071] The scanning drive portion 130 is a drive portion that causes the head portion 110 to perform a scanning operation of relatively moving with respect to the molding object 50 in molding. The relative movement of the head portion 110 with respect to the molding object 50 in molding means relative movement of the head portion 110 with respect to the molding table 120. The scanning operation of the head portion 110 means a scanning operation of the inkjet head possessed by the head portion 110. In this example, the scanning drive portion 130 causes the head portion 110 to perform a main scanning operation (Y scanning), a sub scanning operation (X scanning), and a layering direction scanning (Z scanning) as the scanning operation.

[0072] The main scanning operation means an operation in which the head portion 110 relatively moves with respect to the molding object 50 in molding in the main scanning direction while ejecting ink. The sub scanning operation means an operation in which the head portion 110 relatively moves with respect to the molding object 50 in molding in the sub scanning direction orthogonal to the main scanning direction. With regard to the sub scanning operation, an operation in which the head portion 110 relatively moves with respect to the molding table 120 in the sub scanning direction by a predetermined feed amount, and the like can also be considered. The layering direction scanning means an operation in which the head portion 110 relatively moves with respect to the molding object 50 in molding in the layering direction. The scanning drive portion 130 causes the head portion 110 to perform the layering direction scanning according to the progress of the molding operation, thereby adjusting the relative position of the inkjet head with respect to the molding object 50 in molding in the layering direction. By being configured as such, it is possible to appropriately perform the molding of the molding object 50 by the layering molding method.

[0073] The control portion 140 is a structure including a processor or the like, and is used for controlling the generation of the slice image, the determination of the ejection position at which each ink ejected from each inkjet head lands, and the ejection of each ink from each inkjet head to each ejection position.

[0074] The control section 140 includes a slice image generation unit 141, a color ink ejection position decision unit 142, a transparent ink ejection position decision unit 143, and a layer formation unit 144. The processing performed by each of these units can be implemented by a processor. Specifically, each process can be implemented by a processor that acts based on program or the like information and a memory for storing program or the like information in which the content of each process is described. The processor can implement the functions of each unit by separate hardware, or can implement the functions of each unit by integrated hardware. The processor can use various processors such as a CPU, a GPU, a DSP, or the like. The memory can use a semiconductor memory such as an SRAM, a DRAM, a magnetic storage device such as a hard disk device, an optical storage device, or the like. The memory holds a command that can be read by a computer, and the command implements the processing of each unit of the control section 140 by being executed by the processor.

[0075] Next, the processing performed by each unit included in the control section 140 will be described. In Figure 4 The processing flow is shown in FIG. 17.

[0076] Before performing the formation action of the modeled object 50, the slice image generation unit 141 generates a plurality of slice images showing the cross-sectional shape and the coloration of each layer at each different position in the predetermined layering direction of the modeled object 50, and after converting the plurality of slice images to a resolution and a color matching system that match the modeling device 100, the plurality of slice images are divided by each color represented by each color of ink used in the modeling device 100 (S1: slice image generation step).

[0077] Specifically, first, modeled object data indicating the modeled object 50 is input (S1-1). The modeled object data is data indicating the three-dimensional shape, the surface color, the orientation at the time of modeling, and the like of the modeled object 50. In the modeled object data, the surface color can be represented by any color matching system such as an RGB color matching system, a CMYK color matching system, or the like that is independent of the modeling device 100.

[0078] Next, the slice image generation unit 141 generates a plurality of slice images showing the cross-sectional shape and the coloration of each layer at each different position in the predetermined layering direction of the modeled object 50 based on the modeled object data (S1-2). Specifically, the modeled object data is sliced in the layering direction at the thickness of an ink layer, and the cross-sectional shape and the surface color of each portion resulting from the slicing are extracted, and a slice image showing the cross-sectional shape of the internal region 51 and the colored region 52 and the coloration of the colored region 52 and the like is generated by processes such as providing a colored region 52 having a prescribed thickness to the surface color around the internal region 51. Each slice image corresponds to each ink layer of the plurality of ink layers formed when modeling the modeled object.

[0079] Next, in a case where the resolution of the slice image is different from the modeling resolution of the modeling device 100, the slice image generation unit 141 converts the resolution of the slice image to the modeling resolution of the modeling device 100 (S1-3).

[0080] In addition, in a case where the color expressed in the colored region 52 of the slice image is independent of the color of the modeling device 100, the slice image generation unit 141 converts the color expressed in the colored region 52 to a color matching the color of each of the color inks used in the modeling device 100 (S1-4).

[0081] Specifically, for example, first, the color expressed in the colored region 52 of the slice image in a form independent of the modeling device 100 is subjected to color conversion to the Lab color system based on an input profile prepared in advance. The input profile mentioned here is, for example, an ICC profile that establishes correspondence between the color space of the Lab color system and the color used in the modeling object data. Using this input profile, the color expressed in the modeling object data in the RGB color system or the CMYK color system is converted to a color expressed in the Lab color system, for example.

[0082] After the color conversion to the Lab color system, the slice image generation unit 141 performs color conversion to a color matching the color of the color ink (dependent on the modeling device 100) used in the modeling device 100 using a device profile prepared in advance in accordance with the characteristics of the modeling device 100. The device profile mentioned here is, for example, an ICC profile that establishes correspondence between the color space of the Lab color system and the color of the color ink used in the modeling device 100. Using this device profile, the color expressed in the Lab color system is converted to the color of the color ink (for example, the color of the CMYK color system) used in the modeling device 100.

[0083] Further, in a case where the modeling execution data is generated based on only the modeling object data, color conversion and the like are also considered to be performed by a simpler method without using a profile such as an ICC profile for color conversion and the like. That is, for example, it is also considered that the color expressed in the modeling object data in the RGB color system is converted in form to a color expressed in the CMYK color system and the like according to a fixed conversion formula or the like.

[0084] However, in a case where color conversion is performed by such a simple method, it is sometimes difficult to appropriately express a desired color in the molded article 50. For example, in a case where a three-dimensional molded article 50 is molded, as compared with a case where a two-dimensional image is printed, the range of colors (color gamut) that can be expressed by a combination of the same colors of ink is generally small. Therefore, when color conversion is performed by a simple method without using an ICC profile or the like, a large color deviation or the like is easily generated. Therefore, by performing color conversion using a device profile or the like that matches the ink used, color conversion can be appropriately performed with higher precision.

[0085] Next, the slice image generation unit 141 divides the slice image of each layer after these processes are performed for each color of ink (S1-5).

[0086] Specifically, in a case where each pixel of the colored region 52 of the slice image is expressed in the CMYK color system, for example, four divided slice images corresponding to the inks of C, M, Y, and K are generated in the division. In addition, since at least the internal region 51 is formed by white, a divided slice image corresponding to the white ink is generated. Also, in a case where the support layer 60 is formed, a divided slice image corresponding to the ink used as the support material is generated.

[0087] The color ink ejection position determination unit 142 determines whether to eject the multiple colors of ink for coloring to each ejection position that constitutes an ink layer by quantization processing based on the slice image corresponding to the ink layer (S2: color ink ejection position determination step). Specifically, regarding each ink layer that constitutes the molded article 50, quantization processing is performed on each divided slice image corresponding to each color of ink obtained by the division.

[0088] The quantization processing referred to here means that, regarding each pixel that constitutes a divided slice image, the gradation of the color expressed by a plurality of gradations is converted to a smaller number of gradations, for example, using an error diffusion method or a dithering method.

[0089] In addition, in a case where the inkjet head for color ink provided in the head unit 110 is a head (binary head) that can only set one ejection amount at a normal ejection timing, the smaller number of gradations referred to here is two gradations corresponding to ejection and no ejection. In this case, the divided slice image in which each pixel is expressed by a plurality of gradations is converted to a divided slice image in which each pixel is expressed by two gradations.

[0090] On the other hand, if the color inkjet head equipped with the head 110 is a multi-value head that can select and set multiple ejection amounts (dot sizes), for example, when it is set to be able to select large, medium, and small dot sizes, then fewer gray levels are provided, corresponding to four gray levels respectively for ejection (large dot size), ejection (medium dot size), ejection (small dot size), and no ejection. Therefore, in this case, the segmented slice image representing each pixel with multiple gray levels is converted, for example, into three segmented slice images representing each pixel with two gray levels (i.e., with and without dots) for each dot size of large, medium, and small.

[0091] also, Figure 4 The processing flow of the slice image generation unit 141 is not limited to this, and can be appropriately changed within the scope of the processing contents that can be performed.

[0092] The transparent ink ejection position determination unit 143 determines whether to eject transparent ink, i.e., transparent ink, to each ejection position based on whether to eject ink of each color for coloring to each ejection position as determined in the colored ink ejection position determination unit 142 (S3: transparent ink ejection position determination step).

[0093] Reference Figure 5 The first specific example illustrating the method for determining whether or not to spray transparent ink is explained. Figure 5 In (a) and (b), pixels Pc1, Pc2, Pc3, and Pc4 at the same position in the four segmented slice images corresponding to the four colors of colored ink c1, c2, c3, and c4 are extracted respectively. It can identify whether colored ink of each color is sprayed to the corresponding spray position based on whether the coloring of pixels Pc1, Pc2, Pc3, and Pc4 is black or white. Specifically, white indicates that colored ink is not sprayed to the corresponding spray position, and black indicates that colored ink is sprayed.

[0094] When it is assumed that at most one color of colored ink can be ejected to a single ejection position, the determination is as follows: Figure 5 As illustrated in (a), transparent ink is not sprayed onto the location from which any colored ink (here, colored ink c1) is sprayed, and as Figure 5 As illustrated in (b), transparent ink t is sprayed onto the spraying position of colored ink that has not been sprayed with any color, so that the thickness of the layer is consistent with the position where colored ink has been sprayed, thereby achieving uniformity of the ink layer thickness.

[0095] Reference Figure 6 A second specific example illustrates the method for determining whether or not to spray transparent ink. Figure 5 Similarly, in (a) and (b), Figure 6In (a), (b), and (c), pixels Pc1, Pc2, Pc3, and Pc4 at the same position in the four segmented slice images corresponding to the four colors of colored ink c1, c2, c3, and c4 are extracted respectively. Furthermore, it is possible to identify whether colored ink of each color is ejected to the ejection position corresponding to the pixel position based on whether the pixel Pc1, Pc2, Pc3, and Pc4 are colored black or white.

[0096] exist Figure 5 In the example, it was assumed that at most one color of colored ink was ejected to a single ejection position. However, in systems like CMYK, sometimes two colors are ejected to a single ejection position depending on the desired color. In this case, when the transparent ink is set to a binary printhead, then... Figure 6 As illustrated in (a), transparent ink is not sprayed at the spraying position where two colored inks (in this case, colored inks c1 and c3) are sprayed, and as... Figure 6 As illustrated in (b), transparent ink t is sprayed onto the spraying position of a single-color ink (here, color ink c1), thereby making the layer thickness consistent with the spraying position of a two-color ink. In contrast, as... Figure 6 As illustrated in (c), for the ejection position of colored ink that has not been ejected in any color, it is limited to the position where it can be ejected with the same color as the ink. Figure 6 In case (b), with the same amount of transparent ink t, the layer thickness is insufficient relative to the ejection position where two colors of colored ink are ejected. However, experiments have confirmed that even if the thickness is insufficient at a partial ejection position, for example, when the ink layer is planarized by the planarization roller 113 at a predetermined scanning cycle, the insufficient amount is roughly compensated by excess ink flowing to other positions. Therefore, in the case where a maximum of two colors of colored ink are ejected to one ejection position, by utilizing... Figure 6 The illustrated method determines the ejection position of transparent ink, and can achieve uniform ink layer thickness even when the inkjet head is a binary head.

[0097] Reference Figure 7 A third specific example illustrates the method for determining whether or not to spray transparent ink. Figure 6 Similarly, in (a), (b), and (c), Figure 7 In (a), (b), and (c), pixels Pc1, Pc2, Pc3, and Pc4 at the same position in the four segmented slice images corresponding to the four colors of colored ink c1, c2, c3, and c4 are extracted respectively. Furthermore, it is possible to identify whether colored ink of each color is ejected to the ejection position corresponding to the pixel position based on whether the pixel Pc1, Pc2, Pc3, and Pc4 are colored black or white.

[0098] existFigure 6 The example illustrates the case where a maximum of two colors of colored ink are ejected to a single ejection position, and the transparent ink is ejected using a binary inkjet head. Figure 7 This example illustrates the case where the inkjet head for transparent ink is a multi-value head. In this case, such as... Figure 7 As illustrated in (a), transparent ink is not sprayed towards the spraying location where two colors of colored ink (here, colored inks c1 and c3) are sprayed, as... Figure 7 As illustrated in (b), a transparent ink tS of the same amount as that used in the inkjet head is ejected to the ejection position of a colored ink (here, colored ink c1) that is being ejected in only one color. Figure 7 As illustrated in (c), twice the amount of transparent ink tM as transparent ink tS is sprayed onto the spraying position of colored ink that has not been sprayed with any color, thereby achieving uniformity of ink layer thickness.

[0099] Reference Figure 8 and Figure 9 A fourth specific example illustrates the method for determining whether or not to spray transparent ink. Figure 8 (a), (b), (c) and Figure 9 In (a), (b), and (c), when both the inkjet head for colored ink and the inkjet head for transparent ink are multi-value heads, for example, when each inkjet head can eject ink at three different amounts (e.g., 1x, 2x, 3x) of ink output (dot size), the pixels at the same location in a total of 12 segmented slice images corresponding to the three dot sizes of each of the four colors of colored ink c1, c2, c3, and c4 are extracted: Pc1S (dot size S of colored ink c1 (1x dot size, the same below)), Pc2S (dot size S of colored ink c2), Pc3S (dot size S of colored ink c3), Pc4S (dot size S of colored ink c4), and Pc1M (dot size M of colored ink c1 (2x dot size, the same below)). Pc2M (dot size M of colored ink c2), Pc3M (dot size M of colored ink c3), Pc4M (dot size M of colored ink c4), Pc1L (dot size L of colored ink c1 (3 times the dot size, the same below)), Pc2L (dot size L of colored ink c2), Pc3L (dot size L of colored ink c3), Pc4L (dot size L of colored ink c4), and can identify whether to spray colored ink of various colors / dot sizes to the corresponding spray position based on the two gray levels represented by black or white in the pixels Pc1S, Pc2S, Pc3S, Pc4S, Pc1M, Pc2M, Pc3M, Pc4M, Pc1L, Pc2L, Pc3L, Pc4L.

[0100] In this case, when the dot size is represented by a numerical value that increases with the size of the dot, the dot size of the transparent ink to be sprayed to the spray position is determined in such a way that the sum of the dot size values ​​of each color ink used for coloring to be sprayed to the spray position, as determined in the color ink spray position determination unit 142, and the sum of the dot size value of the transparent ink to be sprayed to the spray position are as close as possible to a predetermined reference value. This allows for the uniformity of the thickness of the formed ink layer.

[0101] Figure 8 This is an example where the specified baseline value is set to 3. For instance, when point dimensions S, M, and L are represented by the values ​​1, 2, and 3, in... Figure 8 In example (a), colored ink c1 with a dot size of 1 and colored ink c3 with a dot size of 2 are ejected to the ejection position, so the total dot size is 3. Therefore, the dot size reaches the specified reference value by colored ink alone, so it is decided not to eject transparent ink.

[0102] In addition, Figure 8 In example (b), colored ink c1 with a dot size of 3 is ejected to the ejection position, so the total dot size is 3. Therefore, the dot size reaches the specified reference value using only colored ink, so it is decided not to eject transparent ink.

[0103] In addition, Figure 8 In example (c), no colored ink is ejected to the ejection position, so the total dot size is 0. Therefore, in this case, it is decided to eject transparent ink with a dot size of 3.

[0104] on the other hand, Figure 9 This is an example where the specified baseline value is set to 6. When using the numerical values ​​1, 2, and 3 to represent point dimensions S, M, and L, in... Figure 9 In example (a), colored ink c1 with a dot size of 3 and colored ink c3 with a dot size of 3 are ejected to the ejection position, so the total dot size is 6. Therefore, the dot size reaches the specified reference value by colored ink alone, so it is decided not to eject transparent ink.

[0105] In addition, Figure 9 In example (b), colored ink c1 with a dot size of 3 is ejected to the ejection position, so the total dot size is 3. Therefore, in this case, it is decided to eject transparent ink with a dot size of 3.

[0106] In addition, Figure 9In the example of (c) of the above, no color ink is ejected to the ejection position, and thus the total of the dot sizes is 0. Therefore, in this case, it is desired to eject the transparent ink with a dot size of 6, but since the maximum dot size that can be ejected by the transparent ink head here is 3, the thickness of the layer is insufficient with respect to the ejection position of the dot size of 6. However, it is confirmed through experiments that even if the thickness at the ejection position of a part is insufficient like this, the amount of the insufficient amount is substantially supplemented due to the ink that is ejected in excess flowing to other positions and the like when the ink layer is flattened by the flattening roller 113 at a prescribed scanning cycle. Therefore, in this case, the dot size of the transparent ink can be determined to be 3. Further, if the transparent ink head possessed by the head unit 110 is capable of being used in a multi-pass manner, it is technically possible, for example, to eject the transparent ink with a dot size of 3 to the same ejection position in both the forward movement and the return movement. That is, according to this method, it is possible to eject the transparent ink with a dot size of 6, and thus the uniformity of the thickness of the ink layer is achieved.

[0107] The transparent ink ejection position determination unit 143 generates a slice image for the transparent ink for each layer, which is, for example, a slice image that expresses whether or not the transparent ink needs to be ejected to each ejection position as determined above for each pixel using two gray scales (i.e., with ejection and without ejection). Further, in the case of a multi-value head for the transparent ink, a slice image for the transparent ink is generated for each dot size.

[0108] The layer formation unit 144 reads information of whether or not the coloring ink needs to be ejected to each ejection position and whether or not the transparent ink needs to be ejected from the quantized divided slice images of each color generated in the color ink ejection position determination unit 142 and the slice image for the transparent ink generated in the transparent ink ejection position determination unit 143, and controls the head unit 110 and the scanning drive unit 130 in accordance with this information to cause the color ink head and the transparent ink head to eject the ink of each color and the transparent ink (S4: layer formation step). Thereby, it is possible to sequentially form each ink layer, and it is possible to shape the shaped object 50 by layering the formed layers.

[0109] (Other Embodiments)

[0110] Hereinafter, other embodiments of the present application will be described. The embodiments described below differ from the previous embodiments in the content of the processing performed by the control unit 140, and the hardware structure of the shaping device 100 and the configuration of the shaped object 50 that is the target of the shaping device 100 are the same as in the previous embodiments.

[0111] In Figure 10The text describes the processing flow of each unit included in the control unit 140 of this embodiment. Furthermore, the content of the slice image generation step (S1) is the same as in the previous embodiment, so its description is omitted. The color ink ejection position determination unit 142 of this embodiment determines whether to eject each of the various colors of ink for coloring to each ejection position constituting the ink layer through quantization processing based on the slice image corresponding to the ink layer (S3: Color Ink Ejection Position Determination Step). Specifically, for each ink layer constituting the model 50, quantization processing is performed on each segmented slice image corresponding to each color of ink obtained by segmentation.

[0112] Furthermore, the fewer gray levels mentioned here refer to two gray levels corresponding to ink ejection and inkless ejection. In this case, the segmented slice image representing each pixel using multiple gray levels is converted into a segmented slice image representing each pixel using only two gray levels.

[0113] Before the quantization process (S3) is performed by the color ink ejection position determination unit 142, the transparent ink ejection position determination unit 143 determines whether transparent ink, which is transparent ink, needs to be ejected to the ejection position corresponding to the pixel based on the density of each pixel in the colored area of ​​the slice image (S2: transparent ink ejection position determination step).

[0114] That is, the method for determining the ejection position is as follows: based on the density of pixels in the slice image before quantization, it is estimated whether colored ink should be ejected to the corresponding ejection position after quantization, thereby determining whether transparent ink needs to be ejected.

[0115] Reference Figure 11 The method for deciding whether or not to spray transparent ink is explained in detail. Figure 11 (a) shows the pixel with the lightest concentration, Pw, the pixel with the concentration being the threshold for whether transparent ink needs to be ejected, and the pixel with the densest concentration, Pb. Figure 11 (b) shows the estimation after quantization of whether colored ink C is ejected to the ejection position. In the case of a pixel with a density lighter than pixel Pt, it is estimated that colored ink C will not be ejected to the corresponding ejection position; in the case of a pixel with a density darker than pixel Pt, it is estimated that colored ink C will be ejected to the corresponding ejection position. Moreover, as Figure 11 As shown in (c), the method of spraying transparent ink T to the spraying position that is estimated not to be sprayed with colored ink C and not spraying transparent ink T to the spraying position that is estimated to be sprayed with colored ink C determines whether spraying is necessary.

[0116] In this way, by not spraying transparent ink T onto the spraying location where colored ink is sprayed, it is possible to achieve uniform ink layer thickness and reduce waste of transparent ink.

[0117] In addition, when the resolution of the slice image is converted after the judgment of the density of the pixel, the correspondence between the pixel and the discharge position needs to be additionally performed, and thus it is desirable that the slice image which is the judgment object of the density of the pixel is a slice image in which the pixels of the slice image and the discharge positions one-to-one correspond after the process (S1-3) for converting the resolution to the modeling resolution of the modeling device 100 is performed.

[0118] On the other hand, if before the quantization process, the slice image which is the judgment object of the density of the pixel can be a slice image before the process (S1-4) for converting the colors which are independent of the modeling device 100 to colors which match the colors of the colored inks used in the modeling device 100 is performed, can be a slice image after the process (S1-4) is performed, and can be a slice image after the division process (S1-5) is performed.

[0119] Specifically, for example, the judgment of the density of each pixel can be performed in the following scales.

[0120] In a case where the slice image which is the judgment object of the density of the pixel is an image before the division process is performed and the color of the pixel is expressed by the RGB colorimetric system, for example, when the sum of the R value, the G value, and the B value of the pixel is equal to or greater than a predetermined threshold value, it can be estimated that the colored ink is not discharged to the corresponding discharge position and decided that the transparent ink needs to be discharged. In addition, for example, when the image is converted to a gray scale image by an arbitrary method and the gray scale value of the pixel is equal to or greater than a predetermined threshold value, it can be estimated that the colored ink is not discharged to the corresponding discharge position and decided that the transparent ink needs to be discharged. Also, for example, when the RGB value of the pixel is converted to the Lab value and the L value which indicates the brightness is equal to or greater than a predetermined threshold value, it can be estimated that the colored ink is not discharged to the corresponding discharge position and decided that the transparent ink needs to be discharged. Further, in a case where the color of the pixel is expressed by a colorimetric system other than the RGB colorimetric system, it is also possible to decide whether the transparent ink needs to be discharged in the same manner as in the case of the RGB colorimetric system described above.

[0121] In a case where the slice image which is the judgment object of the density of the pixel is a division slice image after the division process is performed and the division slice image is a division slice image which is generated for each of the ink colors of C, M, Y, and K, for example, when the sum of the C value, the M value, the Y value, and the K value of the same pixel is less than a predetermined threshold value, it can be estimated that the colored ink is not discharged to the corresponding discharge position and decided that the transparent ink needs to be discharged. Even in a case where the combination of the colors of the division slice image and the number of types of the colors are different, it is also possible to decide whether the transparent ink needs to be discharged in the same manner as in the case of the CMYK colorimetric system described above.

[0122] In addition, although the method of determining whether or not transparent ink needs to be ejected to the corresponding ejection position based on the pixel value of the pixel of the object is exemplified here, the determination can be made, for example, by applying the slice image to a certain filter (e.g., a smoothing filter) or the like to correct the pixel value of the pixel taking into account the pixel values of the surrounding pixels, and then determining whether or not transparent ink needs to be ejected to the corresponding ejection position based on the corrected pixel value.

[0123] The transparent ink ejection position determination unit 143 generates a slice image for transparent ink for each layer, which is, for example, a slice image that represents whether or not transparent ink needs to be ejected to each ejection position as determined above using two gray scales (i.e., with ejection and without ejection) for each pixel.

[0124] Further, in the case where the transparent ink head provided in the head unit 110 is a head (multi-value head) that can select and set a plurality of ejection amounts (dot sizes), the ejection amount of the transparent ink can be set in stages according to the density of the pixel.

[0125] For example, when the colors of the coloring ink used in the modeling device 100 are CMYK four colors, it can be assumed that each ejection position is not ejected with coloring ink, is ejected with one color, and is ejected with two colors. Based on this assumption, two thresholds are set for the gradation of the pixel in the slice image before the quantization process is performed, in the case where the density of the pixel is smaller than the smaller threshold, it can be estimated that the coloring ink is not ejected to the ejection position, in the case where the density of the pixel is larger than the smaller threshold and smaller than the larger threshold, it can be estimated that the coloring ink of one color is ejected, and in the case where the density of the pixel is larger than the larger threshold, it can be estimated that the coloring ink of two colors is ejected. Therefore, in the case where the smaller threshold is small, it is set to eject the transparent ink more (with a larger dot size), in the case where the smaller threshold is large and the larger threshold is small, it is set to eject the transparent ink less (with a smaller dot size), and in the case where the larger threshold is large, it is set to not eject the transparent ink, whereby the uniformization of the thickness of the ink layer can be achieved.

[0126] Reference Signs List Figure 12 The determination method of determining whether or not transparent ink needs to be ejected in this case will be described in detail. Figure 12 (a) of FIG. 10 shows a pixel Pw with the lightest density, a pixel Pt1 with a density that is a first threshold value for determining whether or not transparent ink needs to be ejected, a pixel Pt2 with a density that is a second threshold value smaller than the first threshold value, and a pixel Pb with the darkest density. Figure 12(b) shows whether to eject the first color ink C1 and the second color ink C2 to the ejection position after the quantization process. At this time, in the case of a pixel that is lighter than the pixel Pt1 in density, it is estimated that no color ink is ejected to the corresponding ejection position, in the case of a pixel that is denser than the pixel Pt1 and lighter than the pixel Pt2 in density, it is estimated that only the first color ink C1 is ejected to the corresponding ejection position, and in the case of a pixel that is denser than the pixel Pt2 in density, it is estimated that both color inks are ejected to the corresponding ejection position. Also, as shown in Figure 12 (c) determines whether the transparent ink needs to be ejected in the following manner: more transparent ink Tm is ejected to the ejection position estimated to be ejected with no color ink, less transparent ink Ts is ejected to the ejection position estimated to be ejected with only the first color ink C1, and no transparent ink is ejected to the ejection position estimated to be ejected with both color inks.

[0127] In this case, the transparent ink ejection position determining unit 143 generates two slice images for the transparent ink with respect to each layer, for example, slice images that represent whether the transparent ink needs to be ejected to each ejection position as determined above, with the ejection (point size large), the ejection (point size small), and two gray scales corresponding to the ejection and no ejection.

[0128] In this way, by increasing and decreasing the amount of the transparent ink in accordance with the amount of the color ink, the uniformity of the thickness of the ink layer can be achieved, and the waste of the transparent ink can be reduced.

[0129] In addition, regarding the staging of the amount of the transparent ink, even if the transparent ink head possessed by the head unit 110 is a head (binary head) that can set only one amount of ejection at a normal ejection timing, as long as a multi-pass method can be employed, it is technically possible to eject the transparent ink to the same ejection position in both the forward and return movements, for example. Therefore, in this case, the increase and decrease of the amount of the transparent ink corresponding to the amount of the color ink can also be achieved by the same method as in the case of employing a multi-value head.

[0130] The layer forming unit 144 reads information on whether to eject the coloring ink to each ejection position and whether the transparent ink needs to be ejected from the divided slice images of each color after the quantization process generated in the color ink ejection position determining unit 142 and the slice images for the transparent ink generated in the transparent ink ejection position determining unit 143, and controls the head unit 110 and the scan driving unit 130 in accordance with the information to cause the color ink head and the transparent ink head to eject the ink of each color and the transparent ink (S4: layer forming step). Thereby, each ink layer can be formed in sequence, and the modeled object 50 can be modeled by layering the formed layers.

[0131] The shaping device 100 of the present application described above determines whether or not transparent ink needs to be ejected for each ejection position, and ejects transparent ink accordingly, so it is possible to save the amount of transparent ink used when forming each layer, and also to reduce the amount of ink scraped off when planarizing, so it is possible to suppress a decrease in the quality of the surface of the shaped object.

[0132] The present application is not limited to the above-described embodiments. The above-described embodiments are examples, and technical solutions having substantially the same structure as the technical concept described in the claims of the present application and achieving the same effects are included in the technical scope of the present application. That is, the above-described embodiments can be appropriately changed within the scope of the technical concept exhibited by the present application, and the embodiments obtained after such changes and improvements are also included in the technical scope of the present application.

Claims

1. A modeling apparatus that models a modeled object by forming layers at different positions in a predetermined layering direction of the modeled object as ink layers and layering the ink layers based on a plurality of slice images that show cross-sectional shapes and colorings of the layers of the modeled object, the modeling apparatus comprising: a color ink ejection position decision unit that decides, based on the slice image corresponding to the layer, by quantization processing, whether to eject each ink of a plurality of colors of ink for coloring to each ejection position that constitutes the layer; a transparent ink ejection position decision unit that, before the color ink ejection position decision unit performs quantization processing, decides, based on a pixel value of a pixel, whether to eject transparent ink, that is, transparent ink, to the ejection position corresponding to the pixel, for each pixel in a coloring region of the slice image that is divided by each color of the plurality of colors of ink; a color ink head that can eject each ink of the plurality of colors of ink; a transparent ink head that can eject the transparent ink; and a layer forming unit that causes the color ink head and the transparent ink head to eject the ink of each color and the transparent ink to the ejection position as decided in the color ink ejection position decision unit and the transparent ink ejection position decision unit, thereby forming the layer, the transparent ink ejection position decision unit, when it is decided that ejection is to be performed, further deciding a dot size of the transparent ink based on the pixel value of the pixel, the transparent ink head being capable of ejecting ink of a plurality of dot sizes, the layer forming unit causing the transparent ink head to eject the transparent ink of the dot size as decided in the transparent ink ejection position decision unit to the ejection position.

2. The modeling apparatus according to claim 1, wherein the slice image is an image in which a pixel value is represented by a plurality of gray scales for each color of a prescribed color system in the pixels.

3. The modeling apparatus according to claim 1, wherein the transparent ink ejection position decision unit, when it is decided that ejection is to be performed, sets the dot size of the transparent ink in stages based on a comparison result of the pixel value of the pixel and a plurality of threshold values.

4. A modeling method for modeling a modeled object by forming layers at different positions in a predetermined layering direction of the modeled object as ink layers and layering the ink layers based on a plurality of slice images that show cross-sectional shapes and colorings of the layers of the modeled object, in the modeling method, the following steps are performed: a color ink ejection position decision step of deciding, based on the slice image corresponding to the layer, by quantization processing, whether to eject each ink of a plurality of colors of ink for coloring to each ejection position that constitutes the layer; a transparent ink ejection position decision step of deciding, based on a pixel value of a pixel, whether to eject transparent ink, that is, transparent ink, to the ejection position corresponding to the pixel, for each pixel in a coloring region of the slice image that is divided by each color of the plurality of colors of ink, before performing quantization processing in the color ink ejection position decision step; and ​ ​ wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The layer forming step causes the color ink head and the transparent ink head to eject the inks of the respective colors and the transparent ink to the respective ejection positions in accordance with the determination in the color ink ejection position determination step and the transparent ink ejection position determination step, thereby forming the layer, wherein In the transparent ink ejection position determination step, the dot size of the transparent ink is determined based on the pixel value of the pixel in the case where the ejection is determined to be performed, In the layer forming step, the transparent ink head ejects the transparent ink of the dot size determined in the transparent ink ejection position determination step to the respective ejection positions.

5. The modeling method according to claim 4, wherein The slice image is an image in which the pixel values are represented by a plurality of gradations for each color of a prescribed color system in the respective pixels.

6. The modeling method according to claim 4, wherein wherein In the transparent ink ejection position determination step, the dot size of the transparent ink is set in stages based on the comparison result of the pixel value of the pixel and a plurality of threshold values in the case where the ejection is determined to be performed.

Images