JP2011073163A - Inkjet recording apparatus, inkjet recording method, program for use in inkjet recording, and three-dimensional printed object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus, an inkjet recording method, a program for use in inkjet recording, and a three-dimensional printed object, capable of forming a three-dimensional shape whose surface is beautifully colored without its color becoming dark. <P>SOLUTION: A laminate structure 1000 comprising at least one or more multicolor layer 1001 is formed. The multicolor layer 1001 forming the laminate structure 1000 has a structure such that a photo-curing ink of first color spreads across a predetermined range and a photo-curing ink of second color surrounds a predetermined range on the outer periphery thereof. The multicolor layer 1001 is formed by curing the discharged ink of the first and second color by application of light. Thus, in order to form the multicolor layer 1001, the photo-curing ink of the first color and the photo-curing ink of the second color can be cured at a time. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs three-dimensional printing using a photocurable ink, an ink jet recording method, a program used for ink jet recording, and a three-dimensional printed article.

  2. Description of the Related Art Conventionally, a technique for performing three-dimensional printing on the surface of an ejection medium using ink that is cured by heat, ultraviolet (UV), or the like is known. For example, Patent Document 1 discloses a technique for performing three-dimensional printing using a curable ink and a colored ink. Specifically, in Patent Document 1, curable ink ejected as ink droplets reaches the surface of a planar printing medium. The curable ink is cured or precured by a curing means to form a three-dimensional shape or a precursor thereof on the surface of the printing medium. Furthermore, the colored ink ejected as ink droplets performs printing on the surface of the printing medium and coloring, thereby performing three-dimensional printing on the surface.

JP 2008-188826 A

  In Patent Document 1, first, a three-dimensional shape is formed using a curable ink, and then a three-dimensional shape is colored using the last colored ink. That is, after the step of forming a three-dimensional shape is performed, a step of coloring the three-dimensional shape is performed as a separate step. Since the formation of the three-dimensional shape and the coloring are separate processes, there is a problem that it is difficult to cleanly color the complicated three-dimensional shape. For example, the size increases as the distance from the printing medium increases. In other words, when coloring is performed on a three-dimensional shape in which the upper shape is larger than the lower shape, the three-dimensional shape at a location close to the printing material (lower side) Since the surface of the surface is shielded by the upper portion, it is difficult to color the surface. In order to neatly color the surface of a complicated three-dimensional shape, a method of creating the three-dimensional shape itself with a colored curable ink is also conceivable. However, in this case, since the inside of the three-dimensional shape is formed with colored curable ink, it is considered that the color becomes dark as a result of the color overlap.

  The present invention provides an ink jet recording apparatus, an ink jet recording method, a program used for ink jet recording, and a three-dimensional printed modeled object capable of forming a three-dimensional shape with a color that is not dark and having a beautifully colored surface. Objective.

  The first problem-solving means that reflects the present invention is a darker color than the mounting table on which the ejection medium is mounted, the first color photocurable ink, and the first color photocurable ink. An inkjet head unit configured to be capable of discharging at least the second color photocurable ink, a frame for holding the inkjet head unit above the mounting table, and the inkjet head unit and the mounting table. A moving mechanism that moves the relative position of the placed ejection medium, and a light irradiation unit that is provided above the placing table and that emits light to cure the photocurable ink ejected from the inkjet head unit; A control unit that controls an operation in which the inkjet head unit ejects photocurable ink, an operation in which the light irradiation unit irradiates light, and an operation in which the moving mechanism moves the relative position. The control unit causes the inkjet head unit to discharge the first color photocurable ink and causes the moving mechanism to eject the first color photocurable ink so that the first color photocurable ink spreads over a predetermined range. The relative position is moved, and the second color is applied to the inkjet head unit so that the second color photocurable ink surrounds a predetermined range of the outer periphery of the first color photocurable ink. The photoirradiating ink is discharged and the relative position is moved by the moving mechanism, and the light irradiation unit is irradiated with light to cure the discharged first and second color photocurable inks. A plurality of color layer forming means for forming a plurality of color layers in which a predetermined range of the outer periphery of the first color photocurable ink that is spread is surrounded by the second color photocurable ink by irradiation; Moving the multi-color layer forming means Be to have a laminate forming means for forming a laminate structure in which at least one or more of the plurality color layers are stacked, it is characterized.

  According to a second problem-solving means reflecting the present invention, in the first problem-solving means, the control unit further causes the ink jet ink so that the photocurable ink of the first color spreads over a predetermined range. The light irradiation is performed to cause the head portion to eject the first color photocurable ink and to move the relative position to the moving mechanism to cure the ejected first color photocurable ink. A single-color layer forming unit that forms a single-color layer in which the photo-curable ink of one color spreads over a predetermined range by irradiating the portion with light; By operating the means, the laminated structure in which the plural color layers and the plural monochromatic layers are laminated is formed.

  According to a third problem-solving means reflecting the present invention, in the second problem-solving means, the stack forming means operates the single-color layer forming means more than the multi-color layer forming means, so that the single-color layer Forming the laminated structure including more than the plurality of color layers.

  According to a fourth problem-solving means reflecting the present invention, in any one of the first to third problem-solving means, the control unit further includes a predetermined range on the upper surface of the stacked structure after the operation of the stacked-layer forming means. The second color photocurable ink is ejected onto the upper surface of the laminated structure so as to form an upper surface layer in which the second color photocurable ink spreads over It has an upper surface layer forming unit that moves the relative position to the moving mechanism and irradiates the light irradiation unit with light to cure the discharged second photocurable ink.

  A fifth problem solving means reflecting the present invention is characterized in that, in the fourth problem solving means, the plurality of color layer forming means and the single color layer forming means are not operated after the operation of the upper surface layer forming means. To do.

  A sixth problem-solving means reflecting the present invention is any one of the first to fifth problem-solving means, wherein the inkjet head unit includes a colorless and transparent photocurable ink and the colorless and transparent photocurable ink. A determination unit configured to determine whether or not the colorless and transparent photo-curable ink can be discharged from the inkjet head unit. The control unit determines the colorless and transparent photocurable ink as the first color photocurable ink when the determination result of the determination unit is positive, and the determination result of the determination unit is negative. The method further comprises first color determining means for determining the other color photocurable ink as the first color photocurable ink.

  A seventh problem solving means reflecting the present invention is an ink jet recording method on a discharge medium using photocurable ink, wherein the first color photocurable ink spreads over a predetermined range. A multi-color layer forming step for forming a multi-color layer surrounding a predetermined range of the outer periphery of the photo-curable ink of the second color that is darker than the photo-curable ink of the first color; and the multi-color layer Forming a laminated structure including at least one or more of the plurality of color layers by executing a forming step, wherein the plurality of color layer forming steps includes a step in which the first color photocurable ink is predetermined. The first color photocurable ink is ejected so as to extend over the range, and the first ejection position that is the position from which the first color photocurable ink is ejected is moved. Discharging step and photocurable mold of the second color The second color photocurable ink is discharged so that the ink surrounds a predetermined range of the outer periphery of the first color photocurable ink spreading, and the second color photocurable ink A second ejection step for moving a second ejection position, which is an ejection position, and a first curing step for irradiating light to cure the ejected first color and second color photocurable ink. It is characterized by having.

  The eighth problem-solving means reflecting the present invention is the seventh problem-solving means, further comprising a single-color layer forming step of forming a single-color layer in which the photocurable ink of the one color spreads over a predetermined range. The monochromatic layer forming step ejects the first color photocurable ink and moves the first ejection position so that the first color photocurable ink spreads over a predetermined range. And a second curing step for irradiating light to cure the ejected first color photocurable ink, and the layer forming step further includes the monochromatic layer forming step. Is also performed to form the stacked structure including a plurality of the color layers and a plurality of the monochrome layers.

  According to a ninth problem-solving means reflecting the present invention, in the eighth problem-solving means, the layer forming step executes the single-color layer forming step more than the multi-color layer forming step, so that the single-color layer Forming the laminated structure including more than the plurality of color layers.

  A tenth problem solving means reflecting the present invention is the seventh problem solving means according to any one of the seventh to ninth problem solving means, wherein the second over the predetermined range of the upper surface of the laminated structure after execution of the laminated formation step. An upper surface layer forming step of forming an upper surface layer in which the photo-curable ink of the color of the ink spreads, and the upper surface layer forming step includes bringing the photo-curable ink of the second color into a predetermined range on the upper surface of the laminated structure. A second ejection step of ejecting the second color photocurable ink and moving the second ejection position, and curing the ejected second color photocurable ink so as to spread over And a third curing step of irradiating with light.

  An eleventh problem-solving means reflecting the present invention is characterized in that, in the tenth problem-solving means, the multi-color layer forming step and the single-color layer forming step are not executed after the upper surface layer forming step. To do.

  A twelfth problem solving means reflecting the present invention is that, in any of the seventh to eleventh problem solving means, it is possible to discharge a colorless and transparent photocurable ink as the first color photocurable ink. If the determination result of the determination step and the determination step is affirmative, the colorless and transparent photocurable ink is determined as the first color photocurable ink, and the determination result of the determination step is negative. In this case, the method further includes a first color determination step of determining, as the first color photocurable ink, a photocurable ink of another color that is darker than the colorless and transparent photocurable ink. It is characterized by that.

  According to a thirteenth problem solving means reflecting the present invention, the photocurable ink of the first color spreads over a predetermined range, and the predetermined range of the outer periphery thereof is larger than the photocurable ink of the first color. In order to form a plurality of color layers surrounded by the light-curable ink of the second color that is a dark color, the first color is set so that the light-curable ink of the first color spreads over a predetermined range. And a command to eject the first color photocurable ink to an inkjet head unit configured to be capable of ejecting at least the second color photocurable ink and the second color photocurable ink. A first ejection command step for giving a command to move the relative position to a moving mechanism that moves the relative position between the ink jet head unit and the ejection medium; and the second color photocurable ink is expanded. 1 color photocurable ink outer circumference The inkjet head unit is instructed to eject the second-color photocurable ink to the ejection medium so as to surround the predetermined range, and the relative position is moved with respect to the moving mechanism. A second ejection command step for commanding, and a light irradiation unit capable of irradiating light to the ejection medium in order to cure the ejected photocurable ink of the first color and the second color Then, the computer realizes the first irradiation command step for giving a command to irradiate light.

  According to a fourteenth problem solving means reflecting the present invention, in the thirteenth problem solving means, the first color photocurable ink is formed in order to form a single color layer that spreads over a predetermined range. The inkjet head unit is instructed to eject the first color photocurable ink so that the color photocurable ink spreads over a predetermined range, and the relative position is set to the moving mechanism. A third discharge command step for giving a command to move the light, and a second curing for giving a command to irradiate the light irradiation unit with light to cure the discharged photocurable ink of the first color. A single color layer formation command step having a command step, and the layer formation command step further operates the single color layer forming means to operate the multilayer including the plurality of color layers and the plurality of single color layers. Forming a granulated, to realize the computer that.

  According to a fifteenth problem solving means reflecting the present invention, in the fourteenth problem solving means, the stack formation command step executes the single color layer formation command step more than the plurality of color layer formation command steps. A computer is configured to form the stacked structure including more monochromatic layers than the plurality of color layers.

  According to a sixteenth problem solving means reflecting the present invention, in any one of the thirteenth to fifteenth problem solving means, after the operation of the lamination formation command step, the second problem over the predetermined range of the upper surface of the laminated structure. In order to form an upper surface layer in which the photocurable ink of the color of the ink spreads, the inkjet head unit is instructed to discharge the photocurable ink of the second color to the upper surface of the laminated structure, A fourth ejection command step for instructing the movement mechanism to move the relative position; and irradiating the light irradiation unit with light in order to cure the ejected second color photocurable ink. An upper surface layer formation instruction step having a third curing instruction step for giving an instruction is further realized in the computer.

  According to a seventeenth problem solving means reflecting the present invention, in the sixteenth problem solving means, the plurality of color layer formation command step and the single color layer formation command step are not executed after the execution of the upper surface layer formation command step. Is realized on a computer.

  According to an eighteenth problem solving means reflecting the present invention, in any one of the thirteenth to seventeenth problem solving means, the colorless and transparent photocurable ink is darker than the colorless and transparent photocurable ink. A determination command step for issuing a command for determining whether or not the inkjet head unit configured to be capable of discharging at least a photo-curable ink of a color can discharge the colorless and transparent photo-curable ink; and the determination command If the determination result of step is affirmative, the colorless and transparent photocurable ink is determined as the first color photocurable ink, and if the determination result of the determination command step is negative, the light of the other color is determined. A first color determination command step for determining a curable ink as the first color photocurable ink is further caused to be realized by a computer.

  A nineteenth problem solving means reflecting the present invention covers a predetermined range of the outer periphery of the first color photocurable ink that spreads over a predetermined range and the first color photocurable ink that spreads. A plurality of color layers comprising a second color photocurable ink that is darker than the first color photocurable ink, and the first color photocurable type that extends over a predetermined range. A monochromatic layer made of ink, a laminated structure in which the monochromatic layers are laminated so as to be larger than the multiple-color layers, and photocuring of the second color that extends over a predetermined range of the upper surface of the laminated structure And an upper surface layer made of mold ink.

  In the first, seventh and thirteenth problem solving means reflecting the present invention, a laminated structure in which at least one or more color layers are laminated is formed. In the multi-color layer forming the laminated structure, the photocurable ink of the first color spreads over a predetermined range, and the predetermined range of the outer periphery is darker than the photocurable ink of the first color. The photocurable ink of a certain second color is enclosed. The multi-color layer is formed by curing the ejected first color and second color inks by light irradiation. Therefore, by laminating a plurality of color layers, it is possible to form a laminated structure in which a predetermined range of the outer periphery is surrounded by the photocurable ink of the second color, in other words, a three-dimensional structure with a beautifully colored surface. . Furthermore, since the inside of the laminated structure is formed by the photocurable ink of the first color, the color does not become darker than when a three-dimensional shape is formed only by the photocurable ink of the second color.

  In the second, eighth, and fourteenth problem solving means reflecting the present invention, the monochromatic color in which the photocurable ink of the first color spreads over a predetermined range in addition to the plurality of color layers in the laminated structure. Layers are also included. When the laminated structure formed on the ejection medium is observed, it is often observed from the direction perpendicular to the paper surface, in other words, from the lamination direction of the laminated structure. When this stacked structure is observed from the stacking direction, the predetermined range of the outer periphery of the multi-color layer is surrounded by the photocurable ink of the second color, and therefore the second color is displayed in the stacking direction at the outer periphery of the stacked structure. You will see it over again. That is, as the number of multiple color layers stacked in the stacking direction increases, the optical thickness in the stacking direction on the outer periphery of the stacked structure increases. In other words, the color on the outer periphery of the stacked structure is observed darker as the number of the multiple color layers stacked in the stacking direction increases. The single color layer is formed of the first color photocurable ink, and the second color photocurable ink is darker than the first color photocurable ink. Therefore, by including a monochromatic layer in the stacked structure, even if the number of layers in the stacked structure increases, it is possible to mitigate an increase in the optical thickness in the stacking direction on the outer periphery of the stacked structure. As a result, it is possible to form a solid shape in which the second color on the outer periphery of the laminated structure is observed brightly.

  In the third, ninth, and fifteenth problem solving means reflecting the present invention, the laminated structure includes more monochromatic layers than plural color layers. Therefore, it becomes possible to form a three-dimensional shape with a clearer second color at the outer periphery of the laminated structure.

  In the fourth, tenth, and sixteenth problem solving means reflecting the present invention, an upper surface layer in which the photocurable ink of the second color spreads is formed over a predetermined range of the upper surface of the laminated structure. As described above, when the laminated structure is formed, the predetermined range of the outer periphery of the laminated structure is surrounded by the photocurable ink of the second color. Then, by forming the upper surface layer on the upper surface of the laminated structure, it is possible to form a three-dimensional shape in which the entire outer side is colored with the second color.

  In the fifth, eleventh and seventeenth problem solving means reflecting the present invention, a plurality of color layers and a single color layer are not formed on the upper surface of the upper surface layer. Since the upper surface layer is provided on the uppermost surface of the laminated structure, the color of the upper surface layer is not attenuated by the multi-color layer and the single color layer. Therefore, it is possible to form a three-dimensional shape with a more vivid color in which the entire outer side is colored with the second color.

  In the sixth, twelfth and eighteenth problem solving means reflecting the present invention, when the colorless and transparent photocurable ink can be ejected, the colorless and transparent photocurable ink is used as the first color photocurable ink. Used as On the other hand, when the colorless and transparent photocurable ink cannot be ejected, another color photocurable ink that is darker than the colorless and transparent photocurable ink is used as the first color photocurable ink. . Therefore, even when the transparent photocurable ink cannot be ejected, a three-dimensional shape can be formed.

  In the nineteenth problem solving means reflecting the present invention, the photocurable ink of the first color spreads over a predetermined range, and the photocurable ink of the second color surrounds the predetermined range of the outer periphery. A multilayer structure is provided that includes a plurality of color layers and a single color layer made of the photocurable ink of one color that extends over a predetermined range such that the single color layer is larger than the multiple color layers. And the upper surface layer which consists of a photocurable ink of the said 2nd color extended over a predetermined range is provided in the upper surface of the laminated structure. Therefore, compared to the case where the layers formed only of the photocurable ink of the second color are stacked, the use of the photocurable ink of the first color can provide a bright color stacked structure. It becomes possible. In addition, since more monochromatic layers are included in the laminated structure than in the plurality of color layers, the second color at the outer periphery of the laminated structure is expressed more brightly.

The figure explaining the laminated structure 1000 formed by printing based on the 1st Embodiment of this invention. FIG. 2 is a schematic diagram showing an outline of the inkjet recording apparatus 1 according to the first embodiment. The enlarged schematic diagram of the printing part 10 based on the said 1st Embodiment. FIG. 2 is a block diagram showing an electrical configuration of the inkjet recording apparatus 1 according to the first embodiment. The figure which shows the content memorize | stored in RAM420 and ROM430 based on the said 1st Embodiment. 6 is a flowchart for explaining print processing according to the first embodiment. The flowchart explaining execution of the laminated structure formation means 430c based on the said 1st Embodiment. The flowchart explaining execution of the monochromatic layer formation means 430b based on the said 1st Embodiment. The flowchart explaining execution of the multiple color layer formation means 430a based on the said 1st Embodiment. The flowchart explaining execution of the upper surface layer formation means 430d based on the said 1st Embodiment. The figure explaining the composition of UV curable ink based on the Example of the said 1st Embodiment. The figure explaining the characteristic of the laminated structure based on the said 1st Example. The schematic diagram which shows the structure of the inkjet head part 1100 based on a modification. The figure explaining a reference example and the comparative example 2. FIG.

  Embodiments for implementing the above problem solving means reflecting the present invention will be described below in detail with reference to the drawings. The above-mentioned problem solving means is not limited to the configuration described below, and various configurations can be adopted in the same technical idea. For example, in each configuration described below, a predetermined configuration can be omitted. In each process described below, a predetermined step can be omitted.

<First Embodiment>
[Outline of laminated structure]
The present invention relates to an ink jet recording apparatus, an ink jet recording method, a program, and a three-dimensional print modeled article that perform three-dimensional printing using a photocurable ink such as a UV curable ink. The three-dimensional printed model formed by the present invention is obtained by laminating structures as shown in FIGS. Here, the outline | summary of the three-dimensional printed molded article obtained by this invention is demonstrated using FIG.

  FIG. 1A shows a monochromatic layer 1001 formed using a photocurable ink of the first color. The monochromatic layer 1001 has a structure in which the cured first color photocurable ink spreads over a predetermined range. In FIG. 1A, as an example, the photocurable ink of the first color spreads in a rectangular shape. As the photocurable ink of the first color, a colorless and transparent UV curable clear ink is used. However, a relatively light color ink such as a UV curable white ink or a yellow ink may be used as the first color photocurable ink.

  FIG. 1B shows a multi-color layer 1002 formed using photocurable inks of the first color and the second color. The multi-color layer 1002 has a structure in which the cured first color photocurable ink spreads over a predetermined range, and the outer periphery of the predetermined color range is surrounded by the cured second color photocurable ink. . Here, the photocurable ink of the second color is darker than the photocurable ink of the first color. In FIG. 1B, as an example, the first color photocurable ink spreads in a rectangular shape, and the entire outer periphery thereof is surrounded by the second color photocurable ink. However, the second color photocurable ink may cover only a part of the outer periphery of the first color photocurable ink. As the photocurable ink of the second color, for example, UV curable yellow ink, cyan ink, magenta ink, black ink, and a mixture of these inks can be used.

  Here, the term that the photocurable ink of the second color is darker than the photocurable ink of the first color will be explained. Qualitatively, when the background is viewed through the same amount of ink, the ink that is difficult to visually recognize the background is defined as darker. Quantitatively, if the color of both the first color photocurable ink and the second color photocurable ink can be defined, the second color photocurable ink is the first color photocurable ink. It means that the lightness is lower than that of the color photocurable ink. However, as described above, when the clear ink is used as the first color photocurable ink, the clear ink is colorless and transparent, so that it is impossible to define the color. Therefore, throughout this specification, an ink whose color can be defined is defined to be darker than clear ink. That is, white has the highest brightness among all colors, but white ink is considered to be darker than clear ink. In other words, when clear ink is used as the first color photocurable ink, white ink may be used as the second color photocurable ink.

  FIG. 1C illustrates an upper surface layer 1003 formed using the photocurable ink of the second color. The top layer 1003 has a structure in which the cured photocurable ink of the second color spreads over a predetermined range. The upper surface layer 1003 is provided on the uppermost surface in the stacking direction of a stacked structure 1000 to be described later. Note that in FIG. 1C, the upper surface layer 1003 covers the entire uppermost surface in the stacking direction of the stacked structure 1000. However, the upper surface layer 1003 may cover only a part of the uppermost surface in the stacking direction of the stacked structure 1000.

  FIG. 1D shows a stacked structure 1000 formed by the above-described single color layer 1001, a plurality of color 1002 layers, and an upper surface layer 1003. This stacked structure 1000 includes more monochromatic layers 1001 than the plurality of colored layers 1002, and an upper surface layer 1003 is provided on the uppermost surface in the stacking direction. Since the upper surface layer 1003 is provided on the uppermost surface of the stacked structure 1000, the color of the upper surface layer 1003 is not attenuated by the multi-color layer 1002 and the single color layer 1001. In FIG. 1D, as an example, 20 monochromatic layers 1001a, 2 multicolor layers 1002a, 20 monochromatic layers 1001b, 2 multicolor layers 1002b, 20 monochromatic layers 1001c, and 2 layers. A stacked structure 1000 in which the upper surface layers 1003a are stacked in this order is shown. In FIG. 1D, it appears that the photocurable ink of the second color protrudes in the direction orthogonal to the stacking direction in the multi-color layer 1002. However, this expression is for ease of understanding, and in the actually formed single color layer 1001, the plurality of color layers 1002, and the upper surface layer 1003, the sizes in the direction orthogonal to the stacking direction are substantially the same.

[Outline of Inkjet Recording Apparatus 1]
FIG. 2A is a perspective view of the inkjet recording apparatus 1 according to the embodiment of the present invention for forming the laminated structure 1000 described above. The ink jet recording apparatus 1 includes a printing unit 10, a light irradiation unit 20, and a conveyance unit 30. The exterior of the inkjet recording apparatus 1 is covered with a housing 2. On the Y positive direction side of the inkjet recording apparatus 1, the printing unit 10 is built in the bulging portion 2a where the frame of the housing 2 bulges to the Z direction positive side. A yellow tank 111a, a magenta tank 112a, a cyan tank 113a, and a clear tank 114a for supplying ink of each color to the inkjet head unit 110 included in the printing unit 10 are provided on the X positive direction side of the bulging portion 2a. Be placed. A light shielding plate 2a-1 is provided on the Y negative direction side of the bulging portion 2a so that UV light from the light irradiation unit 20 described later does not reach the printing unit 10. The light shielding plate 2a-1 is provided with an opening portion 2d communicating with the inside of the bulging portion 2a. On the Y negative direction side with respect to the bulging part 2a of the inkjet recording apparatus 1, a pair of columnar parts 2b are erected from the housing 2 toward the Z positive direction side. A beam-like portion 2c is bridged in parallel with the X direction at the end on the Z positive direction side of the pair of columnar portions 2b. The light irradiation unit 20 is built in the beam-like portion 2c. A conveyance unit 30 is provided on the negative side in the Z direction of the beam-like portion 2c. This conveyance part 30 is provided in parallel with the Y direction, and invades the inside of the bulging part 2a through the opening part 2d. The ejection medium ST is placed on the upper surface of the transport unit. An operation unit 500 that receives various operations such as power ON / OFF from the user is provided on the side surface of the housing 2 on the Y negative direction side. An external I / F 600 that electrically connects the inkjet recording apparatus 1 and an external device such as a PC is provided on the side surface of the housing 2 on the X positive direction side.

  The printing unit 10 will be described with reference to FIGS. FIG. 2B is a schematic cross-sectional view of the inkjet recording apparatus 1 taken along the YZ plane at a location indicated by AA in FIG. FIG. 3 is an enlarged schematic diagram of the printing unit 10. An ink jet head unit 110, an ink jet head moving mechanism 130, a guide shaft 140, and an ink suction mechanism 150 are provided in the printing unit 10 built in the bulging portion 2a. The inkjet head unit 110 includes a yellow head 111 capable of ejecting yellow photocurable ink, a magenta head 112 capable of ejecting magenta photocurable ink, and a cyan head 113 capable of ejecting cyan photocurable ink. And a clear head 114 capable of discharging a colorless and transparent photocurable ink. The yellow head 111, the magenta head 112, the cyan head 113, and the clear head 114 are connected to the yellow tank 111a, the magenta tank 112a, the cyan tank 113a, and the clear tank 114a through hollow tubes, respectively. The guide shaft 140 holds the inkjet head unit 110 above a mounting table 310 described later. The guide shaft 140 is fixed to both ends of the bulging portion 2a in the X direction so as to be parallel to the X direction. The inkjet head unit 110 is attached to the guide shaft 140 so as to be slidable along the guide shaft 140. The inkjet head moving mechanism 130 moves the inkjet head unit 110 in the X direction along the guide shaft 140. The inkjet head moving mechanism 130 is constituted by, for example, a timing belt and a motor that moves the timing belt. The inkjet head suction unit 150 is provided below the end of the guide shaft 140 on the X negative direction side. The inkjet head suction unit 150 is configured to be movable up and down in the Z direction by a lifting mechanism (not shown). The inkjet head suction unit 150 is also configured to be able to suck the inside of the cap 150a by a pump (not shown). When the ink jet head unit 110 moves to the end of the guide shaft 140 on the X negative direction side, the ink jet head suction unit 150 rises to the Z direction positive side. The raised inkjet head suction unit 150 is in close contact with the Z-direction negative surface (lower surface) of the inkjet head unit 110 and performs suction until each color ink reaches the nozzles on the lower surfaces of the heads 111 to 114 of each color.

  The light irradiation unit 20 built in the beam-shaped portion 2c irradiates UV light in order to cure the above-described UV curable inks. The light irradiation unit 20 is provided with a UV lamp 220. A metal halide lamp is used as the UV lamp 220. However, a UV-LED may be used.

  The transport unit 30 includes a mounting table 310 on which the ejection medium ST is mounted, and a mounting table moving mechanism 320 (see FIG. 3) that moves the mounting table 310 in the Y direction and the Z direction. The mounting table 310 is composed of, for example, a wide timing belt in the X direction. The mounting table moving mechanism 320 moves the ejection medium ST mounted on the mounting table 310 below the inkjet head unit 110 and below the UV lamp 220. The mounting table moving mechanism 320 also moves in the Y direction in conjunction with the ink discharging operation of the inkjet head section 110 and the movement of the inkjet head moving mechanism 130 in the X direction when ink is discharged from the inkjet head section 110. Perform a slight movement. The mounting table moving mechanism 320 also performs a slight movement in the Z direction so that the distance between the inkjet head unit 110 and the ejection medium ST is kept constant.

[Functional Block of Inkjet Recording Apparatus 1]
FIG. 4 is a block diagram showing a functional configuration of the inkjet recording apparatus 1. The functional configuration of the inkjet recording apparatus 1 includes a printing unit 10, a light irradiation unit 20, a transport unit 30, a control unit 40, an operation panel 500, and an external I / F 600. These elements are electrically connected to each other by a bus 700.

  The control unit 40 includes an operation in which the printing unit 10 ejects the photocurable ink, an operation in which the light irradiation unit 20 irradiates light, and the printing unit 10 and the conveyance unit 30 are relative to the inkjet head unit 110 and the ejection medium ST. Control the movement of the position. The control unit 40 includes a CPU 410, a RAM 420, and a ROM 430. The CPU 410 performs various calculations and processing in cooperation with the RAM 420 and the ROM 430. The RAM 420 temporarily stores various programs processed by the CPU 410 and data processed by the CPU 410 in its address space. The ROM 430 stores various programs for controlling the inkjet recording apparatus 1.

  The printing unit 10 ejects ink using the inkjet head unit 110 and moves the inkjet head unit 110 in the X direction. The printing unit 10 includes an inkjet head unit 110, an ink discharge control circuit 120, an inkjet head moving mechanism 130, and an inkjet head suction mechanism 150. The inkjet head moving mechanism 130 moves the inkjet head unit 110 in the X direction in accordance with a head movement signal from the CPU 410. The motor included in the inkjet head moving mechanism 130 is a stepping motor or the like with a built-in encoder, and can detect the rotation angle and the origin position. The ink ejection control circuit 120 determines the color of ink to be ejected according to the ink ejection signal from the CPU 410. The determined color of the ink to be ejected is transmitted to the inkjet head unit 110 as a color selection signal. The ink ejection control circuit 120 also functions as a determination unit that determines whether or not each color ink can be ejected from the heads 111 to 114 of each color according to the ink remaining amount signal from the inkjet head unit 110. The result of this determination is transmitted to CP 410 as a discharge enable / disable signal. The inkjet head unit 110 ejects ink from the head of the color to be ejected in accordance with the color selection signal from the ink ejection control circuit 120. The inkjet head unit 110 is also configured to detect the remaining amount of ink of each color by using an optical method in which light applied to the ink is received by an optical sensor, or a dot counter method for storing ink consumption. Is done. The detected remaining amount of ink of each color is transmitted to the ink ejection control circuit 120 as an ink remaining amount signal. The inkjet head suction mechanism 150 performs a suction operation and raises and lowers the cap 150a in accordance with a suction signal from the CPU 410. The raising / lowering operation of the inkjet head suction mechanism 150 is performed using a stepping motor with a built-in encoder. Therefore, the inkjet head suction mechanism 150 can detect the movement amount and the origin position in the Z direction.

  The light irradiation unit 20 includes a light source driving circuit 210 and a UV lamp 220. The light source drive circuit 210 transmits to the UV lamp 220 a light source drive signal for controlling lighting, extinction, emission intensity, etc. of the UV lamp light source 200 in accordance with the light source control signal from the CPU 410. The UV lamp 220 irradiates UV light in accordance with the light source drive signal from the light source drive circuit 210.

  The transport unit 30 includes a mounting table moving mechanism 320. The mounting table moving mechanism 320 has a stepping motor with a built-in encoder, and can detect the movement amount and the origin position of the mounting table 310. The mounting table moving mechanism 320 moves the mounting table 310 in the Y direction and the Z direction in accordance with a conveyance signal from the CPU 410.

  The operation panel 500 has various input buttons for accepting operations such as starting, stopping, and starting printing of the inkjet recording apparatus 1 from the user. A user operation input to the operation panel 500 is transmitted to the CPU 410 as an operation signal.

  The external I / F 600 is a configuration for performing communication between the inkjet recording apparatus 1 and the outside. The ink jet recording apparatus 1 receives necessary image data from the external device PC 800 via the external I / F 600. The external I / F 600 can be configured by a known interface such as USB (Universal Serial Bus) or IEEE1394.

  FIG. 5A is a diagram for explaining the contents of data that the RAM 420 temporarily stores in its address space. The RAM 420 temporarily stores monochrome layer image data 420a, monochrome layer printing times 420b, multiple color layer image data 420c, multiple color layer printing times 420d, upper surface layer image data 420e, and upper surface layer printing times 420f. All of these data are received from the PC 800 via the external I / F 600. The monochrome layer image data 420a is image data for printing the monochrome layer 1001 (see FIG. 1A). The monochrome layer printing count 420b is a value indicating the number of times the monochrome layer 1001 should be printed in the monochrome layer forming process (see FIG. 8) described later. The multiple color layer image data 420c is image data for printing the multiple color layer 1002 (see FIG. 1B). The multi-color layer printing count 420d is a value indicating the number of times the multi-color layer 1002 should be printed in the multi-color layer forming process (see FIG. 9) to be described later. The upper layer image data 420e is image data for printing the upper layer 1003 (see FIG. 1C). The upper surface layer printing frequency 420f is a value indicating the number of times the upper surface layer 1003 should be printed in the upper surface layer forming process (see FIG. 10) described later.

  FIG. 5B is a diagram for explaining the contents of various processing means stored in the ROM 430. These processing means are performed by the CPU 410 executing a program for these processing means stored in the ROM 430 on the RAM 420. The ROM 430 is roughly divided into a plurality of color layer forming means 430a, a single color layer forming means 430b, a stacked structure forming means 430c, an upper surface layer forming means 430d, and a first color determining means 430e. Hereinafter, these processing means will be described.

  The multi-color layer forming unit 430a is a program that is executed in the process of forming the multi-color layer 1002. The multi-color layer forming unit 430a includes a first discharge unit 430a1, a second discharge unit 430a2, and a first curing unit 430a3. When the first ejection unit 430a1 is executed, the CPU 410 is based on the multi-color layer image data 420c with respect to the ink ejection control circuit 120 so as to eject ink corresponding to the photocurable ink of the first color. An ink discharge signal is transmitted. Then, the CPU 410 sends a head movement signal to the inkjet head moving mechanism 130 based on the multi-color layer image data 420c so that the ejected first color photocurable ink spreads over a predetermined range. The carrier signal is transmitted to the mounting table moving mechanism 320. At this time, the inkjet head moving mechanism 130 and the mounting table moving mechanism 320 operate in cooperation to move the first position by moving the relative position between the inkjet head unit 110 and the ejection medium ST mounted on the mounting table 310. The first ejection position, which is the position from which the photo-curable ink of the color is ejected, is moved. When the second ejection unit 430a2 is executed, the CPU 410 is based on the multi-color layer image data 420c with respect to the ink ejection control circuit 120 so as to eject ink corresponding to the photocurable ink of the second color. An ink discharge signal is transmitted. Then, the CPU 410 performs inkjet based on the multi-color layer image data 420c so as to surround a predetermined range of the outer periphery of the first color photocurable ink to which the discharged second color photocurable ink spreads. A head movement signal is transmitted to the head movement mechanism 130, and a conveyance signal is transmitted to the mounting table movement mechanism 320. At this time, the inkjet head moving mechanism 130 and the mounting table moving mechanism 320 operate in cooperation to move the second ejection position, which is the position at which the second color photocurable ink is ejected. When the first curing unit 430a3 is executed, the CPU 410 transmits a conveyance signal to the mounting table moving mechanism 320, so that the discharge medium ST mounted on the mounting table 310 is turned on. Move down. The ejection medium ST is disposed under the UV lamp 220 until the ejected first and second color photocurable inks are cured.

  The monochromatic layer forming unit 430b is a program executed during the process of forming the monochromatic layer 1001. The monochromatic layer forming unit 430b includes a third discharge unit 430b1 and a second curing unit 430b2. When the third ejection unit 430b1 is executed, the CPU 410 causes the ink ejection control circuit 120 to eject ink based on the monochromatic layer image data 420a so as to eject ink corresponding to the first color photocurable ink. An ejection signal is transmitted. Then, the CPU 410 transmits a head movement signal to the inkjet head movement mechanism 130 based on the monochromatic layer image data 420a so that the first color photocurable ink that is ejected spreads over a predetermined range. Then, a conveyance signal is transmitted to the mounting table moving mechanism 320. At this time, the inkjet head moving mechanism 130 and the mounting table moving mechanism 320 operate in cooperation to move the first discharge position. When the second curing unit 430b2 is executed, the CPU 410 transmits a conveyance signal to the mounting table moving mechanism 320, so that the discharge medium ST mounted on the mounting table 310 is turned on. Move down. The ejection medium ST is disposed below the UV lamp 220 until the ejected first color photocurable ink is cured.

  The stacked structure forming unit 430c is a program executed in the process of stacking the single color layer 1001 and the multiple color layer 1002. When the stacked structure forming unit 430c is executed, the CPU 410 executes the single color layer forming unit 430b and the multiple color layer forming unit 430a a plurality of times, thereby forming a stacked structure 1000 including a plurality of multiple color layers 1002 and a plurality of single color layers 1001. To do. At this time, the multilayer structure forming unit 430c executes the monochromatic layer forming unit 430b more than the multi-color layer forming unit 430a so that more monochromatic layers 1001 are included in the multilayer structure 1000 than the multi-color layers 1002.

  The upper surface layer forming unit 430d is a program executed in the process of forming the upper surface layer 1003. The upper surface layer forming unit 430d includes a fourth discharge unit 430d1 and a third curing unit 430d2. When the fourth ejection unit 430d1 is executed, the CPU 410 causes the ink ejection control circuit 120 to eject ink based on the upper layer image data 420e so as to eject ink corresponding to the photocurable ink of the second color. An ejection signal is transmitted. Then, the CPU 410 causes the inkjet head moving mechanism 130 to move based on the upper surface layer image data 420e so that the ejected second color photocurable ink spreads over a predetermined range of the upper surface of the multilayer structure 1000. The head movement signal is transmitted, and the conveyance signal is transmitted to the mounting table moving mechanism 320. At this time, the inkjet head moving mechanism 130 and the mounting table moving mechanism 320 operate in cooperation to move the second ejection position. When the third curing unit 430d2 is executed, the CPU 410 transmits a transport signal to the mounting table moving mechanism 320, thereby causing the discharge medium ST mounted on the mounting table 310 to be turned on. Move down. The ejection medium ST is disposed under the UV lamp 220 until the ejected second color photocurable ink is cured.

  The first color determining means 430e is a program executed when determining the color of the ink used as the photocurable ink of the first color. When the first color determination unit 430e is executed, the CPU 410 receives an ejection propriety signal transmitted by the ink ejection control circuit in response to the ink remaining amount signal from the inkjet head unit 110, and clear ink is received from the clear head 114. Judge whether discharge is possible. When clear ink can be ejected, the CPU 410 determines the clear ink as the first color photocurable ink. On the other hand, when the clear ink cannot be ejected, the CPU 410 determines the yellow ink, which is a light color next to the clear ink among the ejectable colors, as the photocurable ink of the first color.

[Flow of print processing]
FIG. 6 is a flowchart for explaining a printing process performed by the inkjet recording apparatus 1. The process shown in FIG. 6 is started when the CPU 410 receives an operation signal generated by a user turning on the power using the operation panel 500. In step S10, the CPU 410 performs an initialization process. With this initialization process, the CPU 410 clears various data temporarily stored in the RAM 420. The CPU 410 transmits a head movement signal to the ink head moving mechanism 130 to move the ink head unit 110 to the end on the X negative direction side. Then, the CPU 410 transmits a suction signal to the ink jet head suction mechanism 150 so that the ink jet head suction mechanism 150 comes into close contact with the Z-direction negative surface (lower surface) of the ink jet head unit 110. The mechanism 150 is raised. The ink jet head suction mechanism 150 that is in close contact makes suction until the ink of each color reaches the nozzles existing on the lower surfaces of the heads 111 to 114 of each color, so that the heads 111 to 114 of each color can be ejected. The CPU 410 further turns on the UV lamp 220 by transmitting a light source control signal to the light source driving circuit 210. Since a metal halide lamp is used as the UV lamp 220, it takes about several minutes to stabilize the light amount. Therefore, the UV lamp 220 is always turned on while the process shown in FIG. 6 is executed. Thereafter, the CPU 410 shifts the processing to step S20.

  In step S20, the CPU 410 executes the laminated structure forming unit 430c (details will be described later with reference to FIG. 7) stored in the ROM 440. That is, the CPU 410 executes the single color layer forming unit 430b and the multiple color layer forming unit 430a a plurality of times, thereby forming the stacked structure 1000 including the multiple color layers 1002 and the single color layer 1001. At this time, the multilayer structure forming unit 430c executes the monochromatic layer forming unit 430b more than the multi-color layer forming unit 430a so that more monochromatic layers 1001 are included in the multilayer structure 1000 than the multi-color layers 1002. When the execution of the stacked structure forming unit 430c ends, the CPU 410 shifts the processing to step S30.

  In step S30, the CPU 410 executes upper surface layer forming means 430d (details will be described later with reference to FIG. 10) stored in the ROM 440. By executing the upper surface layer forming unit 430d, as shown in FIG. 1D, a stacked structure 1000 having two upper surface layers 1003c is formed. Then, the CPU 410 ends a series of printing processes.

[Laminated structure forming process]
FIG. 7 is a flowchart for explaining in detail the laminated structure forming process shown as step S20 in FIG. In step S210, the CPU 410 executes the monochromatic layer forming unit 430b (details will be described later with reference to FIG. 8) stored in the ROM 440. By step S210, 20 monochromatic layers 1001a shown in FIG. 1D are formed. Thereafter, the CPU 410 shifts the processing to step S220.

  In step S220, the CPU 410 executes a multi-color layer forming unit 430a (details will be described later with reference to FIG. 9) stored in the ROM 440. By step S220, the two-color layer 1002a shown in FIG. 1D is formed. Thereafter, the CPU 410 shifts the processing to step S230.

  In step S230, the CPU 410 executes the monochromatic layer forming unit 430b stored in the ROM 440. By step S230, 20 monochromatic layers 1001b shown in FIG. 1D are formed. Thereafter, the CPU 410 shifts the processing to step S240.

  In step S240, the CPU 410 executes the multi-color layer forming unit 430a stored in the ROM 440. By step S220, two layers of multiple color layers 1002b shown in FIG. 1D are formed. Thereafter, the CPU 410 shifts the processing to step S250.

  In step S250, the CPU 410 executes the monochromatic layer forming unit 430b stored in the ROM 440. By step S230, 20 monochromatic layers 1001c shown in FIG. 1D are formed. Thereafter, the CPU 410 ends the laminated structure forming process.

[Monochrome layer forming process]
FIG. 8 is a flowchart for explaining processing performed by the monochromatic layer forming unit 430b, which is executed as steps S210, S230, and S250 of FIG. In step S <b> 2101, the CPU 410 determines whether or not the monochrome layer image data 420 a and the monochrome layer printing count 420 b received from the PC 800 via the external I / F 600 are temporarily stored in the RAM 420. If the determination in step S2101 is affirmative (Y), CPU 410 causes the process to proceed to step S2102. On the other hand, if the determination in step S2101 is negative (N), the CPU 410 proceeds to the step until the monochrome layer image data 420a and the monochrome layer printing count 420b are received from the PC 800 via the external I / F 600 and temporarily stored in the RAM 420. S2101 is repeated.

  In step S2102, the CPU 410 transmits a transport signal to the mounting table moving mechanism 320 to move the mounting table 310 to the Y direction positive side in order to move the ejection medium ST below the inkjet head unit 110. . Thereafter, the CPU 410 shifts the processing to step S2103.

  In step S2103, the CPU 410 executes the first color determination unit 430e. Specifically, the CPU 410 receives an ejection propriety signal transmitted from the ink ejection control circuit in response to the ink remaining amount signal from the inkjet head unit 110, and determines whether or not clear ink can be ejected from the clear head 114. By making this determination, even if the clear ink cannot be ejected, the monochrome layer 1001 can be formed if the yellow ink can be ejected. If the determination result in step S2103 is affirmative (Y), the CPU 410 determines the clear ink as the first color photocurable ink, and the process proceeds to step S2104. On the other hand, if the determination result of step S2103 is negative (N), the CPU 410 determines yellow ink as the first color photocurable ink, and the process proceeds to step S2105.

  In step S2104, the CPU 410 executes the third ejection unit 430b1. Specifically, the CPU 410 transmits an ink ejection signal to the ink ejection control circuit 120 so that clear ink is ejected based on the monochromatic layer image data 420a. Then, the CPU 410 transmits a head movement signal to the inkjet head moving mechanism 130 based on the monochromatic layer image data 420a so that the clear ink discharged from the clear head 114 spreads over a predetermined range, and the mounting is performed. A conveyance signal is transmitted to the table moving mechanism 320. Thereafter, the CPU 410 shifts the processing to step S2106.

  In step S2105, the CPU 410 executes the third ejection unit 430b1. Specifically, the CPU 410 transmits an ink ejection signal to the ink ejection control circuit 120 so that yellow ink is ejected based on the monochromatic layer image data 420a. Then, the CPU 410 transmits a head movement signal to the inkjet head movement mechanism 130 based on the monochromatic layer image data 420a so that the yellow ink ejected from the yellow head 111 spreads over a predetermined range, and the printing is performed. A conveyance signal is transmitted to the table moving mechanism 320. Thereafter, the CPU 410 shifts the processing to step S2106.

  In steps S2106 and S2107, the CPU 410 executes the second curing unit 430b2. Specifically, in step S <b> 2106, the CPU 410 transmits a transport signal to the mounting table moving mechanism 320, so that the ejection medium ST mounted on the mounting table 310 is placed under the already lit UV lamp 220. Moving. Thereafter, the CPU 410 shifts the processing to step S2107. In step S2107, the CPU 410 places the ejection medium ST below the UV lamp 220 so that the ejected clear ink or yellow ink is cured. Specifically, the CPU 410 transmits a conveyance signal to the mounting table moving mechanism 320 so that the discharged clear ink or yellow ink is included in the irradiation range of the UV light for about 5 seconds. To move. The irradiation range of the UV light has an extent of about 50 mm in the Y direction on the mounting table 310, for example. Thereafter, the CPU 410 shifts the processing to step S2108.

  In step S <b> 2108, the CPU 410 determines whether or not the number of monochrome layers 1001 printed so far is the same as the number of monochrome layer printing times 420 b temporarily stored in the RAM 420. If the determination in step S2108 is affirmative (Y), the CPU 410 ends the execution of the monochrome layer forming unit 430b. On the other hand, if the determination in step S2108 is negative (N), CPU 410 returns the process to step S2102. That is, the monochromatic layer 1001 is sequentially laminated by repeating the processing of steps S2102 to S2107 until the monochromatic layer 1001 is formed in the same number as the monochromatic layer printing frequency 420b. For example, when the stacked structure 1000 shown in FIG. 1D is formed, “20” is temporarily stored in the RAM 420 as the monochrome layer print count 420b, and thus, until the number of monochrome layers 1001 reaches 20, S2102 The process of S2107 is repeated.

[Multi-color layer formation processing]
FIG. 9 is a flowchart for explaining processing performed in the multi-color layer forming unit 430a, which is executed as steps S220 and S240 in FIG. In step S2201, the CPU 410 determines whether or not the multi-color layer image data 420c and the multi-color layer printing count 420d received from the PC 800 via the external I / F 600 are temporarily stored in the RAM 420. If the determination in step S2201 is affirmative (Y), CPU 410 moves the process to step S2202. On the other hand, if the determination in step S2201 is negative (N), the CPU 410 receives the multiple color layer image data 420c and the multiple color layer print count 420d from the PC 800 via the external I / F 600 and temporarily stores them in the RAM 420. Step S2201 is repeated.

  In step S2202, the CPU 410 moves the mounting table 310 to the Y direction positive side by transmitting a transport signal to the mounting table moving mechanism 320 in order to move the ejection medium ST below the inkjet head unit 110. Let Thereafter, the CPU 410 shifts the processing to step S2203.

  In step S2203, the CPU 410 executes the first color determination unit 430e as in step S2102 of FIG. By making this determination, even if the clear ink cannot be ejected, the multi-color layer 1002 can be formed if the yellow ink can be ejected. If the determination result of step S203 is affirmative (Y), the CPU 410 determines the clear ink as the first color photocurable ink, and the process proceeds to step S2204. On the other hand, if the determination result of step S2203 is negative (N), the CPU 410 determines yellow ink as the first color photocurable ink, and the process proceeds to step S2205.

  In step S2204, the CPU 410 executes the first ejection unit 430a1. Specifically, the CPU 410 transmits an ink ejection signal to the ink ejection control circuit 120 so that clear ink is ejected based on the multi-color layer image data 420c. Then, the CPU 410 transmits a head movement signal to the inkjet head moving mechanism 130 based on the multi-color layer image data 420c so that the clear ink discharged from the clear head 114 spreads over a predetermined range. A conveyance signal is transmitted to the mounting table moving mechanism 320. Thereafter, the CPU 410 shifts the processing to step S2206.

  In step S2205, the CPU 410 executes the first ejection unit 430b1. Specifically, the CPU 410 transmits an ink ejection signal to the ink ejection control circuit 120 so that yellow ink is ejected based on the multi-color layer image data 420c. Then, the CPU 410 transmits a head movement signal to the inkjet head moving mechanism 130 based on the multi-color layer image data 420c so that the yellow ink ejected from the yellow head 111 spreads over a predetermined range, A conveyance signal is transmitted to the mounting table moving mechanism 320. Thereafter, the CPU 410 shifts the processing to step S2206.

  In step S2206, the CPU 410 executes the second ejection unit 430a2. Specifically, the CPU 410 ejects ink corresponding to the photocurable ink of the second color from at least one of the yellow head 111, the magenta head 112, and the cyan head 113 based on the multi-color layer image data 420c. As described above, an ink discharge signal is transmitted to the ink discharge control circuit 120. The CPU 410 then moves the ink jet head moving mechanism 130 based on the multi-color layer image data 420c so as to surround a predetermined range of the outer periphery of the clear ink or the yellow ink in which the photocurable ink of the second color to be spread spreads. The head movement signal is transmitted to the mounting table moving mechanism 320. Thereafter, the CPU 410 shifts the processing to step S2207. In FIG. 9, the second discharge means 430a2 (S2206) is executed after the first discharge means 430a1 (S2204 or S2205) is executed. However, these operations are actually performed in parallel, and there is no temporal order.

  In steps S2207 and S2208, the CPU 410 executes the first curing unit 430a3. Since this process is substantially the same process as the second curing unit 430b2 (see S2106 and S2107 in FIG. 8), details are omitted. In order to form the multi-color layer 1002, the curing of the clear ink and the curing of the photocurable ink of the second color are performed at a time, so that the stacked structure 1000 can be efficiently formed. After completing steps S2207 and S2208, the CPU 410 shifts the processing to step S2209.

  In step S2209, the CPU 410 determines whether or not the number of monochrome layers 1001 printed so far is the same as the number of monochrome layer printings 420b temporarily stored in the RAM 420. If the determination in step S2209 is affirmative (Y), the CPU 410 ends the execution of the multi-color layer forming unit 430a. On the other hand, if the determination in step S2209 is negative (N), CPU 410 returns the process to step S2202. That is, the multi-color layers 1002 are sequentially stacked by repeating the processing of step S2202 to step S2208 until the same number of multi-color layers 1001 as the multi-color layer printing times 420d are formed. For example, in the case where the stacked structure 1000 shown in FIG. 1D is formed, “2” is temporarily stored in the RAM 420 as the multi-color layer printing count 420d, so that the number of the multi-color layers 1002 reaches two. , S2202 to S2208 are repeated.

[Upper layer forming process]
FIG. 10 is a flowchart illustrating the process performed by the upper surface layer forming unit 430d, which is executed as step S230 of FIG. In step S2301, the CPU 410 determines whether the upper surface layer image data 420e and the upper surface layer printing count 420f received from the PC 800 via the external I / F 600 are temporarily stored in the RAM 420. If the determination in step S2301 is affirmative (Y), the CPU 410 moves the process to step S2302. On the other hand, if the determination in step S2301 is negative (N), the CPU 410 proceeds to the step until the upper layer image data 420e and the upper layer layer print count 420f are received from the PC 800 via the external I / F 600 and temporarily stored in the RAM 420. S2301 is repeated.

  In step S2302, the CPU 410 transmits a transport signal to the mounting table moving mechanism 320 to move the mounting table 310 to the Y direction positive side in order to move the ejection medium ST below the inkjet head unit 110. . Thereafter, the CPU 410 shifts the processing to step S2303.

  In step S2303, the CPU 410 executes the fourth ejection unit 430d1. Specifically, the CPU 410 causes the ink ejection control circuit 120 to eject ink corresponding to the photocurable ink of the second color from at least one of the yellow head 111, the magenta head 112, and the cyan head 113. In contrast, an ink ejection signal based on the upper surface layer image data 420e is transmitted. Then, the CPU 410 causes the inkjet head moving mechanism 130 to move based on the upper surface layer image data 420e so that the ejected second color photocurable ink spreads over a predetermined range of the upper surface of the multilayer structure 1000. The head movement signal is transmitted, and the conveyance signal is transmitted to the mounting table moving mechanism 320. Thereafter, the CPU 410 shifts the processing to step S2304.

  In steps S2304 and S2305, the CPU 410 executes the third curing unit 430d2. Since this process is substantially the same process as the second curing unit 430b2 (see S2106 and S2107 in FIG. 8), details are omitted. After completing steps S2304 and S2305, the CPU 410 shifts the processing to step S2306.

  In step S <b> 2306, the CPU 410 determines whether or not the number of upper surface layers 1003 printed so far is the same as the upper surface layer printing count 420 f temporarily stored in the RAM 420. When the determination in step S2306 is affirmative (Y), the CPU 410 ends the execution of the upper surface layer forming unit 430d. On the other hand, if the determination in step S2306 is negative (N), CPU 410 returns the process to step S2302. That is, the upper surface layer 1003 is sequentially laminated by repeating the processes of steps S2302 to S2305 until the upper surface layer 1003 is formed by the same number as the upper surface layer printing count 420f. For example, when the stacked structure 1000 shown in FIG. 1D is formed, “2” is temporarily stored in the RAM 420 as the upper surface layer printing count 420f. Therefore, until the number of upper surface layers 1003 reaches two, S2302 is obtained. The process of S2305 is repeated.

<First embodiment>
Here, the characteristics of the laminated structure 1000 (see FIG. 1D) actually formed using UV curable ink are measured.

[Composition of UV curable ink]
FIG. 11A is a diagram illustrating the composition of the UV curable ink used in this example. The UV curable ink used in this example contains a UV curable resin, various pigments corresponding to the color of the ink, a pigment dispersant, and a cationic photopolymerization initiator.

  The UV curable resin contains a polyfunctional epoxy compound and an oxetane compound. Specifically, the clear ink containing no pigment contains 19.5% by weight of “Celoxide 2021P” from Daicel Chemical Industries, and 58% by weight of “Celoxide 3000” from Daicel Chemical Industries, as a polyfunctional epoxy compound. As the oxetane compound, 19.5 wt% of “OXT-213” manufactured by Toagosei Co., Ltd. is included. The magenta ink, yellow ink and cyan ink containing pigment contain 17.5 wt% of “Celoxide 2021P” from Daicel Chemical Industries, and 56 wt% of “Celoxide 3000” from Daicel Chemical Industries, as polyfunctional epoxy compounds. As an oxetane compound, 17.5 wt% of “OXT-213” manufactured by Toagosei Co., Ltd. is included.

  In the UV curable ink used in this embodiment, pigments corresponding to the respective colors are used. The magenta ink contains 1.8% by weight of Clariant's “Toner Magenta E02” as a pigment and 1.2% by weight of Lubrizol's “Solsperse 24000” as a pigment dispersant. The yellow ink contains 1.8% by weight of “LIONOGEN YELLOW 1010” manufactured by Toyo Ink Co., Ltd. as a pigment and 1.2% by weight of “Solsperse 24000” manufactured by Lubrizol as a pigment dispersant. The cyan ink contains 1.8% by weight of “LIONOL BLUE FG-7351” manufactured by Toyo Ink Co., Ltd. as a pigment and 1.2% by weight of “Solsperse 24000” manufactured by Lubrizol as a pigment dispersant. The clear ink does not contain a pigment and a pigment dispersant.

  As a cationic photopolymerization initiator, “UVI-6992” manufactured by Dow Chemical Co., Ltd. is contained 3% by weight in the clear ink and 6% by weight in each color ink having a pigment.

[Preparation of UV curable ink]
In the UV curable ink used in this example, each component shown in FIG. 11 (A) is collected in a container at the predetermined ratio described above in a dark room, stirred, and then filtered through a polyflon filter having a pore size of 2 μm. It is prepared by. However, pigment dispersion is performed in advance for yellow, cyan, and magenta inks containing pigments. Specifically, after the pigment dispersion was performed by stirring for 2 hours with zirconia beads having a diameter of 1 mm at a rate shown in FIG. 11 (B) using a bead mill, the ink was adjusted to the rate shown in FIG. 11 (A). Prepared. As the bead mill, a “paint conditioner” manufactured by RED DEVIL EQUIIPMENT is used.

[Printing of UV curable ink]
Printing is performed with the ink jet recording apparatus 1 as shown in FIG. 2 (A) using the ink prepared with the composition shown in FIG. 11 (A). The viscosity of the UV curable ink used in this example is about 10 [mP · s], which is higher than the ink used in a general inkjet printer. Therefore, as the ink jet head unit 110, a piezo ink jet head capable of ejecting ink having this viscosity is used. For example, “Xaar1001 / GS6” manufactured by Xaar, which is generally available on the market, can be used. In this embodiment, a metal halide lamp is used as the UV lamp 220. As a specific example, “Unicure System UVH-0252C” manufactured by USHIO INC. Can be used. In this case, the “switching regulator type power supply VB-12501BY” manufactured by USHIO INC. May be used as the power supply unit. As the ejection medium ST, a seal-like label having an adhesive material already applied to the back surface is used. By printing on the label, the laminated structure 1000 can be used as a decoration for a mobile phone, a nail, a portable music player, or the like. In the present embodiment, the all-weather label “CL71777-10” for monochrome / color laser manufactured by Maxell is used as the ejection medium ST.

FIG. 12 (A) shows the color in the L ^* a ^* b ^* color system of the laminated structure 1000 shown in FIG. 1 (D) using the ink prepared with the composition shown in FIG. 11 (A). It is a measurement result. Specifically, in the stacked structure 1000 illustrated in FIG. 1D, 20 single-color layers 1000a, 1000b, and 1000c are formed using clear ink, and two multi-color layers 1002a and 1002b are formed with clear ink. Each color ink is formed, and two upper surface layers 1003a are formed using each color ink. Note that “L ^* ” represents lightness. The higher the lightness L ^* , the brighter the color. “A ^* ” and “b ^* ” represent hue and saturation. Specifically, when “a ^* ” is a positive value, the direction is red. When “a ^* ” is a negative value, the direction is green. When “b ^* ” is a positive value, the direction is yellow ^. "Is a negative value, it represents the blue direction. “C ^* ” represents saturation. The saturation C ^* is obtained by C ^* = {(a ^* ) ² + (b ^* ) ² } ^1/2 . The greater the saturation C ^* , the brighter the color. A clear ink is used as the first color photocurable ink. As the photocurable ink of the second color, ink of each color shown in FIG. 12A is used. The color was measured using “SpectroEye” manufactured by Gretag Macbeth under an optical condition of D502.

FIG. 12B shows the measurement results of the color in the L ^* a ^* b ^* color system of the laminated structure that does not have the multiple color layer 1002 as Comparative Example 1. Specifically, in this laminated structure, 20 layers of monochromatic layers 1001 using clear ink are laminated as the photocurable ink of the first color, and each color ink is used as the photocurable ink of the second color thereon. It can be obtained by repeating the process of laminating two upper surface layers 1003 using NO. In other words, 20 monochromatic layers 1001, 2 upper surface layers 1003, 20 monochromatic layers 1001, 2 upper surface layers 1003, 20 monochromatic layers 1001, and 2 upper surface layers 1003 are stacked in this order. It is a structured.

As a result of visual observation, the laminated structure 1000 of the example shown in FIG. 12A was colored in the same manner as the side surface and the upper surface. Similarly, in the laminated structure of Comparative Example 1 shown in FIG. However, when viewed from the stacking direction, the stacked structure of Comparative Example 1 appears darker and darker in color. Concretely, an example and comparative example 1 are compared quantitatively using FIG.12 (C). When cyan is used as the photocurable ink of the second color, the lightness L ^* is “35.44” in Comparative Example 1, whereas the lightness L ^* is “49.97” in the example. . When magenta is used as the photocurable ink of the second color, the lightness L ^* is “35.13” in Comparative Example 1, whereas the lightness L ^* is “49.73” in the example. . When yellow is used as the photocurable ink of the second color, the lightness L ^* is “66.55” in Comparative Example 1, whereas the lightness L ^* is “67.19” in the example. . That is, as can be seen from the comparison between the example and the comparative example 1, by including the multi-color layer 1002 in the stacked structure, a light-colored stacked structure with high lightness L ^* can be obtained. When yellow is used as the photocurable ink of the second color, there is no significant difference between the lightness L ^{* of the} example and the lightness L ^* of Comparative Example 1. This means that even when a plurality of yellow layers are stacked, the lightness L ^* does not decrease so much. Therefore, even if yellow ink is used instead of clear ink, it is possible to provide a layered structure with sufficiently bright colors.

<Modification>
The present invention is not limited to the embodiments described so far, and various modifications and changes can be made without departing from the spirit of the present invention. An example of the modification will be described below.

  In the above-described embodiment, the printing unit 10 and the light irradiation unit 20 are configured separately. However, these may be integrated. FIG. 13 is a schematic diagram showing the structure of the inkjet head unit 1100. The inkjet head unit 1100 is different from the inkjet head unit 110 of the above-described embodiment in that UV lamps 2200 are provided at both ends in the X direction. As the UV lamp 2200, a metal halide lamp, a UV mercury lamp, a UV-LED, or the like can be used. Also in this case, the UV lamp 2200 is provided above the mounting table 310 via the guide shaft 140 and the inkjet head unit 1110. Furthermore, there may be a configuration in which UV light is guided from a UV light source provided separately from the inkjet head unit 1100 using an optical waveguide such as an optical fiber as the UV lamp 2200.

  The use of the inkjet head unit 1100 has the following advantageous effects. First, by using the inkjet head unit 1100, a configuration for irradiating light existing outside the printing unit 10, such as the light irradiation unit 20 shown in FIG. In the above-described embodiment, the process of moving the mounting table 310 below the inkjet head unit 110 (see S2102 in FIG. 8, S2202 in FIG. 9, and S2302 in FIG. 10) is performed before ink is ejected. A process (see S2106 in FIG. 8, S2207 in FIG. 9, and S2304 in FIG. 10) in which the mounting table 310 moves below the UV lamp 220 later is performed. However, if the inkjet head unit 1100 is used, the process of moving the mounting table 310 becomes unnecessary. Furthermore, it is possible to perform ink ejection and curing in parallel by irradiating UV light while ejecting ink. In other words, in FIG. 8, the execution of the second curing unit 430b2 (S2106 and S2107) is performed after the execution of the third ejection unit 430b1 (S2104 or S2105), but the inkjet head unit 1100 is used. The second curing unit 430b2 and the third discharge unit 430b1 can be executed in parallel. Similarly, in FIG. 9, by using the inkjet head unit 1100, the first discharge unit 430a1, the second discharge discharge unit 430a2, and the first curing unit 430a3 can be executed in parallel. Of course, in FIG. 10 as well, the fourth discharge means 430d1 and the third curing means 430d2 can be executed in parallel.

  In the above-described embodiment, the stacked structure 1000 illustrated in FIG. 1D includes more single-color layers 1001 than the multiple-color layers 1002. However, the number of layers and the order of stacking may be changed as appropriate. For example, the number of stacked layers of the plurality of color layers 1002 may be larger than the number of stacked layers of the single color layer 1001. In addition, a stacked structure may be formed using only the plurality of color layers 1002. Further, several monochromatic layers 1001 may be laminated as a clear coat on the upper surface of the upper surface layer 1003a. Alternatively, the upper surface layer 1003a may be omitted. Further, the monochromatic layer 1001, the multiple color layer 1002, and the upper surface layer 1003 are all shown in FIG. 1 as a rectangular structure in plan view for the sake of simplicity of explanation. However, the single color layer 1001, the multiple color layer 1002, and the upper surface layer 1003 may be formed in any other shape. Further, the stacked structure 1000 may have a shape in which the size in the direction orthogonal to the stacking direction changes along the stacking direction. In other words, for example, a pyramid-like laminated structure or a hemispherical laminated structure may be used. In particular, even when the shape is such that the size in the direction orthogonal to the laminating direction increases as the distance from the ejection medium ST increases, a multi-layered layer 1000 is obtained by laminating the multiple color layers 1002 to obtain a laminated structure 1000 with a cleanly colored surface. It is done.

  In the above-described embodiment, the inkjet head unit 110 includes the yellow head 111, the magenta head 112, the cyan head 113, and the clear head 114. However, in addition to the heads of these colors, a head that discharges another color may be provided in the inkjet head unit 110. For example, the inkjet head unit 110 may include a black head that ejects black photocurable ink. In this case, a black tank that supplies ink to the black head is also required. The black photocurable ink is ejected as the second photocurable ink.

  In the above-described embodiment, the clear ink is used as the first color photocurable ink, and the yellow ink is used as the first color photocurable ink when the clear ink cannot be ejected. However, the present invention can be implemented even with an inkjet recording apparatus that does not include clear ink, for example. For example, in the case of an inkjet recording apparatus that can eject four colors of yellow ink, magenta ink, cyan ink, and black ink, yellow ink may be used as the first color photocurable ink.

  In the above-described embodiment, the relative position between the ejection medium ST and the inkjet head unit 110 is moved by the cooperation of the inkjet head moving mechanism 130 and the mounting table moving mechanism 320. However, for example, only the inkjet head unit 110 may be configured to be movable in the X direction, Y direction, and Z direction, or only the mounting table moving mechanism 320 may be configured to be movable in the X direction, Y direction, and Z direction. In short, the relative position between the ejection medium ST and the inkjet head unit 110 may be moved.

<Reference example>
In the above-described embodiment, it has been described that the yellow ink may be used as the photocurable ink of the first color instead of the clear ink. For example, when the clear ink cannot be ejected in the single color layer forming unit 430b, the yellow ink is used as the first color photocurable ink (see S2105 in FIG. 8). Here, by comparing the case where the yellow ink is laminated with the case where the darker ink is laminated than the yellow ink, even if the yellow ink is used as the photocurable ink of the first color, It will be explained that it is possible to provide a laminated structure with sufficiently bright colors.

  FIG. 14A illustrates a stacked structure 2000 as a reference example. The laminated structure 2000 includes 50 single-color layers 2001a using yellow ink as the first color photocurable ink, and each color ink as the second color photocurable ink on the upper surface of the single color layer 2001a. A two-layer upper surface layer 2003a using is provided. FIG. 14B is a diagram showing a stacked structure 3000 as Comparative Example 2. The laminated structure 3000 is formed by ten upper surface layers 2003a using inks of the respective colors as the photocurable ink of the second color.

As a result of visual observation, the laminated structure 2000 of the reference example shown in FIG. 14A was colored and the side surface was yellow. Although the laminated structure 3000 of Comparative Example 2 shown in FIG. 14B appears to be colored on the side surface and the upper surface, when viewed from the lamination direction, the color appears darker than the laminated structure 200 of the reference example. Specifically, the reference example and the comparative example 2 are quantitatively compared using FIG. When green is used as the photocurable ink of the second color, the lightness L ^* is “28.10” in Comparative Example 2, whereas the lightness L ^* is “37.50” in the reference example. . When red is used as the photocurable ink of the second color, the lightness L ^* is “24.87” in Comparative Example 2, whereas the lightness L ^* is “38.04” in the reference example. . That is, as can be seen from the comparison between the reference example and the comparative example 2, even when a plurality of yellows are stacked, the lightness L ^* does not decrease so much. That is, even when the yellow ink is used as the first color photocurable ink, it is possible to provide a sufficiently bright laminated structure.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Housing 2a Swelling part 2a-1 Shading plate 2b Columnar part 2c Beam-like part 2d Opening part 10 Printing part 20 Light irradiation part 30 Conveying part 40 Control part 110, 1100 Inkjet head part 111 Yellow head 111a Yellow tank 112 Magenta head 112a Magenta tank 113 Cyan head 113a Cyan tank 114 Clear head 114a Clear tank 120 Ink discharge control circuit 130 Inkjet head moving mechanism 140 Guide shaft 150 Inkjet head suction mechanism 150a Cap 210 Light source drive circuit 220, 2200 UV lamp 310 Mounting table 320 mounting table moving mechanism 410 CPU
420 RAM
430 ROM
500 Operation unit 600 External I / F
700 Bus 800 PC
1000, 2000, 3000 Laminated structure 1001, 1001a, 1001b, 1001c, 2001a Monochromatic layer 1002, 1002a, 1002b Multiple color layer 1003, 1003a, 2003a, 2003b Upper surface layer ST Discharge medium

Claims (19)

A mounting table for mounting the discharge medium;
An ink jet head unit configured to discharge at least a first color photocurable ink and a second color photocurable ink that is darker than the first color photocurable ink;
A frame for holding the inkjet head part above the mounting table;
A moving mechanism for moving a relative position between the inkjet head unit and the ejection medium placed on the mounting table;
A light irradiation unit that is provided above the mounting table and that emits light to cure the photocurable ink discharged from the inkjet head unit;
A control unit that controls an operation in which the inkjet head unit ejects photocurable ink, an operation in which the light irradiation unit irradiates light, and an operation in which the moving mechanism moves the relative position;
The controller is
The ink-jet head unit ejects the first-color photocurable ink so that the first-color photocurable ink spreads over a predetermined range, and the moving mechanism moves the relative position. The second color photocurable ink is applied to the inkjet head portion so that the second color photocurable ink surrounds a predetermined range of the outer periphery of the first color photocurable ink. By causing the moving mechanism to move the relative position and irradiating the light irradiation unit with light in order to cure the discharged first and second color photocurable inks, A plurality of color layer forming means for forming a plurality of color layers in which a predetermined range of the outer periphery of the first color photocurable ink spreading is surrounded by the second color photocurable ink;
Laminating means for forming a laminated structure in which at least one or more of the plural color layers are laminated by operating the plural color layer forming means;
Having
An ink jet recording apparatus. The control unit further includes:
The ink-jet head unit ejects the first-color photocurable ink and the moving mechanism moves the relative position so that the first-color photocurable ink spreads over a predetermined range. A single color in which the light curable ink of the first color spreads over a predetermined range by irradiating the light irradiating portion with light to cure the discharged first color curable ink. Having monochromatic layer forming means for forming a layer;
The stack forming means further operates the single color layer forming means to form the stacked structure in which the plurality of color layers and the plurality of single color layers are stacked.
The inkjet recording apparatus according to claim 1.
The stack forming unit is configured to operate the monochromatic layer forming unit more than the multi-color layer forming unit to form the stacked structure including the monochromatic layer more than the multi-color layer.
The ink jet recording apparatus according to claim 2. The control unit further includes:
After the operation of the stack forming unit, the second color is formed on the inkjet head unit so as to form a top layer in which the photocurable ink of the second color spreads over a predetermined range of the top surface of the stack structure. The photo-curable ink is ejected onto the upper surface of the laminated structure and the relative position is moved by the moving mechanism to cure the ejected second photo-curable ink. Having upper surface layer forming means for irradiating light;
An ink jet recording apparatus according to any one of claims 1 to 3. Do not operate the plurality of color layer forming means and the single color layer forming means after the operation of the upper surface layer forming means,
The inkjet recording apparatus according to claim 4. The inkjet head unit is configured to be capable of discharging at least a colorless and transparent photocurable ink and a photocurable ink of another color that is darker than the colorless and transparent photocurable ink,
A judgment means for judging whether or not the colorless and transparent photocurable ink can be discharged from the inkjet head unit;
The controller is
When the determination result of the determination means is affirmative, the colorless and transparent photocurable ink is determined as the first color photocurable ink, and when the determination result of the determination means is negative, the other color A first color determining means for determining a photocurable ink as the first color photocurable ink;
An ink jet recording apparatus according to any one of claims 1 to 5. An ink jet recording method on a discharge medium using photocurable ink,
The first color photocurable ink spreads over a predetermined range, and the second color photocurable ink has a darker color in the outer periphery than the first color photocurable ink. A multi-color layer forming step for forming a multi-color layer surrounded by;
A laminate forming step of forming a laminate structure including at least one or more of the multiple color layers by executing the multiple color layer forming step;
The multi-color layer forming step includes
The position where the first color photocurable ink is ejected and the first color photocurable ink is ejected so that the first color photocurable ink spreads over a predetermined range. A first discharge step for moving the first discharge position,
The second color photocurable ink is discharged so that the second color photocurable ink surrounds a predetermined range of the outer periphery of the first color photocurable ink, and the second color photocurable ink is discharged. A second ejection step of moving a second ejection position, which is a position from which the two-color photocurable ink is ejected;
A first curing step of irradiating light to cure the ejected first color and second color photocurable inks.
An ink jet recording method. A monochromatic layer forming step of forming a monochromatic layer in which the photocurable ink of the one color spreads over a predetermined range;
The monochromatic layer forming step includes
A third ejection step for ejecting the first color photocurable ink and moving the first ejection position so that the first color photocurable ink spreads over a predetermined range;
A second curing step of irradiating light to cure the discharged first color photocurable ink;
The layer forming step further executes the single color layer forming step, thereby forming the layered structure including the plurality of color layers and a plurality of the single color layers.
The inkjet recording method according to claim 7. The layer forming step forms the layered structure including the single color layer more than the plurality of color layers by performing the single color layer forming step more than the plurality of color layer forming steps.
The inkjet recording method according to claim 8. An upper surface layer forming step of forming an upper surface layer in which the photocurable ink of the second color spreads over a predetermined range of the upper surface of the stacked structure after execution of the stacked layer forming step;
The upper surface layer forming step includes
The second color photocurable ink is ejected and the second ejection position is moved so that the second color photocurable ink spreads over a predetermined range of the upper surface of the laminated structure. A fourth discharging step;
And a third curing step of irradiating light to cure the discharged second color photocurable ink.
An ink jet recording method according to any one of claims 7 to 9. After the upper surface layer forming step, the multi-color layer forming step and the single color layer forming step are not performed.
The inkjet recording method according to claim 10. A determination step of determining whether or not a colorless and transparent photocurable ink can be ejected as the first color photocurable ink;
When the determination result of the determination step is affirmative, the colorless and transparent photocurable ink is determined as the first color photocurable ink, and when the determination result of the determination step is negative, the colorless and transparent light is determined. A first color determining step of determining a photocurable ink of another color that is darker than the curable ink as the photocurable ink of the first color.
The ink jet recording method according to claim 7, wherein the ink jet recording method is performed. The first color photocurable ink spreads over a predetermined range, and the second color photocurable ink has a darker color in the outer periphery than the first color photocurable ink. To form a multi-color layer that surrounds
The first color photocurable ink and the second color photocurable ink can be discharged at least so that the first color photocurable ink spreads over a predetermined range. The inkjet head unit is instructed to eject the photocurable ink of the first color, and the relative position is set with respect to the moving mechanism that moves the relative position of the inkjet head unit and the ejection medium. A first discharge command step for commanding movement;
The photocurable ink of the second color with respect to the ink jet head unit so that the photocurable ink of the second color surrounds a predetermined range of the outer periphery of the photocurable ink of the first color spreading. And a second discharge command step for instructing the moving mechanism to move the relative position;
In order to cure the first and second color photocurable inks to be ejected, a command for irradiating light to a light irradiation unit capable of irradiating light to the ejection medium is performed. 1 irradiation command step;
A multiple color layer formation command step having:
By executing the multi-color layer formation command step, a multi-layer formation command step for forming a multi-layer structure including at least one or more multi-color layers;
A program to make a computer realize. In order to form a monochromatic layer in which the one-color photocurable ink spreads over a predetermined range,
The inkjet head unit is instructed to eject the first color photocurable ink so that the first color photocurable ink spreads over a predetermined range, and the moving mechanism is also instructed. A third discharge command step for giving a command to move the relative position;
A second curing command step for instructing the light irradiation unit to irradiate light to cure the discharged first color photocurable ink;
Further comprising a monochrome layer formation command step having
The stack formation command step further operates the single color layer forming means to form the stack structure including the plurality of color layers and a plurality of the single color layers.
The program of Claim 13 for making a computer implement | achieve. The stack formation command step forms the stack structure including the single color layer more than the multiple color layer by executing the single color layer formation command step more than the multiple color layer formation command step.
The program according to claim 14 for causing a computer to realize the above. In order to form an upper surface layer in which the photocurable ink of the second color spreads over a predetermined range of the upper surface of the stacked structure after the operation of the stacked formation command step,
A fourth discharge for instructing the inkjet head unit to discharge the second color photocurable ink to the upper surface of the laminated structure and for instructing the moving mechanism to move the relative position. A command step;
A third curing command step for instructing the light irradiation unit to irradiate light in order to cure the discharged second-color photocurable ink;
Having an upper surface layer formation command step,
The program according to any one of claims 13 to 15, which is further implemented by a computer. After the execution of the upper surface layer formation command step, do not execute the multiple color layer formation command step and the single color layer formation command step,
The program according to claim 16 for causing a computer to realize the above. The inkjet head unit configured to be capable of discharging at least a colorless and transparent photocurable ink and a photocurable ink of another color that is darker than the colorless and transparent photocurable ink is the colorless and transparent A determination command step for performing a command to determine whether or not the photocurable ink can be discharged;
When the determination result of the determination command step is positive, the colorless and transparent photocurable ink is determined as the first color photocurable ink, and when the determination result of the determination command step is negative, the other A first color determination command step for determining a color photocurable ink as the first color photocurable ink;
Furthermore, the program in any one of Claims 13-17 for making a computer implement | achieve. A first color photocurable ink that spreads over a predetermined range and a darker color than the first color photocurable ink that covers a predetermined range of the outer periphery of the first color photocurable ink that spreads. A second color photocurable ink that is a color, and a plurality of color layers,
A monochromatic layer made of the photocurable ink of the one color extending over a predetermined range,
A laminated structure in which the monochromatic layer is laminated so as to be larger than the plurality of color layers;
An upper surface layer made of the photo-curable ink of the second color extending over a predetermined range of the upper surface of the laminated structure;
A three-dimensional printed structure characterized by comprising: