Printing system and printing method

Abstract

A printing system and a printing method of the present invention form desired printed images on both sides of a medium by ejecting ink only on one side of the medium. Among them, a print head is capable of ejecting ink containing a color component to a first side of the medium, and a functional liquid that changes a color development state of a second side of the medium realized by the ink. A control section receives a setting of a first image for forming on the first side and a second image for forming on the second side, and in order to form the first image on the first side and the second image on the second side by the ejection of the ink and the functional liquid to the first side, it allocates an ink hit amount and a functional liquid hit amount according to a concentration of the first image and a concentration of the second image for each part of a printing area on which the ink and the functional liquid are ejected on the first side, and controls the print head in a manner that the ink and the functional liquid are ejected to the first side in accordance with the ink hit amount and the functional liquid hit amount allocated to each part of the printing area.

Description

Technical Field

[0001] This invention relates to a printing system and a printing method. Background Technology

[0002] Patent Document 1 discloses a method for printing and dyeing a cloth handkerchief on both sides using an inkjet printer. The method includes: a pretreatment step in which a paste-like pretreatment agent is applied to the entire surface of the cloth handkerchief; a back-side printing and dyeing step in which, after the pretreatment step, a pattern is printed on the back side using a color lighter than the surface color; and a surface printing and dyeing step in which, after the back-side printing and dyeing, a portion of the surface remains blank while a darker color than the back color is applied.

[0003] However, in order to form an image on both sides of a medium such as a cloth handkerchief, it is necessary to flip the medium after ink is sprayed from the printhead onto the back side of the medium and then spray ink from the printhead onto the surface of the medium.

[0004] Patent document 1: Japanese Patent Application Publication No. 2016-40425. Summary of the Invention

[0005] The printing system of the present invention is a printing system for printing on a medium having a first surface and a second surface opposite to the first surface, and includes:

[0006] A printhead having a first nozzle capable of spraying ink containing colored components onto a first surface, and a second nozzle capable of spraying a functional liquid onto the first surface that changes the color development state of the second surface achieved by the ink. The control unit controls the ejection of the ink and the functional liquid from the printhead. The amount of ink ejected from the first nozzle to each unit area of ​​the first surface is defined as the ink injection amount, and the amount of functional liquid ejected from the second nozzle to each unit area of ​​the first surface is defined as the functional liquid injection amount. The control unit performs the following processing: The first process is a process of accepting settings for forming a first image on the first surface and a second image on the second surface; The second process is to form the first image on the first surface and the second image on the second surface by spraying the ink and the functional liquid onto the first surface, thereby distributing the amount of ink and the amount of functional liquid sprayed onto each part of the printing area on the first surface where the ink and the functional liquid are sprayed, according to the concentration of the first image and the concentration of the second image. The third process involves controlling the printhead by spraying the ink and functional liquid onto the first surface according to the ink and functional liquid amounts allocated to each part of the printing area.

[0007] Furthermore, the printing method of the present invention includes a method in which ink containing a colored component is ejected from a first nozzle of the print head onto a first surface of the medium, and a functional liquid is ejected from a second nozzle of the print head onto the first surface, wherein... The medium has a second side that is opposite to the first side. The functional liquid causes a change in the color development state of the second surface, which is achieved by the ink. The amount of ink ejected from the first nozzle to each unit area of ​​the first surface is defined as the ink injection amount, and the amount of functional liquid ejected from the second nozzle to each unit area of ​​the first surface is defined as the functional liquid injection amount. The printing method includes the following steps: The first step involves accepting settings for forming a first image on the first surface and a second image on the second surface; In the second process, in order to form the first image on the first surface and the second image on the second surface by spraying the ink and the functional liquid onto the first surface, the amount of ink and the amount of functional liquid are allocated according to the concentration of the first image and the concentration of the second image for each part of the printing area on the first surface where the ink and the functional liquid are sprayed. In the third step, the ink and the functional liquid are sprayed from the print head toward the first surface according to the ink injection amount and the functional liquid injection amount allocated to each part of the printing area. Attached Figure Description

[0008] Figure 1 A diagram illustrating an example of the structure of a printing system.

[0009] Figure 2 A block diagram illustrating an example of the structure of a printing system.

[0010] Figure 3 A bottom view illustrating an example of the nozzle face of a printhead.

[0011] Figure 4 This diagram is intended to schematically illustrate an example of forming a first image on a first surface and a second image on a second surface by spraying ink and functional liquid onto a first surface of a medium.

[0012] Figure 5This diagram illustrates an example of generating printing data that combines a first image of the first side and a second image of the second side, and then printing it.

[0013] Figure 6A , Figure 6B This diagram illustrates examples of ink and functional liquid injection amounts in various regions, as well as examples of functional liquid and ink volume areas in the printing area.

[0014] Figure 7 This diagram schematically illustrates an example of the first side of a test pattern, which includes multiple color marks with different combinations of ink application amount IK and functional liquid application amount FL.

[0015] Figure 8 This diagram schematically illustrates an example of the second side of a test pattern, which includes multiple color marks with different combinations of ink application amount IK and functional liquid application amount FL.

[0016] Figure 9 This diagram illustrates an example of allocating the amount of ink and functional fluid to each area based on the reading results obtained by the reading unit.

[0017] Figure 10 This is a flowchart illustrating an example of the input volume setting process when the reading unit is not in use.

[0018] Figure 11 This diagram illustrates an example of how the color mark selection result input screen is displayed.

[0019] Figure 12 This is a flowchart illustrating an example of the input volume setting process used by the reading unit.

[0020] Figure 13 A flowchart illustrating an example of print control processing.

[0021] Figure 14 This diagram illustrates an example of printing by generating printing data through the inversion of a second image.

[0022] Figure 15 This diagram is used to illustrate an example of generating and printing print data that combines a first image on the first side with a full-page second image on the second side.

[0023] Figure 16 This diagram illustrates an example of generating and printing data that combines a full-page first image on the first side with a second image on the second side. Detailed Implementation

[0024] The embodiments of the present invention will now be described. Of course, the following embodiments are merely illustrative of the present invention, and not all features shown in the embodiments are necessarily necessary for the solution of the invention.

[0025] (1) Summary of the methods included in this invention: First, refer to Figures 1 to 16 The examples shown illustrate the general outline of the methods included in this invention. Furthermore, the accompanying drawings are schematic illustrations of examples, and the magnification of the various directions shown in these drawings may sometimes differ, and the drawings may sometimes not match. Of course, the elements of this invention are not limited to the specific examples shown by the symbols. In the "Summary of the Methods Included in this Invention," the terms in parentheses are supplementary descriptions of the preceding words.

[0026] Furthermore, in this application, the numerical range "Min~Max" refers to the minimum value Min and the maximum value Max.

[0027] Method 1 like Figures 1-4 As illustrated, one type of printing system 1 involves printing on a medium 200 having a first surface 201 and a second surface 202 opposite to the first surface 201, and includes a print head 11 and a control unit 3. The print head 11 has a first nozzle 14a capable of ejecting ink 16 containing colored components onto the first surface 201, and a second nozzle 14b capable of ejecting a functional liquid 26 onto the first surface 201 that alters the color development state of the second surface 202 as achieved by the ink 16. The control unit 3 controls the ejection of the ink 16 and the functional liquid 26 from the print head 11. Here, the amount of ink 16 ejected from the first nozzle 14a per unit area of ​​the first surface 201 is defined as the ink injection amount IK, and the amount of functional liquid 26 ejected from the second nozzle 14b per unit area of ​​the first surface 201 is defined as the functional liquid injection amount FL. Figure 4 , Figure 5 , Figure 13 As illustrated, the control unit 3 performs the following controls.

[0028] (a1) A first process that accepts settings for a first image IM1 to be formed on the first surface 201 and a second image IM2 to be formed on the second surface 202.

[0029] (a2) A second process, which, in order to form the first image IM1 on the first surface 201 and the second image IM2 on the second surface 202 by spraying the ink 16 and the functional liquid 26 onto the first surface 201, allocates the ink injection amount IK and the functional liquid injection amount FL according to the concentration of the first image IM1 and the second image IM2 for each part of the printing area A0 on the first surface 201 where the ink 16 and the functional liquid 26 are sprayed.

[0030] (a3) A third process, which controls the printhead 11 by spraying the ink 16 and the functional liquid 26 onto the first surface 201 according to the ink injection amount IK and the functional liquid injection amount FL allocated to each part of the printing area A0.

[0031] When ink 16 is sprayed onto the first surface 201 of the medium 200, an image is formed not only on the first surface 201, but also penetrates into the medium 200 through ink 16, thereby forming an image on the second surface 202 opposite to the first surface 201. Here, the print head 11 has a second nozzle 14b capable of spraying a functional liquid 26 onto the first surface 201 to change the color development state of the second surface 202 formed by ink 16. Based on this, in order to form a first image IM1 on the first surface 201 and a second image IM2 on the second surface 202 by spraying ink 16 and functional liquid 26 onto the first surface 201, the ink injection amount IK and the functional liquid injection amount FL are distributed according to the concentration of the first image IM1 and the second image IM2 for each part of the printing area A0 of the first surface 201. By spraying ink 16 and functional liquid 26 onto the first surface 201 according to the ink injection amount IK and functional liquid injection amount FL allocated to each part of the printing area A0, a predetermined first image IM1 is formed on the first surface 201, and a predetermined second image IM2 is formed on the second surface 202. In other words, the second image IM2 formed on the second surface 202 is not formed by spraying ink 16 onto the second surface 202, but by the ink 16 sprayed onto the first surface 201. Thus, it can also be said that by spraying ink 16 onto one side of the medium 200, an image is printed simultaneously on both sides of the medium 200. Therefore, the above method can provide a printing system that can form a desired printed image on both sides of the medium by spraying ink only on one side of the medium. As a result, there is no need to flip the medium or flip the transport path of the medium, thereby reducing the time or cost of printing, and it is easy to obtain a printed product that is close to double-sided printing.

[0032] Various examples can be given in the above methods.

[0033] Ink can be either pigment ink or dye ink.

[0034] Colored components can be either chromatic components such as blue-green, magenta, and yellow, or achromatic components such as black or white.

[0035] Functional liquids can be treatment liquids that cause pigments to coagulate, transparent inks without colored components, or penetrating liquids for dye inks, etc.

[0036] The meaning of changing the color development state of the second side is to change the hue that can be visually confirmed when observing the second side by changing the surface state or penetration degree of the ink.

[0037] The amount of ink sprayed per unit area can be the number of ink droplets sprayed per unit area, or the number of ink droplets converted to the largest possible droplet size when spraying ink droplets of different sizes. Alternatively, the amount of ink sprayed per unit area can also be the size of the ink droplets. Similarly, the amount of functional liquid sprayed per unit area can be the number of functional liquid droplets sprayed per unit area, or the number of ink droplets converted to the largest possible droplet size when spraying functional liquid droplets of different sizes. Alternatively, the amount of ink sprayed per unit area can also be the size of the functional liquid droplets.

[0038] The first image refers to the image that can be visually confirmed when observing the first surface. The second image refers to the image that can be visually confirmed when observing the second surface. Forming a second image on a second surface means that a second image is formed on the second surface through the penetration of ink sprayed onto the first surface, etc., and does not mean that ink is sprayed onto the second surface.

[0039] In this application, "first," "second," ... are terms used to identify the individual structural elements contained in a plurality of structural elements that have similarities, and do not necessarily refer to the order.

[0040] Of course, the above additional notes also apply to the following methods.

[0041] Method 2 like Figure 4 , Figure 5As illustrated, the first image IM1 may also include a first portion PT1 of a predetermined concentration and a second portion PT2 that is lighter than the first portion PT1. The second image IM2 may also include a third portion PT3 of a predetermined concentration and a fourth portion PT4 that is lighter than the third portion PT3. The printing area A0 may also include a first portion area AA where the first portion PT1 and the fourth portion PT4 overlap, a second portion area AB where the second portion PT2 and the fourth portion PT4 overlap, a third portion area AC where the first portion PT1 and the third portion PT3 overlap, and a fourth portion area AD where the second portion PT2 and the third portion PT3 overlap. The control unit 3 may also, in the second process, allocate a first ink injection amount IK1, which is the ink injection amount IK, and a first functional liquid injection amount FL1, which is the functional liquid injection amount FL, to the first portion area AA. The control unit 3 may also, in the second process, allocate a second ink injection amount IK2, which is the ink injection amount IK, and a second functional liquid injection amount FL2, which is the functional liquid injection amount FL, to the second portion area AB. The control unit 3 may also, in the second process, allocate a third ink injection amount IK3, which is the ink injection amount IK, and a third functional liquid injection amount FL3, which is the functional liquid injection amount FL, to the third portion region AC. The control unit 3 may also, in the second process, allocate a fourth ink injection amount IK4, which is the ink injection amount IK, and a fourth functional liquid injection amount FL4, which is the functional liquid injection amount FL, to the fourth portion region AD.

[0042] In the above case, a preferred example can be provided in which the desired printed image is formed on both sides of the medium by spraying ink only on one side of the medium. Additionally, either the ink injection amount IK or either the functional liquid injection amount FL can be 0.

[0043] Here, the second image IM2 may not include the fourth portion PT4, but instead has a specified concentration. In this case, the control unit 3 may also, in the second processing, set the second image IM2 as the third portion PT3, and allocate the third ink injection amount IK3 and the third functional liquid injection amount FL3 to the third portion region AC, and allocate the fourth ink injection amount IK4 and the fourth functional liquid injection amount FL4 to the fourth portion region AD.

[0044] Furthermore, the first image IM1 may not include the second portion PT2, but instead has a specified concentration. In this case, the control unit 3 may also, in the second processing, set the first image IM1 as the third portion PT1, and allocate the first ink injection amount IK1 and the first functional liquid injection amount FL1 to the first portion region AA, and allocate the third ink injection amount IK3 and the third functional liquid injection amount FL3 to the third portion region AC.

[0045] The above supplementary explanations also apply to the following methods.

[0046] Method 3 like Figure 7 , Figure 8 , Figure 10 , Figure 11 As illustrated, the control unit 3 can further implement the following controls.

[0047] (a4) A fourth process, which is to control the printhead 11 by forming a test pattern TP1 on the medium 200, which includes multiple color marks PA0 with different combinations of ink injection amount IK and functional liquid injection amount FL.

[0048] (a5) The fifth process is to accept the input of the selection result of the color mark PA0 selected from the plurality of color marks PA0 so that it corresponds to the partial area selected from the first partial area AA, the second partial area AB, the third partial area AC and the fourth partial area AD, and to allocate the ink application amount IK and the functional liquid application amount FL corresponding to the selection result to the partial area.

[0049] In the above scenario, the density of the first image IM1 and the second image IM2 is represented based on the selection result of the color bar PA0 from the test pattern TP1. Therefore, the above method can improve the image quality of both the first and second images.

[0050] Here, the control unit 3 may also, in the fifth process, accept input of the selection result of a color mark PA0 corresponding to the first partial region AA from the plurality of color marks PA0, and set the ink injection amount IK corresponding to the selection result as the first ink injection amount IK1. The control unit 3 may also accept input of the selection result of a color mark PA0 corresponding to the second partial region AB from the plurality of color marks PA0, and set the ink injection amount IK corresponding to the selection result as the second ink injection amount IK2. The control unit 3 may also accept input of the selection result of a color mark PA0 corresponding to the third partial region AC from the plurality of color marks PA0, and set the ink injection amount IK corresponding to the selection result as the third ink injection amount IK3. The control unit 3 may also accept input of the selection result of a color mark PA0 corresponding to the fourth partial region AD from the plurality of color marks PA0, and set the ink injection amount IK corresponding to the selection result as the fourth ink injection amount IK4.

[0051] Method 4 like Figure 7 , Figure 8 , Figure 11 , Figure 12 As illustrated, the control unit 3 can further implement the following controls.

[0052] (a6) A sixth process, which determines at least a portion of the first ink injection amount IK1, the first functional liquid injection amount FL1, the second ink injection amount IK2, the second functional liquid injection amount FL2, the third ink injection amount IK3, the third functional liquid injection amount FL3, the fourth ink injection amount IK4, and the fourth functional liquid injection amount FL4 based on a first reading result obtained by the reading unit 180 reading the concentration of each of the color marks PA0 formed on the first surface 201, and a second reading result obtained by the reading unit 180 reading the concentration of each of the color marks PA0 formed on the second surface 202.

[0053] In the above situation, the density of the first image IM1 and the density of the second image IM2 are represented based on the reading results of the test pattern TP1 read by the reading unit 180. Therefore, the above method can improve the image quality of the first image and the second image.

[0054] Method 5 The ink 16 may also be a pigment ink containing dispersed pigments as the colored component. The functional liquid 26 may also be a treatment liquid containing a coagulant that causes the pigment to agglomerate. For example... Figure 6A , Figure 6BAs illustrated, the fourth functional fluid injection volume FL4 in the fourth region AD can also be lower than the first functional fluid injection volume FL1 in the first region AA.

[0055] In the printing area A0, where the processing liquid has a higher injection volume, the pigment in the pigment ink is more easily fixed to the first surface 201 of the medium 200 due to the greater amount of coagulant in the processing liquid. Therefore, this area appears as a denser portion in the first image IM1 and a lighter portion in the second image IM2. This portion corresponds to the first region AA. In the printing area A0, where the processing liquid has a lower injection volume, the pigment ink easily penetrates into the medium 200. Therefore, this area appears as a lighter portion in the first image IM1 and a denser portion in the second image IM2. This portion corresponds to the fourth region AD.

[0056] Based on the above, the density of different parts of the image on both sides can be controlled according to the amount of processing liquid injected. Therefore, the above method provides a preferred example of forming a desired printed image on both sides of the medium by spraying pigment ink only on one side of the medium.

[0057] Method 6 The functional liquid 26 can also be a transparent ink that does not contain the colored component. The amount of the fourth functional liquid injected in the fourth region AD, FL4, can also be higher than the amount of the first functional liquid injected in the first region AA, FL1.

[0058] In the printing area A0, where the amount of transparent ink applied is relatively high, the colored ink 16 tends to penetrate into the medium 200 due to the greater amount of transparent ink. Therefore, this area appears lighter in the first image IM1 and darker in the second image IM2. This area corresponds to the fourth region AD. In the printing area A0, where the amount of transparent ink applied is relatively low, the colored ink 16 tends to remain on the first surface 201 of the medium 200. Therefore, this area appears darker in the first image IM1 and lighter in the second image IM2. This area corresponds to the first region AA.

[0059] Based on the above, the density of different parts of the image on both sides can be controlled by varying the amount of transparent ink applied. Therefore, the above method can also provide a preferred example of forming a desired printed image on both sides of the medium by spraying ink only on one side of the medium.

[0060] Method 7 The ink 16 may also be a dye ink containing dye as a colored component. The functional liquid 26 may also be a penetrating liquid that assists in the penetration of the dye ink into the medium 200. The amount of the fourth functional liquid injected into the fourth region AD, FL4, may also be higher than the amount of the first functional liquid injected into the first region AA, FL1.

[0061] In the printing area A0, where the penetrant has a higher penetration amount, the dye ink easily penetrates into the medium 200 due to the large amount of penetrant. Therefore, this area appears lighter in the first image IM1 and darker in the second image IM2. This area corresponds to the fourth region AD. In the printing area A0, where the penetrant has a lower penetration amount, the dye ink easily remains on the first surface 201 of the medium 200. Therefore, this area appears darker in the first image IM1 and lighter in the second image IM2. This area corresponds to the first region AA.

[0062] Based on the above, the density of different parts of the image on both sides can be controlled according to the amount of penetrating liquid injected. Therefore, the above method can also provide a preferred example of forming a desired printed image on both sides of the medium by spraying ink only on one side of the medium.

[0063] Method 8 like Figure 14 As illustrated, the control unit 3 may also be configured to, in the first process, display the first image IM1 and the second image IM2 on a display unit (e.g., display device 115) and accept settings for displaying the first image IM1 and the second image IM2 on the display unit (115). The control unit 3 may also be configured to, in the second process, invert the second image IM2 and, based on the first image IM1 and the inverted second image IM2, distribute the ink injection amount IK and the functional liquid injection amount FL to each portion of the printing area A0.

[0064] In the above case, since it is not necessary to reverse the second image IM2 formed on the second surface 202 of the medium 200 beforehand, usability is improved.

[0065] Method 9 like Figure 6A , Figure 6BAs illustrated, the printing area A0 may also include a first functional liquid volume area AF1 where the functional liquid injection amount FL is a first injection amount, and a second functional liquid volume area AF2 where the functional liquid injection amount FL is a second injection amount that is lower than the first injection amount. The control unit 3 may also allocate the first injection amount to the first functional liquid volume area AF1 and the second injection amount to the second functional liquid volume area AF2 during the second processing.

[0066] In the first functional liquid volume region AF1 and the second functional liquid volume region AF2, even if the ink injection volume IK is the same, the color development state of the second surface 202 achieved by the ink 16 is different due to the different functional liquid injection volumes FL. Therefore, it is possible to control the density of each part of the second image IM2 on the second surface 202. Thus, the above method provides a preferred example of forming a desired printed image on both sides of the medium by spraying ink only on one side of the medium.

[0067] Here, the amount of functional fluid injected into the first and second functional fluid volume zones is not fixed and may vary depending on the specific zone. This supplementary explanation also applies to the following methods.

[0068] Method 10 like Figure 6B As illustrated, the first functional liquid volume region AF1 may also include a first ink volume region AI1 where the ink injection amount IK is a third injection amount, and a second ink volume region AI2 where the ink injection amount IK is a fourth injection amount that is lower than the third injection amount. The control unit 3 may also allocate the third injection amount to the first ink volume region AI1 and the fourth injection amount to the second ink volume region AI2 in the second process.

[0069] In the first ink volume region AI1 and the second ink volume region AI2, even if the functional liquid injection amount FL is the same, the color development state of the first surface 201 achieved by the ink 16 is different due to the different ink injection amounts IK. Therefore, it is possible to control the density of each part of the first image IM1 on the first surface 201. Thus, the above method provides a preferred example of forming a desired printed image on both sides of the medium by spraying ink only on one side of the medium.

[0070] Here, the ink amount applied to the first ink volume area and the second ink volume area is not fixed and may vary depending on the region. This supplementary explanation also applies to the following methods.

[0071] Method 11 like Figure 6AAs illustrated, the second functional liquid volume region AF2 may also include a third ink volume region AI3 where the ink injection amount IK is a fifth injection amount, and a fourth ink volume region AI4 where the ink injection amount IK is a sixth injection amount that is lower than the fifth injection amount. The control unit 3 may also allocate the fifth injection amount to the third ink volume region AI3 and the sixth injection amount to the fourth ink volume region AI4 during the second processing.

[0072] In the third ink volume region AI3 and the fourth ink volume region AI4, even if the functional liquid injection amount FL is the same, the color development state of the first surface 201 achieved by the ink 16 is different due to the different ink injection amounts IK. Therefore, it is possible to control the density of each part of the first image IM1 on the first surface 201. Thus, the above method provides a preferred example of forming a desired printed image on both sides of the medium by spraying ink only on one side of the medium.

[0073] Here, the ink application amounts in the third and fourth ink volume zones are not fixed and may vary depending on the specific area. This supplementary explanation also applies to the following methods.

[0074] Method 12 Another printing method involves ejecting ink 16 containing colored components from a first nozzle 14a of a printhead 11 onto a first surface 201 of a medium 200, and ejecting a functional liquid 26 from a second nozzle 14b of the printhead 11 onto the first surface 201. The medium 200 has a second surface 202 opposite to the first surface 201. The functional liquid 26 alters the color development state of the second surface 202 as achieved by the ink 16. Figure 5 , Figure 13 As illustrated, this printing method includes the following steps.

[0075] (b1) First process ST1, accepting the setting of a first image IM1 to be formed on the first surface 201 and a second image IM2 to be formed on the second surface 202.

[0076] (b2) Second step ST2, in order to form the first image IM1 on the first surface 201 and the second image IM2 on the second surface 202 by spraying the ink 16 and the functional liquid 26 onto the first surface 201, the ink injection amount IK and the functional liquid injection amount FL are allocated according to the concentration of the first image IM1 and the concentration of the second image IM2 for each part of the printing area A0 on the first surface 201 where the ink 16 and the functional liquid 26 are sprayed.

[0077] (b3) In the third step ST3, the ink 16 and the functional liquid 26 are sprayed from the print head 11 toward the first surface 201 according to the ink injection amount IK and the functional liquid injection amount FL allocated to each part of the printing area A0.

[0078] The above method provides a printing method that can form a desired printed image on both sides of a medium by spraying ink only on one side of the medium.

[0079] Furthermore, the above-described method can be applied to the printing apparatus included in the above-described printing system, the control method of the printing apparatus, the control program of the printing apparatus, and a computer-readable non-transitory medium recording the control program. The printing apparatus may also be composed of multiple dispersed parts.

[0080] (2) Specific examples of the structure of a printing system: Figure 1 , Figure 2 The structure of a printing system 1, including a main unit 100 and a printing unit 2, is schematically illustrated. The printing system 1 may also include a component for printing a test pattern TP1 (see reference 1). Figure 7 , Figure 8 The reading unit 180 performs the reading. Figure 3 The nozzle surface 11s of the print head 11 is schematically illustrated. Figure 4 The illustration schematically illustrates the formation of a first image IM1 on the first surface 201 of the medium 200 and a second image IM2 on the second surface 202 of the medium 200 by spraying ink 16 and functional liquid 26 onto the first surface 201 of the medium 200.

[0081] exist Figure 1 , Figure 2 In the example shown is a serial inkjet printer, serving as an example of printing section 2. Additionally, Figure 1 The Y-axis direction shown indicates the transport direction D3, which is the direction in which medium 200 is transported. Figure 1 The X-axis direction shown indicates Figure 3 , Figure 4 The first scanning direction D1 is shown, and represents the width direction that intersects the transport direction D3 in the medium 200. The X-axis direction and the Y-axis direction can be as follows: Figure 1 As shown, the direction is horizontal, but it can also be a direction different from horizontal, such as up or down. Although in this specific example, the Y-axis and X-axis are set to be orthogonal, they can also intersect at an angle other than 90°. Figure 1The Z-axis direction shown represents the vertical direction that intersects the X-axis and Y-axis directions. In this specific example, it is set to be orthogonal to the X-axis and Y-axis directions. The Z-axis direction can also be a horizontal direction or other directions different from the vertical direction.

[0082] Figure 1 The medium 200 shown is a relatively light-colored printable material that can be permeated by ink 16 and functional liquid 26, and has a first side 201 and a second side 202 opposite to the first side. Furthermore, if the first side 201 is the surface of the medium 200, then the second side 202 is the back side of the medium 200; conversely, if the first side 201 is the back side of the medium 200, then the second side 202 is the surface of the medium 200. From the perspective that a second image IM2 is formed on the second side 202 by spraying ink 16 onto the first side 201, the medium 200 is preferably a relatively thin printable material such as a thin fabric that is easily permeated by ink 16. In the medium 200, woven or textile fabrics, non-woven fabrics, paper, etc., can be used. For example, fabric is composed of multiple fibers, thereby allowing ink 16 and functional liquid 26 to permeate. Figure 1 The medium 200 shown is a strip of printed material supplied in a state of being wound into a roll. Figure 1 , Figure 2 The printing unit 2 shown includes a drive unit 20 on which the head unit 10 is mounted, a print control unit 30 for controlling the operation of the printing unit 2, etc. The printing unit 2 receives printing data PD1 from the host device 100 and controls the head unit 10 and the drive unit 20 through the print control unit 30 according to the printing data PD1, thereby printing images (IM1, IM2) on the medium 200.

[0083] Figure 2 The illustrated head unit 10 includes a printhead 11 that serves as an inkjet head, and a head control unit 10c that controls the printhead 11. Figure 1 , Figure 3 As shown, the head unit 10 is mounted on a carriage 41 that can move in a first scanning direction D1 and a second scanning direction D2 opposite to the first scanning direction D1, and reciprocates with the carriage 41. The drive unit 20 causes the relative position of the printing head 11 based on the medium 200 to change at least in the first scanning direction D1 and the second scanning direction D2.

[0084] Figures 2-4The printhead 11 shown includes an inkhead 11A capable of ejecting ink 16 containing colored components such as pigments or dyes, and a functional liquidhead 11P capable of ejecting a functional liquid 26 that changes the color development state of the second surface 202 formed by the ink 16. The ink 16 is a colored ink in which a color material such as pigment or dye is contained in a liquid (e.g., water) as a dispersion medium or solvent, serving as a dispersion medium or solute. From the perspective that a second image IM2 is formed on the second surface 202 by ejecting the ink 16 onto the first surface 201, it is preferable that the ink 16 has a low viscosity. The inkhead 11A includes, for example, a C inkhead 11C capable of ejecting C (blue-green) ink, an M inkhead 11M capable of ejecting M (magenta) ink, a Y inkhead 11Y capable of ejecting Y (yellow) ink, and a K inkhead 11K capable of ejecting K (black) ink.

[0085] Functional liquid 26 refers to a liquid that has a specified function of assisting in the formation of an image by colored ink 16. More specifically, functional liquid 26 refers to a liquid that acts on the colored ink 16 to promote the aggregation or penetration of the colored ink 16 relative to the medium 200 onto the surface of the medium, compared to the case where functional liquid 26 is not used. Functional liquid is also referred to as functional ink.

[0086] Ink 16 can also be a pigment ink containing dispersed pigments as a colored component. In pigment inks, liquids containing, for example, a dispersion medium such as water, a pigment as a dispersed phase, and a surfactant can be used. When ink 16 is a pigment ink, the functional liquid 26 can also be a processing liquid containing a coagulant that causes the pigments in the pigment ink to agglomerate. In areas of the first surface 201 where the amount of processing liquid ejected is greater, the pigments in the pigment ink tend to remain on the first surface 201 side, thus the color of the first surface 201 is darker than that of the second surface 202 compared to other areas. In areas of the first surface 201 where the amount of processing liquid ejected is less, the pigments in the pigment ink tend to move from the first surface 201 to the second surface 202 side, thus the color of the first surface 201 is lighter than that of the second surface 202 compared to other areas. In the processing liquid, liquids containing, for example, a solvent such as water, a cationic compound as a coagulant, and a surfactant can be used. Among cationic compounds, polyvalent metal salts, organic acids, cationic resins, and cationic surfactants can be used.

[0087] Furthermore, ink 16 can also be a dye ink containing dye as a colored component. In dye inks, liquids containing solvents such as water, dyes as solutes, surfactants, etc., can be used. When ink 16 is a dye ink, functional liquid 26 can also be a penetrating liquid that assists in the penetration of the dye ink into the medium 200. In areas of the first surface 201 where the amount of penetrating liquid ejected is less, the dye component in the dye ink tends to remain on the first surface 201 side, thus the color of the first surface 201 is darker and the color of the second surface 202 is lighter compared to other areas. In areas of the first surface 201 where the amount of penetrating liquid ejected is greater, the dye component in the dye ink tends to move from the first surface 201 to the second surface 202 side, thus the color of the first surface 201 is lighter and the color of the second surface 202 is darker compared to other areas. From the perspective that a second image IM2 is formed on the second surface 202 by ejecting ink 16 onto the first surface 201, it is preferable that the viscosity of the penetrating liquid is lower than the viscosity of ink 16. The permeate can be a liquid containing solvents such as water or organic solvents such as glycols. Among organic solvents containing glycols, ethylene glycol, 1,3-propanediol, and 1,3-butanediol can be used.

[0088] The functional liquid 26 can also be a transparent ink without colored components. In this case, the ink 16 can be either a pigment ink or a dye ink. In areas of the first surface 201 where the amount of transparent ink ejected is less, the colored components in the ink 16 tend to remain on the first surface 201 side, resulting in a darker color on the first surface 201 and a lighter color on the second surface 202 compared to other areas. In areas of the first surface 201 where the amount of transparent ink ejected is greater, the colored components in the ink 16 tend to move from the first surface 201 to the second surface 202 side, resulting in a lighter color on the first surface 201 and a darker color on the second surface 202 compared to other areas. From the perspective that a second image IM2 is formed on the second surface 202 by ejecting the ink 16 onto the first surface 201, it is preferable that the viscosity of the transparent ink is lower than the viscosity of the ink 16. Liquids containing a dispersion medium such as water, surfactants, etc., can be used in the transparent ink.

[0089] In the following specific example, we will explain the case where ink 16 is pigment ink and functional liquid 26 is processing liquid.

[0090] like Figure 2 , Figure 3As shown, each individual head (11C, 11M, 11Y, 11K, 11P) has a nozzle array NL in which multiple nozzles 14 are arranged in a nozzle arrangement direction intersecting the first scanning direction D1, such as the transport direction D3, and includes a drive circuit 12, a drive element 13, etc. The multiple nozzles 14 included in each nozzle array NL can be arranged in a direction deviating from the transport direction D3, or they can be arranged in a staggered pattern. Each first nozzle 14a of the ink head 11A can eject colored ink 16 as ink droplets 17, and each second nozzle 14b of the functional liquid head 11P can eject functional liquid 26 as functional liquid droplets 27. The drive circuit 12 applies a voltage signal to the drive element 13 according to the drive signal input from the print control unit 30. In the drive element 13, a piezoelectric element that applies pressure to the ink 16 or functional liquid 26 in the pressure chamber connected to the nozzle 14, or a drive element that generates bubbles in the pressure chamber by heat, thereby ejecting ink droplets 17 or functional liquid droplets 27 from the nozzle 14, can be used. Of course, the method of ejecting droplets such as ink droplets 17 or functional liquid droplets 27 is not limited to this. For example, printing can be performed by continuously ejecting ink in droplet form from the nozzle in a strong electric field between the nozzle and the accelerating electrode positioned in front of the nozzle, and by providing a printing information signal from the deflection electrode during the droplet's flight. Furthermore, the method of ejecting droplets can also be electrostatic attraction, mechanical vibration, etc. The electrostatic attraction method is a method of ejecting droplets in accordance with the printing information signal without deflecting them. The mechanical vibration method is a method of forcibly ejecting droplets by applying pressure to the ink with a small pump and mechanically vibrating the nozzle with a crystal oscillator, etc.

[0091] Ink 16 and functional liquid 26 are supplied to the pressure chamber of the print head 11 via the liquid supply unit 19. The liquid supply unit 19 includes containers for ink 16 and functional liquid 26, and supply channels for supplying ink 16 and functional liquid 26 from the containers to the print head 11. The containers, supply channels, and supply paths to the nozzles 14 are independently configured for each of the various types of ink 16 and functional liquid 26. The ink 16 or functional liquid 26 in the pressure chamber is ejected in droplets from the nozzles 14 toward the first surface 201 of the medium 200 via the drive element 13. Under the control of the print control unit 30, droplets are ejected from each nozzle 14 of the nozzle array NL onto the medium 200 on the impression plate 55 while the print head unit 10 moves in the first scanning direction D1 or the second scanning direction D2, thereby printing images (IM1, IM2) on the medium 200.

[0092] In addition, although Figure 2The supply of functional liquid 26 is not illustrated, but the process from when functional liquid 26 is supplied from liquid supply unit 19 to print head 11 and ejected as functional liquid droplet 27 can be regarded as the same as the process when ink 16 is supplied from liquid supply unit 19 to print head 11 and ejected as ink droplet 17.

[0093] The drive unit 20 includes a main scanning unit 40, a transport unit 50, etc., and moves the head unit 10 and the medium 200 relative to each other under the control of the print control unit 30. In this specific example, the main scanning unit 40 includes a carriage 41, a guide shaft 42, a carriage motor (not shown), etc., and moves the head unit 10 in the first scanning direction D1 and the second scanning direction D2 under the control of the print control unit 30. The guide shaft 42 is configured such that its length direction is towards the first scanning direction D1, and supports the carriage 41 so that it can move in the first scanning direction D1 and the second scanning direction D2. The carriage motor (not shown) reciprocates the carriage 41 along the guide shaft 42. Therefore, the main scanning unit 40 moves the print head 11 in the first scanning direction D1 and the second scanning direction D2 under the control of the print control unit 30. The conveying unit 50 of this specific example includes a media supply unit 51, a media storage unit 52, multiple conveying rollers 53, an impression plate 55, etc., and moves the media 200 in the conveying direction D3 under the control of the printing control unit 30. The media supply unit 51 supports the roll in which the media 200 is wound into a cylindrical shape in a rotatable manner and feeds the media 200 onto the conveying path. The media storage unit 52 supports the roll of media 200 wound in a rotatable manner and winds up the printed media 200 from the conveying path. The multiple conveying rollers 53 include drive rollers that move the media 200 in the conveying direction D3, driven rollers that rotate with the movement of the media 200, etc. The media 200 supplied from the media supply unit 51 to the conveying path is wound onto the media storage unit 52 via the printing area on the impression plate 55.

[0094] Furthermore, when printing in the horizontal mode in the printing unit 2, the carriage 41, which carries the printhead 11, can also move in the transport direction D3 and the opposite sub-scanning direction. In addition, the printing unit 2 can also be a line inkjet printer that does not have a carriage 41 but has a printhead with a nozzle array spanning the entire width of the medium 200.

[0095] The print control unit 30 includes a communication I / F (interface) 31, a CPU (Central Processing Unit) 32 (acting as a processor), a memory 33, and a drive control unit 34, and controls the operation of the printing unit 2. The communication I / F 31, CPU 32, memory 33, and drive control unit 34 are electrically connected, enabling them to input and output information to each other. The memory 33 includes, for example, ROM (Read-Only Memory), RAM (Random Access Memory), and NVM (Non-Volatile Memory). In NVM, non-volatile semiconductor memory such as flash memory and magnetic storage devices such as hard disks can be used. The memory 33 is a storage medium that stores the area where the CPU 32 performs operations or the work area where operations are performed.

[0096] Alternatively, the printing control unit 30 may be configured as a SoC (System on Chip) or may include an ASIC (Application Specific Integrated Circuit). Communication I / F 31 is connected to communication I / F 117 of the host device 100. Communication I / F 31 and 117 perform bidirectional data communication. The CPU 32 controls the head unit 10 and the drive unit 20 via the drive control unit 34 by executing a program stored in the memory 33. The drive control unit 34 includes a movement control signal generation circuit 35, an ejection control signal generation circuit 36, and a drive signal generation circuit 37, and controls the operation of the head unit 10 and the drive unit 20 based on the control of the CPU 32. The movement control signal generation circuit 35 generates movement control signals to control the main scanning unit 40 and the transport unit 50 according to instructions from the CPU 32, and outputs these signals to the drive unit 20. The ejection control signal generation circuit 36 ​​generates a head control signal based on the printing data PD1, according to instructions from the CPU 32, for selecting the nozzle for ejecting ink 16 or functional liquid 26, selecting the ejection amount, and controlling the ejection timing, and outputs the signal to the head control unit 10c of the head unit 10. The drive signal generation circuit 37 generates a drive signal to drive the drive element 13 of the printing head 11 and outputs the signal to the drive circuit 12. The drive control unit 34 drives the drive element 13 corresponding to each nozzle 14 based on the head control signal and the drive signal.

[0097] Figure 1 , Figure 2The host device 100 shown includes a CPU 111, ROM 112, RAM 113, storage device 114, display device 115, input device 116, communication I / F 117, etc. These elements 111 to 117 are electrically connected and can input and output information to each other. The CPU 111, ROM 112, and RAM 113 are included in the host-side control unit 110. In this specific example, the host-side control unit 110 and the printing control unit 30 constitute the control unit 3. The display device 115 is an example of a display unit. A reading unit 180 may also be connected to the host device 100. Examples of the host device 100 include computers such as personal computers (including tablet terminals), mobile phones such as smartphones, digital cameras, etc. Although the host device 100 can contain elements 111 to 117 in a single housing, it can also be composed of multiple devices that are separated from each other in a communicable manner. Furthermore, the host device 100 and the printing unit 2 can also coexist in a common housing. The printing system 1 can also be referred to as a printing device.

[0098] Storage device 114 stores various drivers, applications, and setting information, including the operating system and printing control program PRO. CPU 111 appropriately reads the information stored in storage device 114 into RAM 113 and performs various processes by executing the read program. Storage device 114 can use non-volatile semiconductor memory such as flash memory, magnetic storage devices such as hard disks, etc. The computer-readable medium storing the printing control program PRO is not limited to the internal storage device of host device 100, but can also be an external recording medium RD. Display device 115 is a human-machine interface for displaying information and can use liquid crystal display panels, etc. Input device 116 is a human-machine interface for inputting information and can use pointing devices, hard keys including a keyboard, touch panels pasted on the surface of the display panel, etc. Reading unit 180 reads... Figure 7 , Figure 8 The test pattern TP1 is illustrated, and the reading results of the test pattern TP1 can be output to the host device 100. Examples of the reading unit 180 include scanners such as flatbed scanners, cameras, colorimeters, etc. When the host device 100 obtains the reading results of the test pattern TP1 from the reading unit 180, it can obtain the reading values ​​representing the concentration of each color mark PA0 of the test pattern TP1.

[0099] Furthermore, for double-sided printing on medium 200, a scenario is considered where, after forming a printed image on the back side of medium 200 by spraying ink onto the back side, medium 200 is flipped over, and a printed image is formed on the surface by spraying ink onto the surface. However, since flipping medium 200 requires user operations or a medium reversing mechanism in the transport path, there is room for improvement in productivity. Additionally, when medium 200 is thin, sometimes the image printed on the back side appears faintly on the surface, and vice versa, causing interference between the images on both sides, preventing the formation of the intended printed image.

[0100] In this specific example, for instance, considering the case where an image can be formed not only on the surface but also on the back side by ink 16 sprayed onto the surface of the medium 200, it is assumed that the desired printed image is formed on both sides of the medium 200 by spraying ink 16 only onto one side of the medium 200. In this case, it is assumed that ink 16 is sprayed from the first nozzle 14a onto the first surface 201 of the medium 200 according to the ink injection amount IK, and functional liquid 26 is sprayed from the second nozzle 14b onto the first surface 201 of the medium 200 according to the functional liquid injection amount FL, thereby forming the desired printed image on both sides of the medium 200.

[0101] First, refer to Figure 4 An example of forming a printed image on both sides of a medium 200 by spraying pigment ink and processing liquid onto one side of the medium 200 will be described.

[0102] In the first step ST11, Figure 1 , Figure 2 The print control unit 30, as shown, moves the print head 11 in either the first scanning direction D1 or the second scanning direction D2, while simultaneously ejecting functional droplets 27 from the second nozzle 14b of the functional nozzle 11P onto the first surface 201 of the medium 200. At this time, the print control unit 30, according to instructions from the host device 100, can change the amount of functional liquid 26 ejected per unit area from the second nozzle 14b onto the first surface 201, i.e., the functional liquid injection volume FL (refer to...). Figure 5 The functional liquid 26, i.e. the treatment liquid, is sprayed out from the second nozzle 14b in a manner that results in the presence of treatment liquid corresponding to the amount of functional liquid injected, FL, on the first surface 201.

[0103] In the second step ST12, the print control unit 30 moves the print head 11 in either the first scanning direction D1 or the second scanning direction D2, while simultaneously ejecting ink droplets 17 from the first nozzle 14a of the inkjet head 11A onto the first surface 201 of the medium 200. At this time, the print control unit 30, following instructions from the host device 100, can change the amount of ink 16 ejected per unit area from the first nozzle 14a onto the first surface 201, i.e., the ink injection amount IK (refer to...). Figure 5 The ink 16, i.e., pigment ink, is ejected from the first nozzle 14a in a manner that corresponds to the amount of functional liquid injected (FL). The amount of pigment contained in the pigment ink agglomerates on the first surface 201 side, and a portion penetrates to the second surface 202 side. As a result, varying shades are formed on the first surface 201 according to the amount of functional liquid injected (FL) and the amount of ink injected (IK), and also on the second surface 202 according to the amount of functional liquid injected (FL) and the amount of ink injected (IK).

[0104] Furthermore, the ejection of functional liquid 26 and ink 16 can be performed in different main scans or in the same main scan. Additionally, ink 16 can be ejected from the second nozzle 14b to the second surface 202 after ink 16 has been ejected from the first nozzle 14a to the first surface 201.

[0105] When steps ST11 and ST12 are completed, a first image IM1 is formed in the printing area A0 of the first surface 201, and a second image IM2 is formed in the printing area A0 of the second surface 202 (step ST13). The printing area A0 is the area on the first surface 201 where ink 16 and functional liquid 26 are sprayed. The first image IM1 is an image visually confirmed when observing the first surface 201, and is formed by spraying ink 16 and functional liquid 26 onto the first surface 201. Figure 4 In the first image IM1 shown, a denser first portion PT1 and a lighter second portion PT2 are formed based on the amount of functional liquid injected (FL) and the amount of ink injected (IK). The second image IM2, which is visually confirmed when observing the second surface 202, is not formed by the ejection of ink 16 onto the second surface 202, but rather by the ejection of ink 16 and functional liquid 26 onto the first surface 201. Figure 4 In the second image IM2 shown, a denser third portion PT3 and a lighter fourth portion PT4 are formed according to the amount of functional liquid injected FL and the amount of ink injected IK. The printing method of this specific example has the feature that it can make the density pattern of the second image IM2 different from the density pattern of the first image IM1.

[0106] The following is for reference Figure 5An example of a printing method is described, in which a first image IM1 of the first surface 201 and a second image IM2 of the second surface 202 are formed by spraying ink 16 and functional liquid 26 onto the first surface 201.

[0107] Figure 5 A method for generating and printing printing data PD1, which combines a first image IM1 of the first side 201 and a second image IM2 of the second side 202, is illustrated.

[0108] In the first step ST21, Figure 2 The host-side control unit 110 shown performs a first process, which accepts settings for a first image IM1 formed on the first surface 201 of the medium 200 and a second image IM2 formed on the second surface 202 of the medium 200. The host-side control unit 110 may also cause the display device 115 to display the images (IM1, IM2). Step ST21 is an example of the first process ST1. Here, the first image IM1 may also include a first portion PT1 of a predetermined concentration and a second portion PT2 that is lighter than the first portion PT1. The second image IM2 may also include a third portion PT3 of a predetermined concentration and a fourth portion PT4 that is lighter than the third portion PT3. The intensity pattern of the second image IM2 may also be different from that of the first image IM1.

[0109] The two images (IM1, IM2) can be either binary images or images with three or more values. Furthermore, the host-side control unit 110 can accept input of a first original image with three or more values ​​and convert it into a binary first image IM1, or it can accept input of a second original image with three or more values ​​and convert it into a binary second image IM2. Since the first image IM1 and the second image IM2 are formed simultaneously, the first portion PT1, the second portion PT2, the third portion PT3, and the fourth portion PT4 are set to the same color or to colors from the same system. The printing color can be a single color of any one of C, M, Y, and K, or a mixture of two or more of C, M, Y, and K.

[0110] In the second step ST22, the host-side control unit 110 divides the printing area A0, which merges the first image IM1 and the second image IM2, into four partial regions (AA, AB, AC, AD). In the first partial region AA, the denser first portion PT1 of the first image IM1 overlaps with the lighter fourth portion PT4 of the second image IM2. In the second partial region AB, the lighter second portion PT2 of the first image IM1 overlaps with the lighter fourth portion PT4 of the second image IM2. In the third partial region AC, the denser first portion PT1 of the first image IM1 overlaps with the denser third portion PT3 of the second image IM2. In the fourth partial region AD, the lighter second portion PT2 of the first image IM1 overlaps with the denser third portion PT3 of the second image IM2. The printing area A0 includes these partial regions (AA, AB, AC, AD). Since the ink 16 and the functional liquid 26 are only sprayed onto the first surface 201, the second image IM2 is aligned with the first image IM1 even when it is reversed horizontally or vertically.

[0111] In the third step ST23, the host-side control unit 110 allocates ink injection volume IK and functional liquid injection volume FL to four partial regions (AA, AB, AC, AD). The host-side control unit 110 allocates a first ink injection volume IK1 (ink injection volume IK) and a first functional liquid injection volume FL1 (functional liquid injection volume FL) to the first partial region AA. The host-side control unit 110 allocates a second ink injection volume IK2 (ink injection volume IK) and a second functional liquid injection volume FL2 (functional liquid injection volume FL) to the second partial region AB. The host-side control unit 110 allocates a third ink injection volume IK3 (ink injection volume IK) and a third functional liquid injection volume FL3 (functional liquid injection volume FL) to the third partial region AC. The host-side control unit 110 allocates a fourth ink injection volume IK4 (ink injection volume IK) and a fourth functional liquid injection volume FL4 (functional liquid injection volume FL) to the fourth partial region AD.

[0112] Based on the above, in order to form a first image IM1 on the first surface 201 and a second image IM2 on the second surface 202 by ejecting ink 16 and functional liquid 26 onto the first surface 201, the control unit 3 allocates ink injection amount IK and functional liquid injection amount FL according to the concentration of the first image IM1 and the second image IM2 for each part of the printing area A0. Steps ST22 to ST23 are examples of the second process ST2.

[0113] In the fourth step ST24, the host-side control unit 110 combines the injection amounts (IK, FL) of the four partial areas (AA, AB, AC, AD) to generate print data PD1 and sends it to the printing unit 2. In the fifth step ST25, the print control unit 30 controls the print head 11 to spray ink 16 and functional liquid 26 onto the first surface 201 according to the injection amounts (IK, FL) allocated to the partial areas (AA, AB, AC, AD). Ink 16 and functional liquid 26 are sprayed onto the first surface 201 through nozzles (14a, 14b), thereby forming a first image IM1 on the first surface 201 and a second image IM2 on the second surface 202. In other words, different appearance designs can be represented on the first surface 201 and the second surface 202 through the first image IM1 and the second image IM2.

[0114] Based on the above, the control unit 3 controls the print head 11 to spray ink 16 and functional liquid 26 onto the first surface 201 according to the ink injection amount IK and functional liquid injection amount FL allocated to each part of the printing area A0. Steps ST24 to ST25 are examples of the third process ST3. Figure 6A , Figure 6B The illustration schematically illustrates the amount of ink applied to each region (IK, FL), the amount of functional liquid in the printing region A0 (AF1, AF2), and the amount of ink (AI1 to AI4) when ink 16 is pigment ink and functional liquid 26 is processing liquid.

[0115] The injection volume (IK, FL) for each region is set to meet the following conditions.

[0116] (Regarding the conditions of the first image IM1) The first region AA and the third region AC have approximately the same concentration, the second region AB and the fourth region AD have approximately the same concentration, and the first region AA is more concentrated than the third region AC and the second region AB is more concentrated than the fourth region AD.

[0117] (Regarding the conditions of the second image IM2) The third region AC and the fourth region AD have approximately the same concentration, the first region AA and the second region AB have approximately the same concentration, and the third region AC and the fourth region AD and the first region AA are more concentrated than the second region AB.

[0118] exist Figure 6AThe following scenario is illustrated: the first ink injection amount IK1 is 85%, the first functional liquid injection amount FL1 is 60%, the second ink injection amount IK2 is 65%, the second functional liquid injection amount FL2 is 10%, the third ink injection amount IK3 is 99%, the third functional liquid injection amount FL3 is 10%, the fourth ink injection amount IK4 is 85%, and the fourth functional liquid injection amount FL4 is 5%.

[0119] For example, if the threshold TFL for the functional liquid injection volume FL is set to 40%, the printing area A0 is divided into a first part AA, which is the first functional liquid volume area AF1 where the functional liquid injection volume FL exceeds the threshold TFL, and a part AF2, which is the second functional liquid volume area (AB, AC, AD), where the functional liquid injection volume FL does not exceed the threshold TFL. Therefore, the printing area A0 includes the first functional liquid volume area AF1 where the functional liquid injection volume FL is 60% of the first injection volume, and the second functional liquid volume area AF2 where the functional liquid injection volume FL is 5-10% lower than the first injection volume of 60%.

[0120] Furthermore, if the threshold TIK for ink injection volume IK is set to 70%, the second functional liquid volume region AF2 is divided into a portion (AC, AD) of the third ink volume region AI3 where the ink injection volume IK exceeds the threshold TIK, and a second portion AB where the ink injection volume IK does not exceed the threshold TIK. Therefore, the second functional liquid volume region AF2 includes the third ink volume region AI3 where the ink injection volume IK is 85-99% of the fifth injection volume, and the fourth ink volume region AI4 where the ink injection volume IK is 65% of the sixth injection volume, which is lower than the fifth injection volume of 85-99%.

[0121] exist Figure 6B The following scenario is illustrated: the first ink injection amount IK1 is 85%, the first functional liquid injection amount FL1 is 100%, the second ink injection amount IK2 is 65%, the second functional liquid injection amount FL2 is 50%, the third ink injection amount IK3 is 99%, the third functional liquid injection amount FL3 is 50%, the fourth ink injection amount IK4 is 85%, and the fourth functional liquid injection amount FL4 is 10%.

[0122] For example, if the threshold TFL for the functional liquid injection volume FL is set to 40%, the printing area A0 is divided into a first functional liquid volume area AF1 (AA, AB, AC) where the functional liquid injection volume FL exceeds the threshold TFL, and a fourth area AD where the functional liquid injection volume FL does not exceed the threshold TFL, forming a second functional liquid volume area AF2. Therefore, the printing area A0 includes the first functional liquid volume area AF1 where the functional liquid injection volume FL is 50-100% of the first injection volume, and the second functional liquid volume area AF2 where the functional liquid injection volume FL is 10% of the second injection volume, which is lower than the first injection volume of 50-100%.

[0123] Furthermore, if the threshold TIK for ink injection volume IK is set to 70%, the first functional liquid volume region AF1 is divided into a portion of the first ink volume region AI1 (AA, AC) where the ink injection volume IK exceeds the threshold TIK, and a second portion of the second ink volume region AI2 (AB) where the ink injection volume IK does not exceed the threshold TIK. Therefore, the first functional liquid volume region AF1 includes the first ink volume region AI1 where the ink injection volume IK is 85-99% of the third injection volume, and the second ink volume region AI2 where the ink injection volume IK is 65% of the fourth injection volume, which is lower than the third injection volume of 85-99%.

[0124] When ink 16 is pigment ink and functional liquid 26 is processing liquid, such as Figure 6A , Figure 6B As shown, the amount of the fourth functional liquid injected (FL4) in the fourth region AD is lower than the amount of the first functional liquid injected (FL1) in the first region AA. In the first region AA, where the amount of processing liquid injected is higher, the pigment in the ink 16 is more easily fixed to the first surface 201 of the medium 200 by the greater amount of coagulant in the processing liquid. Therefore, the first region AA in the first image IM1 becomes a relatively concentrated first region PT1, and the first region AA in the second image IM2 becomes a relatively light fourth region PT4. In the fourth region AD, where the amount of processing liquid injected is lower, the ink 16 easily penetrates into the medium 200. Therefore, the fourth region AD in the first image IM1 becomes a relatively light second region PT2, and the fourth region AD in the second image IM2 becomes a relatively concentrated third region PT3.

[0125] Based on the above, the density of each part of the image (IM1, IM2) can be controlled on both sides of the medium 200 according to the amount of processing liquid injected.

[0126] The optimal injection volume (IK, FL) for each area varies depending on the type of media 200, the type of ink 16, the type of functional liquid 26, and the printing resolution. For example... Figure 7 , Figure 8 As illustrated, the control unit 3 of this specific example implements control over the formation of a test pattern TP1 on the medium 200 for determining the injection amount (IK, FL) of each partial area.

[0127] Figure 7 The first side 201 of the test pattern TP1 is schematically illustrated, including multiple color marks PA0 with different combinations of ink injection amount IK and functional liquid injection amount FL. Figure 8 The second side 202 of the test pattern TP1 is schematically illustrated, including multiple color marks PA0 with different combinations of ink application amount IK and functional liquid application amount FL. Figure 7 , Figure 8 For ease of illustration, the ink injection volume IK and functional liquid injection volume FL are shown. (The remaining text appears to be incomplete and possibly contains errors.) Figure 7 , Figure 8 In the test pattern TP1 shown, a portion of the multiple color marks PA0, where the ink injection amount IK and the functional liquid injection amount FL are at 5%, are omitted. Figure 7 As shown in the first section 201, the more the color mark PA0 is positioned to the right, the more the ink injection volume IK increases in 5% increments; and the more it is positioned to the top, the more the functional liquid injection volume FL increases in 5% increments. Additionally, Figure 7 , Figure 8 The test patterns TP1 shown are all formed by spraying ink 16 and functional liquid 26 onto the first surface 201 of the medium 200. Therefore, Figure 8 As shown, the more the multiple color marks PA0 on the second surface 202 are positioned to the left, the higher the ink injection amount IK becomes; conversely, the higher they are positioned, the higher the functional liquid injection amount FL becomes. Within each color mark PA0, shades corresponding to the injection amounts (IK, FL) are produced on the first surface 201 and the second surface 202. The ink 16 used in the test pattern TP1 can be either a single color or a mixed color with a fixed mixing ratio throughout the entire test pattern TP1.

[0128] The multiple color marks PA0 contained in the test pattern TP1 can be selected visually or read by the reading unit 180.

[0129] Figure 9 An example illustrating the allocation of input amounts (IK, FL) for each partial region based on the read results obtained by the read unit 180 is shown. Figure 9 In the diagram, the horizontal axis represents the identification number of color mark PA0, and the vertical axis represents the brightness L of color mark PA0. The broken line on the upper side represents the brightness L of the second surface 202. The broken line on the lower side represents the brightness L of the first surface 201. Brightness L This refers to CIE (International Commission on Illumination) L a b Lightness (L) in a color space The meaning is omitted below. "For the first surface 201 and the second surface 202, it can be said that the higher the brightness L, the lighter the color, and the lower the brightness L, the darker the color. Therefore, the brightness L of the first surface 201 corresponds to the density of the first surface 201 of the color mark PA0, and the brightness L of the second surface 202 corresponds to the density of the second surface 202 of the color mark PA0."

[0130] For example, suppose the first surfaces 201 of color marks PA1 and PA3 have approximately the same brightness L, the first surfaces 201 of color marks PA2 and PA4 have approximately the same brightness L and the brightness L is higher than that of the first surfaces 201 of color marks PA1 and PA3, the second surfaces 202 of color marks PA3 and PA4 have approximately the same brightness L, and the second surfaces 202 of color marks PA1 and PA2 have approximately the same brightness L and the brightness L is higher than that of the second surfaces 202 of color marks PA3 and PA4. In this case, the injection amount (IK, FL) of color mark PA1 can be determined as the injection amount (IK, FL) of the first part region AA, the injection amount (IK, FL) of color mark PA2 can be determined as the injection amount (IK, FL) of the second part region AB, the injection amount (IK, FL) of color mark PA3 can be determined as the injection amount (IK, FL) of the third part region AC, and the injection amount (IK, FL) of color mark PA4 can be determined as the injection amount (IK, FL) of the fourth part region AD.

[0131] (3) Specific examples of printing system processing: Figure 10 The host-side control unit 110 is illustrated schematically when the reading unit 180 is not used (see reference). Figure 2 The injection volume setting process implemented. Figure 11 schematically shown Figure 1 , Figure 2 This is an example of the color mark selection result input screen 500 displayed on the display device 115. When the host-side control unit 110 receives a setting instruction for the input amount (IK, FL) of each area, it initiates the input amount setting process. Here, step S102 corresponds to the fourth process and fourth step ST4, and steps S104 to S106 correspond to the fifth process and fifth step ST5. Hereinafter, the description of "step" may be omitted, and the symbol for the step will be shown in parentheses.

[0132] When the injection volume setting process begins, the host-side control unit 110 sends test pattern printing data for printing a test pattern TP1 including multiple color blocks PA0 to the printing unit 2, and causes the printing unit 2 to print the test pattern TP1 (S102). Upon receiving the test pattern printing data, the printing unit 2 controls the print head 11 to form the test pattern TP1 on the medium 200 by ejecting ink 16 and functional liquid 26 onto the first surface 201, according to the test pattern printing data. As a result, a pattern resembling... Figure 7 , Figure 8 The test pattern TP1 is shown.

[0133] Next, the host-side control unit 110 causes the display device 115 to display... Figure 11 The color mark selection result is input into screen 500 (S104) as shown.

[0134] Figure 11 The color mark selection result input screen 500 shown includes an input field 501 for the first ink input amount IK1, an input field 502 for the first functional liquid input amount FL1, an input field 503 for the second ink input amount IK2, an input field 504 for the second functional liquid input amount FL2, an input field 505 for the third ink input amount IK3, an input field 506 for the third functional liquid input amount FL3, an input field 507 for the fourth ink input amount IK4, an input field 508 for the fourth functional liquid input amount FL4, and an OK button 509. The host-side control unit 110 can accept operations that input the input amount (IK, FL) into the input fields 501 to 508 via the input device 116. The user can... Figure 7 , Figure 8 After observing the test pattern TP1 and selecting color marks PA1 to PA4 from the test pattern TP1, the ink application amount (IK1 to IK4) and the functional liquid application amount (FL1 to FL4) corresponding to the color marks PA1 to PA4 are input into the input fields 501 to 508 through the input device 116.

[0135] Furthermore, it is preferable that the first functional fluid injection volume FL1 is greater than the fourth functional fluid injection volume FL4. Therefore, the host-side control unit 110 may also display an error or control the operation of the OK button 509 to be impossible when the input value of the first functional fluid injection volume FL1 is less than the input value of the fourth functional fluid injection volume FL4, that is, when the input value of the fourth functional fluid injection volume FL4 is greater than or equal to the input value of the first functional fluid injection volume FL1. Moreover, it is preferable that the first functional fluid injection volume FL1 is greater than all of the remaining functional fluid injection volumes (FL2 to FL4). Therefore, the host-side control unit 110 may also display an error or control the operation of the OK button 509 to be impossible when any of the input values ​​of the functional fluid injection volumes (FL2 to FL4) is greater than or equal to the input value of the first functional fluid injection volume FL1.

[0136] When the host-side control unit 110 receives an operation from the OK button 509 via the input device 116, it sets the input amount entered into the input fields 501-508 as the ink input amount (IK1-IK4) and the functional liquid input amount (FL1-FL4) (S106), and then completes the input amount setting process. In this manner, the host-side control unit 110 receives the input result of selecting a color mark PA0 from multiple color marks PA0 that corresponds to the first part area AA, the second part area AB, the third part area AC, and the fourth part area AD. Although described later, the host-side control unit 110 implements... Figure 13 The illustrated printing control process allocates the ink inlet amount IK and the functional liquid inlet amount FL corresponding to the selection result of color mark PA0 to certain areas (AA, AB, AC, AD).

[0137] Although details are described later, a portion of input fields 501 to 508 can be omitted. Therefore, the host-side control unit 110 accepts the input of the selection result of selecting a color mark PA0 from multiple color marks PA0 that corresponds to a partial area selected from four partial areas (AA, AB, AC, AD), and assigns the input amount (IK, FL) corresponding to the selection result to the partial area.

[0138] Figure 12 The illustration schematically illustrates the input volume setting process performed by the host-side control unit 110 when using the reading unit 180. When the host-side control unit 110 receives setting instructions for the input volume (IK, FL) of each section area, it causes... Figure 12 The injection volume setting process begins. Here, S152 corresponds to the fourth process and the fourth step ST4, and steps S154 to S160 correspond to the sixth process and the sixth step ST6.

[0139] When the injection volume setting process begins, the host-side control unit 110 implements... Figure 10 The same process as S102 is shown, and the printing section 2 is controlled by forming a test pattern TP1 on the medium 200 by spraying ink 16 and functional liquid 26 onto the first surface 201 (S152).

[0140] Next, the host-side control unit 110 obtains from the reading unit 180 the reading results of the test pattern TP1 formed on the first surface 201 and the reading results of the test pattern TP1 formed on the second surface 202 (S154). The reading results can be luminance L, luminance values ​​representing brightness instead of luminance L, or data that can be converted into luminance L or luminance values. When the reading unit 180 outputs RGB data representing the R (red), G (green), and B (blue) components of each color mark PA0 to the host device 100, the host device 100 can also convert the RGB values ​​into luminance L or luminance values. The luminance value also corresponds to the density of the image (IM1, IM2). If the luminance value of a certain area is darker, it can be said that the area is denser; if the luminance value of a certain area is brighter, it can be said that the area is lighter.

[0141] Next, the host-side control unit 110 obtains a first reading result (S156) representing the concentration of each color bar PA0 from the aforementioned reading results for the first surface 201. The first reading result is as follows: Figure 9 As shown by the broken line on the lower side, the reading unit 180 reads the concentration, for example the brightness L, of each color mark PA0 formed on the first surface 201.

[0142] Next, the host-side control unit 110 obtains a second reading result (S158) from the above reading results for the second surface 202, representing the concentration of each color bar PA0. The second reading result is as follows: Figure 9 As shown by the broken line on the upper side, the reading unit 180 reads the concentration, for example the brightness L, of each color mark PA0 formed on the second surface 202.

[0143] Finally, the host-side control unit 110 sets the ink injection amount (IK1 to IK4) and the functional liquid injection amount (FL1 to FL4) for the four partial regions (AA, AB, AC, AD) in a manner that satisfies the conditions for the first image IM1 and the second image IM2 mentioned above (S160), and ends the injection amount setting process. Here, the determination of whether the two partial regions have approximately the same concentration can be, for example, by determining whether the brightness L between color marks PA0 is below a threshold. If the brightness L between color marks PA0 is below the threshold, it can be determined that the two partial regions have approximately the same concentration; if the brightness L between color marks PA0 exceeds the threshold, it can be determined that the two partial regions have different concentrations.

[0144] Using the above method, the host-side control unit 110 determines the ink injection volume (IK1 to IK4) and the functional liquid injection volume (FL1 to FL4) based on the first and second reading results. Although described later, the host-side control unit 110 implements... Figure 13 The illustrated printing control process allocates the determined injection amounts (IK, FL) to specific areas (AA, AB, AC, AD). The determination of the ink injection amounts (IK1 to IK4) and functional liquid injection amounts (FL1 to FL4) can also be performed only partially. Therefore, the host-side control unit 110 determines at least a portion of the ink injection amounts (IK1 to IK4) and functional liquid injection amounts (FL1 to FL4) based on the first and second read results.

[0145] Figure 13 This schematically illustrates the example of... Figure 2 The printing control process implemented by the host-side control unit 110 shown. Figure 14 An example illustrating printing is shown where printing data PD1 is generated by inverting the second image IM2. When the host-side control unit 110 receives a printing instruction for the media 200, it initiates the printing control process. Here, S202 corresponds to the first process and the first step ST1, S204 to S208 correspond to the second process and the second step ST2, and S210 corresponds to the third process and the third step ST3. In S204 to S208, a portion of the fifth step ST5 and a portion of the sixth step ST6 are performed.

[0146] When the printing control process begins, such as Figure 5 , Figure 14As shown, the host-side control unit 110 accepts settings for a first image IM1 to be formed on the first surface 201 and a second image IM2 to be formed on the second surface 202 (S202). At this time, the host-side control unit 110 causes the display device 115 to display a UI (user interface) screen (not shown) and performs the process of displaying the accepted images (IM1, IM2) on the UI screen. Essentially, the host-side control unit 110 accepts settings for the first image IM1 and the second image IM2 that can be displayed on the display device 115. For example, the host-side control unit 110 accepts any one of a plurality of images stored in the storage device 114, etc., as the first image IM1 via the input device 116, and accepts another image as the second image IM2 via the input device 116. If the original image is a three-dimensional or higher image, the host-side control unit 110 converts the original image into a binary image (IM1, IM2). In this manner, a first image IM1, comprising a relatively dark first portion PT1 and a relatively light second portion PT2, and a second image IM2, comprising a relatively dark third portion PT3 and a relatively light fourth portion PT4, are set. Simultaneously, the host-side control unit 110 also handles the setting of common colors in the images (IM1, IM2).

[0147] exist Figure 14 The image shows a first image IM1 with the text "WELCOME" and a second image IM2 with the text "THANKYOU".

[0148] like Figure 14 As shown, when the set second image IM2 is reversed, and a different appearance is displayed, in order to synthesize the images (IM1, IM2) as printing data PD1, it is necessary to reverse the second image IM2 horizontally or vertically. Therefore, the host-side control unit 110, as Figure 14 The process of inverting the second image IM2 is performed as shown (S204). The host-side control unit 110 inverts the second image IM2 horizontally when the second surface 202 of the printing medium 200 is inverted horizontally, and inverts the second image IM2 vertically when the second surface 202 of the printing medium 200 is inverted vertically. Figure 14 The image shows an example of a second image IM2 with "THANKYOU" being flipped horizontally through the inversion process of S204.

[0149] Next, as Figure 5As shown, the host-side control unit 110 divides the printing area A0, which merges the first image IM1 and the second image IM2, into four partial regions (AA, AB, AC, AD) (S206). As described above, in the first partial region AA, the darker portion of the first image IM1 overlaps with the lighter portion of the second image IM2; in the second partial region AB, the lighter portion of the first image IM1 overlaps with the lighter portion of the second image IM2; in the third partial region AC, the darker portion of the first image IM1 overlaps with the darker portion of the second image IM2; and in the fourth partial region AD, the lighter portion of the first image IM1 overlaps with the darker portion of the second image IM2.

[0150] Next, as Figure 5 , Figure 14 As shown, the host-side control unit 110 allocates ink injection volume IK and functional liquid injection volume FL to four partial regions (AA, AB, AC, AD), and generates printing data PD1 (S208) that combines the four partial regions (AA, AB, AC, AD). The host-side control unit 110 allocates a first ink injection volume IK1 and a first functional liquid injection volume FL1 to the first partial region AA, a second ink injection volume IK2 and a second functional liquid injection volume FL2 to the second partial region AB, a third ink injection volume IK3 and a third functional liquid injection volume FL3 to the third partial region AC, and a fourth ink injection volume IK4 and a fourth functional liquid injection volume FL4 to the fourth partial region AD.

[0151] Based on the above, the control unit 3, based on the first image IM1 and the inverted second image IM2, distributes the ink injection amount IK and the functional liquid injection amount FL to each part of the printing area A0. Furthermore, if referring to... Figure 6A To illustrate, control unit 3 allocates a first injection amount of 60% to the first functional liquid volume area AF1, a second injection amount of 5-10% to the second functional liquid volume area AF2, a third injection amount of 85% to the first ink volume area AI1, a fifth injection amount of 85-99% to the third ink volume area AI3, and a sixth injection amount of 65% to the fourth ink volume area AI4. If referring to... Figure 6B To illustrate, the control unit 3 allocates a first injection amount of 50-100% to the first functional liquid volume area AF1, a second injection amount of 10% to the second functional liquid volume area AF2, a third injection amount of 85-99% to the first ink volume area AI1, a fourth injection amount of 65% to the second ink volume area AI2, and a fifth injection amount of 85% to the third ink volume area AI3.

[0152] Finally, the host-side control unit 110 sends the printing data PD1 to the printing unit 2 (S210) and terminates the printing control process. The printing control unit 30 controls the print head 11 by ejecting ink 16 and functional liquid 26 onto the first surface 201 according to the injection amount (IK, FL) of each partial area contained in the printing data PD1. Ink 16 and functional liquid 26 are ejected onto the first surface 201 through nozzles (14a, 14b), thereby forming a first image IM1 on the first surface 201 containing a relatively dense first portion PT1 and a relatively light second portion PT2, and simultaneously forming a second image IM2 on the second surface 202 containing a relatively dense third portion PT3 and a relatively light fourth portion PT4. Figure 14 In the example shown, images (IM1, IM2) displaying "WELCOME" on the first side 201 of the medium 200 and "THANKYOU" on the second side 202 of the medium 200 are printed. In this way, the second image IM2 formed on the second side 202 is not an image obtained by inverting the first image IM1 formed on the first side 201, but an image that does not depend on the first image IM1.

[0153] As explained above, the second image IM2 formed on the second surface 202 of the medium 200 is not formed by spraying ink 16 onto the second surface 202, but by spraying ink 16 onto the first surface 201. Therefore, it can also be said that by spraying ink 16 onto only one side of the medium 200, an image is printed simultaneously on both sides of the medium 200. Thus, this embodiment, by spraying ink 16 onto only one side of the medium 200, enables the formation of the desired printed image on both sides of the medium 200. As a result, there is no need to flip the medium 200 or reverse its transport path, thereby reducing printing time and costs, and easily obtaining a printed product that approximates double-sided printing.

[0154] (4) When the functional liquid is a transparent ink: As described above, when the functional liquid 26 is a transparent ink, ink 16 can be either a pigment ink or a dye ink. (Refer to...) Figure 6AThe case where the functional ink 26 is a transparent ink will be explained. The injection amounts (IK, FL) for each region are set, for example, as follows: IK1=85%, FL1=5%, IK2=65%, FL2=10%, IK3=99%, FL3=10%, IK4=85%, and FL4=60%. In this way, the injection amount of the fourth functional ink FL4 in the fourth region AD is higher than the injection amount of the first functional ink FL1 in the first region AA. In the fourth region AD, where the injection amount of transparent ink in printing area A0 is higher, the ink 16 containing colored components easily penetrates into the medium 200 due to the greater amount of transparent ink. Therefore, the fourth region AD becomes a lighter portion in the first image IM1 and a darker portion in the second image IM2. Alternatively, ink 16 can be ejected from the first nozzle 14a before the transparent ink is ejected from the second nozzle 14b to the first surface 201, so that the colored components can easily penetrate from the first surface 201 to the second surface 202 in the medium 200. In the first part of the printing area A0, where the amount of transparent ink applied is relatively low, the ink 16 containing colored components tends to remain on the first surface 201 of the medium 200. Therefore, the first part of the printing area AA becomes a relatively dark part in the first image IM1 and a relatively light part in the second image IM2.

[0155] Based on the above, the density of each part of the image (IM1, IM2) on both sides of the medium 200 can be controlled according to the amount of transparent ink applied.

[0156] In addition, Figure 11 In the color mark selection result input screen 500 shown, it is preferable that the first functional liquid injection volume FL1 is less than the fourth functional liquid injection volume FL4. Therefore, the host-side control unit 110 may also display an error or control the operation to the OK button 509 to be infeasible when the input value of the first functional liquid injection volume FL1 is greater than or equal to the input value of the fourth functional liquid injection volume FL4, that is, when the input value of the fourth functional liquid injection volume FL4 is less than or equal to the input value of the first functional liquid injection volume FL1.

[0157] (5) The case where the ink is a dye ink and the functional liquid is a penetrating liquid: Reference Figure 6AThe following explanation addresses the case where ink 16 is a dye ink and functional liquid 26 is a penetrant. The injection amounts (IK, FL) for each region are set, for example, as follows: IK1 = 85%, FL1 = 5%, IK2 = 65%, FL2 = 10%, IK3 = 99%, FL3 = 10%, IK4 = 85%, and FL4 = 60%. In this manner, the injection amount of the fourth functional liquid FL4 in the fourth region AD is higher than the injection amount of the first functional liquid FL1 in the first region AA. In the fourth region AD, where the penetrant injection amount in printing region A0 is higher, the dye ink easily penetrates into the medium 200 due to the large amount of penetrant. Therefore, the fourth region AD appears lighter in the first image IM1 and darker in the second image IM2. Alternatively, the dye ink can be ejected from the first nozzle 14a before the penetrant is ejected from the second nozzle 14b to the first surface 201, so that the dye ink can easily penetrate from the first surface 201 to the second surface 202 in the medium 200. In the first part of the printing area A0, where the amount of penetrant injected is relatively low, the dye ink tends to remain on the first surface 201 of the medium 200. Therefore, in the first image IM1, the first part of the printing area AA becomes a relatively dense part, while in the second image IM2, the first part of the printing area AA becomes a relatively light part.

[0158] Based on the above, the density of each part of the image (IM1, IM2) can be controlled on both sides of the medium 200 according to the amount of permeate injected.

[0159] In addition, Figure 11 In the color mark selection result input screen 500 shown, it is preferable that the first functional liquid injection volume FL1 is less than the fourth functional liquid injection volume FL4. Therefore, the host-side control unit 110 may also display an error or control the operation to the OK button 509 to be infeasible when the input value of the first functional liquid injection volume FL1 is greater than or equal to the input value of the fourth functional liquid injection volume FL4, that is, when the input value of the fourth functional liquid injection volume FL4 is less than or equal to the input value of the first functional liquid injection volume FL1.

[0160] (6) The case where the second image is a full-page image: Figure 15 The method of generating and printing print data PD1, which combines a first image IM1 on the first side 201 and a full-page second image IM2 on the second side 202, is illustrated schematically. The second image IM2 is a full-page image with a specified density.

[0161] In the first step ST31, Figure 2The host-side control unit 110 shown performs a first process, which accepts settings for a first image IM1 formed on the first surface 201 of the medium 200 and a full-page second image IM2 formed on the second surface 202 of the medium 200. Step ST31 is an example of the first process ST1. The first image IM1 includes a first portion PT1 of a specified density and a second portion PT2 that is lighter than the first portion PT1. The second image IM2 is an image of the same density without the aforementioned fourth portion PT4 and with the aforementioned third portion PT3 extended as a whole. Therefore, it can be said that the first image IM1 and the second image IM2 have different density patterns.

[0162] In the second step ST32, the host-side control unit 110 divides the printing area A0, which merges the first image IM1 and the second image IM2, into a third part region AC corresponding to the first part PT1 and a fourth part region AD corresponding to the second part PT2. In the third part region AC, the denser portion of the first image IM1, PT1, overlaps with the second image IM2. In the fourth part region AD, the lighter portion of the first image IM1, PT2, overlaps with the second image IM2. The printing area A0 includes these part regions (AC, AD).

[0163] In the third step ST33, the host-side control unit 110 sets the second image IM2 as the third part PT3 and allocates ink injection amount IK and functional liquid injection amount FL to the two part areas (AC, AD). The host-side control unit 110 allocates a third ink injection amount IK3 and a third functional liquid injection amount FL3 to the third part area AC, and allocates a fourth ink injection amount IK4 and a fourth functional liquid injection amount FL4 to the fourth part area AD. For example, as Figure 6A As shown, the injection amounts (IK, FL) are set as follows: IK3 = 99%, FL3 = 10%, IK4 = 85%, and FL4 = 5%. Steps ST32 to ST33 are examples of the second process ST2.

[0164] In the fourth step ST34, the host-side control unit 110 combines the injection amounts (IK, FL) of the two partial areas (AC, AD) to generate print data PD1 and sends it to the printing unit 2. In the fifth step ST35, the print control unit 30 controls the print head 11 to spray ink 16 and functional liquid 26 onto the first surface 201 according to the injection amounts (IK, FL) allocated to the partial areas (AC, AD). Ink 16 and functional liquid 26 are sprayed onto the first surface 201 through nozzles (14a, 14b), thereby forming a first image IM1 on the first surface 201, and simultaneously forming a full-page second image IM2 on the second surface 202. Steps ST34 to ST35 are examples of the third process ST3.

[0165] Figure 15 The example shown can also form the desired printed image on both sides of the medium 200 by spraying ink 16 onto only one side of the medium 200.

[0166] (7) The case where the first image is a full-page image: Figure 16 The method of generating and printing print data PD1, which combines a full-page first image IM1 on the first side 201 and a second image IM2 on the second side 202, is illustrated schematically. The first image IM1 is a full-page image with a specified density.

[0167] In the first step ST41, Figure 2 The host-side control unit 110 shown performs a first process, which is to accept the setting of a full-page first image IM1 formed on the first surface 201 of the medium 200 and a second image IM2 formed on the second surface 202 of the medium 200. Step ST41 is an example of the first process ST1. The first image IM1 is an image without the second part PT2 and with the first part PT1 being expanded to the same density. The second image IM2 includes a third part PT3 of a specified density and a fourth part PT4 that is lighter than the third part PT3. Therefore, it can be said that the first image IM1 and the second image IM2 have different density patterns.

[0168] In the second step ST42, the host-side control unit 110 divides the printing area A0, which merges the first image IM1 and the second image IM2, into a first part region AA corresponding to the fourth part PT4 and a third part region AC corresponding to the third part PT3. In the first part region AA, the lighter fourth part PT4 in the second image IM2 overlaps with the first image IM1. In the third part region AC, the darker third part PT3 in the second image IM2 overlaps with the first image IM1. The printing area A0 includes these part regions (AA, AC).

[0169] In the third step ST43, the host-side control unit 110 sets the first image IM1 as the first portion PT1 and allocates ink injection amount IK and functional liquid injection amount FL to two portion areas (AA, AC). The host-side control unit 110 allocates the first ink injection amount IK1 and the first functional liquid injection amount FL1 to the first portion area AA, and allocates the third ink injection amount IK3 and the third functional liquid injection amount FL3 to the third portion area AC. For example, as Figure 6A As shown, the injection amounts (IK, FL) are set as follows: IK1 = 85%, FL1 = 60%, IK3 = 99%, and FL3 = 10%. Steps ST42 to ST43 are examples of the second process ST2.

[0170] In the fourth step ST44, the host-side control unit 110 combines the injection amounts (IK, FL) of the two partial areas (AA, AC) to generate print data PD1 and sends it to the printing unit 2. In the fifth step ST45, the print control unit 30 controls the print head 11 to spray ink 16 and functional liquid 26 onto the first surface 201 according to the injection amounts (IK, FL) allocated to the partial areas (AA, AC). Ink 16 and functional liquid 26 are sprayed onto the first surface 201 through nozzles (14a, 14b), thereby forming a full-page first image IM1 on the first surface 201, and simultaneously forming a second image IM2 on the second surface 202. Steps ST44 to ST45 are examples of the third process ST3.

[0171] Figure 16 The example shown can also form the desired printed image on both sides of the medium 200 by spraying ink 16 onto only one side of the medium 200.

[0172] (8) Variation example: Various variations of this invention can be cited.

[0173] For example, the medium is not limited to a long strip; it can also be a cut medium.

[0174] The color of ink 16 is not limited to C, M, Y, and K; it can also be orange, green, etc. Of course, the method of this application can still be applied even if the color of ink 16 does not include any of C, M, Y, and K.

[0175] The display section may replace the display device 115 of the main unit 100 or be provided on the printing section 2 together with the display device 115.

[0176] The entity performing the above processing is not limited to a CPU; it can also be an electronic component other than a CPU, such as an ASIC (Application Specific Integrated Circuit). Of course, multiple CPUs can work together to perform the above processing, or a CPU can work together with other electronic components (such as an ASIC) to perform the above processing.

[0177] The above processing allows for appropriate changes such as rearranging the order. For example, in Figure 12 In the injection volume setting process, the processing of S156 and S158 can be switched.

[0178] (9) Summary: As explained above, according to the present invention, various structures can be provided to form desired printed images on both sides of a medium by spraying ink onto only one side of the medium. Of course, even in a configuration consisting only of the structural elements involved in the technical solution, the aforementioned basic functions and effects can be achieved.

[0179] Furthermore, it is also possible to implement structures obtained by substituting or changing the various structures disclosed in the above examples, as well as structures obtained by substituting or changing the various structures disclosed in the prior art and the above examples. This invention also includes these structures.

[0180] Symbol Explanation 1…Printing system, 2…Printing section, 3…Control section, 10…Head unit, 11…Print head, 11A…Ink head, 11P…Functional liquid head, 14…Nozzle, 14a…First nozzle, 14b…Second nozzle, 16…Ink, 17…Ink droplet, 20…Driver, 26…Functional liquid, 27…Functional liquid droplet, 30…Printing control section, 40…Main scanning section, 50…Transport section, 100…Main unit, 110…Main unit-side control section, 114…Storage device, 115…Display device, 116…Input device, 180…Reading section, 200…Media, 201…First surface, 202…Second surface, 500…Color mark selection result input screen, A0…Printing area, AA…First part area, AB…Second part area, AC…Third part area, AD…Fourth part area, AF1…First functional liquid volume area, AF2…Second functional liquid volume area, AI1…First ink volume area AI2…Second ink volume area, AI3…Third ink volume area, AI4…Fourth ink volume area, FL…Functional liquid injection volume, FL1…First functional liquid injection volume, FL2…Second functional liquid injection volume, FL3…Third functional liquid injection volume, FL4…Fourth functional liquid injection volume, IK…Ink injection volume, IK1…First ink injection volume, IK2…Second ink injection volume, IK3…Third ink injection volume, IK4…Fourth ink injection volume, IM1…First image, IM2…Second image, PA0…Color mark, PD1…Printing data, PR0…Printing control program, PT1…First part, PT2…Second part, PT3…Third part, PT4…Fourth part, ST1…First process, ST2…Second process, ST3…Third process, ST4…Fourth process, ST5…Fifth process, ST6…Sixth process, TFL, TIK…Threshold, TP1…Test pattern.

Claims

1. A printing system for printing on a medium having a first side and a second side opposite to the first side, and comprising: A printhead having a first nozzle capable of spraying ink containing colored components onto a first surface, and a second nozzle capable of spraying a functional liquid onto the first surface that changes the color development state of the second surface achieved by the ink. The control unit controls the ejection of the ink and the functional liquid from the printhead. The amount of ink ejected from the first nozzle to each unit area of ​​the first surface is defined as the ink injection amount, and the amount of functional liquid ejected from the second nozzle to each unit area of ​​the first surface is defined as the functional liquid injection amount. The control unit performs the following processing: The first process is a process of accepting settings for forming a first image on the first surface and a second image on the second surface; The second process is to form the first image on the first surface and the second image on the second surface by spraying the ink and the functional liquid onto the first surface, thereby distributing the amount of ink and the amount of functional liquid sprayed onto each part of the printing area on the first surface where the ink and the functional liquid are sprayed, according to the concentration of the first image and the concentration of the second image. The third process involves controlling the printhead by spraying the ink and functional liquid onto the first surface according to the ink and functional liquid amounts allocated to each part of the printing area.

2. The printing system as claimed in claim 1, wherein, The first image includes a first portion of a predetermined density and a second portion that is lighter compared to the first portion. The second image includes a third portion of a predetermined concentration and a fourth portion that is lighter compared to the third portion. The printing area includes a first portion overlapping the first portion and the fourth portion, a second portion overlapping the second portion and the fourth portion, a third portion overlapping the first portion and the third portion, and a fourth portion overlapping the second portion and the third portion. In the second process, the control unit allocates a first ink injection amount as the ink injection amount and a first functional liquid injection amount as the functional liquid injection amount to the first partial region, allocates a second ink injection amount as the ink injection amount and a second functional liquid injection amount as the functional liquid injection amount to the second partial region, allocates a third ink injection amount as the ink injection amount and a third functional liquid injection amount as the functional liquid injection amount to the third partial region, and allocates a fourth ink injection amount as the ink injection amount and a fourth functional liquid injection amount as the functional liquid injection amount to the fourth partial region.

3. The printing system as described in claim 2, wherein, The control unit further performs the following processing: The fourth process is a process of controlling the printhead by forming test patterns on the medium, including multiple color marks with different combinations of ink injection amount and functional liquid injection amount. The fifth process involves receiving an input of a selection result from the plurality of color marks that corresponds to a portion of the region selected from the first portion region, the second portion region, the third portion region, and the fourth portion region, and allocating the ink application amount and functional liquid application amount corresponding to the selection result to the portion of the region.

4. The printing system as claimed in claim 2, wherein, The control unit further performs the following processing: The fourth process is a process of controlling the printhead by forming test patterns on the medium, including multiple color marks with different combinations of ink injection amount and functional liquid injection amount. The sixth process is a process that determines at least a portion of the first ink injection amount, the first functional liquid injection amount, the second ink injection amount, the second functional liquid injection amount, the third ink injection amount, the third functional liquid injection amount, the fourth ink injection amount, and the fourth functional liquid injection amount based on a first reading result obtained by the reading unit from the concentration of each of the color marks formed on the first surface, and a second reading result obtained by the reading unit from the concentration of each of the color marks formed on the second surface.

5. The printing system according to any one of claims 2 to 4, wherein, The ink is a pigment ink containing dispersed pigments as the colored component. The functional liquid is a treatment liquid containing a coagulant that causes the pigment to agglomerate. The amount of the fourth functional liquid injected in the fourth part of the region is lower than the amount of the first functional liquid injected in the first part of the region.

6. The printing system according to any one of claims 2 to 4, wherein, The functional liquid is a transparent ink that does not contain the colored component. The amount of the fourth functional liquid injected in the fourth part of the region is higher than the amount of the first functional liquid injected in the first part of the region.

7. The printing system according to any one of claims 2 to 4, wherein, The ink is a dye ink that contains dye as a colored component. The functional liquid is a penetrating liquid used to assist the dye ink in penetrating into the medium. The amount of the fourth functional liquid injected in the fourth part of the region is higher than the amount of the first functional liquid injected in the first part of the region.

8. The printing system according to any one of claims 1 to 4, wherein, In the first process, the control unit is capable of displaying the first image and the second image on the display unit, and accepts settings for displaying the first image and the second image on the display unit. In the second process, the control unit reverses the second image and distributes the ink injection amount and the functional liquid injection amount to each part of the printing area based on the first image and the reversed second image.

9. The printing system of claim 1, wherein, The printing area includes a first functional liquid volume area where the functional liquid injection amount is a first injection amount, and a second functional liquid volume area where the functional liquid injection amount is a second injection amount that is lower than the first injection amount. In the second process, the control unit allocates the first injection amount to the first functional liquid volume area and allocates the second injection amount to the second functional liquid volume area.

10. The printing system of claim 9, wherein, The first functional liquid volume region includes a first ink volume region where the ink injection amount is a third injection amount, and a second ink volume region where the ink injection amount is a fourth injection amount that is lower than the third injection amount. In the second process, the control unit allocates the third injection amount to the first ink quantity region and the fourth injection amount to the second ink quantity region.

11. The printing system of claim 9 or claim 10, wherein, The second functional liquid volume region includes a third ink volume region where the ink injection amount is a fifth injection amount, and a fourth ink volume region where the ink injection amount is a sixth injection amount that is lower than the fifth injection amount. In the second process, the control unit allocates the fifth ink injection amount to the third ink quantity region and the sixth ink injection amount to the fourth ink quantity region.

12. A printing method comprising spraying ink containing a colored component from a first nozzle of a printhead onto a first surface of a medium and spraying a functional liquid from a second nozzle of the printhead onto the first surface, wherein... The medium has a second side that is opposite to the first side. The functional liquid causes a change in the color development state of the second surface, which is achieved by the ink. The amount of ink ejected from the first nozzle to each unit area of ​​the first surface is defined as the ink injection amount, and the amount of functional liquid ejected from the second nozzle to each unit area of ​​the first surface is defined as the functional liquid injection amount. The printing method includes the following steps: The first step involves accepting settings for forming a first image on the first surface and a second image on the second surface; In the second process, in order to form the first image on the first surface and the second image on the second surface by spraying the ink and the functional liquid onto the first surface, the amount of ink and the amount of functional liquid are allocated according to the concentration of the first image and the concentration of the second image for each part of the printing area on the first surface where the ink and the functional liquid are sprayed. In the third step, the ink and the functional liquid are sprayed from the print head toward the first surface according to the ink injection amount and the functional liquid injection amount allocated to each part of the printing area.

Images