JP6710901B2 - Recording device, recording method, and program - Google Patents

Description

The present invention relates to an inkjet type recording apparatus, a recording method, and a program for recording an image or the like by attaching ink to a recording medium.

As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, and a composite machine of these, an inkjet recording apparatus using a recording head including a liquid ejection head (droplet ejection head) ejecting ink droplets is known. There is.

Further, in an inkjet recording apparatus, by irradiating the ultraviolet curable ink ejected and landed on a recording medium with ultraviolet rays (UV), the ultraviolet curable ink is cured and fixed to obtain an image. There is a so-called UV inkjet printer. In a UV inkjet printer, a head mounted on a head carriage moves the head carriage along a recording medium and ejects ultraviolet curable ink onto the recording medium to land it. The recording medium on which the ink has landed is irradiated with ultraviolet rays from an ultraviolet light source, and the ultraviolet curable ink on the recording medium is cured and stabilized to print an image.

However, when a color image is formed on a non-penetrable medium (for example, glass, metal, plastic, or coated paper) with a UV inkjet printer, the inks of different colors that have landed on each other bleed near the uncured boundary before UV irradiation. If so, there is a problem that an unclear image with mixed colors or an abnormal image with an unexpected tint is obtained.

To avoid this, if you repeat the process of ejecting each color ink and irradiating with UV each time an image is formed and curing it for the number of colors, another new ink droplet will land on the cured image area. Even if you do, you can prevent each other from bleeding and mixing colors.

However, if UV irradiation is performed (cured and fixed) each time each color ink is landed, the time required for that is too long and the productivity drops. In addition, UV that is irradiated to cure the ink that has landed later is superimposed and irradiated onto the ink that has landed in the initial stage, and the amount of UV irradiation (integrated) light is more than necessary for the ink that has cured in the initial stage. Therefore, there is a possibility that image deterioration such as yellowing of the ink due to excessive UV irradiation or peeling at the interface with the recording medium due to excessive curing may occur.

As an invention that addresses such a problem, there is an image forming method described in Japanese Patent Application Laid-Open No. 2004-242242. In the present invention, a phenomenon in which the ink droplet soil immediately after landing on the recording medium moves on the surface of the recording medium by coalescing before the fixing, and the ink droplets are fixed while deviating from the original landing positions of the ink droplets, The phenomenon in which the shape of an ink droplet is deformed and the shape is destroyed is called landing interference.If the landing interference occurs on the recording medium, the ink of the same color is visually recognized as density unevenness and the line quality deteriorates. In the case of different color inks, the problem of color mixture bleeding is solved.

According to this image forming method, "an image formed on the recording medium is formed in an image forming area on the recording medium covered with an image formed based on image data and a peripheral area of the image forming area. A diffusion preventing agent that suppresses the spread of dots, a polymerization initiator, and a first liquid containing a high boiling point organic solvent, and a first liquid attaching step of attaching the first liquid, and the first liquid attaching step, A second liquid ejecting step of ejecting a second liquid containing a radiation-curable polymerizable compound and a coloring material in the image forming area on the recording medium based on the image data, After the first liquid deposition step and before the second liquid droplet deposition step, radiation curing is performed outside the outer edge of the image forming area in the peripheral area of the image forming area on the recording medium. A third liquid depositing step of depositing a third liquid containing a type polymerizable compound and being transparent or having a color similar to that of the recording medium, the first liquid on the recording medium, And a radiation irradiation step of irradiating the third liquid with radiation.” (Claim 1).

From the viewpoint of further suppressing the occurrence of bleeding and landing interference, the first liquid referred to herein as the treatment liquid is one that satisfies the following conditions (i) to (iii).
(I) The viscosity at 25°C is 100 mPa·s or less, or the viscosity at 60°C is 100 mPa·s or less.
(Ii) Contain a high-boiling organic solvent having a boiling point higher than 100°C.
(Iii) Second liquid: It contains a diffusion inhibitor and a polymerization initiator that suppress the spread of the KCMY ink (spread of dots formed by the KCMY ink) after the KCMY ink has landed on the treatment liquid.

Therefore, by depositing the second liquid deposited on the first liquid based on the image data, the high boiling point organic solvent and the diffusion inhibitor, which are the components of the first liquid, cause the second liquid to drop. It is possible to prevent landing interference. At this time, the second liquid droplet ejection area and the peripheral area of the second liquid droplet ejection area are set as the first liquid adhesion area, so that the liquid surface of the first liquid is flat. The second liquid lands on the second liquid, the displacement of the landing position of the second liquid is prevented, and the preferable image can be obtained without the displacement of the dots formed by the second liquid.

Here, the deviation of the landing position of the second liquid does not depend on the variation in the flight direction of the second liquid, but when the second liquid lands on the inclined portion of the boundary portion of the first liquid. , A phenomenon in which the second liquid moves on the inclined portion of the first liquid.

Further, in the area around the image forming area where the second liquid does not exist among the areas to which the first liquid has adhered, a third liquid having a transparent or similar color to that of the recording medium is ejected, and these liquids are deposited. Since the liquid is irradiated with radiant rays and cured reliably, it is possible to prevent excess liquid from remaining on the recording medium.

Further, the first liquid adhesion region to which the first liquid is adhered includes an image forming region where the second liquid is ejected based on the image data and its peripheral region. When there is a hollow portion in the image, the first liquid adhesion region also exists in the hollow portion.

As described above, according to the image forming apparatus and the image forming method described in Patent Document 1, the droplet ejection area of the second liquid ejected based on the image data and the periphery of the droplet ejection area of the second liquid are ejected. By setting the area and the area where the first liquid adheres, the second liquid lands on the portion where the liquid surface of the first liquid is flat, and the deviation of the landing position of the second liquid is prevented. A preferable image can be obtained. In addition, in the region where the second liquid does not exist in the region where the first liquid is adhered, a third liquid having a transparent or similar color to that of the recording medium is deposited to drop the first liquid and the second liquid. The liquid and the third liquid can be irradiated with radiant rays to reliably cure them, and the excess liquid is prevented from remaining on the recording medium. This makes it possible to prevent image deterioration due to landing interference on the medium during high-speed printing and to form a preferable image on the medium.

However, the image forming apparatus and the image forming method have the following problems (1) to (3).
(1) Since the process of depositing the first liquid is necessary, the productivity is reduced.
(2) The cost of the first liquid increases the cost of the product.
(3) Since the volume of the first liquid is required for the droplet ejection region of the second liquid and the droplet ejection region of the third liquid, the volume of the image becomes high accordingly, and A step is conspicuous with a region where the third liquid is not ejected (the recording medium is directly visible).

The present invention has been made to solve such a problem, and an object thereof is to prevent deterioration of an image due to bleeding or color mixture that occurs at a boundary between image areas due to inks having different hues and lightness. It is to realize it by a simple means that suppresses the decrease of power consumption and the increase of cost.

According to the present invention, a plurality of types of ink are deposited on a recording medium or an ink deposited on a recording medium, and the first recording ink region and the second recording ink region in which the mixing ratios of the plurality of types of ink are different from each other. When the first droplet discharge means for forming a before the first droplet ejection means to form the first recording ink region and the second recording ink region, and the first recording ink area the between the second recording ink area, before the second droplet discharge means by landing ink boundary forms a boundary ink region, said first droplet ejection means to form the recording ink area A boundary ink area fixing means for fixing the boundary ink area, and a recording ink area fixing means for fixing the recording ink area, wherein the boundary ink area has a volume not less than that of the recording ink area. In the recording apparatus, the boundary ink area is formed by ink droplets that are deposited on the same position in an overlapping manner , and the pitch of ink dots in the boundary ink area is smaller than the pitch of ink dots in the recording ink area. ..

According to the present invention, it is possible to realize image deterioration prevention due to bleeding or color mixing that occurs at the boundary between image areas formed by inks having different hues and lightnesses by a simple means that suppresses a decrease in productivity and an increase in cost. I can. Further, even if the image areas of different colors having different saturation and lightness are adjacent to each other with the boundary ink area interposed therebetween, it is possible to prevent the image areas from overflowing and bleeding. Furthermore, it is possible to obtain a sufficient bulk even though the dot diameter is small, and the cross-sectional shape of the boundary ink dot hangs down in a spindle shape until the ink deposited on the same position is cured, resulting in a sharper image. The tip shape makes it less noticeable.

FIG. 6 is a diagram showing a first example of a dot pattern in a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment of the present invention and the recording apparatus according to the second embodiment. It is a figure which shows the dot pattern of the color ink area|region of the 1st layer formed in the area|region in a boundary shown in FIG. FIG. 4 is a diagram showing a first example of a dot pattern of a color ink area of a second layer formed on the color ink area of the first layer shown in FIG. 2. FIG. 9 is a diagram showing a second example of a dot pattern of a color ink region of the second layer formed on the color ink region of the first layer shown in FIG. 2. FIG. 6 is a diagram showing a second example of a dot pattern of a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment. FIG. 6 is a diagram showing an example of a dot pattern of a color ink region of a first layer formed in a boundary region shown in FIG. 5. FIG. 7 is a diagram showing an example of a dot pattern of a second-layer color ink area formed on the first-layer color ink area shown in FIG. 6. FIG. 11 is a diagram showing a third example of a dot pattern of a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment. It is a figure which shows the example of the dot pattern of the color ink area|region of the 1st layer formed in the area|region in a boundary shown in FIG. It is a figure which shows the example of the dot pattern of the color ink area|region of the 2nd layer formed on the color ink area|region of the 1st layer shown in FIG. FIG. 11 is a diagram showing a fourth example of a dot pattern in a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment. It is a figure which shows the example of the dot pattern of the color ink area|region of the 1st layer formed in the area|region in a boundary shown in FIG. FIG. 13 is a diagram showing an example of a dot pattern of a second layer color ink area formed on the first layer color ink area shown in FIG. 12. A fifth example of a dot pattern in a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment, and a color of the first layer FIG. 6 is a diagram showing an example of a dot pattern of an ink area and a dot pattern of a color ink area of a second layer. It is a figure which shows about the relationship of the volume of a boundary ink dot, and the volume of the color ink dot of a 1st layer and a 2nd layer. FIG. 3 is a perspective view of the recording apparatus according to the first embodiment of the present invention. FIG. 3 is a sectional view of the recording apparatus according to the first embodiment of the present invention in the main scanning direction. FIG. 3 is a plan view of the recording apparatus according to the first embodiment of the present invention. 6A and 6B are diagrams for explaining a process of ejecting and curing boundary ink dots by the recording apparatus according to the first embodiment of the present invention. FIG. 6 is a diagram for explaining a process of ejecting and curing color ink dots by the recording apparatus according to the first embodiment of the present invention. FIG. 6 is a plan view of a recording device according to a second embodiment of the present invention. It is a block diagram for explaining a configuration of a control unit of the recording apparatus according to the first embodiment of the present invention. 23 is a flowchart showing an example of the operation of the control unit shown in FIG. It is a flow chart which shows processing which generates an image field pattern and a boundary pattern from image data. It is a figure which shows the approximate gradation pattern which reduced the gradation number of a monochrome multi-gradation image. It is a figure which shows the boundary pattern extracted from the approximate gradation pattern shown in FIG. It is a figure which shows schematic structure of the cross section of the three-dimensional molded object formed by the recording device which concerns on the 3rd Embodiment of this invention. It is a figure which shows the outline of the layered modeling process of the three-dimensional molded item formed by the recording device which concerns on the 3rd Embodiment of this invention. It is a figure for demonstrating the problem which arises in the horizontal colored surface of a three-dimensional molded item. It is a figure for explaining a problem which arises in a perpendicular coloring side of a three-dimensional model. FIG. 28 is a diagram showing an example of a barrier layer formed on a horizontal colored surface of the three-dimensional structure shown in FIG. 27. FIG. 28 is a diagram showing an example of a barrier layer formed on a vertical colored surface of the three-dimensional structure shown in FIG. 27. It is a figure which shows the processing flow of the lamination modeling process of the three-dimensional molded article by the recording device which concerns on the 3rd Embodiment of this invention. It is a figure for demonstrating the three-dimensional modeling data and the recording information of each layer produced|generated by the process flow of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First example of dot pattern in boundary ink area>
FIG. 1 is a diagram showing a first example of a dot pattern of a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment of the present invention. Is. Here, FIG. 1A is a plan view and FIG. 1B is a sectional view. Further, in this figure, the X axis is the main scanning direction and the Y axis is the sub scanning direction. The main scanning direction and the sub scanning direction are common to FIGS. 2 to 20 described later. Also in each of FIGS. 12 to 14 described later, each drawing A is a plan view and each drawing B is a sectional view. The details of the configurations of the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment, and the details of the main scanning direction and the sub-scanning direction will be described later.

As shown in the figure, on the surface of the recording medium 50, a boundary ink area composed of a plurality of bulky boundary ink dots (transparent ink dots) 100C1 made of transparent UV curable ink as boundary ink is formed. Here, the boundary ink area has a shape in which five rhombuses drawn by thick dotted lines are connected in the main scanning direction. Then, five inside-boundary regions 50-c are formed inside the diamond, and outside-boundary regions 50-o are formed outside. Adjacent boundary ink dots 100C1 do not contact each other, and a gap is formed.

<Dot pattern in the color ink area of the first layer>
FIG. 2 is a diagram showing an example of a dot pattern of the color ink region of the first layer formed in the boundary region shown in FIG.

After the boundary ink area is irradiated with UV (ultraviolet) to be cured (fixed), a color ink of a plurality of colors as a plurality of types of recording ink is landed on the boundary area 50-c to form a recording ink area. Image the color ink areas of the first layer of. The color ink dots of each color forming the color ink region of the first layer are ejected so as not to overlap the center of the boundary ink dot 100C1.

Here, in order from the left side of the drawing, a first-layer cyan ink area formed of a plurality of first-layer cyan ink dots 101C, a first-layer magenta ink area formed of a plurality of first-layer magenta ink dots 101M, and a plurality of A first layer yellow ink area consisting of the first layer yellow ink dots 101Y, a first layer magenta ink area consisting of a plurality of first layer magenta ink dots 101M, a plurality of first layer cyan ink dots 101C, and A cyan/magenta ink region of the first layer is formed by combining a plurality of magenta ink dots 101M of the first layer.

Since there are boundary ink dots 100C1 between adjacent color ink regions of different colors, the color ink dots forming the color ink regions of different colors do not contact each other. Here, an example in which there is no black ink region is shown, but it may be present.

<First Example of Dot Pattern in Color Ink Area of Second Layer>
FIG. 3 is a diagram showing a first example of a dot pattern in the second layer color ink area formed on the first layer color ink area shown in FIG.

After the color ink area of the first layer is irradiated with UV to be cured, the color ink area of the second layer is formed on the color ink area of the first layer. The color ink dots of the second layer forming the color ink area of the second layer are 1/th in the main scanning direction and the sub-scanning direction with respect to the color ink dots of the first layer forming the color ink area of the first layer. It is arranged by shifting by 2 pitches. Further, among the color ink dots of the second layer, the color ink dots arranged on the outermost side of the in-boundary area 50-c are completely formed by the boundary ink dots 100C1 although they partially overlap with the boundary ink dots 100C1. It is deposited so that it fits inside the bulky boundary.

In the drawing, in order from the left side, a cyan ink region of a second layer formed of a plurality of cyan ink dots 102C of the second layer on the cyan ink region of the first layer, and a plurality of second layers on the magenta ink region of the first layer. On the magenta ink region of the second layer formed of the magenta ink dots 102M, on the yellow ink region of the first layer, on the yellow ink region of the second layer formed of a plurality of second layer yellow ink dots 102Y, on the magenta ink region of the first layer A plurality of second layer magenta ink dots 102M and a plurality of second layer yellow ink dots 102Y in a combination of a second layer magenta/yellow ink area and a first layer cyan/magenta ink area. A cyan/magenta ink region of the second layer is formed by a combination of the cyan ink dot 102C and the plurality of second-layer magenta ink dots 102M. Also in the color ink area of the second layer, the ink dots in the different color ink areas adjacent to each other are not in contact with each other with the boundary ink dot 100C1 as a boundary.

<Second example of dot pattern in color ink area of second layer>
FIG. 4 is a diagram showing a second example of the dot pattern of the color ink region of the second layer formed on the color ink region of the first layer shown in FIG.

In the color ink area of the second layer shown in this figure, the area where the color ink dots are ejected is wider than the color ink area of the second layer shown in FIG. That is, each color ink dot forming the color ink region of the second layer is displaced from the color ink dot of the first layer by 1/2 pitch in the main scanning direction and the sub scanning direction, and further, the boundary ink dots having a larger volume are formed. By forming a droplet in the center between the formed boundary dots, it is formed to be one dot wider than the color ink area of the second layer in FIG.

More specifically, while overlapping the boundary ink dot 101C at the center in the direction of an angle of 45 degrees, a cyan ink region of a second layer formed of a plurality of cyan ink dots 102C of a second layer and a plurality of second ink layers are arranged in order from the left side. Layer magenta ink dots 102M, second layer magenta ink regions, second layer yellow ink dots 102Y, second layer yellow ink regions, second layer magenta ink dots 102M, and second layers Second layer magenta/yellow ink region formed of a combination of yellow ink dots 102Y, a plurality of second layer cyan ink dots 102C and a plurality of second layer magenta ink dots 102M, and a second layer cyan. A magenta ink area is formed.

As shown in FIG. 4B, since the color ink areas of the second layer are separated by the apex of the boundary ink dots 100C1 of the lower layer, the ink dots of the color ink areas of different colors that are extremely close to each other. Is prevented from bleeding.

In order to form the color ink area by bringing the color ink dots having different saturations and lightness close to each other to such a marginal area as described above, it is necessary to confirm in advance the condition of the volume of the transparent ink area that does not cause sufficient bleeding. Although it is necessary to carry out, since the boundary between the color ink areas can be made as narrow as possible, an image with no noticeable gap can be obtained.

<Second example of dot pattern in boundary ink area>
FIG. 5 is a diagram showing a second example of a dot pattern of a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment. Is.

As shown in FIG. 1, when the density of the boundary ink dots 100C1 is low and a gap is formed between the adjacent boundary ink dots 100C1, the color ink dots of each color deposited in the boundary area 50-c. Ink may leak from the gap.

Therefore, in the second example of the dot pattern shown in FIG. 5, a gap is not formed between the adjacent boundary ink dots 100C1 in order to enhance the closing property of the boundary inner area 50-c. It can be said that this dot pattern has the boundary ink dots 100C1 added so as to close the gaps between the five boundary areas 50-c in the dot pattern shown in FIG. 1 from the outside of the boundary ink area. Since the five boundary inner areas 50-c are surrounded by the bulky boundary ink dots 100C1, it is possible to prevent the leakage of the ink of the color ink dots of each color deposited on the inner boundary areas 50-c.

<Dot pattern in the color ink area of the first layer>
FIG. 6 is a diagram showing a dot pattern of the color ink area of the first layer formed in the boundary area shown in FIG.

After irradiating the boundary ink area with UV to cure it, the color ink area of the first layer is imaged in the boundary area 50-c. The color ink dots of each color forming the color ink region of the first layer are arranged so as not to overlap the boundary ink dots 100C1.

Here, as in the case of FIG. 2, in the order from the left side of the drawing, a cyan ink region of a first layer composed of a plurality of first layer cyan ink dots 101C and a first layer composed of a plurality of first layer magenta ink dots 101M. Magenta ink region, a first layer yellow ink region composed of a plurality of first layer yellow ink dots 101Y, a first layer magenta ink region composed of a plurality of first layer magenta ink dots 101M, a plurality of first layers The cyan/magenta ink area of the first layer is formed by the combination of the cyan ink dot 101C and the plurality of first layer magenta ink dots 101M.

Similar to FIG. 2, since there are boundary ink dots 100C between adjacent color ink areas of different colors, the color ink dots forming the color ink areas of different colors do not contact each other. Here, an example in which there is no black ink region is shown, but it may be present. Further, the ink is not limited to cyan, magenta, and yellow, and ink of other hues may be used.

<Dot pattern of the second layer color ink area>
FIG. 7 is a diagram showing an example of a dot pattern of the color ink area of the second layer formed on the color ink area of the first layer shown in FIG.

As shown in the figure, similar to FIG. 4, the respective color ink dots forming the color ink areas of the second layer at five places are separated from the color ink dots of the first layer by 1/2 pitch in the main scanning direction and the sub scanning direction. The color ink area of the second layer is 1 more than the color ink area of the second layer in FIG. 3 by shifting and ejecting a droplet in the center between the dots of the boundary ink formed by the more bulky boundary ink dots 100C1. It is formed by expanding the dots. Furthermore, since the area 50-c in the boundary is more occluded, it is possible to prevent ink dots in different color ink areas that are extremely close to each other from bleeding.

<Third example of dot pattern in boundary ink area>
FIG. 8 is a diagram showing a third example of a dot pattern in a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment of the present invention. Is.

The boundary small-diameter ink dot 100C2 forming the dot pattern in the boundary ink area shown in this figure has the dot pitch of the boundary ink dot 100C1 shown in FIG. 5 narrowed to 1/2, and the landing dot diameter is also reduced by that amount. Is.

According to this dot pattern, as in the second example of the dot pattern (FIG. 5), the boundary ink area can be a closed area with continuous boundary lines. Further, since the boundary ink region can be formed with an area that is half the area of the second example of the dot pattern, the amount of boundary ink used can be reduced.

<Dot pattern in the color ink area of the first layer and dot pattern in the color ink area of the second layer>
FIG. 9 is a diagram showing a dot pattern of the color ink area of the first layer formed in the boundary area shown in FIG. 8, and FIG. 10 is formed on the color ink area of the first layer shown in FIG. FIG. 7 is a diagram showing an example of a dot pattern of a color ink region of a second layer, which is

As shown in FIG. 9 and FIG. 10, by ejecting color ink dots on the in-boundary area 50-c shown in FIG. 8, the color ink areas of different colors are changed to the color ink areas of different colors in FIG. 6 and FIG. Can be closer than. Even in that state, it is possible to prevent ink dots of different colors from bleeding. Therefore, the boundary between the color ink dots can be made as narrow as possible and inconspicuous, so that an image in which a gap is inconspicuous can be obtained.

<Fourth Example of Dot Pattern in Boundary Ink Area, Dot Pattern in Color Ink Area of First Layer and Dot Pattern in Color Ink Area of Second Layer>
FIG. 11 is a diagram showing a fourth example of a dot pattern of a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment of the present invention. Is. FIG. 12 is a diagram showing an example of a dot pattern of the first layer color ink area formed in the boundary area shown in FIG. 11, and FIG. 13 is a first layer color ink area shown in FIG. It is a figure which shows the example of the dot pattern of the color ink area|region of the 2nd layer formed above.

As shown in FIG. 11, in the fourth example of the dot pattern of the boundary ink area, the boundary ink area covers the area other than between the adjacent color ink areas on the recording medium 50 (the entire surface other than the color ink area). A plurality of boundary ink dots 100C1 were ejected onto.

As a result, as shown in FIG. 13, since there is no difference in the presence or absence of ink dots on the entire surface of the recording medium 50 on the printing surface side, the image surface as shown in FIGS. 3B, 4B, 7B, and 10B is displayed. It is possible to obtain an image with high smoothness without generating a step.

<Fifth Example of Boundary Ink Area Dot Pattern, and Dot Pattern of First Layer Color Ink Area and Second Layer Color Ink Area>
FIG. 14 is a fifth example of a dot pattern of a boundary ink area formed on the surface of a recording medium by the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment, and FIG. It is a figure which shows the example of the dot pattern of the color ink area|region of 1 layer, and the dot pattern of the color ink area|region of 2nd layer.

The dot pattern of the boundary ink area shown in this figure is obtained by arranging the boundary ink dot 100C1 on the boundary ink dot 100C1 shown in FIG. 13 with a 1/2 pitch shift. According to the pattern shown in this figure, the heights of the boundary ink areas and the color ink areas are the same, so that an image with even higher smoothness than the dot pattern shown in FIG. 13 can be obtained.

<Ink dot bulk relationship>
FIG. 15 is a diagram showing the relationship between the volume of the boundary ink dots and the volume of the color ink dots of the first and second layers.

With the boundary ink dot 100C1 as a boundary, on the left side, a first layer cyan ink area composed of a plurality of first layer cyan ink dots 101C and a second layer cyan ink area composed of a plurality of second layer cyan ink dots 102C. On the right side, there is a first-layer magenta/cyan ink area composed of a plurality of first-layer magenta ink dots 101M and a second-layer magenta ink area composed of a plurality of second-layer magenta ink dots 102M.

The boundary ink dot 100C1 has a volume of Hc, the first layer color ink dot has a maximum volume of H1, and the droplets are overlapped so as to fill the gap of the dot pitch of the color ink region of the first layer or above (1). Let H2 be the maximum bulk of the color ink dots in the second layer (including the first layer). That is, H2 is the maximum height of the ink dot in the color ink area.

In this case, by setting H2 to be equal to or less than Hc, even if image areas (color ink areas) of colors with different saturation and lightness are adjacent to each other across the boundary ink area, they do not overflow and blur. Can be

In order to obtain the volume: Hc of the boundary ink dot 100C1, the volume of the boundary ink (transparent ink) ejected once is increased, so that the volume is reduced in a short time (at least one scan). You can also use the method of earning money.

However, since the dot diameter greatly expands by that amount, the adjacent color ink regions become narrow, and the boundary ink region becomes thick and conspicuous. Therefore, in order to avoid this, a method is preferable in which the volume is increased by repeatedly depositing droplets at the same position in a slightly larger amount than the droplet volume of the droplets in the “image area (color ink area)”.

By doing so, it is possible to obtain Hc having a small dot diameter but being sufficiently bulky, and the cross-sectional shape of the boundary ink dot is overlapped at the same position as the droplet cross-section of the boundary ink dot 100C1 shown in the figure. The ejected ink drips in a spindle shape until it is cured by UV, and has a sharper tip shape, so that an effect of making it less noticeable is also obtained.

The relationship (Hc≧H2>H1) of the volume of the boundary ink dot 100C1 shown in this figure: Hc, the volume of the color ink dot of the first layer: H1, and the volume of the color ink dot of the second layer: H2 (Hc≧H2>H1) has been described above. It can be applied to FIGS. 3B, 4B, 7B, and 13B. Further, the volume of the boundary small diameter ink dot 100C2 in FIG. 10B, the volume of the color ink dot of the first layer, and the volume of the color ink dot of the second layer can also be applied.

<Recording device according to the first embodiment>
FIG. 16 is a perspective view of the recording apparatus according to the first embodiment of the present invention. This recording apparatus is a UV curing type inkjet recording apparatus.

This UV-curable inkjet recording apparatus forms an image by dropping the UV-curable ink onto a desired position on the surface of the recording medium 50 using an inkjet head as a droplet discharge means. Then, UV irradiation is performed on the surface with a UV lamp 8 as an actinic ray irradiation means (fixing means). By this UV irradiation, the photo-curing initiator contained in the ejected UV-curable ink monomer undergoes a cross-linking reaction and is cured as a polymer, so that it is fixed on the recording medium 50 to form an image.

The recording medium 50 is placed on the solid base 1 serving as a base, and the mounting table 9 for conveying the recording medium 50 is in the ±X direction (main scanning direction. Main scanning is the recording medium 50 in the X-axis direction with respect to the head). Is carried out on the recording medium 50 while the recording medium 50 is being conveyed.) is attached to the X-axis linear motor 7.

In this figure, the UV curable ink is ejected from the head unit 6 at the main scanning timing when the recording medium 50 on the mounting table 9 passes under the head unit 6 which will be described later, whereby a plurality of boundary ink dots 100C1 are ejected. Alternatively, a state is shown in which a boundary ink area composed of the boundary small-diameter ink dots 100C2 is formed, and further a color ink area composed of a plurality of color ink dots (101C, 101M, 101Y) of the first layer of each color is formed.

A gate-shaped beam 2 is provided on the base 1 in a direction orthogonal to the X-axis linear motor 7, and a Y-axis linear motor 3 that operates in the ±Y directions (sub-scanning directions) is attached. Then, from the Y-axis HP (home position), sub-scanning is sequentially performed in the -Y direction (after the image is formed in the main scanning direction, and then the head is not ejecting ink for main scanning a new image forming area. There is a Y-axis scan carrier 4 which makes a line feed in the direction.

Further, this UV-curable inkjet recording device is provided with a Z-axis head stage 5 that moves up and down in the ±Z-axis directions by rotation of a z-axis head stage motor 5a (FIG. 22) according to the thickness of the recording medium 50. .. On the Z-axis head stage 5, a head unit 6 that integrally holds an IJ (inkjet) head that individually ejects various types (multicolors) of ink, and a UV lamp 8 are integrally mounted adjacent to each other.

Here, the IJ heads are arranged in the order of the transparent IJ head 10, the black IJ head 11, the cyan IJ head 12, the magenta IJ head 13, and the yellow IJ head 14 from the left front side of the drawing. However, the arrangement order other than the transparent IJ head 10 may be different from the arrangement order in this figure.

Here, the transparent IJ head 10, the black IJ head 11, the cyan IJ head 12, the magenta IJ head 13, and the yellow IJ head 14 are a transparent UV curable ink, a black transparent UV curable ink, and a cyan transparent UV curable ink, respectively. The magenta transparent UV curable ink and the yellow transparent UV curable ink are ejected. That is, the transparent IJ head 10 functions as a first droplet ejection unit, and the black IJ head 11, cyan IJ head 12, magenta IJ head 13, and yellow IJ head 14 function as a second droplet ejection unit.

Here, since the head unit 6 and the UV lamp 8 are integrally attached to the Z-axis head stage 5, the positional relationship between the head unit 6 and the UV lamp 8 is always constant. The ejection scanning timing in the X-axis direction for ejecting and the scanning timing in the X-axis direction for irradiating UV by the UV lamp 8 do not necessarily have to be the same. That is, for example, when ejecting ink, the mounting table 9 is moved in the -X direction at a high speed, once moved in the +X direction where the original X-axis HP is, returned to the home position, and again moved in the -X direction. It is also possible to perform UV irradiation in which a sufficient amount of integrated light for the curing reaction by UV is secured by performing only UV irradiation.

FIG. 17 is a cross-sectional view in the main scanning direction of the recording apparatus according to the first embodiment of the present invention.
In this figure, the arrangement of the UV lamp 8 and various IJ heads, and the recording medium 50 which is mounted on the mounting table 9 during printing are shown.

The array of IJ heads is as follows. A transparent IJ head 10 is located immediately to the right of the UV lamp 8, and a black IJ head 11, a cyan IJ head 12, a magenta IJ head 13, and a yellow IJ head 14 are provided in this order.

FIG. 18 is a plan view of the recording apparatus according to the first embodiment of the present invention.
As described above, the head unit 6 that integrally holds the IJ head that individually ejects various (multicolored) inks, and the UV lamp 8 are adjacently attached integrally to the Z-axis head stage 5. This figure shows a state in which the position of the head unit 6 in the Y-axis direction is positioned on the Y-axis HP by the Y-axis scanning carrier 4 whose position is controlled on the Y-axis linear motor 3.

<Discharge and curing process of boundary ink dots>
FIG. 19 is a diagram for explaining the process of ejecting and curing the boundary ink dots by the recording apparatus according to the first embodiment of the present invention.

This drawing is a cross-sectional view of the apparatus shown in FIG. 17, and immediately after the transparent UV curing type ink is ejected from the transparent IJ head 10 to the recording medium 50 to land the boundary ink dots 100C1 or the boundary small diameter ink dots 100C2. It shows a state where a boundary ink area or a boundary small diameter ink area is being formed by irradiating UV from a UV lamp 8 installed on the left side and sequentially curing it.

<Discharge and curing process of color ink dots>
FIG. 20 is a diagram for explaining a process of ejecting and curing color ink dots by the recording apparatus according to the first embodiment of the present invention.

In this figure, after the boundary ink area or the small-diameter boundary ink area is formed on the recording medium 50 shown in FIG. 19, the black IJ head 11, the cyan IJ head 12, and the magenta IJ are formed in the boundary area 50-c. The head 13 and the yellow IJ head 14 respectively show a state in which a plurality of black ink dots 101Bk, cyan ink dots 101C, magenta ink dots 101M, and yellow ink dots 101Y are being formed as appropriate. ..

<Recording device according to second embodiment>
FIG. 21 is a plan view of a recording device according to the second embodiment of the present invention. In this figure, parts that are the same as or correspond to those in FIG. 17 are assigned the same reference numerals as in FIG.

In this recording apparatus, the transparent IJ head 10 is mounted on the transparent IJ head unit 6A, and the transparent IJ head unit 6A is mounted on the transparent IJ head Y-axis scanning carrier 4A. The color IJ heads (black IJ head 11, cyan IJ head 12, magenta IJ head 13, yellow IJ head 14) are mounted on the color IJ head unit 6B, and the color IJ head unit 6B is the Y axis for the color IJ head. It is attached to the scanning carrier 4B. The color IJ head Y-axis scan carrier 4B is arranged in the +Y direction with respect to the transparent IJ head Y-axis scan carrier 4A.

That is, the transparent IJ head 10 and the color IJ head are arranged at different positions in the sub-scanning direction, and the sub-scanning is possible independently, that is, the transparent IJ head 10 and the color IJ head can individually move in the Y-axis direction while facing the surface of the recording medium 50. Is configured. Further, the transparent IJ UV lamp 8A as the boundary ink area fixing means and the color IJ UV lamp 8B as the recording ink area fixing means are provided as separate means, that is, the transparent IJ head 10 and the color IJ head (black IJ head). 11, cyan IJ head 12, magenta IJ head 13, and yellow IJ head 14). Other than that is the same as the first embodiment.

According to this recording apparatus, first, the transparent IJ head unit 6A equipped with the transparent IJ head 10 sufficiently precedes to eject the boundary ink dot 100C1 or the boundary small-diameter ink dot 100C2 onto the recording medium 50, and immediately to the left thereof. The arranged transparent IJ UV lamp 8A is turned on to rapidly cure the boundary ink dot 100C1 or the boundary small diameter ink dot 100C2 to form a boundary ink area.

Then, the transparent IJ head Y-axis scanning carrier 4A is sequentially moved in the -Y direction, and immediately thereafter, the color IJ head Y-axis scanning carrier 4B is independently made to follow, and a color ink dot is ejected to the area within the boundary. By turning on the color IJ UV lamp 8B arranged immediately on the left side of the color IJ head unit 6B, a cured color ink area is rapidly formed.

In the first embodiment, the transparent IJ head 10 and the color IJ head are integrally arranged on one head unit 6, and the UV lamp 8 serving as both the boundary ink area fixing means and the recording ink area fixing means is one. Since there is only a light, the bulky boundary ink area is still completely blocked in some cases (when UV irradiation is performed immediately after the transparent ink droplet is ejected for each main scan to deposit the color ink dot on the color ink area). The color ink dots have to be ejected onto the in-boundary area 50-c in a state where the ink is not left (partially opened), which may cause a problem of ink bleeding. The embodiment can solve it.

Further, in the present embodiment, since the transparent IJ head unit 6A and the color IJ head unit 6B can move independently on the Y-axis linear motor 3, it is possible to arbitrarily set the mutual spacing in the Y-axis direction. is there. Therefore, by sufficiently widening the interval, the color IJ head unit 6B is configured to scan after forming (securing) the range of the boundary inner area 50-c of the boundary ink area formed earlier sufficiently wide. Can be set to With this setting, since the color ink dots can be ejected after the boundary area 50-c is surely closed, the effect of preventing bleeding can be enhanced.

<Structure of control unit of recording device>
FIG. 22 is a block diagram for explaining the configuration of the control unit of the recording apparatus according to the first embodiment of the present invention.

The control unit 200 includes a CPU 201 that controls the entire apparatus, a ROM 202 that stores a program executed by the CPU 201 and other fixed data, a RAM 203 that temporarily stores image data and the like, and a power source of the apparatus while the power is cut off. Also includes a non-volatile memory (NVRAM) 204 for holding data, and an ASIC 205 for performing image processing such as various signal processing and rearrangement, and input/output signal processing for controlling the entire apparatus.

The control unit 200 also includes a host I/F (interface) 206 for transmitting and receiving data and signals to and from the host device 90 side which is an information processing device such as a personal computer.

The control unit 200 also includes a head drive control unit 207 and a head driver 208 for driving and controlling the head unit 6, and a UV lamp driving unit 209 for driving the UV lamp 8.

Further, the control unit 200 moves up and down the Y-axis linear motor drive unit 210 for driving the Y-axis linear motor 3, the X-axis linear motor drive unit 211 for driving the X-axis linear motor 7, and the Z-axis head stage 5. A z-axis head stage motor driving section 212 for driving the z-axis head stage motor 5a and an I/O 213 for inputting detection signals from various sensors 320 are provided.

Further, the control unit 200 is connected to an operation panel 310 for inputting and displaying information necessary for this device.

In the controller of the recording apparatus according to the second embodiment, the head unit 6 in this figure is divided into a transparent IJ head unit 6A and a color IJ head unit 6B, and the UV lamp 8 is a transparent IJ UV lamp 8A. The UV lamp 8B for color IJ is divided, and the transparent and color UV lamps are separately movable.

<Operation of control unit of recording device>
The operation of the control unit 200 having the above configuration will be described. FIG. 23 is a flowchart showing an example of the operation of the control unit 200.

In a general recording apparatus, a decomposed image area pattern including black, cyan, magenta, yellow, etc. is generated from input image data, and an image is formed through a printing process related to image formation of each color.

On the other hand, in the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment of the present invention, before that, the boundary which is droplet ejection control data for forming the boundary ink area from the image data is used. A boundary ink region is formed by generating a pattern and ejecting a boundary ink based on the boundary pattern. At this time, the boundary pattern is generated by recognizing (palette-like) image areas for each color space having different color combinations that may cause image deterioration due to bleeding from each other. The flowchart shown in FIG. 23 is a process including a procedure for generating the boundary pattern.

First, the CPU 201 loads the image data received by the host I/F 206 from the host device 90 (step S1, image data loading). Next, the CPU 201 or the ASIC 205 determines that the grayscale gradation of each color (black, cyan, magenta, yellow) differs from the image data acquired in step S1 by a predetermined threshold or more (palette shape). The color space is divided in order to generate a region decomposed for each color space (step S2, color space division). Next, the CPU 201 or the ASIC 205 extracts only the boundary line from the boundary of the regions decomposed for each color space, and generates the boundary pattern (step S3, boundary pattern generation).

Next, based on the boundary pattern generated in step S3, a transparent ink dot is ejected by the transparent IJ head 10 to form a boundary ink area (step S4, boundary pattern printing).

Next, in order to cure (fix) the boundary ink area by UV irradiation from the UV lamp 8, a curing process by UV irradiation is performed (step S5, boundary ink area fixing). Next, it is determined whether or not the desired "boundary pattern printing" is completed (step S6). If not completed (step S6: No), the process returns to step S4, and if completed (step S6: Yes). , And proceeds to step S7.

In step S7, an image area pattern is generated for causing the color IJ head to eject a color ink dot composed of a combination of dots such as cyan, magenta, and yellow (image area pattern generation). Next, the IJ heads of the respective colors are driven based on the image area pattern, and the color ink dots of the respective colors are ejected to form the color ink areas of the respective colors (step S8, image area pattern printing).

Next, in order to cure (fix) the color ink regions of each color by UV irradiation from the UV lamp 8, a curing process by UV irradiation is performed (step S9, color ink region fixing).

Next, it is determined whether or not the desired “image area pattern printing” is completed (step S10). If it is not completed (step S10: No), the process returns to step S8, and if completed (step S10: Yes). ), the process shown in this figure is ended.

<Process of generating image area pattern and boundary area pattern from image data>
FIG. 24 is a flowchart showing a process of generating an image area pattern and a boundary pattern from image data.

This flow includes step S11, which is a process of generating CMYK output data that forms an image area pattern, and step S12, which is a process of generating a boundary pattern.

Step S11 is a known process, which is a process of converting input image data in RGB format into a standard color signal in L*a*b format (step S11-1), performing gamut compression on the standard color signal, Processing for converting standard color signals in the *'a*'b*' format (step S11-2), processing for converting standard color signals in the L*'a*'b*' format to CMY signals (step S11-3). ), black processing is performed on the CMY signal to convert it into a C'M'Y'K signal (step S11-4), total amount regulation is performed on the C'M'Y'K signal, and a cmyk signal is obtained. The conversion process (step S11-5) includes a process of performing γ conversion on the cmyk signal and converting it to a c′m′y′k signal (step S11-6).

Step S12 is a process unique to the present embodiment, which is a process of reducing the number of gradations of the c'm'y'k signal to generate an approximate gradation pattern (step S12-1), and an approximate gradation pattern. To generate a boundary pattern (step S12-2).

Note that in FIG. 24, in addition to the process of generating CMYK output data for performing normal image formation from image data (step S11), a process of generating a boundary pattern characteristic of the present case and generating boundary output data (step S11). Although S12) is shown, it is not limited to the process of generating the CMYK output data shown in this example, and another method may be used.

<Process for generating boundary pattern from monochrome multi-tone image>
FIG. 25 is a diagram showing an approximate gradation pattern in which the number of gradations of a monochrome multi-gradation image is reduced, and FIG. 26 is a diagram showing a boundary pattern extracted from the approximate gradation pattern shown in FIG.

Not only the boundary of different colors, but even if the hue is the same, image deterioration due to bleeding and color mixing occurs at the boundary between regions of extremely different brightness, so the number of gradations is reduced from multi-gradation image data, It is also possible to further extract a boundary pattern from the image pattern of the approximate gradation.

Therefore, as an example, the gradation number is reduced from the original image data of 256 gradations of monochrome to 8 gradations, and the approximate gradation pattern shown in FIG. 25 is generated as an example of an image divided by each approximate gradation. Then, by extracting only the image showing the boundary from the approximate gradation pattern, the boundary pattern shown in FIG. 26 was generated.

First, printing is performed on the recording medium based on this boundary pattern, and then image formation is performed based on appropriate multi-tone image data, so that bleeding at a boundary portion having different lightness (image density) can be reduced.

As described in detail above, the recording apparatus according to the first embodiment and the recording apparatus according to the second embodiment of the present invention have the following features (1) to (10).
(1) By forming a boundary ink region in advance between image regions having different mixing ratios of recording inks, that is, image regions having different tints and lightness, a clear image can be obtained without causing color bleeding between recording inks. It can be formed.

(2) Similar effects can be obtained by the droplet ejection process of two kinds of ink, that is, the boundary ink and the recording ink, without the need for the three liquid droplet ejection processes as in the conventional method. Therefore, by reducing the number of steps and the number of ink types and the number of heads, it is possible to reduce the apparatus cost and simplify the apparatus.

(3) By using an ink containing a polymerization initiator (UV curing agent) as the boundary ink and using actinic ray irradiation means (UV lamps 8, 8A, 8B) as the fixing means, a liquid monomer immediately after landing Since the photo-curing agent which is sensitive to UV contained in (4) is changed to a polymer which is cured by UV irradiation, a bulky boundary can be formed on the surface of the recording medium 50 in a short time.

(4) By using the ink containing the polymerization initiator as the boundary ink and the actinic ray irradiating means as the fixing means, the kind of the recording ink is, for example, a water-based pigment ink or a solvent containing an organic solvent. The effect of preventing bleeding can be obtained even with the type of ink that easily causes bleeding.
Therefore, the recording ink does not have to be the “second liquid containing at least the radiation-curable polymerizable compound and the coloring material”, that is, the UV ink as in the conventional method, that is, the corresponding recording ink. The versatility of can be expanded.

(5) By creating a dot pattern so that the dot array of the ink dots in the boundary ink area becomes a closed area with a continuous boundary line, inks between adjacent image areas having different shades and lightness bleed out The effect of reliably preventing color mixing is enhanced, and a high-quality image with less color fringing can be obtained.

(6) According to the recording apparatus of the second embodiment, first, the transparent IJ head unit 6A mounting the transparent IJ head 10 sufficiently precedes to eject the boundary ink dot 100C1 on the recording medium 50, and By turning on the transparent IJ UV lamp 8A arranged immediately on the left side, it is possible to quickly form a hardened boundary ink region.
Then, the sub-scanning is sequentially performed in the −Y direction while forming the boundary ink region, and immediately after that, the color ink is arranged in the boundary region 50-c so that the color IJ head unit 6B arranged in the +Y direction independently follows. By ejecting a dot and turning on the color IJ UV lamp 8B disposed immediately to the left of the dot, a cured color ink region can be rapidly formed.
That is, it is possible to form the image area while chasing the boundary ink area on one recording medium 50. Therefore, the process of forming the “boundary ink area” must be completed once in the next step. It is possible to eliminate the waste of time such that the image forming process of the image area of 1 cannot be performed.

(7) In the recording apparatus according to the first embodiment, the transparent IJ head 10 and the color IJ heads 11 to 14 are integrally arranged on one head unit 6, and the UV lamp 8 is only one. Therefore, in some cases (when UV curing is performed immediately after droplet ejection of transparent ink for each main scan to deposit recording ink on the image area), the bulky boundary ink area is not yet completely blocked ( The color ink dots 101 have to be ejected onto the in-boundary area 50-c in the state where the portions are opened). In this case, there occurs a problem that ink bleeding occurs here.
On the other hand, according to the recording apparatus according to the second embodiment, the transparent IJ head unit 6A and the color IJ head unit 6B can independently drive on the Y-axis linear motor 3, so that the Y-axis direction of each other can be changed. The interval of can be set arbitrarily. Therefore, the color IJ head unit 6B is formed after the transparent IJ head 10 formed in advance forms (secures) a sufficiently wide range of the in-boundary area 50-c of the boundary ink area by sufficiently widening the interval. Can be operated to scan. As a result, since the color ink dots can be ejected after the boundary area 50-c is surely closed, the effect of preventing bleeding can be enhanced.

(8) The dot diameter of the boundary ink dots and at least one dot pitch in the main scanning direction or the sub-scanning direction are made smaller than the dot diameter of the color ink dots and at least one dot pitch in the main scanning direction or the sub-scanning direction. .. This makes it possible to reduce the width of the boundary area (line) and to catch both recording inks between adjacent image areas with different shades and luminosity. Since it is possible to eject droplets, the “boundary” becomes even more inconspicuous, and a further good image can be obtained.
That is, since the boundary small-diameter ink dot 100C2, which has the dot diameter and the dot pitch narrower than the boundary ink dot 100C1 by half, is ejected, the dot arrangement of the “boundary ink area” is “closed area” by “continuous boundary line”. It is possible to form a pattern so as to have an area of 1/2. For this reason, it is possible to prevent ink dots in different color ink regions that are adjacent to each other even closer to each other from causing bleeding, and to make the boundaries between color ink dots as small and unnoticeable as possible, so that an image with no noticeable gap is obtained. Can be done.

(9) By forming the boundary ink area and the image area so that the ink volume Hc of the boundary ink area becomes equal to or less than the ink volume H ₂ of the adjacent image area, the adjacent color is satisfied while the function as the boundary is satisfied. The effect of preventing bleeding of the recording inks between the image areas having different tastes and lightness is enhanced.

(10) In the fourth example and the fifth example of the dot pattern of the boundary ink area, a plurality of boundary ink areas are provided so as to cover areas other than the color ink area on the recording medium 50 (entire outer surface of the color ink area). The boundary ink dot 100C1 was ejected. As a result, there is no difference in the presence or absence of ink dots on the entire surface of the recording medium 50 on the printing surface side, so that an image with high smoothness can be obtained.

<Three-dimensional model formed by the recording device according to the third embodiment>
FIG. 27 is a diagram showing a schematic configuration of a cross section of a three-dimensional structure formed by the recording apparatus according to the third embodiment of the invention, and FIG. 28 is a recording according to the third embodiment of the invention. It is a figure which shows the outline of the layered modeling process of the three-dimensional molded item formed by the apparatus.

As shown in FIG. 27, the three-dimensional structure is laminated on the base 301 and divided into a modeling layer 302 that determines the shape of the three-dimensional structure and a surface layer that is responsible for coloring the surface of the modeling layer 302. Be done. As the surface layer, a base layer 303, a barrier layer 304, and a coloring layer 305 are arranged in this order.

Then, in a part such as a part surrounded by a circle 311, where the surface stands upright, the respective layers are vertically stacked and the head of the modeled part such as the part surrounded by a circle 312 is stacked. At the top (the flat portion at the top), the layers are stacked in the horizontal direction.

As shown in FIG. 28, each layer ejects ink droplets for the modeling layer, the underlayer, the barrier layer, and the Y/M/C/K colored layer while moving the head (main scanning). Are formed at the same time. This figure shows a state in which a vertically raised part and a part inside thereof are formed in the modeled object. Here, white ink is used as the underlayer ink, and transparent ink is used as the barrier layer ink. As the ink for the modeling layer, any ink may be used because it is not exposed on the surface of the modeled object.

Note that FIG. 28 shows a total of seven inkjet heads, one for the modeling layer, one for the underlayer, and one for the barrier layer, and four for the colored layer, but a special color ink (R/G/B, etc.) is used. In that case, the ink type will increase. On the contrary, by making the ink for the modeling layer common to any of the inks used for the surface layer, it is possible to reduce the type of ink. Further, although the colored layer is formed as the outermost surface layer in the figure, the transparent ink layer used as the barrier layer may be further laminated from above in order to impart gloss to the surface of the modeled object.

<Problems that occur on the colored surface of a three-dimensional structure>
FIG. 29 is a diagram for explaining a problem that occurs on a horizontal colored surface of a three-dimensional model, and FIG. 30 is a diagram for explaining a problem that occurs on a vertical colored surface of a three-dimensional model. is there. These problems are problems that occur in a three-dimensional structure having a known structure in which the barrier layer 304 does not exist in FIG. 27, and are problems that are solved by the recording device according to the embodiment of the present invention.

In the case of a horizontal colored surface, as shown in FIG. 29, if there is a difference in height on the upper surface of the underlayer, the ink droplets for the colored layer flow toward the lower side, so that the underlayer is exposed and the color layer ink is mixed. Turbidity occurs due to. If there is a deviation in the ejection timing of the colored layer ink droplets or a bend in the ejection direction, these are emphasized.

Further, in the case of a vertical colored surface, as shown in FIG. 30, the ink droplet for the colored layer, which is hit at a portion corresponding to the surface layer of the wall surface, flows downward from the wall surface to expose the wall surface underlying layer, or In some cases, the underlayer ink may flow out together.

Although FIGS. 29 and 30 are only examples, the white ink of the underlayer is often exposed from the gap between the outermost colored layers due to the ejection state, mechanical fluctuations, etc. As a result, the half-color image in the two-dimensional image is half-colored. The image density and saturation are reduced in the same way as when the void is created by tone processing.

However, unlike the halftone process, in the exposure of a white background due to the unintended flow of landing droplets, the exposure position itself is not controlled, so the density does not decrease uniformly and local density occurs. I will end up. Since it is unintended, it is not possible to perform color matching correction on the coloring data in advance, and the graininess is deteriorated due to the uneven density.

Therefore, in the recording apparatus according to the present embodiment, in order to suppress the outflow and exposure of the white ink that forms the underlayer, a barrier layer made of transparent ink is formed between the colored layer and the underlayer. The white ink layer as the base is necessary to color the modeled object vividly. On the other hand, unlike two-dimensional printing, the base layer (white ink layer) is not always a smooth surface, which affects the coloring. A transparent ink barrier layer is provided to prevent the white ink from flowing out, and the surface on which the colored layer ink lands is smoothed. Hereinafter, the barrier layer formed on the horizontal colored surface and the barrier layer formed on the vertical colored surface will be described in this order.

<Barrier layer for horizontal colored surface of 3D object>
FIG. 31 is a diagram showing an example of the barrier layer formed on the horizontal colored surface of the three-dimensional structure shown in FIG. 27.

As shown in the figure, when the barrier layer 304 is formed on the horizontal colored surface, the transparent ink droplets 304a larger than the white ink droplets 303a formed for forming the base layer 303 are used to cover the base layer 303. If the viscosity of the transparent ink used at this time is low, it spreads more quickly, so the viscosity is preferably low. The viscosity can be adjusted by selection/amount of the solvent when formulating the ink, and it is also possible to simply lower the viscosity by heating.

<Barrier layer on vertical colored surface of 3D object>
FIG. 32 is a diagram showing an example of a barrier layer formed on a vertical colored surface of the three-dimensional structure shown in FIG. 27.

As shown in the drawing, on the vertical colored surface, a barrier formed by the transparent ink droplet 304a is provided so as to separate the base layer 303 formed by the white ink droplet 303a and the colored layer 305 formed by the colored layer ink droplet 305a. Form layer 304. At this time, as shown in the figure, it is preferable that the transparent ink droplet 304a is smaller than the other ink droplets (ink droplet 302a for forming layer, ink droplet 303a for white layer, ink droplet 305a for coloring layer) and has high resolution. ..

As shown in FIG. 31, when the barrier layer 304 is formed in the horizontal direction, the thickness of the barrier layer 304 is suppressed by the transparent ink droplets 304a being drawn by gravity and spreading, but in the vertical direction, the spread. Since the amount of increase becomes the thickness of the barrier layer 304 as it is, the space between the colored layer 305 and the base layer 303 may be too wide.

When the distance between the colored layer 305 and the base layer 303 becomes wide, diffuse reflection in the barrier layer 304 causes “the density and saturation of the colored portion to be reduced” and “the unevenness between the colored portion and the colored portion at the place where the base should be exposed”. Since there is a fear that "steps are conspicuous", the barrier layer 304 made of transparent ink should be formed as thin as possible.

For that purpose, it is suitable to eject droplets with higher resolution with smaller droplets. When small droplets are used, there is a risk that a gap will be created in one recording operation, so even if the recording operation is divided so that only the barrier part is formed first and then the colored part/base part is formed. Good.

Since transparent ink is transparent, it transmits activation energy rays (UV light, etc.) to every corner of the ink, so that it cures faster than the ink for the coloring layer, and after curing it cures other inks. Since it is easy to pass a light beam, it is suitable for forming the barrier layer 304 by droplet ejection first.

Note that in the case of an inclined surface having an angle, the formation method of the barrier layer 304 may be switched depending on the angle. For example, a vertical barrier layer may be formed on a steep slope of 45 degrees or more, and a horizontal barrier layer may be formed on a gentle slope of 45 degrees or less.

<Schematic configuration of recording device>
The schematic configuration of the recording apparatus according to this embodiment is the same as that of the inkjet head (transparent/Y/M/C/K) in the recording apparatus according to the first embodiment described with reference to FIGS. As described with reference to FIG. 3, for example, it is changed to modeling layer/underlayer/transparent/Y/M/C/K.

<Structure of control unit of recording device>
The configuration of the control unit according to the present embodiment is the same as the control unit 200 of the recording apparatus according to the first embodiment shown in FIG. In this embodiment, stereoscopic information from a 3D (three-dimensional) scanner, which will be described later, and color information from a digital camera or the like are input to the I/O 213.

In the modeling operation itself, after recording/curing for one layer (layer), the z-axis head stage 5 is raised by a distance corresponding to the layer thickness to model the next layer. By repeating this, modeling for the required height is performed. It should be noted that the height adjustment of the z-axis head stage 5 need not be performed layer by layer as long as it does not affect the quality of the modeled object.

<Processing flow of additive manufacturing process of 3D object>
FIG. 33 is a diagram showing a processing flow of a layered modeling process of a three-dimensional model by the recording apparatus according to the third embodiment of the present invention, and FIG. 34 is a three-dimensional model generated by the processing flow of FIG. It is a figure for explaining data and record information on each layer.

In the processing flow of this figure, the 3D modeling data uses the duplicated data of the modeled object (original) captured by the 3D scanner, but artificial data created by 3D CAD or the like is used according to a specific rule for the 2D image. It is also possible to use processing data having a thickness.

First, three-dimensional modeling data is created based on the data from the 3D scanner 60 and the data from the digital camera 70 (step S21). The three-dimensional modeling data includes stereoscopic information (3D coordinate data) and coloring information.

As shown in FIG. 34, the 3D coordinate data is composed of vertical and horizontal coordinates and height information when the modeled object is viewed from the upper surface, and is three-dimensional (vertical, horizontal, height)=(x, y, z). The coordinate value manages the coordinate of each grid (division unit). The coloring information is composed of ordinate and abscissa coordinates and color information when the modeled portion is viewed from above, and is managed by three-dimensional coordinate values of (vertical, horizontal, color)=(x, y, c).

Next, color information is added to the model managed by the three-dimensional coordinate values of (length, width, height)=(x, y, z), and recording information for each layer is created. Yes (step S22).
That is, as shown in FIG. 34, for example, a range surrounded by four points of (x1,y1,z1) to (x1,y1,z0) to (xn,y1,z0) to (xn,y1,z1) Gives the color information of the surface portion such as "color A". When the data is created by three-dimensional CAD or other three-dimensional data generation tool, it is possible to directly specify the color or paste the texture data.

Next, for each pixel of the recording information of the first layer created in step S22, whether the pixel is a colored part, a barrier part, or a base part based on the number of pixels (distance) from the outer edge of the base. It is determined whether it is a site or a modeling site, and the ink used for image formation is determined based on the determination result.

That is, if the pixel (x, y) is within a pixels from the outer edge (step S23: Yes), it is determined that the pixel (x, y) is a colored portion (outermost surface layer to a predetermined range a), and the color ink Then, it is decided to form an image (step S24).

If the pixel (x, y) is not within the a pixel from the outer edge but within the b (b>a) pixel (step S23: No→S25: Yes), the pixel (x, y) is the barrier part (coloring). It is determined that the image is within the region to a predetermined range b), and it is determined to form an image with transparent ink (step S26).

Further, if the pixel (x, y) is not within a pixels or b pixels from the outer edge and is within c (c>b) pixels (step S23: No → S25: No → S27: Yes), the pixel (x , Y) is a base portion (inside the barrier portion to a predetermined range c), and it is determined to form an image with white ink (step S28).

In addition, if the pixel (x, y) is not within a pixel, b pixel, or c pixel from the outer edge (step S23: No → S25: No → S27: No), the pixel (x, y) is the molding site. It is determined to be (inside the base portion), and it is determined to form an image with the modeling ink (step S29).

After performing any of steps S24, S26, S28, and S29, the droplet ejection ink information used for image formation is set (step S30). Note that the widths (a, b-a, c-b) of the respective parts do not always have the same value. One or more optimal values can be set according to the color development characteristics of each ink.

Next, steps S23 to S30 are repeated (step S31: No→S23 to S30) until the droplet ejection ink information is set for all pixels in the layer, and when it is completed (step S31: Yes), all It is determined whether or not the ink droplet ejection information has been set for the pixels of the recording layer (step S32).

If the result of determination is that recording has not been completed (step S32: No), recording information for the next layer is created (step S22), and the processing in and after step S23 described above is repeated. On the other hand, if it has been completed (step S32: Yes), three-dimensional image formation is performed (step S33), and the processing shown in this figure ends.

In this figure, one-layer recording information is created in step S22, one-layer droplet ejection information is set in steps S23 to S30, and these steps are repeated for the number of layers, but in step S22. It is also possible to create recording information for all layers. In this case, a step of selecting a layer may be provided between steps S22 and S23.

As described in detail above, the recording apparatus according to the third embodiment of the present invention has the following features (1) to (4).
(1) When the three-dimensional modeled object is formed and colored at the same time, a transparent barrier layer is formed between the outermost colored layer and the white ink layer, which is a base layer thereof, so that the white ink seeps out. It is possible to achieve vivid coloring.
(2) When forming a barrier layer on a horizontal colored surface, by using a transparent ink droplet that is larger than the white ink droplet that is ejected to form the underlayer, the barrier layer is easily smoothed. be able to. Further, by setting the viscosity of the transparent ink to be low, the underlayer can be coated more quickly.
(3) When forming a barrier layer on a vertical colored surface, the transparent ink droplets are made smaller than other ink droplets and have a high resolution, so that the space between the base layer and the colored layer is too wide. It is possible to prevent a decrease in the density and saturation of the colored layer due to the above.
(4) The barrier layer made of the transparent ink can be used not only as a boundary with the underlying layer but also as a boundary between the colored layer inks. When color mixing at the color boundary becomes a problem, a barrier layer made of transparent ink may be formed for the purpose of preventing color mixing.

8, 8A, 8B... UV lamp, 10... Transparent IJ head, 11... Black IJ head, 12... Cyan IJ head, 13... Magenta IJ head, 14... Yellow IJ head, 50... Recording medium, 50-c... Boundary Inner area, 100C1... Boundary ink dot, 100C2... Boundary small diameter ink dot, 101Bk... Black ink dot, 101C, 102C... Cyan ink dot, 101M, 102M... Magenta ink dot, 101Y, 102Y... Yellow ink dot, 301... Base, 302... Modeling layer, 302a... Modeling layer ink drop, 303... Underlayer, 303a... White ink drop, 304... Barrier layer, 304a... Transparent ink drop, 305... Coloring layer, 305a... Coloring layer ink drop.

Japanese Patent No. 4827450

Claims (9)

A plurality of types of ink are made to land on the recording medium or the ink made to land on the recording medium to form a first recording ink region and a second recording ink region having different mixing ratios of the plurality of types of ink. First droplet discharging means for
Before the first droplet ejection means to form the first recording ink region and the second recording ink area, between the first recording ink region and the second recording ink areas, the ink boundary Second droplet discharging means for landing to form a boundary ink area;
Boundary ink area fixing means for fixing the boundary ink area before the first droplet discharge means forms the recording ink area,
Recording ink area fixing means for fixing the recording ink area,
Have
The volume of the boundary ink area is equal to or greater than the volume of the recording ink area, and the boundary ink area is formed by ink droplets that are ejected in the same position .
The recording apparatus , wherein the pitch of the ink dots in the boundary ink area is smaller than the pitch of the ink dots in the recording ink area . In the recording device according to claim 1,
The recording apparatus, wherein the boundary ink contains a polymerization initiator, and the boundary ink area fixing unit is an actinic ray irradiation unit. In the recording device according to claim 1,
The recording apparatus, wherein the boundary ink area forms a closed area by a boundary line in which an array of ink dots is continuous. The recording apparatus according to any one of claims 1 to 3 ,
The recording apparatus, wherein the second droplet ejecting unit causes the boundary ink to land on the entire surface other than the recording ink area. The recording apparatus according to any one of claims 1 to 4 ,
The recording apparatus, wherein the first droplet discharge means and the second droplet discharge means are independently movable in a predetermined direction while facing the surface of the recording medium. The recording apparatus according to claim 5 ,
The recording apparatus, wherein the recording ink area fixing means and the boundary ink area fixing means are separate fixing means corresponding to the first droplet discharging means and the second droplet discharging means, respectively. In the recording device according to claim 1,
The recording apparatus, wherein the plurality of types of ink include white ink. A plurality of types of ink are made to land on the recording medium or the ink made to land on the recording medium to form a first recording ink region and a second recording ink region having different mixing ratios of the plurality of types of ink. A first droplet discharging step of
Before the first droplet discharging step forms the first recording ink area and the second recording ink area, a boundary ink is formed between the first recording ink area and the second recording ink area. A second droplet discharge step of landing to form a boundary ink area;
A boundary ink area fixing step of fixing the boundary ink area before the first droplet discharging step forms the recording ink area ;
A recording ink area fixing step of fixing the recording ink area;
Have
The volume of the boundary ink area is equal to or greater than the volume of the recording ink area, and the boundary ink area is formed by ink droplets that are ejected in the same position .
The recording method , wherein the pitch of the ink dots in the boundary ink area is smaller than the pitch of the ink dots in the recording ink area . A program for causing a recording device controlled by a computer to execute each step of the recording method according to claim 8 .

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