Printer, control method, and control program

Abstract

To provide a printer, a control method, and a control program capable of contributing to suppression of peeling off of a formed ink layer from a medium while suppressing degradation of image quality.SOLUTION: A printer performs printing to a permeable medium. The printer is provided with: a first head discharging first ink; a second head discharging second ink; an intermediate discharge part discharging an intermediate processing liquid that condenses the second ink; and a control part. The control part discharges from the first head the first ink to a medium to which preprocessing liquid condensing the first ink is discharged (S22). The control part discharges from the intermediate discharge part the intermediate processing liquid to the medium to which the first ink is discharged (S23). The control part discharges from the second head the second ink to the medium to which the intermediate processing liquid is discharged (S24).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a printer, a control method, and a control program. [Background technology]

[0002] The textile printing apparatus described in Patent Document 1 includes a pretreatment liquid application device and an ink ejection unit. The pretreatment liquid application device ejects a pretreatment liquid onto a medium to aggregate the ink. The ink ejection unit ejects ink onto the medium onto which the pretreatment liquid has been ejected by the pretreatment liquid application device. This forms an ink layer on the medium, thereby printing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-193943 Summary of the Invention [Problem to be solved by the invention]

[0004] If the medium is permeable, if a large amount of pretreatment liquid is ejected onto the medium by the pretreatment liquid application device, the pretreatment liquid may not fully penetrate the medium, causing the incompletely penetrated pretreatment liquid to overflow from the surface of the medium. If the pretreatment liquid overflows from the surface of the medium, components in the pretreatment liquid that cause ink to aggregate may remain on the surface of the medium. If ink is ejected onto the medium from the ink ejection unit while components that cause ink to aggregate remain on the surface of the medium, the components that cause ink to aggregate may cause the ink to aggregate on the surface of the medium. If the ink aggregates on the surface of the medium, the formed ink layer will be less likely to adhere to the medium, making the formed ink layer more likely to peel off from the medium. On the other hand, if the amount of pretreatment liquid ejected onto the medium by the pretreatment liquid application device is reduced, the image quality due to the formed ink layer may be degraded.

[0005] An object of the present invention is to provide a printer, a control method, and a control program that contribute to preventing a formed ink layer from peeling off from a medium while suppressing a deterioration in image quality. [Means for solving the problem]

[0006] A printer according to a first aspect of the present invention is a printer that prints on a permeable medium, and includes a first head that ejects a first ink, a second head that ejects a second ink, an intermediate ejection unit that ejects an intermediate treatment liquid that aggregates the second ink, and a control unit, wherein the control unit performs a first ejection process of ejecting the first ink from the first head onto the medium onto which a pretreatment liquid that aggregates the first ink has been ejected, an intermediate ejection process of ejecting the intermediate treatment liquid from the intermediate ejection unit onto the medium onto which the first ink has been ejected by the first ejection process, and a second ejection process of ejecting the second ink from the second head onto the medium onto which the intermediate treatment liquid has been ejected by the intermediate ejection process.

[0007] According to the first aspect, by reducing the amount of pretreatment liquid ejected onto the medium, the possibility that components in the pretreatment liquid that cause the first ink to aggregate remain on the surface of the medium is reduced. This reduces the likelihood that the formed first ink layer will peel off from the medium. Even if the amount of pretreatment liquid ejected onto the medium is reduced, the first ink will aggregate due to the intermediate treatment liquid in addition to the pretreatment liquid, thereby reducing degradation of image quality. Therefore, the printer contributes to reducing degradation of image quality while also reducing the likelihood that the formed first ink layer will peel off from the medium.

[0008] The printer may include a pre-ejection unit that ejects the pretreatment liquid, the control unit may perform a pre-ejection process of ejecting the pretreatment liquid from the pre-ejection unit onto the medium, and in the first ejection process, the first ink may be ejected from the first head onto the medium onto which the pretreatment liquid has been ejected by the pre-ejection process. In this case, because the printer includes the pre-ejection unit, the printer contributes to omitting a process in which the medium onto which the pretreatment liquid has been ejected is transported from another device to the printer.

[0009] In the printer, the intermediate discharge unit may discharge the intermediate treatment liquid, which is the same liquid as the pretreatment liquid. In this case, the printer contributes to reducing the number of types of liquid used.

[0010] In the printer, the control unit may selectively perform the pre-discharge process and the intermediate discharge process in which a ratio of an intermediate discharge amount, which is an amount of the intermediate treatment liquid discharged by the intermediate discharge unit in the intermediate discharge process, to a pre-discharge amount, which is an amount of the pretreatment liquid discharged by the pre-discharge unit in the pre-discharge process, is a first treatment liquid ratio, and the pre-discharge process and the intermediate discharge process in which the ratio of the intermediate discharge amount to the pre-discharge amount is a second treatment liquid ratio different from the first treatment liquid ratio. In this case, the printer contributes to further suppressing deterioration in image quality and suppressing peeling of the formed first ink layer from the medium, compared to when the ratio of the intermediate discharge amount to the pre-discharge amount is constant.

[0011] In the printer, the control unit may eject a pre-ejection amount of the pretreatment liquid less than an intermediate ejection amount onto the medium from the pre-ejection unit in the pre-ejection process, and eject the intermediate ejection amount of the intermediate treatment liquid onto the medium from the intermediate ejection unit in the intermediate ejection process. In this case, compared to when the pre-ejection amount exceeds the intermediate ejection amount, the possibility of components in the pretreatment liquid that cause the first ink to aggregate remaining on the surface of the medium is reduced. This reduces the likelihood of the formed first ink layer peeling off from the medium. Therefore, the printer contributes to reducing the likelihood of the formed first ink layer peeling off from the medium.

[0012] In the printer, the control unit may perform the pre-discharge process, the intermediate discharge process, the first discharge process, and the second discharge process such that a ratio of an intermediate discharge amount, which is the amount of the intermediate treatment liquid discharged by the intermediate discharge unit in the intermediate discharge process, to a pre-discharge amount, which is the amount of the pretreatment liquid discharged by the pre-discharge unit in the pre-discharge process, is the same as a ratio of a second discharge amount, which is the amount of the second ink discharged by the second head in the second discharge process, to a first discharge amount, which is the amount of the first ink discharged by the first head in the first discharge process. In this case, the printer contributes to reducing the possibility of a discrepancy between the aggregation state of the first ink and the aggregation state of the second ink, compared to a case in which the ratio of the intermediate discharge amount to the pre-discharge amount is different from the ratio of the second discharge amount to the first discharge amount.

[0013] In the printer, the second head may eject the second ink, which is the same ink as the first ink. In this case, the printer contributes to reducing the number of types of ink used.

[0014] The printer may include a third head that ejects color inks, and the control unit may perform a third ejection process in which the color inks are ejected from the third head onto the medium onto which the second ink has been ejected by the second ejection process, thereby printing a color image. In this case, the color image is printed on a layer of the second ink. Thus, the printer contributes to preventing the formed layers of the first ink and second ink from peeling off from the medium while improving the color development of the color image.

[0015] In the printer, the control unit may selectively perform the first ejection process and the second ejection process in which a ratio of a second ejection amount, which is an amount of the second ink ejected by the second head in the second ejection process, to a first ejection amount, which is an amount of the first ink ejected by the first head in the first ejection process, is a first ink ratio, or the first ejection process and the second ejection process in which a ratio of the second ejection amount to the first ejection amount is a second ink ratio. In this case, the printer contributes to further suppressing peeling of the formed first ink layer from the medium while suppressing deterioration in image quality, compared to when the ratio of the second ejection amount to the first ejection amount is constant.

[0016] In the printer, the control unit may eject a first ejection amount of the first ink onto the medium using the first head in the first ejection process, and eject a second ejection amount of the second ink onto the medium using the second head in the second ejection process, the second ejection amount being greater than the first ejection amount. In this case, the layer of the second ink becomes thicker than when the second ejection amount is less than the first ejection amount. This contributes to improving the color development of the layer of the second ink.

[0017] In the printer, the pre-ejection unit and the intermediate ejection unit may be the same ejection unit, which contributes to preventing the printer from becoming larger than when the printer is provided with a separate pre-ejection unit and intermediate ejection unit.

[0018] In the printer, the first head and the second head may be the same head, which contributes to preventing the printer from becoming larger than when the printer is provided with separate first and second heads.

[0019] A control method according to a second aspect of the present invention is a control method for a printer that prints on a permeable medium, and is characterized by comprising a first ejection process of ejecting a first ink onto the medium onto which a pretreatment liquid that aggregates the first ink has been ejected, an intermediate ejection process of ejecting an intermediate treatment liquid that aggregates the second ink onto the medium onto which the first ink has been ejected by the first ejection process, and a second ejection process of ejecting the second ink onto the medium onto which the intermediate treatment liquid has been ejected by the intermediate ejection process.

[0020] The second aspect contributes to the same effect as the first aspect.

[0021] A control program according to a third aspect of the present invention is characterized in that it causes a computer that controls a printer that includes a first head that ejects a first ink, a second head that ejects a second ink, and an intermediate ejection unit that ejects an intermediate treatment liquid that aggregates the first ink and that prints on a permeable medium to execute a first ejection process of ejecting the first ink from the first head onto the medium onto which a pretreatment liquid that aggregates the second ink has been ejected, an intermediate ejection process of ejecting the intermediate treatment liquid from the intermediate ejection unit onto the medium onto which the first ink has been ejected by the first ejection process, and a second ejection process of ejecting the second ink from the second head onto the medium onto which the intermediate treatment liquid has been ejected by the intermediate ejection process.

[0022] The third aspect contributes to the same effect as the first aspect. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic plan view of a printer 1. [Figure 2] FIG. 2 is a schematic right side view of the printer 1. [Figure 3] 2 is a block diagram showing the electrical configuration of the printer 1. FIG. [Figure 4] 10 is a flowchart of a main process. [Figure 5] 10A and 10B are diagrams showing the flow of stacking onto the medium M in the main process. [Figure 6] FIG. 9 is a conceptual diagram of a setting table 921. DETAILED DESCRIPTION OF THE INVENTION

[0024] A printer 1 according to one embodiment of the present invention will be described with reference to the drawings. The left, right, bottom, and top of Fig. 1 correspond to the left, right, front, and rear of the printer 1, respectively. The left, right, bottom, and top of Fig. 2 correspond to the front, rear, bottom, and top of the printer 1, respectively.

[0025] The schematic configuration of printer 1 will be described with reference to Figures 1 and 2. Printer 1 is an inkjet printer that prints on medium M. Medium M is fabric, paper, etc. For example, medium M is a T-shirt. Printer 1 includes a platen transport mechanism 11, a platen 7, a head transport mechanism 12, multiple heads 10, and a pretreatment spray 6.

[0026] The platen transport mechanism 11 includes a pair of guide rails 111, 112 and a support base 8. The pair of guide rails 111, 112 extend in the front-rear direction and are aligned with each other in the left-right direction. The pair of guide rails 111, 112 are fixed to a frame (not shown) of the printer 1. The support base 8 is supported by the pair of guide rails 111, 112. The support base 8 moves in the front-rear direction along the pair of guide rails 111, 112. A platen 7 is attached to the upper end of the support base 8. The platen transport mechanism 11 transports the platen 7 in the front-rear direction by driving a sub-scanning motor 14 shown in FIG. 3 (see arrow Y2). Therefore, the front-rear direction of the printer 1 is the sub-scanning direction. The platen 7 has a plate shape and extends in the front-rear and left-right directions. A loading surface 71 is formed on the upper surface of the platen 7. The medium M is placed on the loading surface 71 and set on the platen 7.

[0027] The head transport mechanism 12 includes a pair of guide rails 121, 122 and a carriage 2. The pair of guide rails 121, 122 each extend in the left-right direction and are aligned with each other in the front-to-rear direction. The pair of guide rails 121, 122 are fixed to a frame (not shown) of the printer 1. The carriage 2 is plate-shaped and extends in the front-to-rear and left-to-right directions. The carriage 2 is supported by the pair of guide rails 121, 122. The carriage 2 moves left-to-right along the pair of guide rails 121, 122. Multiple heads 10 are mounted on the carriage 2. The head transport mechanism 12 transports the multiple heads 10 left-to-right by driving a main scanning motor 13 shown in FIG. 3 (see arrow Y1). Therefore, the left-to-right direction of the printer 1 is the main scanning direction.

[0028] The multiple heads 10 have a rectangular parallelepiped shape, and in this embodiment, include a white head 3, a color head 4, and a post-processing head 5. The white head 3, color head 4, and post-processing head 5 are arranged in a line from front to rear in the order of color head 4, post-processing head 5, white head 3.

[0029] Multiple nozzle rows are formed on the underside of the white head 3. Each of the multiple nozzle rows of the white head 3 has multiple nozzles 31. The multiple nozzles 31 are aligned in the front-to-rear direction. The multiple nozzle rows of the white head 3 are aligned in the left-to-right direction. Multiple nozzle rows are formed on the underside of the color head 4. Each of the multiple nozzle rows of the color head 4 has multiple nozzles 41. The multiple nozzles 41 are aligned in the front-to-rear direction. The multiple nozzle rows of the color head 4 are aligned in the left-to-right direction. Multiple nozzle rows are formed on the underside of the post-processing head 5. Each of the multiple nozzle rows of the post-processing head 5 has multiple nozzles 41. The multiple nozzles 41 are aligned in the front-to-rear direction. The multiple nozzle rows of the post-processing head 5 are aligned in the left-to-right direction. The undersides of the white head 3, color head 4, and post-processing head 5 are located above the mounting surface 71 of the platen 7 and are exposed downward from openings (not shown) provided in the carriage 2.

[0030] White ink is supplied from a white ink container (not shown) to the white head 3. The white head 3 ejects white ink downward from a plurality of nozzles 31. The white ink forms the base of a color image or represents white portions in a color image.

[0031] The color head 4 is supplied with color inks (cyan, magenta, yellow, and black) from multiple color ink containers (not shown). The color head 4 ejects the color inks downward from multiple nozzles 41. For example, the multiple nozzles 41 are divided into a first nozzle row, a second nozzle row, a third nozzle row, and a fourth nozzle row. Cyan color ink is ejected from the first nozzle row of the multiple nozzles 41, magenta color ink is ejected from the second nozzle row of the multiple nozzles 41, yellow ink is ejected from the third nozzle row of the multiple nozzles 41, and black ink is ejected from the fourth nozzle row of the multiple nozzles 41. The color inks form a color image.

[0032] The post-treatment head 5 is supplied with post-treatment liquid from a post-treatment liquid container (not shown). The post-treatment head 5 ejects the post-treatment liquid downward from multiple nozzles 51. The post-treatment liquid is a coating liquid that protects the color image. The post-treatment liquid improves the glossiness of the color image. The post-treatment liquid is ejected onto the color image after printing on the medium M. The post-treatment liquid is an aqueous solution containing a resin emulsion, an aqueous solution containing a cross-linking agent, or the like.

[0033] The pretreatment spray 6 is disposed on the movement path of the platen 7, ahead of the movement paths of the multiple heads 10. The pretreatment spray 6 extends in the left-right direction from left of the left end of the platen 7 to right of the right end of the platen 7, and is fixed to a frame (not shown) of the printer 1. Multiple nozzles 61 are formed on the underside of the pretreatment spray 6. The multiple nozzles 61 are aligned in the left-right direction. The underside of the pretreatment spray 6 is located above the mounting surface 71 of the platen 7. The pretreatment spray 6 is supplied with pretreatment liquid from a pretreatment liquid container (not shown). The pretreatment spray 6 ejects the pretreatment liquid downward from the multiple nozzles 61. In this embodiment, the pretreatment liquid ejected by the pretreatment spray 6 reaches from the left end to the right end of the platen 7 in the left-right direction.

[0034] The pretreatment liquid is an aqueous solution containing an aggregating component, which improves the color development of the white ink. The aggregating component aggregates the solid components in the white ink. Hereinafter, aggregating the solid components in the white ink will also be simply referred to as "aggregating the white ink." The pretreatment liquid aggregates the white ink, thereby fixing the solid components in the white ink to the medium M. The solid components in the white ink are, for example, the pigment or resin components in the white ink. The aggregating component is a cationic polymer, a polyvalent metal salt, a carboxylic acid, etc. The polyvalent metal salt is a calcium salt, a magnesium salt, etc. The carboxylic acid is formic acid, acetic acid, etc.

[0035] As shown in FIG. 2, the platen 7 is transported in the front-to-rear direction between a front end position P1 and a rear end position P2 by a platen transport mechanism 11. At the front end position P1, the platen 7 is positioned forward of the pre-treatment spray 6, and at the rear end position P2, it is positioned rearward of the white head 3. The platen 7 is transported rearward from the front end position P1 toward the rear end position P2, and then turns back forward at the rear end position P2. The platen 7 is transported forward from the rear end position P2 toward the front end position P1, and then turns back backward at the front end position P1. For example, a medium M is set on the platen 7 when the platen 7 is positioned at the front end position P1.

[0036] In a plan view, the movement paths of the multiple heads 10 and the movement path of the platen 7 intersect with each other (see arrows Y1 and Y2 in FIG. 1 ). When the multiple heads 10 and the platen 7 are arranged in an area where the movement paths of the multiple heads 10 and the movement path of the platen 7 intersect with each other in a plan view, at least one of the lower surfaces of the white head 3, the color head 4, and the post-processing head 5 and the mounting surface 71 of the platen 7 face each other in the vertical direction, with the medium M between them. Hereinafter, the state in which at least one of the lower surfaces of the white head 3, the color head 4, and the post-processing head 5 and the mounting surface 71 of the platen 7 face each other in the vertical direction, with the medium M between them, will be referred to as the "facing state."

[0037] The operation of moving the multiple heads 10 in the left-right direction while facing each other and causing the heads 10 to eject liquid is called the "ejection scan of the heads 10." For example, the ejection scan of moving the white head 3 in the left-right direction while facing each other and causing the white head 3 to eject white ink from the nozzles 31 is called the "ejection scan of the white head 3." The operation of moving the platen 7 from front to rear or rear to front is called the "sub-scan of the platen 7 from front to rear" or the "sub-scan of the platen 7 from rear to front." The printer 1 prints on the medium M by repeating the ejection scan of the heads 10 and the sub-scan of the platen 7 a predetermined amount from one side to the other in the front-to-rear direction.

[0038] The electrical configuration of the printer 1 will be described with reference to FIG. 3. The printer 1 includes a CPU 91 and a memory 92. The CPU 91 and the memory 92 are electrically connected to each other. The CPU 91 controls the printer 1. The memory 92 includes volatile memory and non-volatile memory, and stores various information. For example, the memory 92 stores programs, print data, and a setting table 921 (see FIG. 6) described below. The programs include a control program for executing the main processing (see FIG. 4) described below, and are executed by the CPU 91. The print data includes image data, and indicates the area of the medium M where the base is to be printed, the area of the medium M where the color image is to be printed, the total amount of white ink to be ejected (described below), etc.

[0039] The CPU 91 is electrically connected to the main scanning motor 13, sub-scanning motor 14, white head drive unit 30, color head drive unit 40, post-processing head drive unit 50, spray drive unit 60, display 97, and operation unit 98. The main scanning motor 13 transports the plurality of heads 10 in the left-right direction together with the carriage 2 under the control of the CPU 91. The sub-scanning motor 14 transports the platen 7 in the front-rear direction together with the support base 8 under the control of the CPU 91.

[0040] The white head driver 30 is, for example, a heating element or a piezoelectric element, and is provided corresponding to each of the multiple nozzles 31. The white head driver 30 is controlled by the CPU 91 to cause the white head 3 to selectively eject white ink from the multiple nozzles 31. The color head driver 40 is, for example, a heating element or a piezoelectric element, and is provided corresponding to each of the multiple nozzles 41. The color head driver 40 is controlled by the CPU 91 to cause the color head 4 to selectively eject color ink from the multiple nozzles 41.

[0041] The post-treatment head driver 50 is, for example, a heating element or a piezoelectric element, and is provided corresponding to each of the plurality of nozzles 51. The post-treatment head driver 50 causes the post-treatment head 5 to selectively eject the post-treatment liquid from the plurality of nozzles 51 under the control of the CPU 91. The spray driver 60 is, for example, a compressor for sending compressed air to the pre-treatment spray 6. The spray driver 60 causes the pre-treatment spray 6 to eject the pre-treatment liquid from the plurality of nozzles 61 under the control of the CPU 91.

[0042] The display 97 displays various screens under the control of the CPU 91. The operation unit 98 is, for example, a button or touch panel, and outputs a signal to the CPU 91 in response to an operation by the user. For example, the user can operate the operation unit 98 to input a print instruction to the printer 1 to cause the printer 1 to print based on print data. The print instruction specifies the print data to be controlled.

[0043] The main processing will be described with reference to FIG. 4, and the order in which layers are formed on the medium M by the main processing will be described with reference to FIG. 5. With the medium M set on the platen 7, the user operates the operation unit 98 to input a print instruction to the printer 1. When the CPU 91 receives the print instruction, it starts the main processing. In this embodiment, it is assumed that the main processing starts with the platen 7 positioned at the front end position P1.

[0044] In the main process, so-called wet-on-wet printing is controlled, in which ink is ejected onto a medium M that is wetted with a pretreatment liquid. In this embodiment, the medium M is permeable. For example, the medium M is permeable when it contains polyester fiber. Wet-on-wet printing is performed when the medium M is permeable, improving the fixation of the white ink. As shown in state A1 in FIG. 5, at the start of the main process, no layer is formed on the medium M.

[0045] 4, when the main processing starts, the CPU 91 performs a setting acquisition process (S11). In the setting acquisition process (S11), the CPU 91 refers to the setting table 921 shown in FIG. 6 and acquires a setting number, which will be described later.

[0046] As shown in FIG. 6, the setting table 921 has a "Setting No." column, a "Media Thickness" column, an "Ink Ratio" column, and a "Treatment Liquid Ratio" column, which are associated with each other. The setting No. is an identifier for distinguishing between each setting type. In this embodiment, setting 1, setting 2, and setting 3 are defined in the setting No. column. The media thickness indicates the range of thickness of the medium M. In this embodiment, small, medium, and large are defined in the media thickness column. Small indicates that the thickness of the medium M is less than a predetermined first thickness (for example, 0.5 mm). Large indicates that the thickness of the medium M exceeds a predetermined second thickness (for example, 2 mm). Medium indicates that the thickness of the medium M is equal to or greater than the first thickness and equal to or less than the second thickness.

[0047] The ink ratio is the ratio of the second ejection amount to the first ejection amount (second ejection amount:first ejection amount). The first ejection amount is the amount of white ink ejected from the white head 3 in the first base printing process (S22) described below. The second ejection amount is the amount of white ink ejected from the white head 3 in the second base printing process (S24) described below. In this embodiment, the first ink ratio, second ink ratio, and third ink ratio are defined in the ink ratio column. The first ink ratio, second ink ratio, and third ink ratio are different ratios from each other. For example, the first ink ratio is "80:20" or "4". The second ink ratio is "70:30" or "7 / 3". The third ink ratio is "60:40" or "1.5".

[0048] The treatment liquid ratio is the ratio of the intermediate discharge amount to the pre-discharge amount (intermediate discharge amount: pre-discharge amount). The pre-discharge amount is the amount of pre-treatment liquid discharged by the pre-treatment spray 6 by the pre-discharge process (S21) described below. The intermediate discharge amount is the amount of pre-treatment liquid discharged by the pre-treatment spray 6 by the intermediate discharge process (S23) described below. In this embodiment, the treatment liquid ratio column specifies a first treatment liquid ratio, a second treatment liquid ratio, and a third treatment liquid ratio. The first treatment liquid ratio, the second treatment liquid ratio, and the third treatment liquid ratio are different ratios from one another. For example, the first treatment liquid ratio is 80:20, which is "4". The second treatment liquid ratio is "70:30", which is "7 / 3". The third treatment liquid ratio is "60:40", which is "1.5".

[0049] According to the setting table 921, in each of Settings 1, 2, and 3, the treatment liquid ratio is set to the same ratio as the ink ratio. That is, the first treatment liquid ratio (4) is the same as the first ink ratio (4), the second treatment liquid ratio (7 / 3) is the same as the second ink ratio (7 / 3), and the third treatment liquid ratio (1.5) is the same as the third ink ratio (1.5). The ink ratios are set to a ratio exceeding "1." That is, the second ejection volume exceeds the first ejection volume. The treatment liquid ratio is set to a ratio exceeding "1." That is, the intermediate ejection volume exceeds the pre-ejection volume. According to the configuration of the ink ratios in the setting table 921, as the thickness of the medium M increases in the order of "small," "medium," and "large," the ratios decrease in the order of "4," "7 / 3," and "1.5." According to the configuration of the treatment liquid ratios in the setting table 921, as the thickness of the medium M increases in the order of "small," "medium," and "large," the ratios decrease in the order of "4," "7 / 3," and "1.5."

[0050] In the setting acquisition process (S11), the CPU 91 identifies the thickness of the medium M. An example of how the CPU 91 identifies the thickness of the medium M will be described. The CPU 91 may identify the thickness of the medium M based on a signal from a sensor (not shown) for detecting the thickness of the medium M. Alternatively, if the user operates the operation unit 98 to input the thickness of the medium M to the printer 1, the CPU 91 may identify the thickness of the medium M based on the input information. In the setting acquisition process (S11), the CPU 91 acquires the setting number corresponding to the identified thickness of the medium M. For example, if the thickness of the medium M is "small", the CPU 91 acquires setting 1.

[0051] 4, after the setting acquisition process (S11), the CPU 91 performs a calculation process (S12). Hereinafter, the sum of the first ejection amount and the second ejection amount will be referred to as the "total amount of white ink ejection," and the sum of the pre-ejection amount and the intermediate ejection amount will be referred to as the "total amount of treatment liquid ejection."

[0052] In the calculation process (S12), the CPU 91 identifies the total amount of white ink ejection based on, for example, print data. The CPU 91 calculates the first ejection amount and the second ejection amount based on the identified total amount of white ink ejection and the ink ratio according to the acquired setting number. For example, if the total amount of white ink ejection is 200 mL and the acquired setting number is setting 1, the first ejection amount will be 40 mL and the second ejection amount will be 160 mL.

[0053] In the calculation process (S12), the CPU 91 acquires the total amount of treatment liquid discharged from the memory 92. The total amount of treatment liquid discharged is, for example, stored in advance in the memory 92. The CPU 91 calculates the pre-discharge amount and the intermediate discharge amount based on the acquired total amount of treatment liquid discharged and the treatment liquid ratio corresponding to the acquired setting number. For example, if the total amount of treatment liquid discharged is 100 mL and the acquired setting number is setting 1, the pre-discharge amount will be 20 mL and the intermediate discharge amount will be 80 mL.

[0054] After the calculation process (S12), the CPU 91 performs a pre-discharge process (S21). In the pre-discharge process (S21), the CPU 91 causes the pre-treatment spray 6 to discharge the pre-treatment liquid while the platen 7 is sub-scanned from the front to the rear from the front end position P1 to the rear end position P2. The pre-treatment liquid discharged from the pre-treatment spray 6 adheres to the entire medium M on the platen 7 in the left-right direction, from the left end to the right end, for example. When the entire medium M in the front-to-rear direction from the rear end to the front end passes directly under the pre-treatment spray 6, the pre-treatment liquid is discharged onto the entire medium M. In the pre-discharge process (S21), the CPU 91 causes the pre-discharge amount of pre-treatment liquid calculated in the calculation process (S12) to be discharged from the pre-treatment spray 6.

[0055] 5, when the pre-ejection process (S21) is performed, a first pre-treatment layer S1 is formed on the medium M. The first pre-treatment layer S1 is a layer of the pre-treatment liquid, and is formed by the pre-treatment liquid permeating into the medium M.

[0056] 4, after the pre-ejection process (S21), the CPU 91 performs a first base printing process (S22). The first base printing process (S22) is performed in a state in which the medium M is wet with the pretreatment liquid by the pre-ejection process (S21). In other words, the first base printing process (S22) is performed before the moisture in the pretreatment liquid that has permeated the medium M by the pre-ejection process (S21), i.e., the moisture in the first pretreatment layer S1, has completely evaporated.

[0057] In the first base printing process (S22), the CPU 91 repeats ejection scans of the white head 3 and sub-scans of the platen 7 from rear to front a predetermined amount based on the print data. As a result, the white head 3 ejects white ink onto the medium M on the platen 7 that has been wet with the ejected pretreatment liquid ejected in the pre-ejection process (S21). The white ink ejected from the white head 3 lands on the medium M. The CPU 91 transports the platen 7 from the rear end position P2 to the front end position P1 by repeatedly sub-scanning the platen 7 from rear to front a predetermined amount. In the first base printing process (S22), the CPU 91 causes the white head 3 to eject the first ejection amount of white ink calculated in the calculation process (S12).

[0058] As shown in state A3 in FIG. 5, when the first base printing process (S22) is performed, a first base W1 is printed in the area of the medium M where base printing is planned. The first base W1 is a layer of white ink and is formed on the first pretreatment layer S1. A portion of the first base W1 penetrates into the medium M. As a result, a coagulation layer WS is formed at the contact area between the first base W1 and the first pretreatment layer S1. The coagulation layer WS is a layer in which the white ink and the pretreatment liquid mix together, and is formed below the surface of the medium M. In the coagulation layer WS, the white ink coagulates while entangled with the fibers of the medium M. This promotes fixation of the first base W1 to the medium M.

[0059] As shown in FIG. 4, after the first base printing process (S22), the CPU 91 performs an intermediate discharge process (S23). In the intermediate discharge process (S23), the CPU 91 causes the pretreatment spray 6 to discharge pretreatment liquid while performing a sub-scan of the platen 7 from front to rear from the leading edge position P1 to the trailing edge position P2. As a result, the pretreatment liquid is discharged from the pretreatment spray 6 onto the medium M on the platen 7 onto which the white ink was discharged in the first base printing process (S22). The pretreatment liquid discharged from the pretreatment spray 6 adheres to the entire medium M in the left-right direction, for example, from the left edge to the right edge. When the entire medium M in the front-to-rear direction from the trailing edge to the leading edge passes directly under the pretreatment spray 6, the pretreatment liquid is discharged onto the entire medium M. In the intermediate discharge process (S23), the CPU 91 causes the pretreatment spray 6 to discharge the intermediate discharge amount of pretreatment liquid calculated in the calculation process (S12).

[0060] 5, when the intermediate discharge process (S23) is performed, a second pretreatment layer S2 is formed on the medium M. The second pretreatment layer S2 is a layer of the pretreatment liquid, and is formed on the first base layer W1.

[0061] 4, after the intermediate ejection process (S23), the CPU 91 performs a second base printing process (S24). The second base printing process (S24) is performed before the water content in the second pretreatment layer S2 formed by the intermediate ejection process (S23) has completely evaporated.

[0062] In the second base printing process (S24), the CPU 91 repeats ejection scans of the white head 3 and sub-scans of the platen 7 from rear to front by a predetermined amount based on the print data. As a result, white ink is ejected from the white head 3 onto the medium M on the platen 7 onto which the pretreatment liquid was ejected in the intermediate ejection process (S23). The white ink ejected from the white head 3 lands on the medium M. The CPU 91 transports the platen 7 from the rear end position P2 to the front end position P1 by repeated sub-scans of the platen 7 from rear to front by a predetermined amount. In the second base printing process (S24), the CPU 91 causes the white head 3 to eject the second ejection amount of white ink calculated in the calculation process (S12).

[0063] As shown in state A5 in FIG. 5, when the second base printing process (S24) is performed, a second base W2 is printed in the area of the medium M where base printing is planned. The second base W2 is a layer of white ink and is formed on the second pre-treatment layer S2. At the contact surface between the second base W2 and the second pre-treatment layer S2, the white ink in the second base W2 and the pre-treatment liquid in the second pre-treatment layer S2 mix with each other. This causes the white ink in the second base W2 to aggregate.

[0064] 4, after the second base printing process (S24), the CPU 91 performs a first conveying process (S25). In the first conveying process (S25), the CPU 91 conveys the platen 7 from the front end position P1 to the rear end position P2.

[0065] After the first conveying process (S25), the CPU 91 performs a color image printing process (S26). In the color image printing process (S26), the CPU 91 repeats ejection scans of the white head 3 and color heads 4 and a predetermined amount of sub-scanning of the platen 7 from rear to front based on the print data. As a result, white ink is ejected from the white head 3 and color inks are ejected from the color head 4 onto the medium M on the platen 7 onto which white ink was ejected in the second base printing process (S24). The white ink ejected from the white head 3 and the color inks ejected from the color head 4 each land on the medium M. The CPU 91 transports the platen 7 from the rear end position P2 to the front end position P1 by repeatedly performing a predetermined amount of sub-scanning of the platen 7 from rear to front.

[0066] As shown in state A6 in FIG. 5, when the color image printing process (S26) is performed, a color layer C is printed in the area of the medium M where the color image is scheduled to be printed. The color layer C is a layer of color inks and white ink, and forms a color image. The color layer C is formed on the second base W2. In the color image printing process (S26), the CPU 91 does not need to perform an ejection scan of the white head 3. In this case, the color layer C does not contain white ink.

[0067] 4, after the second base printing process (S26), the CPU 91 performs a second transport process (S27). In the second transport process (S27), the CPU 91 transports the platen 7 from the front end position P1 to the rear end position P2.

[0068] After the second conveying process (S27), the CPU 91 performs post-processing (S28). In post-processing (S28), the CPU 91 repeats the discharge scan of the post-processing head 5 and the sub-scan of the platen 7 from rear to front by a predetermined distance. The post-processing liquid discharged from the post-processing head 5 via the nozzles 51 adheres to the medium M on the platen 7. The CPU 91 transports the platen 7 from the rear end position P2 to the front end position P1 by the repeated sub-scan of the platen 7 from rear to front by a predetermined distance. Furthermore, the CPU 91 repeats the discharge scan of the post-processing head 5 and the sub-scan of the platen 7 from front to rear by a predetermined distance. The post-processing liquid discharged from the post-processing head 5 via the nozzles 51 adheres to the medium M on the platen 7. The CPU 91 transports the platen 7 from the front end position P1 to the rear end position P2 by the repeated sub-scan of the platen 7 from front to rear by a predetermined distance. As a result of post-processing (S28), the post-processing liquid is discharged onto the entire medium M.

[0069] As shown in state A7 in Figure 5, when post-processing (S28) is performed, a post-processing layer OC is formed. The post-processing layer OC is a layer of post-processing liquid and is formed on the color layer C. The post-processing layer OC is translucent and forms the surface of the printed medium M.

[0070] As shown in Figure 4, after the post-processing (S28), the CPU 91 performs a third conveying process (S29). In the third conveying process (S29), the CPU 91 conveys the platen 7 from rear to front from the rear end position P2 to the front end position P1. With the platen 7 positioned at the front end position P1, the user removes the printed medium M from the platen 7. The CPU 91 then ends the main processing.

[0071] The main effects of the above embodiment will be described. The above embodiment also achieves effects other than those described below. Hereinafter, the pretreatment liquid ejected in the pre-ejection process (S21) will be referred to as the "first pretreatment liquid," and the pretreatment liquid ejected in the intermediate ejection process (S23) will be referred to as the "second pretreatment liquid." The white ink ejected in the first base printing process (S22) will be referred to as the "first white ink," and the white ink ejected in the second base printing process (S24) will be referred to as the "second white ink." The layer formed by stacking the first base W1 and the second base W2 will be referred to simply as the "base."

[0072] In the above embodiment, in the first base printing process (S22), the CPU 91 ejects white ink from the white head 3 for the first time onto the medium M onto which the first pretreatment liquid was ejected in the pre-ejection process (S21). In the intermediate ejection process (S23), the CPU 91 ejects pretreatment liquid from the pretreatment spray 6 for the second time onto the medium M onto which the first white ink was ejected in the first base printing process (S22). In the second base printing process (S24), the CPU 91 ejects white ink from the white head 3 for the second time onto the medium M onto which the second pretreatment liquid was ejected in the intermediate ejection process (S23). In this way, by reducing the amount of pretreatment liquid for the first time, the possibility of aggregated components in the first pretreatment liquid remaining on the surface of the medium M is reduced. This prevents the formed base from peeling off from the medium M. Even if the amount of pretreatment liquid for the first time is reduced, the white ink aggregates due to the second pretreatment liquid in addition to the first pretreatment liquid, thereby preventing a decrease in image quality. Therefore, the printer 1 contributes to preventing the formed base from peeling off from the medium M while suppressing deterioration in image quality.

[0073] In the above embodiment, in the pre-ejection process (S21), the CPU 91 ejects the first pretreatment liquid from the pretreatment spray 6 onto the medium M. This contributes to omitting the process in which the medium M onto which the first pretreatment liquid has been ejected is transported from another device to the printer 1.

[0074] In the above embodiment, the first pretreatment liquid and the second pretreatment liquid are the same type of liquid. This contributes to reducing the types of liquids used by the printer 1. For example, if the first pretreatment liquid and the second pretreatment liquid are different liquids, the printer 1 may be provided with a pretreatment spray for discharging the first pretreatment liquid and a pretreatment spray for discharging the second pretreatment liquid. If the first pretreatment liquid and the second pretreatment liquid are the same liquid, the printer 1 does not need to be provided with separate pretreatment sprays. This contributes to making the printer 1 more compact.

[0075] In the above embodiment, the first treatment liquid ratio, the second treatment liquid ratio, and the third treatment liquid ratio are different ratios in each of Settings 1, 2, and 3. The CPU 91 selects one of Settings 1, 2, and 3. As a result, the CPU 91 selectively performs the pre-ejection process (S21) and the intermediate ejection process (S23) in which the treatment liquid ratio is the first treatment liquid ratio, the pre-ejection process (S21) and the intermediate ejection process (S23) in which the treatment liquid ratio is the second treatment liquid ratio, and the pre-ejection process (S21) and the intermediate ejection process (S23) in which the treatment liquid ratio is the third treatment liquid ratio. Therefore, compared to when the treatment liquid ratio is constant, the printer 1 further contributes to suppressing peeling of the formed base from the medium M while suppressing degradation in image quality.

[0076] In the above embodiment, the pre-discharge amount is less than the intermediate discharge amount. In this case, the possibility that aggregated components in the pretreatment liquid remain on the surface of the medium M is reduced compared to when the pre-discharge amount exceeds the intermediate discharge amount. This reduces the likelihood that the formed base will peel off from the medium M. Therefore, the printer 1 contributes to reducing the likelihood that the formed base will peel off from the medium M.

[0077] If the treatment liquid ratio is different from the ink ratio, there is a possibility that a discrepancy will occur between the degree of aggregation of the white ink in the first printing and the degree of aggregation of the white ink in the second printing. In other words, there is a possibility that aggregation will progress in the first printing and slow down in the second printing, or that aggregation will slow down in the first printing and progress in the second printing. In the above embodiment, the treatment liquid ratio is the same as the ink ratio in each of Settings 1, 2, and 3. The CPU 91 selects one of Settings 1, 2, and 3. As a result, the CPU 91 performs the pre-ejection process (S21), intermediate ejection process (S23), first base printing process (S22), and second base printing process (S24) in which the treatment liquid ratio is the same as the ink ratio. In this case, the printer 1 contributes to reducing the possibility of a discrepancy occurring between the degree of aggregation of the white ink and the degree of aggregation of the white ink, compared to when the treatment liquid ratio is different from the ink ratio.

[0078] In the above embodiment, the first and second white inks are the same color. This contributes to reducing the number of types of ink used by the printer 1. For example, if the first and second white inks are different colors, the printer 1 may be equipped with an inkjet head for ejecting the first white ink and an inkjet head for ejecting the second white ink. If the first and second white inks are the same color, the printer 1 does not need to be equipped with separate inkjet heads. This contributes to making the printer 1 more compact.

[0079] In the above embodiment, in the color image printing process (S26), the CPU 91 prints a color image by ejecting color inks from the color head 4 onto the medium M onto which white ink has been ejected in the second base printing process (S24). In this case, the color image is printed on the base. The printer 1 contributes to preventing the formed base from peeling off from the medium M while improving the color development of the color image.

[0080] In the above embodiment, the first ink ratio, second ink ratio, and third ink ratio are different from one another in each of Settings 1, 2, and 3. The CPU 91 selects one of Settings 1, 2, and 3. As a result, the CPU 91 selectively performs the first base printing process (S22) and the second base printing process (S24) in which the ink ratio is the first ink ratio, the first base printing process (S22) and the second base printing process (S24) in which the ink ratio is the second ink ratio, and the first base printing process (S22) and the second base printing process (S24) in which the ink ratio is the third ink ratio. Therefore, compared to when the ink ratio is constant, the printer 1 further contributes to suppressing peeling of the formed base from the medium M while suppressing degradation in image quality.

[0081] The first white ink is ejected onto the medium M without forming a layer on the surface of the medium M. Therefore, the first white ink easily penetrates into the medium M. Therefore, even if the first ejection amount is increased, the first base layer W1 is less likely to become thick and is less likely to obscure the surface of the medium M. "An ink layer obscures the medium M" means that the color development of the ink layer is improved. Therefore, even if the first ejection amount is increased, the color development of the first base layer W1 is less likely to improve. On the other hand, the second white ink is ejected onto the medium M after the first base layer W1 and the second pretreatment layer S2 have been formed on the surface of the medium M. Therefore, the second white ink does not easily penetrate into the medium M. Therefore, even if the second ejection amount is increased, the second base layer W2 is more likely to become thick and is more likely to obscure the surface of the medium M. Therefore, even if the second ejection amount is increased, the color development of the second base layer W2 is more likely to improve. In other words, the second ejection amount contributes more to improving the color development of the base than the first ejection amount. In the above embodiment, the second ejection amount exceeds the first ejection amount. In this case, the second base W2 becomes thicker than when the second discharge amount is less than the first discharge amount. Therefore, the printer 1 contributes to improving the color development of the base (in the above embodiment, the whiteness of the base). Note that even when the first discharge amount is less than the second discharge amount, a coagulation layer WS is formed. Therefore, even when the first discharge amount is less than the second discharge amount, peeling of the base from the medium M is suppressed.

[0082] In the above embodiment, the pretreatment spray 6 ejects both the first and second pretreatment liquids, which contributes to preventing the printer 1 from becoming larger than when the printer 1 is provided with separate pretreatment sprayers 6 for ejecting the first and second pretreatment liquids.

[0083] In the above embodiment, the white head 3 ejects both the first and second white inks, which contributes to preventing the printer 1 from becoming larger than when the printer 1 is provided with separate white heads 3 for ejecting the first and second white inks.

[0084] In the above embodiment, the white ink corresponds to the "first ink" and "second ink" of the present invention. The white head 3 corresponds to the "first head" and "second head" of the present invention. The pre-treatment liquid corresponds to the "intermediate treatment liquid" and "pre-treatment liquid" of the present invention. The pre-treatment spray 6 corresponds to the "intermediate ejection section" and "pre-ejection section" of the present invention. The CPU 91 corresponds to the "control section" and "computer" of the present invention. The processing of S22 corresponds to the "first ejection process" of the present invention. The processing of S23 corresponds to the "intermediate ejection process" of the present invention. The processing of S24 corresponds to the "second ejection process" of the present invention. The processing of S21 corresponds to the "pre-ejection process" of the present invention. The color head 4 corresponds to the "third head" of the present invention. The processing of S26 corresponds to the "third ejection process" of the present invention.

[0085] The present invention may be modified from the above-described embodiment. The modified examples described below may be combined with each other to the extent that no contradictions arise. In the above-described embodiment, the first pretreatment liquid and the second pretreatment liquid may be different treatment liquids. The first white ink and the second white ink may be different inks. In this case, the pretreatment liquid may contain a first aggregation component and a second aggregation component. The first aggregation component aggregates the first white ink. The second aggregation component aggregates the second white ink. For example, if the first pretreatment liquid and the second pretreatment liquid are different treatment liquids and the first white ink and the second white ink are different inks, the first pretreatment liquid may contain at least the first aggregation component, and the second pretreatment liquid may contain at least the second aggregation component. The pre-discharge amount may be the same as the intermediate discharge amount or may exceed the intermediate discharge amount. The second discharge amount may be the same as the first discharge amount or may be less than the first discharge amount.

[0086] In the above-described embodiment liquid, one or both of the treatment liquid ratio and the ink ratio may be constant. For example, when both the treatment liquid ratio and the ink ratio are constant, only one of setting 1, setting 2, and setting 3 may be defined in the setting table 921.

[0087] In the above embodiment, the treatment liquid ratio may be smaller than the ink ratio, or may be larger than the ink ratio. For example, the setting table 921 may define a setting in which the treatment liquid ratio is the same as the ink ratio, and a setting in which the treatment liquid ratio is different from the ink ratio. The printer 1 may omit the color head 4. In this case, the CPU 91 may omit the color image printing process (S26).

[0088] In the above embodiment, the pretreatment spray 6 for discharging the pretreatment liquid the second time may be separate from the pretreatment spray 6 for discharging the pretreatment liquid the first time. For example, the pretreatment spray 6 for discharging the pretreatment liquid the first time may be disposed in a pretreatment device external to the printer 1. In this case, the CPU 91 may omit the pre-discharge process (S21), and the medium M onto which the first pretreatment liquid has been discharged may be transported from the pretreatment device to the printer 1. After the first pretreatment liquid has been discharged in the pretreatment device, the medium M in a dry state may be transported from the pretreatment device to the printer 1. In this case, the printer 1 may perform so-called wet-on-dry printing, in which white ink is discharged the first time onto the medium M in a dry state. For example, if the medium M contains cotton, wet-on-dry printing may be performed.

[0089] In the above embodiment, the white head 3 for ejecting the second white ink may be separate from the white head 3 for ejecting the first white ink. The printer 1 may omit the post-treatment head 5. The printer 1 may be provided with a pre-treatment head for ejecting one or both of the first and second pre-treatment liquids instead of or in addition to the pre-treatment spray 6. The multiple heads 10 may be line heads.

[0090] In the above embodiment, the printer 1 may omit the pretreatment spray 6. In this case, the pretreatment spray 6 may be disposed in a pretreatment device external to the printer 1. The medium M onto which the first pretreatment liquid has been ejected by the pretreatment spray 6 may be transported from the pretreatment device to the printer 1. The medium M onto which the first white ink has been ejected by the white head 3 may be transported from the printer 1 to the pretreatment device. The medium M onto which the second pretreatment liquid has been ejected by the pretreatment spray 6 may be transported from the pretreatment device to the printer 1. In other words, one or both of the pre-ejection process (S21) and the intermediate ejection process (S23) may be executed by a CPU (not shown) of the pretreatment device.

[0091] The arrangement order of the white head 3, color heads 4, and post-processing head 5 in the front-to-back direction is not limited to that of the above embodiment. In the pre-discharge process (S21), first base printing process (S22), intermediate discharge process (S23), second base printing process (S24), and color image printing process (S26), the direction of sub-scanning of the platen 7 is not limited to that of the above embodiment. For example, in the first base printing process (S22), the platen 7 may be sub-scanned from front to rear, or the platen 7 may be sub-scanned back and forth in the front-to-back direction.

[0092] In the above embodiment, the CPU 91 may omit the second base printing process (S24). In this case, the color layer C is formed on the second pretreatment layer S2. In the second base printing process (S24), the CPU 91 may eject color inks from the color head 4 in addition to ejecting white ink from the white head 3.

[0093] The configuration of the setting table 921 is not limited to the above embodiment. For example, the setting number does not have to be determined according to the thickness of the medium M. The setting number may be determined according to the material of the medium M, for example. The number of setting numbers may be two or more than three. The user may operate the operation unit 98 to select one of multiple setting numbers. The user may operate the operation unit 98 to change one or both of the ink ratio and the treatment liquid ratio. For example, when the user operates the operation unit 98 to change the ink ratio, the treatment liquid ratio may be automatically changed to the same ratio as the ink ratio. The CPU 91 may calculate the ink ratio and the treatment liquid ratio based on, for example, the thickness of the medium M, the type of material, or print settings such as high resolution or low resolution.

[0094] Instead of the CPU 91, a microcomputer, an ASIC (Application Specific Integrated Circuits), an FPGA (Field Programmable Gate Array), or the like may be used as a processor. The main processing may be distributed among multiple processors. A non-transitory storage medium such as the memory 92 may be any storage medium capable of retaining information regardless of the period for which the information is stored. A non-transitory storage medium may not include a temporary storage medium (e.g., a transmitted signal). The control program may be downloaded (i.e., transmitted as a transmission signal) from a server connected to a network (not shown) and stored in the memory 92. In this case, the control program may be stored in a non-transitory storage medium such as a hard disk drive (HDD) provided in the server. [Explanation of symbols]

[0095] 1: Printer 3: White head 4: Color head 6: Pre-treatment spray 91: CPU 92: Memory

Claims

1. A printer that prints on a porous medium, a first head that ejects a first ink; a second head that ejects a second ink; an intermediate discharge unit that discharges an intermediate treatment liquid that aggregates the second ink; Control unit and Equipped with The control unit a first ejection process of ejecting the first ink from the first head onto the medium onto which a pretreatment liquid that aggregates the first ink has been ejected; an intermediate ejection process of ejecting the intermediate treatment liquid from the intermediate ejection unit onto the medium onto which the first ink has been ejected by the first ejection process; a second ejection process of ejecting the second ink from the second head onto the medium onto which the intermediate treatment liquid has been ejected by the intermediate ejection process; A printer characterized by performing the above.

2. a pre-discharge unit that discharges the pretreatment liquid, The control unit performing a pre-discharge process of discharging the pretreatment liquid from the pre-discharge unit onto the medium; In the first ejection process, the first ink is ejected from the first head onto the medium onto which the pretreatment liquid has been ejected in the pre-ejection process.

2. The printer according to claim 1.

3. The intermediate discharge unit discharges the intermediate treatment liquid, which is the same liquid as the pretreatment liquid.

3. The printer according to claim 2.

4. The control unit The pre-discharge process and the intermediate discharge process are selectively performed such that a ratio of an intermediate discharge amount, which is an amount of the intermediate treatment liquid discharged by the intermediate discharge section in the intermediate discharge process, to a pre-discharge amount, which is an amount of the pre-treatment liquid discharged by the pre-discharge section in the pre-discharge process, is a first treatment liquid ratio, and the pre-discharge process and the intermediate discharge process are selectively performed such that a ratio of the intermediate discharge amount to the pre-discharge amount is a second treatment liquid ratio different from the first treatment liquid ratio.

4. The printer according to claim 2 or 3.

5. The control unit In the pre-discharge process, the pretreatment liquid is discharged from the pre-discharge unit onto the medium in a pre-discharge amount less than an intermediate discharge amount; In the intermediate discharge process, the intermediate discharge amount of the intermediate treatment liquid is discharged from the intermediate discharge unit onto the medium.

4. The printer according to claim 2 or 3.

6. The control unit The pre-discharge process, the intermediate discharge process, the first discharge process, and the second discharge process are performed so that a ratio of an intermediate discharge amount, which is the amount of the intermediate treatment liquid discharged by the intermediate discharge section in the intermediate discharge process, to a pre-discharge amount, which is the amount of the pretreatment liquid discharged by the pre-discharge section in the pre-discharge process, is the same as a ratio of a second discharge amount, which is the amount of the second ink discharged by the second head in the second discharge process, to a first discharge amount, which is the amount of the first ink discharged by the first head in the first discharge process.

4. The printer according to claim 2 or 3.

7. The second head ejects the second ink, which is the same ink as the first ink.

2. The printer according to claim 1.

8. a third head that ejects color ink; The control unit a third ejection process for ejecting the color ink from the third head onto the medium onto which the second ink has been ejected in the second ejection process, thereby printing a color image; 8. The printer according to claim 7.

9. The control unit The first ejection process and the second ejection process are selectively performed such that a ratio of a second ejection amount, which is an amount of the second ink ejected by the second head in the second ejection process, to a first ejection amount, which is an amount of the first ink ejected by the first head in the first ejection process, is a first ink ratio, and the first ejection process and the second ejection process are selectively performed such that a ratio of the second ejection amount to the first ejection amount is a second ink ratio.

4. The printer according to claim 1, wherein the ink jet head is a laser printer.

10. The control unit In the first ejection process, a first ejection amount of the first ink is ejected onto the medium by the first head; In the second ejection process, the second ink is ejected onto the medium by the second head at a second ejection amount that is greater than the first ejection amount.

4. The printer according to claim 1, wherein the ink jet head is a laser printer.

11. The pre-ejection unit and the intermediate ejection unit are the same ejection unit.

4. The printer according to claim 2 or 3.

12. The first head and the second head are the same head.

4. The printer according to claim 1, wherein the ink jet head is a laser printer.

13. 1. A method for controlling a printer that prints on a porous medium, comprising: a first ejection process of ejecting the first ink onto the medium onto which a pretreatment liquid that aggregates the first ink has been ejected; an intermediate ejection process of ejecting an intermediate treatment liquid that aggregates the second ink onto the medium onto which the first ink has been ejected by the first ejection process; a second ejection process of ejecting the second ink onto the medium onto which the intermediate treatment liquid has been ejected by the intermediate ejection process; A control method comprising:

14. a computer that controls a printer that includes a first head that ejects a first ink, a second head that ejects a second ink, and an intermediate ejection unit that ejects an intermediate treatment liquid that aggregates the first ink, and that prints on a permeable medium; a first ejection process of ejecting the first ink from the first head onto the medium onto which the pretreatment liquid that aggregates the second ink has been ejected; an intermediate ejection process of ejecting the intermediate treatment liquid from the intermediate ejection unit onto the medium onto which the first ink has been ejected by the first ejection process; a second ejection process of ejecting the second ink from the second head onto the medium onto which the intermediate treatment liquid has been ejected by the intermediate ejection process; A control program characterized by causing the program to execute the above.

Images