Printer and printing method

Abstract

A printer 10 comprises: a first discharge control unit which forms a first ink layer LA1; a second discharge control unit which forms a second ink layer LA2; a first unevenness control unit 94 which processes the first ink layer LA1 such that the first ink layer LA1 is matte-finished; and a second unevenness control unit 95 which processes the second ink layer LA2 such that the second ink layer LA2 is gloss-finished. The second ink layer LA2 is formed in a region smaller than the first ink layer LA1. The second discharge amount D2 when the second ink layer LA2 is formed is smaller than the first discharge amount D1 when the first ink layer LA1 is formed.

Description

Printer and printing method

[0001] The present invention relates to a printer and a printing method.

[0002] Conventionally, printing has been known in which a gloss overcoat layer is formed on a matte clear layer and the clear layers are stacked in two layers. Patent Document 1 discloses a method of printing so as to make the area of the gloss overcoat layer slightly narrower than the area of the matte clear layer when forming the area of the gloss overcoat layer. According to such a printing method, since the edge of the matte clear layer and the edge of the overcoat layer do not overlap, it is possible to suppress the edge from bulging.

[0003] Japanese Unexamined Patent Application Publication No. 2015-214133

[0004] By the way, in printing in which ink layers are stacked as described above, even if the area of the upper ink layer is made narrower than the area of the lower ink layer, the upper ink layer may protrude from the lower ink layer due to displacement of the landing position of the ink or the like. In such a case, the shape of the ink layer may collapse.

[0005] The present invention has been made in view of such a point, and an object thereof is to provide a printer capable of suppressing the shape of an ink layer from collapsing when the ink layer is formed by stacking.

[0006] The printer according to the present invention includes a mounting table on which media is placed, an ink head for ejecting droplets of ink toward the media placed on the mounting table, a surface texture processing device for determining the surface texture of the ink ejected onto the media, and a control device for controlling the ink head and the surface texture processing device. The control device includes a first ejection control unit for ejecting a first ejection amount of the ink from the ink head onto the media to form a first ink layer, a second ejection control unit for ejecting a second ejection amount of the ink from the ink head onto the first ink layer in an area smaller than the first ink layer to form a second ink layer, a first surface texture control unit for processing the first ink layer with the surface texture processing device so that the first ink layer becomes matte, and a second surface texture control unit for processing the second ink layer with the surface texture processing device so that the second ink layer becomes glossy. The second ejection amount is smaller than the first ejection amount.

[0007] In the printer of the present invention, the first ink layer is finished to a matte finish, and the second ink layer is finished to a gloss finish. Here, the second ink layer is formed in a smaller area than the first ink layer. Therefore, for example, even if the landing position of the ink by the ink head is shifted, the formation of the second ink layer beyond the first ink layer is suppressed. Also, until the second ink layer hardens, the second ink layer spreads over the first ink layer. The second ejection amount when forming the second ink layer is smaller than the first ejection amount when forming the first ink layer. Therefore, the spreading of the second ink layer is suppressed compared to when the ink is ejected at the first ejection amount. As a result, the formation of the second ink layer beyond the first ink layer is suppressed. Therefore, even when the first and second ink layers are formed on top of each other, the deformation of the ink layer shape can be suppressed.

[0008] According to the present invention, it is possible to provide a printer that can suppress the deformation of the ink layer when the ink layer is formed by stacking ink layers.

[0009] Figure 1 is a front view of the printer according to this embodiment. Figure 2 is a bottom view showing the configuration of the ink head according to this embodiment. Figure 3 is a block diagram of the control device according to this embodiment. Figure 4 is a schematic diagram showing how to create first print data and second print data from image data. Figure 5 is a table showing the relationship between droplet size, ejection density, ejection amount per unit area, and surface treatment in the first print data and second print data. Figure 6 is a schematic diagram showing dots and pixels. Figure 7 is a cross-sectional view of the media when printed based on the first print data and second print data. Figure 8A is a schematic diagram showing the ON / OFF control of the light irradiation device when printing the first ink layer. Figure 8B is a schematic diagram showing the ON / OFF control of the light irradiation device when printing the second ink layer. Figure 9 is a flowchart showing the process of forming the first ink layer and the second ink layer LA2. Figure 10A is a front view of the area around the ink head when forming the first ink layer. Figure 10B is a front view of the area around the ink head when forming the second ink layer.

[0010] The following describes a printer according to an embodiment of the present invention with reference to the drawings. It should be noted that the embodiments described herein are not intended to particularly limit the present invention. Furthermore, the same reference numerals are used for components and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0011] Figure 1 is a front view of the printer 10 according to this embodiment. Figure 2 is a bottom view showing the configuration of the ink head 40 according to this embodiment. The symbols F, Rr, L, R, U, and D in the drawings indicate the front, back, left, right, top, and bottom of the printer 10, respectively. The symbol Y indicates the main scanning direction. The main scanning direction Y is, for example, the left-right direction. The symbol X indicates the sub-scanning direction. The sub-scanning direction X is, for example, the front-back direction. In a plan view, the sub-scanning direction X intersects (in this case is orthogonal to) the main scanning direction Y. However, these directions are merely defined for the convenience of explanation and do not limit the installation configuration of the printer 10 in any way, nor do they limit the present invention in any way.

[0012] The printer 10 shown in Figure 1 is an inkjet printer, a so-called inkjet printer. However, the printing method of the printer 10 is not limited to the inkjet method; for example, it may be a thermal printer or a laser printer. In this embodiment, the printer 10 is a roll-to-roll type printer that unfolds the media 5 on the platen 12 and moves it in the sub-scanning direction X.

[0013] In this embodiment, the printer 10 prints on the media 5. The media 5 is, for example, a sheet made of polyethylene terephthalate (PET) or acrylic resin. However, the material of the media 5 is not limited to these. The media 5 may be, for example, polyester resins such as polyethylene naphthalate (PEN) resin, polyethylene (PE) resin, polyolefin resins such as polypropylene (PP) resin, ethylene-propylene copolymer, polyether resins such as polyurethane resin, polycarbonate (PC) resin, polyimide resin, polyamide resin, fluororesin, glass, or composites of multiple such materials. Alternatively, the material of the media 5 may be, for example, paper such as plain paper or inkjet printing paper, metals such as aluminum, iron, or copper, rubber, composite paper such as metallized paper, coated paper, art paper, coated paper, cast paper, matte paper, or gloss paper.

[0014] As shown in Figure 1, the printer 10 comprises a platen 12, an operation panel 13, a carriage movement mechanism 20, a carriage 30, a media transport mechanism 50, a light irradiation device 65, and a control device 90. The carriage 30 is equipped with an ink head 40. The light irradiation device 65 is connected to the left of the carriage 30.

[0015] The platen 12 is a component that supports the media 5 during printing. The platen 12 is an example of a mounting platform in the present invention. The platen 12 extends in the main scanning direction Y. The media 5 is placed on the platen 12. The platen 12 is provided in the main body case 70.

[0016] The control panel 13 is located on the main unit case 70. The control panel 13 can display the status of the printer 10 and information related to printing. The control panel 13 is also configured to allow the user to input information related to printing. The control panel 13 is, for example, a touch panel. However, the control panel 13 may also have a structure that includes keys or the like for the user to use for input.

[0017] The carriage movement mechanism 20 is a mechanism for moving the carriage 30 in the main scanning direction Y. The carriage movement mechanism 20 comprises a guide rail 21, a pulley 22, a pulley 23, a belt 24, and a carriage motor 25. The guide rail 21 guides the movement of the carriage 30 in the main scanning direction Y. The guide rail 21 is located above the platen 12. The guide rail 21 is provided on the main case 70. The guide rail 21 extends in the main scanning direction Y. The pulley 22 is provided to the left of the left end of the guide rail 21. The pulley 23 is provided to the right of the right end of the guide rail 21. The belt 24 is wrapped around the pulleys 22 and 23. The carriage motor 25 is connected to the right pulley 23. However, the carriage motor 25 may also be connected to the left pulley 22. The carriage motor 25 is driven, causing the pulley 23 to rotate, which in turn causes the belt 24 to travel between the pulley 22 and the pulley 23. The carriage 30 is attached to the belt 24. The carriage 30 is engaged with the guide rail 21 and is slidably mounted on the guide rail 21. Therefore, the drive of the carriage motor 25 causes the belt 24 to travel, and the carriage 30 moves in the main scanning direction Y.

[0018] Hereinafter, the right side of the main scanning direction Y will be referred to as the first scanning direction Y1, and the left side as the second scanning direction Y2. In this embodiment, the carriage movement mechanism 20 moves the carriage 30 in the first scanning direction Y1 and the second scanning direction Y2, which are orthogonal to the sub-scanning direction X of the media 5.

[0019] The carriage 30 is equipped with an ink head 40. When the carriage 30 moves in the main scanning direction Y, printing is performed by ejecting photocurable ink (photocurable ink) onto the media 5 from the ink head 40. However, the ink ejected from the ink head 40 is not limited to photocurable ink.

[0020] Photocurable inks have the property of hardening when exposed to light. Photocurable inks contain a coloring agent such as a pigment, a photopolymerizable monomer, and a photopolymerization initiator, and may optionally contain other various additives such as photosensitizers, polymerization inhibitors, scavengers, antioxidants, UV absorbers, plasticizers, surfactants, leveling agents, thickeners, dispersants, defoamers, preservatives, and solvents. Examples of photocurable inks include process color inks, white inks, and clear inks. Examples of process color inks include cyan ink, magenta ink, yellow ink, black ink, light cyan ink, and light magenta ink. Examples of photocurable inks include UV-curable inks.

[0021] As shown in Figure 2, there are four ink heads 40 in this embodiment. The four ink heads 40 are arranged in a line in the main scanning direction Y. The ink heads 40 are positioned in a line with respect to the sub-scanning direction X. The ink heads 40 are formed such that the length in the sub-scanning direction X is longer than the length in the main scanning direction Y. The four ink heads 40 are formed to be the same shape and size. Multiple nozzles 42 from which ink is ejected are formed on the lower surface of the ink heads 40. A row of multiple nozzles 42 arranged in the sub-scanning direction X is called a nozzle row. Here, two nozzle rows are formed for each ink head 40. Therefore, in this embodiment, eight nozzle rows are formed. The eight nozzle rows will be referred to as nozzle rows 41a, 41b, 41c, 41d, 41e, 41f, 41g, and 41h from left to right. In this embodiment, nozzle rows 41a and 41h are nozzle rows that eject white ink. Nozzle rows 41b and 41g are nozzle rows that eject clear ink. Nozzle row 41c is a nozzle row that ejects yellow ink. Nozzle row 41d is a nozzle row that ejects magenta ink. Nozzle row 41e is a nozzle row that ejects black ink. Nozzle row 41f is a nozzle row that ejects cyan ink. However, the arrangement order of the ink colors ejected from each nozzle row is not limited to this. Also, the colors of the ink ejected from each nozzle row are not limited to this. Furthermore, the number of ink heads 40 is not limited to four; it may be three or fewer, or five or more. Also, the number of nozzle rows formed on one ink head 40 is not limited to two; it may be one, or three or more.

[0022] Each of the nozzle rows 41a to 41h is connected to a pressure chamber (not shown) where ink is stored. The ink head 40 is provided with a plurality of actuators (not shown) that expand / contract each pressure chamber. The actuators are, for example, piezoelectric elements. When the actuators are driven, the pressure chambers expand / contract, causing ink to be ejected from the nozzle rows 41a to 41h. A drive waveform is applied to the actuators to drive them. The actuators are connected to a control device 90 and controlled by the control device 90. By changing the drive waveform that drives the actuators, the amount of ink ejected per unit area can be changed. In addition, by controlling the shape of the drive waveform that drives the actuators, the timing of ink ejection can be controlled.

[0023] Although not shown in the diagram, the printer 10 has multiple ink tanks for storing ink. Each ink tank stores one color of ink. In this embodiment, the printer 10 has ink tanks for storing at least white ink, clear ink, yellow ink, magenta ink, black ink, and cyan ink, respectively. Each ink tank is connected to the ink head 40 by, for example, a flexible ink tube (not shown).

[0024] As shown in Figure 1, the printer 10 is equipped with a media transport mechanism 50. The media transport mechanism 50 is a mechanism that moves the media 5 placed on the platen 12 in the sub-scanning direction X. The media transport mechanism 50 includes a grit roller 51, a pinch roller 52, and a feed motor 53. The grit roller 51 is provided on the platen 12. Here, a part of the grit roller 51 is embedded in the platen 12. The pinch roller 52 is positioned above the grit roller 51 so as to face it in the vertical direction. The pinch roller 52 is a member that presses down on the media 5 from above. The pinch roller 52 may be configured to move vertically according to the thickness of the media 5. The respective positions and numbers of the grit roller 51 and pinch roller 52 are not particularly limited. The feed motor 53 is connected to the grit roller 51. With the media 5 sandwiched between the grit roller 51 and the pinch roller 52, the feed motor 53 is driven and the grit roller 51 rotates, transporting the media 5 in the sub-scanning direction X. The printer 10 moves the carriage 30 back and forth in the main scanning direction Y and ejects ink from the ink head 40 (hereinafter referred to as "pass"), then rotates the grit roller 51 by a predetermined amount to transport the media 5 forward. By repeating this process, the media 5 is printed.

[0025] As shown in Figure 2, a light irradiation device 65 is connected to the left side of the carriage 30. The light irradiation device 65 cures the ink on the media 5 (see Figure 1) by irradiating it with light (typically ultraviolet light) directed at the photocurable ink ejected onto the media 5. The light irradiation device 65 is an example of a surface texture processing device in the present invention. The light irradiation device 65 is equipped with an ultraviolet irradiation LED 66. Multiple ultraviolet irradiation LEDs 66 are arranged in a line in the sub-scanning direction X. However, the arrangement of the ultraviolet irradiation LEDs 66 is not limited to this. The ultraviolet irradiation LEDs 66 may be arranged in a line in the main scanning direction Y, or only one ultraviolet irradiation LED 66 may be arranged. Since the light irradiation device 65 is connected to the carriage 30, when the carriage 30 moves in the main scanning direction Y, the light irradiation device 65 also moves in the main scanning direction Y. Note that the light emitted by the light irradiation device 65 is not limited to ultraviolet light. For example, the light emitted by the light irradiation device 65 may be infrared light or the like. Furthermore, in this embodiment, one light irradiation device 65 is connected to the carriage 30, but the number of light irradiation devices 65 provided in the printer 10 is not particularly limited. Also, the light irradiation devices 65 do not necessarily have to be connected to the carriage 30.

[0026] The light irradiation device 65 has a light source array 67 in which a plurality of ultraviolet irradiation LEDs 66 are arranged in a row. The light source array 67 includes a first light source array 67a in which some of the plurality of ultraviolet irradiation LEDs 66 are aligned in the sub-scanning direction X, a second light source array 67b positioned in front of the first light source array 67a and in which the other portion of the plurality of ultraviolet irradiation LEDs 66 are aligned in the sub-scanning direction X, and a third light source array 67c positioned in front of the second light source array 67b and in which the other portion of the plurality of ultraviolet irradiation LEDs 66 are aligned in the sub-scanning direction X. In this embodiment, the first light source array 67a, the second light source array 67b, and the third light source array 67c have the same length in the sub-scanning direction X. That is, the number of ultraviolet irradiation LEDs 66 included in the first light source array 67a, the second light source array 67b, and the third light source array 67c is the same. In this embodiment, the first light source array 67a and the nozzle arrays 41a to 41h are positioned in a aligned position with respect to the sub-scanning direction X. However, the positional relationship between the light irradiation device 65 and the nozzle rows 41a to 41h is not limited thereto.

[0027] The ultraviolet irradiation LEDs 66 are connected to the control device 90 and are configured to be controllable independently. However, the ultraviolet irradiation LEDs 66 may be controllable for each of the first light source arrays 67a, the second light source array 67b, and the third light source array 67c. In this embodiment, the light source array 67 is divided into three: the first light source array 67a, the second light source array 67b, and the third light source array 67c, but the number of divisions of the light source array 67 is not particularly limited. Furthermore, the length of the sub-scanning direction X of the divided light source arrays is not particularly limited. That is, the number of ultraviolet irradiation LEDs 66 included in the divided light source arrays is also not particularly limited.

[0028] Figure 3 is a block diagram of the control device 90 according to this embodiment. The control device 90 is a device that controls printing to the media 5 (see Figure 1). The configuration of the control device 90 is not particularly limited. The control device 90 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, but for example, it includes an interface (I / F) for receiving print data from an external device such as a host computer, a central processing unit (CPU) for executing instructions of the control program, a ROM (read-only memory) for storing the program executed by the CPU, a RAM (random access memory) used as a working area for expanding the program, and a storage device such as memory for storing the program and various data. As shown in Figure 1, the control device 90 is located inside the main case 70. However, the control device 90 does not have to be located inside the main case 70. For example, the control device 90 may be a computer located outside the main case 70. In this case, the control device 90 is connected to the printer 10 via wired or wireless communication.

[0029] As shown in Figure 3, the control device 90 is communicatively connected to the operation panel 13, the carriage motor 25, the feed motor 53, the ink head 40, and the light irradiation device 65. The control device 90 controls the carriage motor 25, causing the carriage 30 (see Figure 1) to move in the main scanning direction Y. The control device 90 controls the feed motor 53, causing the media 5 (see Figure 1) to be transported in the sub-scanning direction X. The control device 90 controls the ink head 40, controlling the ink ejection amount and timing. The control device 90 controls the light irradiation device 65, controlling the ON / OFF state of the ultraviolet irradiation LED 66 (see Figure 2). The control device 90 may also control the intensity of the irradiation from the ultraviolet irradiation LED 66.

[0030] The control device 90 comprises a storage unit 91, a first ejection control unit 92, a second ejection control unit 93, a first unevenness control unit 94, and a second unevenness control unit 95. The functions of each part of the control device 90 are realized by a program. This program is read from a recording medium such as a CD or DVD. This program may also be downloaded via the Internet. Furthermore, the functions of each part of the control device 90 may also be realized by a processor and / or circuits.

[0031] The storage unit 91 stores the first print data DT1 and the second print data DT2. The first print data DT1 and the second print data DT2 are data converted from the image data P10 (see Figure 4) desired by the user so that it can be processed by the printer 10. The first print data DT1 and the second print data DT2 are print data to be printed in the same area of ​​the media 5 (see Figure 1). In other words, when the first print data DT1 and the second print data DT2 are printed, overprinting is performed on the media 5. The storage unit 91 is composed of, for example, a non-volatile storage area.

[0032] Figure 4 is a schematic diagram illustrating the creation of first print data DT1 and second print data DT2 from image data P10. The process of creating first print data DT1 and second print data DT2 from image data P10 can be performed, for example, by a processing device (not shown) connected to the printer 10 wirelessly or by wire. Image data P10 is image data desired by the user, for example, data in PDF (Portable Document Format) format. Image data P11 is an image obtained by processing image data P10 so that its contour is narrower than that of image data P10. Image data P11 is created, for example, by extracting the contour of image data P10 and processing that contour.

[0033] The first print data DT1 is created by processing image data P10 using a RIP (Raster Image Processor). The second print data DT2 is created by processing image data P11 using a RIP. Here, the contour of the second print data DT2 is processed to be located 3 pixels inside the contour of the first print data DT1. In Figure 4, the contour of the second print data DT2 is shown as a dashed line in the first print data DT1 for reference. The processing device that creates the first print data DT1 and the second print data DT2 from image data P10 may, for example, have an application that performs RIP processing. The method for creating the first print data DT1 and the second print data DT2 is not limited to this.

[0034] The method by which the printer 10 acquires the first print data DT1 and the second print data DT2 is not particularly limited. For example, the printer 10 may acquire the first print data DT1 and the second print data DT2 by communication between the processing unit that creates the first print data DT1 and the second print data DT2 and the control unit 90, and the storage unit 91 may store the first print data DT1 and the second print data DT2. Alternatively, the first print data DT1 and the second print data DT2 may be stored in the storage unit 91 via a network connecting the processing unit and the control unit 90.

[0035] The first print data DT1 and the second print data DT2 contain information on the droplet size, ejection density, ejection amount per unit area, and surface treatment when the respective data is printed. Here, the ink head 40 of the printer 10 is configured to allow setting of four types of droplet sizes, for example, S size, M size, Ls size, and L size. The droplet size increases in the order of S size, M size, Ls size, and L size. The droplet size is controlled by the shape of the drive waveform applied to actuators (not shown) provided in the nozzle rows 41a to 41h (see Figure 2). The ejection density is expressed as a percentage (%) of the maximum number of dots per predetermined area. Surface treatment here refers to either a matte finish or a gloss finish. A matte finish refers to a treatment that creates irregularities on the surface of the printed material. A gloss finish refers to a treatment that creates a smooth surface on the printed material. The surface treatment is controlled by the first irregularity control unit 94 and the second irregularity control unit 95, which will be described later.

[0036] Figure 5 is a table showing the relationship between droplet size, ejection density, ejection rate per unit area, and surface treatment in the first print data DT1 and the second print data DT2. As shown in Figure 5, the droplet size in the first print data DT1 is L size, and the droplet size in the second print data DT2 is Ls size. Therefore, the droplet size in the second print data DT2 is smaller than that of the first print data DT1. Figure 6 is a schematic diagram showing dots and pixels. The dot DL shown in Figure 6 is a dot formed when an L-sized droplet lands on the media 5 (see Figure 1). The dot DLs are dots formed when an Ls-sized droplet lands on the media 5 (see Figure 1). For the sake of explanation, dot DL and dot DLs are shown superimposed here. The rectangle shown in Figure 6 represents a single pixel PX. As shown in Figure 6, the size of the area of ​​dot DLs is larger than that of pixel PX. The size of the area of ​​dot DL is larger than the size of the area of ​​dot DLs. Although not shown in the diagram, the size of the dot area formed when an M-sized droplet lands on the media 5 is smaller than the pixel PX. The size of the pixel PX is determined by the print resolution. In high-resolution print modes, the size of the pixel PX is smaller, and in low-resolution print modes, the size of the pixel PX is larger.

[0037] As shown in Figure 5, the first print data DT1 has an ejection density of 100%, and the second print data DT2 has an ejection density of 80%. An ejection density of 100% means that ink is ejected to all pixels PX included in the printing area. Therefore, in the case of an ejection density of 80%, ink is ejected to 80% of the pixels included in the printing area, and ink is not ejected to the remaining 20% ​​of the pixels.

[0038] As shown in Figure 5, the first print data DT1 has a discharge rate of first discharge rate D1 per unit area, and the second print data DT2 has a discharge rate of second discharge rate D2 per unit area. The discharge rate per unit area decreases as the dot size decreases. Also, the discharge rate decreases as the discharge density decreases. In this embodiment, as described above, the droplet size and discharge density of the second print data DT2 are smaller than those of the first print data. That is, in this embodiment, the second discharge rate D2 is less than the first discharge rate D1.

[0039] The first ejection control unit 92 shown in Figure 3 ejects ink onto the media 5 (see Figure 1) to form the first ink layer LA1 (see Figure 7), which will be described later. In this embodiment, the first ejection control unit 92 ejects clear ink from nozzle rows 41b (see Figure 2) and 41g (see Figure 2) to form the first ink layer LA1. In this embodiment, the first ejection control unit 92 ejects clear ink based on the first print data DT1 (see also Figure 5). Therefore, the first ejection control unit 92 ejects clear ink in a first ejection amount D1 from nozzle rows 41b and 41g onto the media 5 to form the first ink layer LA1. The first ejection control unit 92 ejects clear ink in the form of first droplets with a droplet size of L to form the first ink layer LA1. The L size, which is the size of the first droplet, is an example of the first size in this invention. Furthermore, the first ejection control unit 92 ejects clear ink so that the ink ejection density is 100% to form the first ink layer LA1. An ejection density of 100% is an example of the first ejection density in the present invention. In this embodiment, the first ejection control unit 92 ejects clear ink from nozzle rows 41b and 41g when the carriage 30 moves toward the first scanning direction Y1 (see Figure 2). However, the direction of movement of the carriage 30 when the ink is ejected is not limited to this.

[0040] The second ejection control unit 93 ejects ink onto the media 5 (see Figure 1) to form the second ink layer LA2 (see Figure 7), which will be described later. The second ejection control unit 93 ejects ink onto the first ink layer LA1 and into an area smaller than the first ink layer LA1 to form the second ink layer LA2. In this embodiment, the second ejection control unit 93 ejects clear ink from nozzle rows 41b (see Figure 2) and 41g (see Figure 2) to form the second ink layer LA2. In this embodiment, the second ejection control unit 93 ejects ink based on the second print data DT2 (see also Figure 5). Therefore, the second ejection control unit 93 ejects a second ejection amount D2 of ink from the ink head 40 onto the media 5 to form the second ink layer LA2. The second ejection control unit 93 ejects clear ink in the form of second droplets with a droplet size of Ls to form the second ink layer LA2. The Ls size, which is the size of the second droplet, is an example of the second size in this invention. The second ejection control unit 93 ejects clear ink so that the ink ejection density is 80% to form the second ink layer LA2. An ejection density of 80% is an example of the second ejection density in this invention. In this embodiment, the second ejection control unit 93 ejects clear ink from nozzle rows 41b and 41g when the carriage 30 moves toward the first scanning direction Y1. However, the direction of movement of the carriage 30 when the ink is ejected is not limited to this.

[0041] Figure 7 is a cross-sectional view of the media 5 when printed based on the first print data DT1 and the second print data DT2. The media 5 has a first ink layer LA1 and a second ink layer LA2 formed on it. In this embodiment, the first ink layer LA1 and the second ink layer LA2 are formed of clear ink. As described above, the first ink layer LA1 and the second ink layer LA2 are formed by the ejection of clear ink from nozzle rows 41b (see Figure 2) and 41g (see Figure 2). However, the inks forming the first ink layer LA1 and the second ink layer LA2 are not limited to clear ink. For example, the inks forming the first ink layer LA1 and the second ink layer LA2 may be process color inks such as yellow ink, magenta ink, black ink, and cyan ink, or they may be white ink. As long as the inks forming the first ink layer LA1 and the inks forming the second ink layer LA2 are the same, the types of inks forming each ink layer are not limited. Furthermore, the first ink layer LA1 and the second ink layer LA2 may each be formed with multiple colors of ink. As described above, the contour of the second print data DT2 (see Figure 4) is processed to be located inside the contour of the first print data DT1 (see Figure 4). Therefore, as shown in Figure 7, the second ink layer LA2 is formed in a smaller area than the first ink layer LA1.

[0042] The first unevenness control unit 94 shown in Figure 3 performs a process (matte varnish) on the first ink layer LA1 so that it becomes matte. Figure 8A is a schematic diagram showing the ON / OFF control of the light irradiation device 65 when printing the first ink layer LA1. When printing the first ink layer LA1 (see Figure 7), the light irradiation device 65 is controlled by the first unevenness control unit 94 (see Figure 3). In Figure 8A, the word "ON" is superimposed on the first light source array 67a, the second light source array 67b, and the third light source array 67c, indicating that the ultraviolet irradiation LEDs 66 (see Figure 2) included in the first light source array 67a, the second light source array 67b, and the third light source array 67c are in the ON state. Therefore, the clear ink ejected from nozzle rows 41b and 41g while the carriage 30 moves in the first scanning direction Y1 is irradiated with light from the first light source row 67a located upstream (in this case, to the left) of the first scanning direction Y1. Thus, the clear ink ejected from nozzle rows 41b and 41g is irradiated with light immediately after ejection. Because the first ink layer LA1 hardens immediately after the clear ink is ejected, the surface has relatively large irregularities. That is, the first ink layer LA1 has a matte finish. The surface of the first ink layer LA1 is a low-gloss surface.

[0043] Furthermore, after the first ink layer LA1 is irradiated with light from the first light source array 67a, the media 5 is transported forward. At this time, the first ink layer LA1 is irradiated with light from the second light source array 67b or the third light source array 67c each time the carriage 30 moves in the main scanning direction Y. However, the method of controlling the ON / OFF state of the light irradiation device 65 when forming the first ink layer LA1 is not limited to this. Also, the first unevenness control unit 94 may control the intensity of the irradiated light rather than the ON / OFF state of the light from the light irradiation device 65.

[0044] The second concavo-convex control unit 95 shown in FIG. 3 performs processing (gloss varnish) on the second ink layer LA2 so that the second ink layer LA2 becomes a gloss finish. FIG. 8B is a schematic diagram showing the ON / OFF control of the light irradiation device 65 when printing the second ink layer LA2. When printing the second ink layer LA2 (see FIG. 7), the light irradiation device 65 is controlled by the second concavo-convex control unit 95 (see FIG. 3). In FIG. 8B, the characters "OFF" are superimposed on the first light source row 67a and the second light source row 67b, and the characters "ON" are superimposed on the third light source row 67c. This indicates that the ultraviolet irradiation LEDs 66 (see FIG. 2) included in the first light source row 67a and the second light source row 67b are in the OFF state, and the ultraviolet irradiation LEDs 66 included in the third light source row 67c are in the ON state. Therefore, the ink ejected from the nozzle rows 41b and 41g while the carriage 30 moves in the first scanning direction Y1 is not irradiated with light from the first light source row 67a located on the upstream side (here, the left side) in the first scanning direction Y1. Thereafter, the conveyance of the pass and the medium 5 is repeated, and the second ink layer LA2 is disposed at a position aligned with the third light source row 67c with respect to the sub-scanning direction X. When the carriage 30 moves in the main scanning direction Y, the second ink layer LA2 is irradiated with light from the third light source row 67c. Therefore, the time from when the clear ink is ejected until it is irradiated with light is longer for the second ink layer LA2 than for the first ink layer LA1. Therefore, the second ink layer LA2 is cured after the clear ink spreads and wets, and a smooth surface is formed. That is, the second ink layer LA2 is finished with a gloss finish. The surface of the second ink layer LA2 is a high-gloss surface.

[0045] As described above, the configuration of the printer 10 according to the present embodiment has been described. Next, a process for forming the first ink layer LA1 and the second ink layer LA2 by the printer 10 will be described. FIG. 9 is a flowchart showing the process for forming the first ink layer LA1 and the second ink layer LA2.

[0046] In step S101, the storage unit 91 stores the first print data DT1 and the second print data DT2. As described above, the method by which the printer 10 acquires the first print data DT1 and the second print data DT2 is not particularly limited.

[0047] In step S102, the first ejection control unit 92 forms the first ink layer LA1 on the medium 5 (see FIG. 1) based on the first print data DT1. FIG. 10A is a front view around the ink head 40 when forming the first ink layer LA1. When the carriage 30 moves in the first scanning direction Y1 by the carriage movement mechanism 20 (see FIG. 1), the first ejection control unit 92 (see FIG. 4) ejects the clear ink from the nozzle rows 41b and 41g. Thereby, the first ink layer LA1 is formed at a predetermined position on the medium 5. The first ejection control unit 92 ejects the clear ink with the droplet size being the L size, the ejection density being 100%, and the ejection amount being the first ejection amount D1. Step S102 is an example of the first ejection step in the present invention.

[0048] After step S102 (see FIG. 9), the carriage 30 continues to move in the first scanning direction Y1 as it is. In step S103 (see FIG. 9), a process for determining the unevenness of the first ink layer LA1 is performed. Here, the process is performed so that the first ink layer LA1 becomes matte. At this time, the first unevenness control unit 94 (see FIG. 3) controls the first light source row 67a of the light irradiation device 65 to be turned on (see also FIG. 8A). Therefore, in step S102, after the first ink layer LA1 is formed when the carriage 30 moves in the first scanning direction Y1 of the main scanning direction Y, the carriage 30 and the ink head 40 further move in the first scanning direction Y1, and the first light source row 67a is disposed above the formed first ink layer LA1. At this time, the first ink layer LA1 is irradiated with light and the first ink layer LA1 is cured. Since the time from when the clear ink is ejected until the light is irradiated to the first ink layer LA1 is relatively short, the first ink layer LA1 is finished to be matte. Also, thereafter, when the medium 5 is conveyed forward in the sub-scanning direction X and the second light source row 67b and the third light source row 67c are disposed above the first ink layer LA1, the first ink layer LA1 is irradiated with light and the first ink layer LA1 is further cured. Step S103 is an example of the first unevenness processing step in the present invention.

[0049] Once the first ink layer LA1 has been formed and cured completely, the media transport mechanism 50 moves the media 5 upstream (rear in this case) in the sub-scanning direction X, and the portion of the media 5 on which the first ink layer LA1 has been formed is transported again.

[0050] In step S104 shown in Figure 9, the second ejection control unit 93 (see Figure 3) prints onto the media 5 based on the second print data DT2. Figure 10B is a front view of the area around the ink head 40 when the second ink layer LA2 is formed. When the carriage 30 moves in the first scanning direction Y1 by the carriage movement mechanism 20 (see Figure 1), the second ejection control unit 93 (see Figure 3) ejects clear ink from nozzle rows 41b and 41g. As a result, the second ink layer LA2 is formed on top of the first ink layer LA1. The second ejection control unit 93 ejects clear ink with a droplet size of Ls size, an ejection density of 80%, and an ejection amount of second ejection amount D2. As described above, the second ink layer LA2 is formed in a smaller area than the first ink layer LA1. Step S104 is an example of the second ejection process in the present invention.

[0051] In step S105 (see Figure 9), a process is performed to determine the surface irregularities of the second ink layer LA2. Here, the second ink layer LA2 is processed to have a glossy finish. After step S104, the carriage 30 continues to move in the first scanning direction Y1. At this time, the first light source row 67a, which is positioned in alignment with the nozzle rows 41b and 41g with respect to the sub-scanning direction X, is turned OFF. Therefore, the formed second ink layer LA2 is not irradiated with light during the same pass. Subsequently, the transport of the pass and the media 5 forward is repeated, and the formed second ink layer LA2 is positioned in alignment with the third light source row 67c (see Figure 8B) with respect to the sub-scanning direction X. The second surface irregularity control unit 95 (see Figure 3) controls the light irradiation device 65 so that the first light source row 67a and the second light source row 67b are turned OFF and the third light source row 67c is turned ON, as shown in Figure 8B. At this time, when the carriage 30 moves in the main scanning direction Y, light is irradiated onto the second ink layer LA2 from the third light source row 67c. Because the time between the ejection of the clear ink and the irradiation of light is relatively long, the second ink layer LA2 is finished to a glossy finish. Step S105 is an example of the second unevenness processing step in the present invention.

[0052] As described above, according to the printer 10 of this embodiment, the first ink layer LA1 is finished to a matte finish, and the second ink layer LA2 is finished to a gloss finish. Here, the second ink layer LA2 is formed in a smaller area than the first ink layer LA1. Therefore, for example, even if the position of ink ejection by the ink head 40 is shifted, the formation of the second ink layer LA2 in a position that extends beyond the first ink layer LA1 is suppressed. Also, until the second ink layer LA2 hardens, the second ink layer LA2 wets and spreads on top of the first ink layer LA1. The second ejection amount D2 when forming the second ink layer LA2 is smaller than the first ejection amount D1 when forming the first ink layer LA1. Therefore, compared to when ejected at the first ejection amount D1, the wetting and spreading of the second ink layer LA2 is suppressed. As a result, the formation of the second ink layer LA2 extending beyond the first ink layer LA1 is suppressed. Therefore, when the first ink layer LA1 and the second ink layer LA2 are formed by overlapping them, it is possible to suppress the deformation of the ink layer shape.

[0053] In this embodiment, the media 5 is made of polyethylene terephthalate (PET) or a resin sheet made of acrylic resin. PET and acrylic resin have relatively high wettability, and the ink tends to spread easily. By forming the second ink layer LA2 on top of the first ink layer LA1, as in this embodiment, the spreading of the second ink layer LA2 can be suppressed regardless of the type of media 5.

[0054] In the printer 10 of this embodiment, the first ink layer LA1 is formed by the ejection of L-sized droplets. The second ink layer LA2 is formed by the ejection of Ls-sized droplets. Ls-sized droplets are smaller than Ls-sized droplets. Therefore, the droplets that form the second ink layer LA2 are less likely to wet and spread than the droplets that form the first ink layer LA1. This prevents the second ink layer LA2 from forming beyond the first ink layer LA1.

[0055] In the printer 10 of this embodiment, the size of the dots DLs formed by the second droplet of ink landing on the media 5 is larger than the size of the pixels PX. If the size of the dots DLs is smaller than the pixels PX, the second ink layer LA2 may not spread sufficiently, potentially reducing the quality of the glossy finish. However, as in this embodiment, by making the size of the dots DLs larger than the pixels PX, the reduction in the quality of the glossy finish can be suppressed. Therefore, it is possible to suppress the second ink layer LA2 from overflowing from the first ink layer LA1 and to suppress the reduction in the quality of the glossy finish.

[0056] In the printer 10 of this embodiment, the first ink layer LA1 is formed with an ejection density of 100%. The second ink layer LA2 is formed with an ejection density of 80%. Therefore, the second ink layer LA2 has a lower ejection density. As a result, the ink in the second ink layer LA2 is less likely to spread than that in the first ink layer LA1. Therefore, the formation of the second ink layer LA2 beyond the first ink layer LA1 is suppressed.

[0057] In the printer 10 of this embodiment, by controlling the first light source array 67a of the light irradiation device 65 to be ON, the time from when the first ink layer LA1 is formed until light is irradiated onto the first ink layer LA1 is relatively short, resulting in a matte finish for the first ink layer LA1. Furthermore, by controlling the first light source array 67a and the second light source array 67b of the light irradiation device 65 to be OFF and the third light source array 67c to be ON, the time from when the second ink layer LA2 is formed until light is irradiated onto the second ink layer LA2 is relatively long, resulting in a glossy finish for the second ink layer LA2. Therefore, by using the light irradiation device 65 as a surface texture processing device, it is possible to suppress the formation of the second ink layer LA2 extending beyond the first ink layer LA1.

[0058] Preferred embodiments of the present invention have been described above. However, the embodiments described above are merely illustrative, and the present invention can be implemented in various other forms.

[0059] In the embodiments described above, the first ink layer LA1 was formed on the media 5, but the invention is not limited to this. The first ink layer LA1 may be formed on top of an ink layer formed with, for example, color ink or white ink.

[0060] In the embodiments described above, the second ink layer LA2 had smaller droplet size and ejection density than the first ink layer LA1, but is not limited to this. The second ink layer LA2 may have smaller droplet size and ejection density than the first ink layer LA1, as long as the second ejection amount D2 is smaller than the first ejection amount D1. Also, in the embodiments described above, the first ejection control unit 92 ejected ink with droplet size L, and the second ejection control unit 93 ejected ink with droplet size Ls, but is not limited to this. For example, the first ejection control unit 92 may eject ink with droplet size L, and the second ejection control unit 93 may eject ink with droplet size M. Alternatively, the first ejection control unit 92 may eject ink with droplet size M, and the second ejection control unit 93 may eject ink with droplet size S. Furthermore, the first ejection control unit 92 and the second ejection control unit 93 may eject ink of multiple droplet sizes. For example, the first ejection control unit 92 may eject ink with droplet sizes L and M, and the second ejection control unit 93 may eject ink with droplet sizes Ls and M.

[0061] In the embodiment described above, the second ink layer LA2 was formed after the first ink layer LA1 had been completely formed, but the invention is not limited to this. For example, the first ink layer LA1 may be formed by the rear portion of the nozzle rows 41a to 41h, and the second ink layer LA2 may be formed by the front portion of the nozzle rows 41a to 41h. In this case, for example, the ultraviolet irradiation LED 66 located at a position aligned with the rear portion of the nozzle rows 41a to 41h with respect to the sub-scanning direction X may be turned ON, the ultraviolet irradiation LED 66 located at a position aligned with the front portion of the nozzle rows 41a to 41h with respect to the sub-scanning direction X may be turned OFF, and the ultraviolet irradiation LED 66 located further forward than the front portion of the nozzle rows 41a to 41h may be turned ON.

[0062] In the embodiment described above, the time between the ejection of clear ink and the irradiation of light was controlled to finish the printed surface to either a matte or glossy finish. However, the control method of the light irradiation device 65 as a surface texture processing device is not limited to this. For example, the first surface texture control unit 94 may set the intensity of the light irradiated onto the first ink layer LA1 to be relatively strong, and the second surface texture control unit 95 may set the intensity of the light irradiated onto the second ink layer LA2 to be relatively weak, thereby finishing the first ink layer LA1 to a matte finish and the second ink layer LA2 to a glossy finish. In this case, the first ink layer LA1 hardens relatively quickly due to the irradiation of strong light, and the surface texture becomes larger. The second ink layer LA2 hardens relatively slowly due to the irradiation of weak light, resulting in a smooth surface.

[0063] In the embodiment described above, the printer 10 was equipped with a light irradiation device 65 as a surface texture processing device, but the surface texture processing device is not limited to this. The surface texture processing device may be, for example, a drying device provided in the printer 10. The drying device is positioned, for example, opposite the media 5 being transported. The drying device sends heated air toward the ink on the transported media 5 to dry and harden the ink on the media 5. In this case, the first surface texture control unit 94 and the second surface texture control unit 95 control the temperature of the air sent from the drying device and the timing of the air being sent, thereby making the first ink layer LA1 matte and the second ink layer LA2 glossy. For example, the first unevenness control unit 94 can shorten the time from when the first ink layer LA1 is formed until air is supplied from the drying device to the first ink layer LA1, and the second unevenness control unit 95 can lengthen the time from when the second ink layer LA2 is formed until air is supplied from the drying device to the second ink layer LA2, thereby enabling the first ink layer LA1 to have a matte finish and the second ink layer LA2 to have a glossy finish. Alternatively, the first unevenness control unit 94 can set the temperature of the air supplied to the first ink layer LA1 to a relatively high temperature, and the second unevenness control unit 95 can set the temperature of the air supplied to the second ink layer LA2 to a relatively low temperature, thereby enabling the first ink layer LA1 to have a matte finish and the second ink layer LA2 to have a glossy finish.

[0064] Furthermore, the surface texture processing device may be a heating device that heats the conveyed media 5. The heating device is positioned, for example, below the platen 12. The first surface texture control unit 94 and the second surface texture control unit 95 control the heating temperature of the heating device and the position where the media 5 is heated (i.e., the timing of heating the first ink layer LA1 and the second ink layer LA2), thereby enabling the first ink layer LA1 to have a matte finish and the second ink layer LA2 to have a glossy finish. When controlling the position where the media 5 is heated, for example, the heating device may be positioned directly below the nozzle rows 41a to 41h and in front of the nozzle rows 41a to 41h. In such cases, when forming the first ink layer LA1, the first unevenness control unit 94 heats the heating device located directly below the nozzle rows 41a to 41h so that the time until the first ink layer LA1 is heated is relatively short, and when forming the second ink layer LA2, the second unevenness control unit 95 does not heat the heating device located directly below the nozzle rows 41a to 41h, but heats the heating device located in front of the nozzle rows 41a to 41h so that the time until the second ink layer LA2 is heated is relatively long, thereby making the first ink layer LA1 a matte finish and the second ink layer LA2 a glossy finish. Alternatively, when controlling the heating temperature of the heating device, the first unevenness control unit 94 can set the heating temperature of the heating device to a relatively high level when forming the first ink layer LA1, and the second unevenness control unit 95 can set the heating temperature of the heating device to a relatively low level when forming the second ink layer LA2, thereby giving the first ink layer LA1 a matte finish and the second ink layer LA2 a glossy finish.

[0065] The technology disclosed herein can be applied to various types of printers. In addition to the roll-to-roll type printers shown in the embodiments described above, it can also be applied to so-called flatbed type printers, for example, in which the media is fixed on a table and the table is transported for printing. Furthermore, it can also be applied to so-called gantry type printers, in which the media is placed on a table and the carriage is moved relative to the table in the main scanning direction Y and the sub-scanning direction X for printing.

[0066] 5 Media 10 Printer 12 Platen (mounting base) 40 Ink head 65 Light irradiation device (relief treatment device) 90 Control device 92 First ejection control unit 93 Second ejection control unit 94 First relief control unit 95 Second relief control unit LA1 First ink layer LA2 Second ink layer

Claims

1. A printer comprising: a mounting table on which media is placed; an ink head for ejecting ink droplets toward the media placed on the mounting table; a surface texture processing device for performing a process to determine the surface texture of the ink ejected onto the media; and a control device for controlling the ink head and the surface texture processing device, wherein the control device comprises: a first ejection control unit for ejecting a first ejection amount of the ink from the ink head onto the media to form a first ink layer; a second ejection control unit for ejecting a second ejection amount of the ink from the ink head onto the first ink layer in an area smaller than the first ink layer to form a second ink layer; a first surface texture processing device for processing the first ink layer so that the first ink layer becomes matte; and a second surface texture processing device for processing the second ink layer so that the second ink layer becomes glossy, wherein the second ejection amount is smaller than the first ejection amount.

2. The printer according to claim 1, wherein the first ejection control unit ejects the ink of a first droplet having a first size to form the first ink layer, and the second ejection control unit ejects the ink of a second droplet having a second size smaller than the first size to form the second ink layer.

3. The printer according to claim 2, wherein the size of the area of ​​the dot formed when the ink of the second droplet lands on the media is larger than the size of the pixel.

4. The printer according to any one of claims 1 to 3, wherein the first ejection control unit ejects the ink so that the ejection density of the ink becomes a first ejection density to form the first ink layer, and the second ejection control unit ejects the ink so that the ejection density of the ink becomes a second ejection density which is lower than the first ejection density to form the second ink layer.

5. The printer according to any one of claims 1 to 4, wherein the ink is a photocurable ink, the unevenness processing device is a light irradiation device that irradiates light toward the photocurable ink, the first unevenness control unit irradiates the first ink layer with light from the light irradiation device so that the first ink layer becomes matte, and the second unevenness control unit irradiates the second ink layer with light from the light irradiation device so that the second ink layer becomes glossy.

6. A printing method comprising: a first ejection step of ejecting a first ejection amount of ink from an ink head onto a media to form a first ink layer; a second ejection step of ejecting a second ejection amount of the ink from the ink head onto an area smaller than the first ink layer to form a second ink layer; a first unevenness processing step of performing a process to determine the unevenness of the first ink layer; and a second unevenness processing step of performing a process to determine the unevenness of the second ink layer, wherein the first unevenness processing step processes the first ink layer so that it becomes matte, the second unevenness processing step processes the second ink layer so that it becomes glossy, and the second ejection amount is smaller than the first ejection amount.

7. The printing method according to claim 6, wherein in the first dispensing step, ink in first droplets having a first size is dispensed to form the first ink layer, and in the second dispensing step, ink in second droplets having a second size smaller than the first size is dispensed to form the second ink layer.

8. The printing method according to claim 7, wherein the size of the area of ​​the dot formed when the ink of the second droplet lands on the medium is larger than the size of the pixel.

9. The printing method according to any one of claims 6 to 8, wherein in the first dispensing step, the ink is dispensed such that the ink dispensing density is a first dispensing density to form the first ink layer, and in the second dispensing step, the ink is dispensed such that the ink dispensing density is a second dispensing density which is lower than the first dispensing density to form the second ink layer.

10. The printing method according to any one of claims 6 to 9, wherein the ink ejected in the first ejection step and the second ejection step is a photocurable ink, the first unevenness treatment step is a step of irradiating the first ink layer with light so that the first ink layer becomes matte, and the second unevenness treatment step is a step of irradiating the second ink layer with light so that the second ink layer becomes glossy.

Images