JP2021066026A - Printing method and printer - Google Patents

Abstract

To provide a printing method or a printer capable of expressing brightness and hue with anisotropy or directivity.SOLUTION: A printing method includes performing a plurality of times a step which includes: a process of forming dots by discharging light-curing type ink droplets to a record medium, making a light-curing type ink layer into a first layer, and forming a plurality of dot groups of the first layer in which a plurality of light-curing type ink dots discharged to the first layer are aligned without clearances; a process of curing by irradiating the first layer with light; a process of forming dots by discharging light-curing type ink droplets onto the dot groups of the first layer, making a light-curing type ink layer discharged onto the dot groups of the first layer into a second layer, and forming as dot groups of the second layer, a plurality of light-curing type ink dot groups having a width smaller than that of the dot groups of the first layer; and a process of curing by irradiating the second layer with light. Thus, a plurality of laminates having combinations of the dot groups of the first layer and the dot groups of the second layer are formed.SELECTED DRAWING: Figure 6

Description

The present invention relates to a printing method and a printing apparatus.

An inkjet printing apparatus that prints using color ink and metallic ink is known as a prior art (Patent Document 1).

JP-A-2019-107852

In printing with the above printing device, although it is possible to express using the gloss and color of the ink, it expresses anisotropic or directional gloss or color in which the light intensity changes depending on the viewing angle. I couldn't. In addition, the structural color could not be developed by printing with the above printing apparatus. Structural color is color development due to light scattering, interference, or diffraction due to the fine three-dimensional structure of the printed ink surface.

In view of the above problems, an object of the present invention is to provide a printing method or printing apparatus capable of expressing anisotropic or directional gloss or color.

In order to solve the above problems, the present invention provides, as one aspect, a printing method in which a plurality of metallic layers are laminated to form a diffused reflection block. The diffused reflection block is composed of a set of dots made of a plurality of metallic inks, and adjacent dots are arranged horizontally and vertically without gaps to form a diffused reflection block made of an upper metallic ink layer. The size of is equal to or smaller than the size of the layers that make up the diffuse reflection block by the lower metallic layer. Diffuse reflection blocks are, for example, in the shape of a cone, or all or part of a pyramid.

As one aspect of the present invention, droplets of photocurable ink are ejected toward a recording medium to form dots, the photocurable ink layer is used as a first layer, and the photocurable ink ejected to the first layer is photocured. A process of forming a plurality of dots of the first layer in which a plurality of dots of the mold ink are lined up without gaps, a process of irradiating the first layer with light to cure the ink, and a process of photocuring the dots on the first layer. Dots are formed by ejecting droplets of the mold ink, and the layer of the photocurable ink ejected on the dot group of the first layer is used as the second layer, which is wider than the dot group of the first layer. The first step is performed by performing a plurality of steps including a process of forming a plurality of small dots of the photocurable ink as a group of dots of the second layer and a process of irradiating the second layer with light to cure the second layer. Provided is a printing method for forming a plurality of laminates having a combination of a dot group of one layer and a dot group of the second layer.

Further, as one aspect of the present invention, a head unit for ejecting ink droplets, an irradiation unit for irradiating light, and a control unit are provided, and the control unit emits light from the head unit toward a recording medium. A first layer in which droplets of curable ink are ejected to form dots, the layer of the photocurable ink is the first layer, and a plurality of dots of the photocurable ink ejected to the first layer are lined up without gaps. A process of forming a plurality of dot groups of the above, a process of irradiating the first layer with light from the irradiation portion to cure the first layer, and a process of photocuring from the head portion onto the dot group of the first layer. Dots are formed by ejecting droplets of the type ink, and the layer of the photocurable ink ejected on the dot group of the first layer is used as the second layer, which is wider than the dot group of the first layer. A step including a process of forming a plurality of small dots of the photocurable ink as a group of dots of the second layer, and a process of irradiating the second layer with light from the irradiation unit to cure the second layer. Provided is a printing apparatus for forming a plurality of laminates having a combination of the dot group of the first layer and the dot group of the second layer by performing the above a plurality of times.

With the above configuration, the present invention can provide a printing method or printing apparatus capable of expressing anisotropic or directional gloss or color.

It is a schematic explanatory drawing of the printing system which concerns on embodiment. It is a block diagram of the printing system which concerns on embodiment. It is explanatory drawing of the member mounted on the carriage of the printing apparatus which concerns on embodiment. It is a schematic explanatory view of the irradiation part of this embodiment. It is a flowchart which shows the printing process which concerns on embodiment. The processes in which the base layer, the first layer, the second layer, and the third layer are formed in the printing process are shown in FIGS. (A) to (d) as cross-sectional views. The process of forming the first layer, the second layer, and the third layer in the printing process is shown in FIGS. (A) to (c) as a top view. (A) is a cross-sectional view of a diffused reflection block before the gloss layer is formed, (b) a cross-sectional view showing a printed portion in a state where the gloss layer is formed, and (c) a perspective view of the diffused reflection block. It is sectional drawing which shows the arrangement of a plurality of diffuse reflection blocks, and shows (a) diffuse reflection block which has a regular triangular cross section, and (b) diffuse reflection block which has a right-angled triangular cross section. It is sectional drawing which shows the state which the dot of the color ink was formed above the gloss layer, and (b) is the sectional view which shows the state which the gloss layer was formed above the dot of a color ink. It is a figure which shows (a) a figure which shows the printed part formed by a printing process, and (b) is a figure which shows the state which further formed the pattern by using color ink. Modification examples of the diffused reflection block are shown in the figures (a) to (d). For ease of understanding, the outer shape of the block is shown by a dotted line, and only the first layer is shown by a solid line. This is a modification of the arrangement of the diffused reflection blocks, and shows (a) a state in which the diffused reflection blocks are arranged in a staggered manner, and (b) a state in which the diffused reflection blocks are arranged diagonally with respect to the transport direction and the scanning direction.

<Basic configuration of printing system 1>
FIG. 1 is a schematic explanatory view of the printing system 1 of the present embodiment. FIG. 3 is an explanatory view of a member mounted on the carriage 21 of the printing device 10.

In the following description, the moving direction of the carriage 21 may be referred to as a "scanning direction" or a "left-right direction". Further, the moving direction of the flat table 31 (or the medium M) is referred to as a "conveying direction", and the discharge side of the printed medium M (the operator's side when viewed from the flat table 31) is the "front side" or " It may be referred to as "downstream side in the transport direction", and the opposite side may be referred to as "back side" or "upstream side in the transport direction". The direction perpendicular to the mounting surface of the flat table 31 is called the "vertical direction", the side on which the medium M is mounted as viewed from the flat table 31 is called "upper", and the opposite side is called "lower". is there.

The printing system 1 is a system for ejecting ink droplets onto the medium M to perform printing. The printing system 1 includes a computer 3 and a printing device 10. However, the printing system 1 may be configured by the printing device 10 alone by realizing the function performed by the computer 3.

The computer 3 is a print control device for controlling the print device 10. The computer 3 generates a command code for controlling the printing device 10, and transmits the command code to the printing device 10. The printing device 10 that has received the command code from the computer 3 controls each part according to the command code to print on the medium M. The computer 3 also transmits image data to be printed to the printing device 10. The computer 3 is, for example, a general-purpose personal computer in which a print control program (so-called printer driver) is installed. The processing device (for example, CPU) of the computer 3 functions as a print control unit that generates a command code by executing a print control program stored in a storage medium (for example, a memory).

The printing device 10 is a device for ejecting ink droplets onto the medium M to perform printing. The printing apparatus 10 of the present embodiment is a UV printer that ejects ultraviolet curable ink (so-called UV ink) onto the medium M and irradiates the dots formed on the medium M with ultraviolet rays to cure the dots. The printing device 10 of the present embodiment includes a controller 11, a carriage unit 20, a transport unit 30, a printing unit 40, and an irradiation unit 50 (FIG. 2).

The controller 11 is a control unit that controls the printing device 10. The controller 11 controls each drive unit (carriage motor 22, transport motor 32, head drive unit 42, LED drive unit 52) of the printing device 10 based on a command code from the computer 3.

The carriage unit 20 is a unit for reciprocating the carriage 21 in the scanning direction (left-right direction). The carriage portion 20 has a carriage 21 and a carriage motor 22. The carriage 21 is a member that reciprocates in the scanning direction. A head 41 and an irradiation unit 50 are mounted on the carriage 21 (see FIG. 3). By reciprocating the carriage 21 in the scanning direction, it is possible to reciprocate the members (head 41 and the irradiation unit 50) mounted on the carriage 21 in the scanning direction. The carriage motor 22 is a drive unit for moving the carriage 21 in the scanning direction. The controller 11 controls the movement of the carriage 21 by controlling the drive of the carriage motor 22.

The carriage unit 20 has a scanning position detecting unit 23 for detecting the position of the carriage 21 in the scanning direction. By detecting the position of the carriage 21 in the scanning direction, the scanning position detection unit 23 substantially detects the position of the members (head 41 and the irradiation unit 50) mounted on the carriage 21 in the scanning direction. ing. The scanning position detection unit 23 outputs the detection result to the controller 11. Here, the scanning position detection unit 23 is composed of an origin sensor and a linear encoder.

The transport unit 30 is a mechanism for transporting the medium M. The medium M to be transported is, for example, a thick plastic plate-shaped member. However, the medium M is not limited to this, and may be a single sheet paper, a film, a cloth, or the like. Further, the print surface of the medium M is not limited to a flat surface. For example, when the medium M is a spherical ball or the like, the printed surface has a curved surface.

The transport unit 30 has a flat table 31 and a transport motor 32. The flat table 31 is a mounting table (supporting table) on which the medium M is placed, and is movable in the transport direction. On the flat table 31, not only the medium M but also, for example, a jig for supporting the medium M, a suction device for sucking the medium M, and the like can be placed. The transport motor 32 is a drive unit for transporting the flat table 31 in the transport direction. The controller 11 controls the movement of the flat table 31 (or the medium M) by controlling the drive of the transport motor 32.

The transport unit 30 has a transport position detection unit 33 for detecting the position of the flat table 31 (or the medium M) in the transport direction. The transport position detection unit 33 outputs the detection result to the controller 11.

The printing unit 40 is a unit for ejecting ink droplets (also referred to as droplets) onto the medium M. The printing unit 40 has a head 41 and a head driving unit 42. The head 41 has a nozzle row for ejecting ink. The head drive unit 42 is a drive unit that ejects and does not eject ink droplets from each nozzle of the head 41. The head drive unit 42 is, for example, a drive unit that drives a piezo element if the head 41 is a piezo type. The head 41 is mounted on the carriage 21 (see FIG. 3) and can move together with the carriage 21 in the scanning direction. The controller 11 controls the ejection of ink droplets from the head 41 by controlling the head drive unit 42.

Although a longitudinal vibration type piezoelectric element is used as the pressurizing means of the present embodiment, for example, a flexible deformation type piezoelectric element in which a lower electrode, a piezoelectric layer, and an upper electrode are laminated and formed may be used. Further, as the pressure generating means, a so-called electrostatic actuator or the like may be used. Further, it may be a print head that ejects droplets using a heating element.

A nozzle row is formed on the lower surface of the head 41. The nozzle row is composed of a plurality of nozzles arranged in the transport direction. Four heads 41 are mounted on the carriage 21 (see FIGS. 3 and 4). The four heads 41 are arranged side by side in the scanning direction. In other words, the plurality of nozzle rows are arranged side by side in the scanning direction.

In the present embodiment, the ink ejected from the head 41 is a photocurable ink (photocurable resin) that cures when irradiated with light. Here, the photocurable ink is an ultraviolet curable ink (so-called UV ink), but it may be an ink that is cured by being irradiated with light of another wavelength. The photocurable ink has fluidity before being irradiated with light, but has the property of solidifying when irradiated with a predetermined irradiation amount of light. When the ink (dots) ejected to the medium M is irradiated with light, the ink (dots) is cured and the dots can be fixed on the medium M.

The irradiation unit 50 is a unit that irradiates light for curing the photocurable ink. In the present embodiment, the irradiation unit 50 includes an LED array 51 and an LED drive unit 52. The LED array 51 is a group of light emitting elements in which LEDs, which are light emitting elements 512, are arranged. The LED array 51 can irradiate a predetermined range with light by arranging the light emitting elements 512 in two dimensions. Although the light emitting element 512 irradiates ultraviolet rays, it may irradiate light other than ultraviolet rays. The LED drive unit 52 is a drive unit for driving an LED to be a light emitting element 512 to turn on / off (turn on / off) the light emitting element 512. By controlling the LED drive unit 52, the controller 11 controls the on / off of the light emitting element 512 (LED) of the LED array 51. The configurations of the LED array 51 and the LED drive unit 52 will be described later.

The irradiation unit 50 is mounted on the carriage 21 (see FIGS. 3 and 4) and can move in the scanning direction together with the carriage 21 (and the head 41). The irradiation unit 50 irradiates light downward, and irradiates light toward the flat table 31 (or medium M). A pair of irradiation units 50 are mounted on the carriage 21, and the pair of irradiation units 50 are arranged on the left and right sides of the head 41 so as to sandwich the head 41 from the scanning direction. This enables so-called bidirectional printing. However, instead of arranging the pair of irradiation units 50 so as to sandwich the head 41 from the left-right direction, the irradiation units 50 may be arranged on either the left or right side.

FIG. 4 shows a schematic explanatory view of the irradiation unit 50 of the present embodiment. The LED array 51 is configured by two-dimensionally arranging LEDs serving as light emitting elements 512 in the scanning direction and the transport direction. Here, the LED array 51 is configured by arranging four light emitting element rows in which a large number of light emitting elements 512 are arranged in the transport direction in the scanning direction.

In the printing device 10 having the above configuration, at the time of printing, the controller 11 controls each drive unit (carriage motor 22, transport motor 32, head drive unit 42, LED drive unit 52) of the printing device 10 to obtain " An image is printed on the medium M by alternately performing an operation called "pass" and a transport operation. The “pass” is an operation of ejecting ink from the head 41 while moving the carriage 21 in the scanning direction. In the present embodiment, since the printing device 10 is a UV printer, the controller 11 not only ejects ink from the head 41 moving in the scanning direction while the carriage 21 is moving, but also ejects dots (medium M) from the irradiation unit 50. The operation of irradiating the ink discharged from the printer with light is also performed. In a certain pass, the irradiation unit 50 may not only irradiate the dots formed in the pass with light, but also irradiate the dots formed in the pass before the pass with light.

[Operation during printing]
The operation during printing will be described in detail below. As shown in FIGS. 6 and 7, a base layer W, a first layer (a layer containing a plurality of dot groups L1 described later), a second layer (a layer containing a plurality of dot groups L2 described later), and a first layer on the medium M. A printing process for sequentially forming three layers (a layer containing a plurality of dot groups L3, which will be described later) and a gloss layer G will be used as an example of the embodiment. The dot group L1 of the first layer, the dot group L2 of the second layer, and the dot group L3 of the third layer are formed so that the width of the dot group of the upper layer is shorter than that of the dot group of the lower layer, and are substantially square as a whole. A weight-shaped diffuse reflection block B is formed. The diffused reflection block B is an example of the laminated body in the present invention.

The controller 11 executes the process according to the flowchart of FIG. First, the controller 11 uses the carriage 21 to execute a process of ejecting a droplet of white ink onto the medium M. The ejected white ink droplets land on the medium M to form dots (S1). A plurality of dots of white ink are arranged so as to be arranged without gaps in the scanning direction and the transport direction to form the base layer W (FIG. 6A). The controller 11 irradiates the base layer W with light (ultraviolet rays) from the light emitting element 512 to cure the base layer W.

Next, as shown in FIGS. 6B and 7A, the controller 11 ejects droplets of the ultraviolet curable metallic ink to a plurality of regions on the base layer W in the scanning direction and the transport direction. A plurality of dot groups L1 of the first layer composed of a set of a plurality of dots arranged side by side (appropriately referred to as a dot group) are formed (S3). The dot group L1 of the first layer is cured by the light (ultraviolet rays) emitted from the light emitting element 512. The ultraviolet curable metallic ink is an ink having a metallic luster, and generally contains a large number of fine scaly or particulate metal pieces.

The dot group L1 of the first layer is formed by ink droplets of a plurality of metallic inks arranged without gaps in the scanning direction and the transport direction, and one dot group has a width D1 in the transport direction and a width W1 in the scanning direction. It is formed by three dots in the transport direction and three dots in the scanning direction so as to be (FIG. 8 (c)). The lengths of the width D1 and the width W1 can be set to desired lengths by the user, respectively. That is, the number of dots constituting one dot group can be set as appropriate. Further, the number and arrangement of the plurality of dot groups in the transport direction and the number and arrangement in the scanning direction can be appropriately set.

Next, the controller 11 prints the upper layer (S5). Specifically, the controller 11 ejects droplets of the ultraviolet curable metallic ink onto the dot group L1 of the first layer to form a plurality of dot groups L2 in the scanning direction and the transport direction. Since the droplets are ejected after the dot group L1 of the first layer is cured, the dot group L2 of the second layer is arranged on the dot group L1 of the first layer, and the dot group L1 of the first layer as a whole is arranged. A second layer of dot group L2 is formed on top of the above (FIGS. 6 (c) and 7 (b)). The light (ultraviolet rays) emitted from the light emitting element 512 cures the dot group L2 of the second layer.

The dot group L2 of the second layer is formed by a plurality of ink droplets of metallic ink arranged in the scanning direction and the transport direction, and one dot group has a width D2 in the transport direction and a width W2 in the scanning direction. (FIG. 6 (c), FIG. 8 (c)). The dot group L2 of the second layer is formed smaller than the dot group L1 of the first layer. Specifically, the width D2 is shorter than the width D1 or the width W2 is shorter than the width W1. Alternatively, the width D2 and the width W2 are formed shorter than the width D1 and the width W1, respectively (FIG. 8 (c)). In the present embodiment, the dot group L2 of the second layer is formed by two dots in the transport direction and two dots in the scanning direction, and the dot group of the first layer is formed in both the transport direction and the scanning direction. It has a width shorter than L1. As described above, the formation of the upper layer is performed so as to have a width shorter than that of the overlapping dots of the lower layer in at least one direction such as the bottom direction, the transport direction, or the scanning direction of the diffused reflection block B.

As described above, the controller 11 stacks a plurality of dot groups formed by the ultraviolet curable metallic ink upward with respect to the lower dot group, and forms a layer having a short width in at least one direction upward. To go. The controller 11 repeats this process until the number of layers reaches a set value (predetermined number of layers) (S7: NO).

In this embodiment, the number of layers is set to three. Therefore, step S5 is executed again, and the dot group L3 of the third layer is formed so as to overlap the dot group L2 of the second layer (FIGS. 6 (d) and 7 (c)). The dot group L3 of the third layer is formed smaller than the dot group L2 of the second layer. Specifically, the width D3 is shorter than the width D2, or the width W3 is shorter than the width W2. Alternatively, the width D3 and the width W3 are formed shorter than the width D2 and the width W2, respectively (FIG. 8 (c)). In the present embodiment, the dot group L3 of the third layer is formed by one dot in the transport direction and one dot in the scanning direction, and the dot group of the second layer is formed in both the transport direction and the scanning direction. It has a width shorter than L2.

When the number of layers (three layers in this embodiment) reaches the set value (S7: YES), the controller 11 proceeds to step S9 and forms the gloss layer G using the ultraviolet curable ink that transmits visible light. (Fig. 8 (b)). In the present embodiment, it is assumed that a colorless and transparent ink is used for the gloss layer G, but the ink may be colored or translucent. The controller 11 ejects droplets of ultraviolet curable ink from the head 41 to form dots so as to fill the gaps between the dot groups of each layer. The formed dots are cured by the light (ultraviolet rays) emitted from the light emitting element 512. By repeating this and laminating the dots, the gloss layer G is formed. The formation of the gloss layer G is carried out until the surface becomes flat.

As shown in FIG. 8B, the printed portion P thus formed has a plurality of diffused reflection blocks B forming an inclined slope with respect to the medium M. The angle of inclination of the slope and the like can be appropriately changed according to the purpose of printing. For example, as shown in FIGS. 9 (a) and 9 (b), it may be formed into a substantially right-angled triangular shape or a substantially triangular shape in a vertical cross-sectional view.

The light incident on the printed portion P is reflected as strong light in a specific direction by the slope of the diffused reflection block B as shown by the alternate long and short dash line in FIGS. 9 (a) and 9 (b). That is, the light reflected by the diffuse reflection block B has directivity. Therefore, as shown in FIG. 11A, the printed portion P has a so-called anisotropic or directional unique gloss in which the intensity of the reflected light changes depending on the viewing angle, and is diffusely reflected or specified. It is visually recognized as if it shines strongly in the direction of.

It is also possible to develop a structural color on the printed portion P depending on the size of the diffused reflection block B, the angle of the slope, and the arrangement interval of the diffused reflection block B. For example, it is possible to form a diffraction grating with a plurality of diffused reflection blocks B so that the reflection angle differs depending on the wavelength of the incident light. In this case, the portion where the diffused reflection block B is formed is visually recognized in rainbow colors like a hologram or a compact disc. Alternatively, the diffuse reflection block B can be formed and arranged so as to reflect only light having a specific wavelength. At this time, the printed portion P is visually recognized as a specific color such as blue or red.

The print portion P can also be used as a base for printing a pattern. The controller 11 can further print the dots C on the gloss layer G using the color ink to form the pattern Z (FIGS. 10A and 11B). Further, the controller 11 can further form the gloss layer G after the symbol Z is formed. (Fig. 10 (b)). As a result, it is possible to prevent the dot C from being removed from the printed portion P or being worn, and the symbol Z can be fixed.

<Modification example>
In the above embodiment, the number of layers of the diffused reflection block B is three, but the diffused reflection block B may be composed of two layers or four or more layers. Further, the shape of the diffused reflection block B is not limited to the square pyramid shape. As shown in FIGS. 12 (a) to 12 (d), the diffuse reflection block B can have a three-dimensional shape including a triangular weight, a cone, and other polygonal weight shapes. In each figure of FIG. 12, for ease of understanding, the outer shape of the diffused reflection block B is shown by a dotted line, and only the first layer is shown by a solid line. Further, the shape of the diffused reflection block B is not limited to the weight shape, and may be a triangular columnar shape as shown in FIG. 12 (c), or may be a shape that forms a part of a pyramid such as a truncated cone shape. .. Regardless of the shape, in the diffused reflection block B, one of the layers constituting the diffused reflection block B and the end face formed by the upper layer thereof form an inclined slope with respect to the medium M. For example, in the diffused reflection block B of FIG. 8C, the end faces formed by the first layer L1, the second layer L2, and the third layer L3 are relative to the medium M in both the transport direction and the scanning direction. It forms a sloping slope. As described above, since the diffused reflection block B has a slope, the light incident on the printed portion P is diffusely reflected or reflected as strong light in a specific direction, and the above-mentioned effect can be obtained.

In the embodiment, all the diffused reflection blocks B are formed so as to have substantially the same shape, but the present invention is not limited to such a configuration. The shapes of the diffuse reflection blocks B can also be formed so as to be different from each other. Further, the plurality of diffused reflection blocks B may be divided into a plurality of groups, and the shapes may be different for each group. Further, the base layer W is not an indispensable structure, and it is possible to directly form the diffused reflection block B on the medium M. Further, the gloss layer G is not an essential configuration in the printed portion P. Therefore, it is also possible to form the print portion P only by the diffused reflection block B.

In the above embodiment, the diffused reflection blocks B are arranged in the transport direction and the scanning direction, but the present invention is not limited to such a configuration. That is, the arrangement of the diffuse reflection blocks B is not limited to the arrangement in the orthogonal direction. For example, as shown in FIG. 13B, the diffused reflection blocks B may be arranged obliquely with respect to the transport direction and the scanning direction. In FIG. 13, the array of only the first layer L1 is displayed for easy understanding. Further, the diffused reflection blocks B may be arranged in a staggered manner (FIG. 13 (a)) or may be arranged randomly. The arrangement interval of the diffuse reflection block B may be random or may not be provided.

<Effect>
In the printing system 1 of the above embodiment, a process of ejecting droplets of the photocurable ink toward the medium M to form dots and forming a layer of the photocurable ink as a dot group L1 of the first layer ( S1), a process of irradiating the dot group L1 of the first layer with light to cure it, and ejecting droplets of photocurable ink onto the first layer to form dots, which are smaller in width than the first layer. By performing a process including a process (S2) of forming a layer of photocurable ink as a second layer of dot group L2 and a process of irradiating the dot group L2 of the second layer with light to cure the ink, a plurality of times. , A plurality of diffused reflection blocks B having an overlap (combination) of the dot group L1 of the first layer and the dot group L2 of the second layer are formed.

With this configuration, the light reflected by the diffuse reflection block B has directivity. In other words, it has a so-called anisotropic and unique luster in which the intensity of light changes depending on the angle, and it is visually recognized as diffusely reflected or strongly shining in a specific direction. Further, depending on the arrangement interval of the diffused reflection block B and the shape and size of the inclined surface, it is possible to develop a structural color.

The diffused reflection block B forms an inclined surface inclined with respect to the medium M. Also, the diffuse reflection block B forms at least a part of the pyramid. Alternatively, the diffuse reflection blocks B are arranged at intervals from each other.

With the above configuration, the light reflected by the diffuse reflection block B is easily reflected in a specific direction, and is visually recognized as being diffusely reflected or strongly shining in a specific direction. Further, depending on the arrangement interval and the shape and size of the inclined surface, it is possible to develop a structural color.

In the printing system 1 of the above embodiment, a process of ejecting ink droplets that transmit light at intervals between diffused reflection blocks B to form a gloss layer G and filling the intervals is performed (FIGS. 5 and S9). By filling the gap with the gloss layer G in this way, it is possible to prevent the shape of the diffused reflection block B from being deformed or deformed. This prevents the angle of the reflected light from the printed portion P from changing and the color development from being deteriorated.

The photocurable ink has a metallic luster. Therefore, the light is more easily reflected than when ordinary ink is used, and the reflected light from the printed portion P is easily visible.

1 Printing system 10 Printing device 40 Printing unit 50 Irradiation unit L1 First layer L2 Second layer L3 Third layer M Medium P Printing site

Claims (7)

Droplets of the photocurable ink are ejected toward the recording medium to form dots, the layer of the photocurable ink is used as the first layer, and a plurality of dots of the photocurable ink ejected to the first layer are formed. The process of forming multiple dots of the first layer that are lined up without gaps,
The process of irradiating the first layer with light to cure it,
Droplets of the photocurable ink are ejected onto the dots of the first layer to form dots, and the layer of the photocurable ink ejected onto the dots of the first layer is designated as the second layer. A process of forming a plurality of dots of the photocurable ink having a width smaller than that of the dots of the first layer as a dot group of the second layer.
By performing the process including the process of irradiating the second layer with light to cure it a plurality of times,
A printing method for forming a plurality of laminates having a combination of a dot group of the first layer and a dot group of the second layer. The printing method according to claim 1, wherein the laminated body forms an inclined surface inclined with respect to the recording medium. The printing method according to claim 1 or 2, wherein the laminate forms at least a part of a pyramid. The printing method according to any one of claims 1 to 3, wherein the laminated bodies are arranged at intervals from each other. The printing method according to claim 4, further comprising a process of ejecting droplets of ink transmitting light at the intervals to fill the gaps. The printing method according to any one of claims 1 to 5, wherein the photocurable ink has a metallic luster. The head part that ejects ink droplets and
The irradiation part that irradiates light and
With a control unit
The control unit
Droplets of the photocurable ink are ejected from the head portion toward the recording medium to form dots, and the photocurable ink layer is used as the first layer of the photocurable ink ejected to the first layer. A process of forming a plurality of dots in the first layer in which a plurality of dots are lined up without gaps,
A process of irradiating the first layer with light from the irradiation unit to cure the first layer,
A droplet of the photocurable ink is ejected from the head portion onto the dots of the first layer to form dots, and a layer of the photocurable ink ejected onto the dots of the first layer is formed. A process of forming a plurality of dots of the photocurable ink as a second layer and having a width smaller than that of the dots of the first layer as a second layer.
By performing the process including the treatment of irradiating the second layer with light from the irradiation unit to cure the second layer a plurality of times.
A printing apparatus that forms a plurality of laminates having a combination of a dot group of the first layer and a dot group of the second layer.

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