Printer, control method, and control program

Abstract

The present invention contributes to suppressing liquid discharge disruptions caused by a head when laminating a plurality of layers.　A printer of the present invention comprises a target head that discharges liquid to a medium, and a control unit. The control unit performs first discharge processing for discharging the liquid from the target head to the medium at a first resolution and forming a first layer, and second discharge processing for discharging the liquid from the target head to the medium at a second resolution and forming a second layer on the first layer. During the first discharge processing and the second discharge processing, a first total amount, which is the total amount of the liquid discharged from the target head at the lower resolution from among the first resolution and the second resolution, is less than a second total amount, which is the total amount of the liquid discharged from the target head at the higher resolution from among the first resolution and the second resolution.

Description

Printer, control method, and control program

[0001] The present disclosure relates to a printer, a control method, and a control program.

[0002] The recording device described in Patent Document 1 includes a recording head. The recording head ejects ink onto one recording area of ​​a print medium in multiple separate jets to build up multiple layers. In the recording device, the amount of ink ejected from the recording head when forming the first layer is greater than the amount of ink ejected from the recording head when forming the second layer.

[0003] JP 2014-114529 A

[0004] In the above-mentioned recording device, simply ejecting a larger amount of liquid than other layers to form one layer can create an airflow between the recording head and the print medium, a so-called ejection flow, which is an airflow that flows from the print medium toward the recording head. When an ejection flow occurs, mist of the liquid can be stirred up by the ejection flow and adhere to the recording head. If mist adheres to the recording head, it can disrupt the ejection of liquid by the recording head.

[0005] An object of the present disclosure is to provide a printer, a control method, and a control program that contribute to suppressing disturbances in the ejection of liquid from a head when multiple layers are stacked.

[0006] A printer according to a first aspect of the present disclosure comprises a target head that ejects liquid onto a medium, and a control unit, wherein the control unit performs a first ejection process in which the liquid is ejected from the target head onto the medium at a first resolution to form a first layer, and a second ejection process in which the liquid is ejected from the target head onto the medium at a second resolution to form a second layer on the first layer, and is characterized in that in the first ejection process and the second ejection process, a first total amount, which is the total amount of the liquid ejected from the target head at the lower resolution of the first resolution and the second resolution, is less than a second total amount, which is the total amount of the liquid ejected from the target head at the higher resolution of the first resolution and the second resolution.

[0007] If the first total amount and the second total amount are equal, a discharge flow is more likely to occur when a layer is formed at a low resolution than when a layer is formed at a high resolution. In the first aspect, the first total amount is less than the second total amount. Therefore, the discharge flow is suppressed when a layer is formed at a low resolution, and as a result, the discharge flow is suppressed overall in the first discharge process and the second discharge process. Therefore, the printer contributes to suppressing disturbances in the discharge of liquid from the target head when stacking multiple layers.

[0008] In the printer, the ratio of the first total amount to the second total amount may be equal to or greater than the ratio of the low resolution to the high resolution and less than 1. In this case, the printer contributes to suppressing an increase in the discharge flow when forming a layer at high resolution, while suppressing the discharge flow when forming a layer at low resolution.

[0009] In the printer, the ratio of the first total amount to the second total amount may be equal to the ratio of the low resolution to the high resolution, in which case the printer contributes to the greatest suppression of the ejection flow of the first ejection process and the second ejection process as a whole.

[0010] The printer may include a color head that ejects color inks that form a color image onto the medium, the target head that ejects base ink that forms a base for the color image, and the control unit may perform a color ink ejection process that is performed in parallel with or after the second ejection process, in which the color inks are ejected from the color head onto the medium and a color ink layer that forms the color image is formed on the second layer that forms the base. In this case, the printer contributes to improving the image quality of the base by suppressing disruption of the ejection of the base ink by the target head.

[0011] The printer may include a color head that ejects color inks that form a color image onto the medium, the target head that ejects post-treatment liquid that covers the color image, and the control unit may perform a color ink ejection process that ejects the color inks from the color head onto the medium and forms color ink layers that make up the color image, and a first ejection process that is performed in parallel with the color ink ejection process or after the color ink ejection process and ejects the post-treatment liquid from the target head onto the medium at the first resolution and forms the first layer on the color ink layer. In this case, the printer contributes to reliably covering the color image with post-treatment liquid by suppressing disruption of the ejection of post-treatment liquid by the target head.

[0012] In the printer, the low resolution may be the first resolution and the high resolution may be the second resolution. In this case, the printer forms a second layer that is an upper layer of the first layer at a high resolution, thereby contributing to improving the image quality of the layer close to the surface.

[0013] The printer may include a pretreatment liquid ejection unit that ejects a pretreatment liquid onto the medium, the target head ejects ink, and the control unit may perform a pretreatment liquid ejection process in which the pretreatment liquid is ejected from the pretreatment liquid ejection unit onto the medium to form a pretreatment liquid layer, and a first ejection process, which is performed in parallel with the pretreatment liquid ejection process or after the pretreatment liquid ejection process, in which the ink is ejected from the target head at the first resolution onto the medium in a state wetted with the pretreatment liquid to form the first layer on the pretreatment liquid layer. In this case, the printer performs so-called wet-on-wet printing, in which ink is ejected onto the medium in a state wetted with the pretreatment liquid, by the first ejection process, while the second ejection process contributes to ensuring a constant total amount of ink ejected by the first and second ejection processes.

[0014] The printer includes a receiving unit that accepts a designation of either a first mode or a second mode, which are different from each other. The control unit, when the designation received by the receiving unit is the first mode, performs the first ejection process and the second ejection process. When the designation received by the receiving unit is the second mode, the control unit, when the designation received by the receiving unit is the second mode, performs a third ejection process in which the target head ejects the liquid onto the medium at the first resolution to form a third layer, and a fourth ejection process in which the target head ejects the liquid onto the medium at the second resolution to form a fourth layer on the third layer. The third total amount, which is the total amount of liquid ejected from the target head in the third ejection process, and the fourth total amount, which is the total amount of liquid ejected from the target head in the fourth ejection process, may be equal. In this case, by selecting either the first mode or the second mode, the user can specify whether the first and second layers are formed with different amounts of liquid depending on the resolution, or whether the third and fourth layers are formed with equal amounts of liquid regardless of the resolution. Thus, the printer allows the user to specify the allocation of liquid amounts to multiple layers.

[0015] A control method according to a second aspect of the present disclosure is a control method for a printer equipped with a target head that ejects liquid onto a medium, comprising a first ejection process in which the liquid is ejected from the target head onto the medium at a first resolution to form a first layer, and a second ejection process in which the liquid is ejected from the target head onto the medium at a second resolution to form a second layer on the first layer, characterized in that in the first ejection process and the second ejection process, a first total amount, which is the total amount of the liquid ejected from the target head at the lower resolution of the first resolution and the second resolution, is less than a second total amount, which is the total amount of the liquid ejected from the target head at the higher resolution of the first resolution and the second resolution.

[0016] The second aspect offers similar advantages as the first aspect.

[0017] A control program according to a third aspect of the present disclosure is a control program that causes a computer controlling a printer equipped with a target head that ejects liquid onto a medium to execute a first ejection process in which the liquid is ejected from the target head onto the medium at a first resolution to form a first layer, and a second ejection process in which the liquid is ejected from the target head onto the medium at a second resolution to form a second layer on the first layer, wherein in the first ejection process and the second ejection process, a first total amount, which is the total amount of the liquid ejected from the target head at the lower resolution of the first resolution and the second resolution, is less than a second total amount, which is the total amount of the liquid ejected from the target head at the higher resolution of the first resolution and the second resolution.

[0018] The third aspect offers similar advantages as the first aspect.

[0019] 1 is a schematic plan view of the printer 1. FIG. 1 is a schematic right side view of the printer 1. FIG. 2 is a schematic view of the white head 3 as seen from below. FIG. 3 is a diagram for explaining the flow of layer formation on the medium M. FIG. 4 is a side view of the white head 3 ejecting white ink I from a plurality of nozzles 31 onto the medium M from the white head 3. FIG. 5 is a block diagram showing the electrical configuration of the printer 1. FIG. 6 is a flowchart of the main process. FIG. 7 is a flowchart continuing from FIG. 7. FIG. 8 is a diagram showing the movement of the white head 3 and the platen 7 in the first printing process in the fixed rate mode. FIG. 9 is a diagram continuing from FIG. 9. FIG. 10 is a diagram showing the movement of the white head 3 and the platen 7 in the second printing process in the fixed rate mode. FIG. 11 is a diagram continuing from FIG. 12. FIG. 13 is a diagram showing the movement of the white head 3 and the platen 7 in the first printing process in the fixed rate mode. FIG. 15 is a diagram continuing from FIG. 17. FIG. 18 is a diagram continuing from FIG. 19. FIG. 20 is a table explaining an example of duty ratios in the fixed rate mode. FIG. 21 is a table explaining an example of duty ratios in the fixed rate mode.

[0020] A printer 1 according to an embodiment of the present disclosure 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.

[0021] 1 and 2, the schematic configuration of the printer 1 will be described. The printer 1 is an inkjet printer that prints on a medium M. The medium M may be fabric, paper, or the like. The medium M may be, for example, a T-shirt. The printer 1 includes a platen transport mechanism 11, a platen 7, a head transport mechanism 12, multiple heads 10, and a pretreatment spray 6.

[0022] 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. 6 (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. A medium M is placed on the loading surface 71 and set on the platen 7.

[0023] The head transport mechanism 12 includes a pair of guide rails 121, 122 and a carriage 2. The pair of guide rails 121, 122 extend in the left-right direction and are aligned with each other in the front-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-rear and left-right directions. The carriage 2 is supported by the pair of guide rails 121, 122. The carriage 2 moves left-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-right by driving a main scanning motor 13 shown in FIG. 6 (see arrow Y1). Therefore, the left-right direction of the printer 1 is the main scanning direction.

[0024] 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 the left end of the platen 7 to 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 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.

[0025] The pretreatment liquid is an aqueous solution containing an aggregating component, and improves the color development of the white ink. The aggregating component aggregates solid components in the white ink. Hereinafter, aggregating 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, pigments 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.

[0026] The multiple heads 10 have a rectangular parallelepiped shape and, in this embodiment, include a white head 3, color heads 4, and post-processing head 5. The white head 3, color heads 4, and post-processing head 5 are aligned in a row from front to rear in the order of color head 4, post-processing head 5, white head 3. The bottom surfaces 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.

[0027] 3, multiple nozzle rows W1, W2, W3, and W4 are formed on the underside of the white head 3. The multiple nozzle rows W1, W2, W3, and W4 are arranged in this order from left to right. Each of the multiple nozzle rows W1, W2, W3, and W4 of the white head 3 has multiple nozzles 31. The multiple nozzles 31 are openings, and are arranged in a line in the front-to-rear direction in each of the multiple nozzle rows W1, W2, W3, and W4.

[0028] The distance D indicates the distance between the centers of a pair of nozzles 31 adjacent in the front-to-rear direction. The distance D is not limited to a specific size, but in this embodiment, it is 1 / 300 inch. That is, for example, the density of the multiple nozzles 31 in the front-to-rear direction in the nozzle row W1 is 300 dpi. Note that the multiple nozzles 31 may be arranged in multiple rows in the front-to-rear direction in each of the multiple nozzle rows W1, W2, W3, and W4.

[0029] The undersides of the color head 4 and the post-processing head 5 are configured in the same manner as the underside of the white head 3. That is, multiple nozzle rows (not shown) are formed on the underside of the color head 4, and multiple nozzle rows (not shown) are formed on the underside of the post-processing head 5. The multiple nozzle rows of the color head 4 each have multiple nozzles 41 as shown in FIG. 2. The multiple nozzles 41 are aligned in the front-to-back direction in each nozzle row. The multiple nozzle rows of the color head 4 are aligned in the left-to-right direction. The multiple nozzle rows of the post-processing head 5 each have multiple nozzles 51 as shown in FIG. 2. The multiple nozzles 51 are aligned in the front-to-back direction in each nozzle row. The multiple nozzle rows of the post-processing head 5 are aligned in the left-to-right direction.

[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 a plurality of color ink containers (not shown). The color head 4 ejects the color inks downward from a plurality of nozzles 41. For example, the plurality of 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 plurality of nozzles 41, magenta color ink is ejected from the second nozzle row of the plurality of nozzles 41, yellow ink is ejected from the third nozzle row of the plurality of nozzles 41, and black ink is ejected from the fourth nozzle row of the plurality of 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 a plurality of 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] 2, the platen 7 is transported in the front-to-rear direction between a front end position P11 and a rear end position P12 by a platen transport mechanism 11. At the front end position P11, the platen 7 is positioned forward of the pre-treatment spray 6, and at the rear end position P12, the platen 7 is positioned rearward of the white head 3. For example, a medium M is set on the platen 7 with the platen 7 positioned at the front end position P11.

[0034] 1, the head 10 is transported left and right between a left end position P21 and a right end position P22 by a head transport mechanism 12. The head 10 is positioned to the left of the platen 7 at the left end position P21, and is positioned to the right of the platen 7 at the right end position P22.

[0035] 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). When the multiple heads 10 and the platen 7 are arranged in a region 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."

[0036] The operation of causing the heads 10 to eject liquid while transporting the multiple heads 10 in the left-right direction in an opposed state is called the "ejection scan of the heads 10." For example, an ejection scan of causing the white head 3 to eject white ink from the nozzles 31 while transporting the white head 3 in the left-right direction in an opposed state is called the "ejection scan of the white head 3." The operation of transporting the platen 7 in the front-to-back direction is called the "sub-scan of the platen 7." 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.

[0037] Hereinafter, the number of times the head 10 performs an ejection scan during printing by the printer 1 will be referred to as the "number of passes." For example, when the head 10 performs a single one-way ejection scan from either the left end position P21 or the right end position P22 to the other, the number of passes is one. For example, when the head 10 performs an ejection scan by returning from either the left end position P21 or the right end position P22 to the other, the number of passes is two.

[0038] Printing by the printer 1 will be described with reference to FIG. 4 . The printer 1 performs printing on the medium M by stacking multiple layers on the medium M. In this embodiment, when printing is performed by the printer 1, each layer is formed on the medium M in the order of state ST1, ST2, ST3, ST4, ST5, ST6, and ST7. In detail, pretreatment liquid is ejected from the pretreatment spray 6 shown in FIG. 1 onto the medium M shown in state ST1. As a result, a pretreatment layer S1 is formed on the medium M as shown in state ST2. The pretreatment layer S1 is a layer of pretreatment liquid, and is formed by the pretreatment liquid permeating into the medium M.

[0039] The medium M shown in state ST2 is wet with the pretreatment liquid. White ink is ejected from the white head 3 shown in FIG. 1 onto the medium M shown in state ST2. As a result, as shown in state ST3, a base B1 is layered on the pretreatment layer S1 on the medium M. The base B1 is a layer of white ink. As a result, the white ink in the base B1 becomes entangled with the fibers of the medium M and aggregates due to the action of the pretreatment layer S1, accelerating the fixation of the base B1 to the medium M.

[0040] White ink is ejected from the white head 3 shown in FIG. 1 onto the medium M shown in state ST3. As a result, as shown in state ST4, a base B2 is layered on top of a base B1 on the medium M. The base B2 is a layer of white ink. This ensures the density of the white ink in the base B. The base B is a layer composed of the bases B1 and B2.

[0041] Color ink is ejected from the color head 4 shown in FIG. 1 onto the medium M shown in state ST4. As a result, a color layer C1 is layered on the base B2 of the medium M, as shown in state ST5. The color layer C1 is a layer of color ink and constitutes a color image. As a result, a color image is printed on the medium M.

[0042] Post-treatment liquid is ejected from the post-treatment head 5 shown in FIG. 1 onto the medium M shown in state ST5. As a result, a post-treatment layer OC1 is layered on the color layer C1 on the medium M, as shown in state ST6. The post-treatment layer OC1 is a layer of post-treatment liquid and covers the printed image from above. Post-treatment liquid is ejected from the post-treatment head 5 shown in FIG. 1 onto the medium M shown in state ST6. As a result, a post-treatment layer OC2 is layered on the post-treatment layer OC1 on the medium M, as shown in state ST7. The post-treatment layer OC2 is a layer of post-treatment liquid and forms the surface of the printed medium M, that is, the surface exposed upward. This ensures the thickness of the post-treatment layer OC. The post-treatment layer OC is a layer composed of post-treatment layers OC1 and OC2, and is translucent.

[0043] As described above, in this embodiment, the pre-treatment layer S1, base B1, base B2, color layer C1, post-treatment layer OC1, and post-treatment layer OC2 are stacked on the medium M from the bottom up, and printing is performed on the medium M.

[0044] Hereinafter, the total amount of white ink used to form base B will be referred to as the "total white ink amount of base B," the total amount of white ink used to form base B1 will be referred to as the "white ink allocation amount of base B1," and the total amount of white ink used to form base B2 will be referred to as the "white ink allocation amount of base B2." The total white ink amount of base B is the sum of the white ink allocation amount of base B1 and the white ink allocation amount of base B2. The white ink allocation amount of base B1 is the total amount of white ink ejected from the white head 3 when forming base B1. The white ink allocation amount of base B2 is the total amount of white ink ejected from the white head 3 when forming base B2.

[0045] Hereinafter, the total amount of post-processing liquid used to form the post-processing layer OC will be referred to as the "total amount of post-processing liquid for the post-processing layer OC," the total amount of post-processing liquid used to form the post-processing layer OC1 will be referred to as the "post-processing liquid allocation amount for the post-processing layer OC1," and the total amount of post-processing liquid used to form the post-processing layer OC2 will be referred to as the "post-processing liquid allocation amount for the post-processing layer OC2." The total amount of post-processing liquid for the post-processing layer OC is the sum of the post-processing liquid allocation amount for the post-processing layer OC1 and the post-processing liquid allocation amount for the post-processing layer OC2. The post-processing liquid allocation amount for the post-processing layer OC1 is the total amount of post-processing liquid ejected from the post-processing head 5 when forming the post-processing layer OC1. The post-processing liquid allocation amount for the post-processing layer OC2 is the total amount of post-processing liquid ejected from the post-processing head 5 when forming the post-processing layer OC2.

[0046] As described above, a printing method in which white ink is ejected onto a medium M wetted with a pretreatment liquid to form a base B1 on the medium M is called "wet-on-wet printing." A printing method in which white ink is ejected onto a medium M in a dry state to form a base B1 on the medium M is called "wet-on-dry printing." The printer 1 performs wet-on-wet printing when the medium M is permeable. The medium M is permeable when it is a fabric containing, for example, one or both of cotton and polyester fibers, unlike, for example, a film. When wet-on-wet printing is performed on a permeable medium M, bleed-through of the white ink that has landed on the medium M can be suppressed and the fixation of the white ink in the base B1 to the medium M can be improved compared to when wet-on-dry printing is performed. For this reason, in wet-on-wet printing, it is important that the base B1 is formed on the medium M using white ink before the medium M, which has been wetted with the pretreatment liquid, dries.

[0047] In this embodiment, the printing method of dividing a layer made of the same liquid into multiple layers and laminating the multiple divided layers on the medium M is called "division printing." In this embodiment, as described above, the printer 1 divides the base B into two layers, base B1 and base B2, by division printing, and laminates the divided bases B1 and B2 on the medium M. Furthermore, the printer 1 divides the post-processing layer OC into two layers, post-processing layer OC1 and post-processing layer OC2, by division printing, and laminates the divided post-processing layers OC1 and OC2 on the medium M.

[0048] Define main scanning resolution and sub-scanning resolution. Main scanning resolution is the resolution in the main scanning direction (see arrow Y1 in FIG. 1), that is, the left-right direction. Main scanning resolution is determined by the ejection interval in the main scan of the head 10. Sub-scanning resolution is the resolution in the sub-scanning direction (see arrow Y2 in FIG. 1), that is, the front-to-back direction. Sub-scanning resolution depends on the distance D, which is the distance between the centers of a pair of nozzles 31 adjacent to each other in the sub-scanning direction, and the distance the platen 7 moves in one sub-scan of the platen 7 relative to the distance D. Generally, the sub-scanning resolution often increases as the distance the platen 7 moves in one sub-scan of the platen 7 decreases.

[0049] The main scanning resolution and sub-scanning resolution of each of the base B1, base B2, color layer C1, post-processing layer OC1, and post-processing layer OC2 are specified, for example, by print data or by print settings of the printer 1. The main scanning resolution of each of the base B1, base B2, color layer C1, post-processing layer OC1, and post-processing layer OC2 is not limited to a specific value, but is, for example, 1200 dpi.

[0050] The sub-scanning resolution of the color layer C1 is not limited to a specific value, but is, for example, 1200 dpi. The sub-scanning resolution of the base B1 can be set lower than the sub-scanning resolution of the base B2. The sub-scanning resolution of the base B1 is not limited to a specific value, but is 600 dpi in this embodiment. The sub-scanning resolution of the base B2 is not limited to a specific value, but is 1200 dpi in this embodiment. The sub-scanning resolution of the post-processing layer OC1 is not limited to a specific value, but is 600 dpi in this embodiment. The sub-scanning resolution of the post-processing layer OC2 is not limited to a specific value, but is 1200 dpi in this embodiment. The sub-scanning resolution of the post-processing layer OC1 can be set lower than the sub-scanning resolution of the post-processing layer OC2. The sub-scanning resolutions of the base B1 and the post-processing layer OC1 may be different from each other, and the sub-scanning resolutions of the base B2 and the post-processing layer OC2 may be different from each other. Similarly, the main scanning resolutions may also be different from each other.

[0051] For example, if the sub-scanning resolution of base B1 is lower than the sub-scanning resolution of base B2, the number of passes required to form base B1 will be less than the number of passes required to form base B2. Therefore, the time required to form base B1 will be shorter than the time required to form base B2. In this embodiment, by performing divided printing, base B1, which has a lower resolution than base B2, is formed before base B2 is formed, thereby preventing base B from being formed on the medium M in a dry state. In this embodiment, base B2 is formed on base B1 by divided printing. This ensures the total amount of white ink in base B is secured, improving the color development of base B. As described above, by performing divided printing, the printer 1 improves the color development of base B while improving the fixation of white ink on the medium M.

[0052] The duty and duty ratio are defined. The duty is the amount of white ink allocated to the base B1 or base B2 per pass. For example, if the sub-scan resolution of the base B1 is lower than the sub-scan resolution of the base B2, the duty of the base B1 will be higher than the duty of the base B2. The duty ratio is the ratio of the duty of the base B1 to the duty of the base B2 (duty of the base B1 / duty of the base B2).

[0053] The duty may be defined by the ejection frequency or the density of the white ink. The ejection frequency is determined, for example, by the amount of white ink allocated to the base B1 or B2 per time required for one pass. The density of the white ink is determined, for example, by the amount of white ink allocated to the base B1 or B2 (the number of dots DT) per number of pixels PX aligned in the horizontal direction.

[0054] Referring to Figure 5, the ejection flow F will be described using the white head 3 as an example. Note that the ejection flow F can occur not only in the white head 3 but also in the color heads 4 and post-treatment heads 5, just like the white head 3. The ejection flow F is an air current that is generated upward by the rebound of the white ink I when the white ink I ejected from the multiple nozzles 31 of the white head 3 lands on the medium M. For this reason, when the frequency, density, etc. of the white ink I landing on the medium M is high, the ejection flow F is more likely to occur, or the ejection flow F that occurs is more likely to become strong. Therefore, the ejection flow F is more likely to occur when the duty is high than when the duty is low.

[0055] If the white ink allocation amount for the base B1 and the white ink allocation amount for the base B2 are equal, the duty cycle will be higher when the base B1 is formed at a sub-scanning resolution of 600 dpi than when the base B2 is formed at a sub-scanning resolution of 1200 dpi. Therefore, the discharge flow F is more likely to occur when the base B1 is formed at a sub-scanning resolution of 600 dpi than when the base B2 is formed at a sub-scanning resolution of 1200 dpi. The discharge flow F is more likely to occur when the duty ratio is high than when the duty ratio is low. Therefore, for example, the discharge flow F is more likely to occur when the base B1 is formed at a duty ratio of "2" than when the base B1 is formed at a duty ratio of "1." In this embodiment, the discharge flow F is suppressed by performing the main process shown in FIG. 7 (described later).

[0056] The electrical configuration of the printer 1 will be described with reference to FIG. 6 . 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 a non-volatile memory and stores various information. For example, the memory 92 stores programs and print data. The programs include a control program for executing the main processing (see FIG. 8 ), which will be described later, and are executed by the CPU 91. The print data includes image data and indicates the total amount of white ink in the base B, the sub-scanning and main-scanning resolutions of the base B1, the sub-scanning and main-scanning resolutions of the base B2, the total amount of post-treatment liquid in the post-treatment layer OC, the sub-scanning and main-scanning resolutions of the post-treatment layer OC1, and the sub-scanning and main-scanning resolutions of the post-treatment layer OC2, etc.

[0057] 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-treatment 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.

[0058] The white head driver 30 is, for example, a heating element or a piezoelectric element, and is provided corresponding to each of the plurality of nozzles 31. The white head driver 30 is controlled by the CPU 91 to selectively eject white ink from the plurality of nozzles 31 in the white head 3. The color head driver 40 is, for example, a heating element or a piezoelectric element, and is provided corresponding to each of the plurality of nozzles 41. The color head driver 40 is controlled by the CPU 91 to selectively eject color ink from the plurality of nozzles 41 in the color head 4.

[0059] The post-treatment head driving units 50 are, for example, heating elements or piezoelectric elements, and are provided corresponding to each of the plurality of nozzles 51. The post-treatment head driving units 50 are controlled by the CPU 91 to cause the post-treatment head 5 to selectively eject the post-treatment liquid from the plurality of nozzles 51. The spray driving units 60 are, for example, compressors for sending compressed air to the pre-treatment spray 6. The spray driving units 60 are controlled by the CPU 91 to cause the pre-treatment spray 6 to eject the pre-treatment liquid from the plurality of nozzles 61.

[0060] The display 97 displays various screens under the control of the CPU 91. The operation unit 98 is a user interface, such as a button or touch panel. The operation unit 98 outputs a signal to the CPU 91 in response to an operation by the user. For example, the operation unit 98 accepts a print start operation and a mode change operation. The print start operation is an operation performed by the user to input a print instruction to the printer 1 to cause the printer 1 to print based on the print data. The print instruction specifies the print data to be controlled. The mode change operation is an operation performed by the user to specify either the fixed rate mode or the fixed quantity mode, which will be described later.

[0061] The main processing will be described with reference to Figures 7 and 8. When the printer 1 is powered on, the CPU 91 starts the main processing by reading and running a control program from the memory 92. In this embodiment, the main processing is started with the platen 7 positioned at the front end position P11 shown in Figure 1 and the head 10 positioned at the left end position P21 shown in Figure 1. Below, a case will be described as an example where the base B is formed with a total amount of white ink for the base B of 12 mL, and the post-treatment layer OC is formed with a total amount of post-treatment liquid for the post-treatment layer OC of 12 mL.

[0062] 7, when the main process starts, the CPU 91 determines whether a mode change operation to change the designated mode has been received via the operation unit 98 (S11). The designated mode is either the fixed quantity mode or the fixed rate mode, which is designated by the user via the operation unit 98, and is stored in the memory 92. The designated mode specifies the type of print control to be performed by the printer 1.

[0063] The fixed quantity mode is a mode in which the white ink allocation amount for the base B1 and the white ink allocation amount for the base B2 are set so that they are equal to each other. The fixed quantity mode is a mode in which the post-treatment liquid allocation amount for the post-treatment layer OC1 and the post-treatment liquid allocation amount for the post-treatment layer OC2 are set so that they are equal to each other.

[0064] The fixed ratio mode is a mode in which the white ink allocation amount of the base B1 and the white ink allocation amount of the base B2 are set so that the ratio of the white ink allocation amount of the base B2 to the white ink allocation amount of the base B1 (white ink allocation amount of the base B2 / white ink allocation amount of the base B1) is equal to the ratio of the sub-scan resolution of the base B2 to the sub-scan resolution of the base B1 (sub-scan resolution of the base B2 / sub-scan resolution of the base B1). The fixed ratio mode is a mode in which the post-processing liquid allocation amount of the post-processing layer OC1 and the post-processing liquid allocation amount of the post-processing layer OC2 are set so that the ratio of the post-processing liquid allocation amount of the post-processing layer OC2 to the post-processing liquid allocation amount of the post-processing layer OC1 (post-processing liquid allocation amount of the post-processing layer OC2 / post-processing liquid allocation amount of the post-processing layer OC1) is equal to the ratio of the sub-scanning resolution of the post-processing layer OC2 to the sub-scanning resolution of the post-processing layer OC1 (sub-scanning resolution of the post-processing layer OC2 / sub-scanning resolution of the post-processing layer OC1).

[0065] If a mode change operation has not been received (S11: NO), the CPU 91 proceeds to the determination in S21. If a mode change operation has been received (S11: YES), the CPU 91 changes the designated mode (S12). For example, if a mode change operation is received when the designated mode is fixed rate mode, the CPU 91 changes the designated mode from fixed rate mode to fixed quantity mode. If a mode change operation is received when the designated mode is fixed rate mode, the CPU 91 changes the designated mode from fixed quantity mode to fixed rate mode. The CPU 91 proceeds to the determination in S21.

[0066] The CPU 91 determines whether a print instruction has been received via the operation unit 98 (S21). For example, with the medium M set on the platen 7, the user performs a print start operation on the operation unit 98 and inputs a print instruction to the printer 1. If a print instruction has not been received (S21: NO), the CPU 91 returns the process to the determination in S11. If a print instruction has been received (S21: YES), the CPU 91 proceeds to the determination in S22 shown in FIG. 8.

[0067] As shown in Fig. 8, the CPU 91 references the memory 92 and determines whether the specified mode is the fixed rate mode (S22). If the specified mode is the fixed rate mode (S22: NO), the CPU 91 performs printing control in the fixed rate mode (S31-S48). If the specified mode is the fixed rate mode (S22: YES), the CPU 91 performs printing control in the fixed rate mode (S51-S68). When printing control in the fixed rate mode (S31-S48) or printing control in the fixed rate mode (S51-S68) is completed, the CPU 91 returns the process to the determination in S11 shown in Fig. 7.

[0068] Print control in fixed quantity mode will now be described. The CPU 91, for example, references specified print data and specifies the total amount of white ink for base B (S31). The CPU 91 calculates the white ink allocation amount for base B1 and the white ink allocation amount for base B2 based on the specified total amount of white ink for base B (S32). In the process of S32, the CPU 91 calculates half of the total amount of white ink for base B as the white ink allocation amount for base B1. The CPU 91 calculates half of the total amount of white ink for base B as the white ink allocation amount for base B2. As a result, the white ink allocation amounts for base B1 and B2 are set so that the white ink allocation amounts for base B1 and B2 are equal. For example, if the total amount of white ink for base B is 12 mL, the white ink allocation amount for base B1 will be 6 mL, and the white ink allocation amount for base B2 will also be 6 mL.

[0069] The CPU 91, for example, refers to the specified print data and specifies the total amount of post-treatment liquid for the post-treatment layer OC (S33). The CPU 91 calculates the post-treatment liquid allocation amount for the post-treatment layer OC1 and the post-treatment liquid allocation amount for the post-treatment layer OC2 based on the specified total amount of post-treatment liquid for the post-treatment layer OC (S34). In the process of S34, the CPU 91 calculates half of the total amount of post-treatment liquid for the post-treatment layer OC as the post-treatment liquid allocation amount for the post-treatment layer OC1. The CPU 91 calculates half of the total amount of post-treatment liquid for the post-treatment layer OC as the post-treatment liquid allocation amount for the post-treatment layer OC2. As a result, the post-treatment liquid allocation amount for the post-treatment layer OC1 and the post-treatment liquid allocation amount for the post-treatment layer OC2 are set so that the post-treatment liquid allocation amount for the post-treatment layer OC1 and the post-treatment liquid allocation amount for the post-treatment layer OC2 are equal.

[0070] The CPU 91 performs pretreatment (S41). In pretreatment (S41), the CPU 91 causes the pretreatment spray 6 to spray pretreatment liquid while the platen 7 is sub-scanned from front to rear from the front end position P11 to the rear end position P12. The pretreatment liquid sprayed from the pretreatment 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 pretreatment spray 6, the pretreatment liquid is sprayed over the entire medium M. As a result, a pretreatment layer S1 is formed over the entire medium M, as shown in state ST2 in FIG. 4 .

[0071] 8, after the pretreatment (S41), the CPU 91 performs a first printing process (S42). The first printing process (S42) is performed while the medium M is wet with the pretreatment liquid due to the pretreatment (S41). In other words, the first printing process (S42) is performed before the moisture in the pretreatment liquid that has permeated the medium M due to the pretreatment (S41), i.e., the moisture in the pretreatment layer S1, dries.

[0072] In the first printing process (S42), the CPU 91 repeats the ejection scan of the white head 3 and the predetermined amount of sub-scan from rear to front of the platen 7. In the first printing process (S42), the CPU 91 causes the white head 3 to eject white ink in the amount of white ink allocated to the base B1 calculated in the process of S32.

[0073] In the first printing process (S42), white ink is ejected from the white head 3 onto the medium M on the platen 7, which is wet with the pretreatment liquid ejected in the pretreatment process (S41). 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 P12 to the front end position P11 by repeatedly sub-scanning the platen 7 a predetermined distance from rear to front. As a result, a base B1 is formed on the area of ​​the medium M where the base B is scheduled to be formed, as shown in state ST3 in FIG.

[0074] In detail, in the first printing process (S42), the CPU 91 repeats the ejection scan of the white head 3 and the sub-scan of the platen 7 from rear to front by a predetermined amount so that the main scanning resolution of the base B1 is 1200 dpi and the sub-scan resolution of the base B1 is 600 dpi.

[0075] 9 and 10 , the movement of the white head 3 and platen 7 during the first printing process (S42) in which the main scanning resolution of the base B1 is 1200 dpi and the sub-scanning resolution of the base B1 is 600 dpi will be described. To simplify the explanation, the following assumptions are made: Two nozzles 31 are aligned in the front-to-back direction in the white head 3. The printing area of ​​the medium M includes eight pixels PX aligned in the left-to-right direction at 1200 dpi and four pixels PX aligned in the front-to-back direction at 600 dpi. In other words, the printing area of ​​the medium M includes 32 (8 x 4) pixels PX. Lines L11, L12, L13, and L14 of pixels PX aligned in the left-to-right direction are aligned in the order of line L11, line L12, line L13, and line L14 from front to back. Under these assumptions, the calculated white ink allocation of 6 mL for the base B1 corresponds to 32 dots DT in the first printing process in fixed-volume mode. The number of dots DT is the number of pixels PX onto which ink is ejected out of the plurality of pixels PX included in the printing area of ​​the medium M.

[0076] In this embodiment, the main scanning resolution is not a value indicating the density of dots DT arranged in the main scanning direction, but a value indicating the density of pixels PX arranged in the main scanning direction. Similarly, the sub-scanning resolution is not a value indicating the density of dots DT arranged in the sub-scanning direction, but a value indicating the density of pixels PX arranged in the sub-scanning direction. For example, FIG. 10 and FIG. 16 (described later) show the state after formation of the base B1 is completed. While the arrangement of dots DT differs between FIG. 10 and FIG. 16, the arrangement of multiple pixels PX is the same. Therefore, in both the first printing process in S42 and the first printing process in S62 (described later), the main scanning resolution is 1200 dpi and the sub-scanning resolution is 600 dpi. Similarly, while the arrangement of dots DT differs between FIG. 14 and FIG. 20 (described later), the arrangement of multiple pixels PX is the same. Therefore, in both the second printing process in S44 and the second printing process in S64 described below, the main scanning resolution is 1200 dpi and the sub-scanning resolution is 1200 dpi.

[0077] As shown in FIG. 9 , the white head 3 is positioned at the leftmost position P21 with its two nozzles 31 positioned on lines L11 and L13 in the front-to-back direction. As indicated by arrow A11, the white head 3 performs an ejection scan from the leftmost position P21 to the rightmost position P22. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 at each pixel PX on each of lines L11 and L13. For example, the white head 3 selects to eject white ink at all pixels PX on each of lines L11 and L13. As a result, dots DT made of white ink are formed at each of the eight pixels PX on line L11, and dots DT made of white ink are formed at each of the eight pixels PX on line L13.

[0078] As indicated by arrow A12 in FIG. 10 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B1 (1 / 600 inch in this embodiment). As a result, the white head 3 is positioned at the right end position P22 with its two nozzles 31 aligned on lines L12 and L14 in the front-to-rear direction. As indicated by arrow A13, the white head 3 performs an ejection scan from the right end position P22 to the left end position P21. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L11 and L13. For example, the white head 3 selects to eject white ink at all pixels PX on each of lines L11 and L13. As a result, dots DT are formed with white ink at each of the eight pixels PX on line L12, and dots DT are formed with white ink at each of the eight pixels PX on line L14.

[0079] As a result of the above, a base B11 is formed by 32 dots DT on the medium M. The base B11 is the base B1 formed by the first printing process (S42). In the first printing process (S42), the base B11 is formed in two passes.

[0080] 9 and 10 illustrate a case in which white ink is ejected from two nozzles 31 adjacent in the front-to-rear direction in the white head 3 to form dots DT on multiple lines. In contrast, the multiple nozzles 31 that form dots DT on multiple lines do not have to be adjacent in the front-to-rear direction. For example, the multiple nozzles 31 that form dots DT on multiple lines may be aligned in the front-to-rear direction with other nozzles 31 between them. Dots DT may also be formed on multiple lines by a single nozzle 31. The same applies to the examples shown in FIGS. 11 to 20, which will be described later.

[0081] 8, after the first printing process (S42), the CPU 91 performs a first conveying process (S43). In the first conveying process (S43), the CPU 91 conveys the platen 7 from the front end position P11 to the rear end position P12.

[0082] After the first conveying process (S43), the CPU 91 performs a second printing process (S44). In the second printing process (S44), the CPU 91 repeats parallel scanning of the white head 3 and the color heads 4 and a predetermined amount of sub-scanning of the platen 7 from rear to front. The parallel scanning of the white head 3 and the color heads 4 is a head 10 ejection scan in which the respective ejection scans of the white head 3 and the color heads 4 are performed in parallel. In the second printing process (S44), the CPU 91 causes the white head 3 to eject white ink in the amount of white ink allocated to the base B2 calculated in the process of S32.

[0083] In the second printing process (S44), 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 first printing process (S42). 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 P12 to the front end position P11 by repeatedly sub-scanning the platen 7 a predetermined distance from rear to front. As a result, as shown in state ST4 in FIG. 4, a base B2 is formed in the area of ​​the medium M where the base B is scheduled to be printed, and as shown in state ST5 in FIG. 4, a color layer C1 is formed on the base B2 in the area of ​​the medium M where the color image is scheduled to be printed.

[0084] More specifically, in the second printing process (S44), the CPU 91 repeats ejection scans of the white head 3 and predetermined sub-scans of the platen 7 from rear to front so that the main scanning resolution of the base B2 is 1200 dpi and the sub-scan resolution of the base B2 is 1200 dpi. The CPU 91 repeats ejection scans of the color head 4 and predetermined sub-scans of the platen 7 from rear to front so that the main scanning resolution of the color layer C1 is 1200 dpi and the sub-scan resolution of the color layer C1 is 1200 dpi. For example, by the CPU 91 executing sub-scans of the platen 7 in S44 by a predetermined amount that is half the sub-scan of the platen 7 in S42, the sub-scan resolution of the base B2 becomes 1200 dpi, which is twice the sub-scan resolution of the base B1 in S42 (600 dpi).

[0085] 11 to 14, the movement of the white head 3 and platen 7 in the second printing process (S44) in which the main scanning resolution of the base B2 is 1200 dpi and the sub-scanning resolution of the base B2 is 1200 dpi will be described. To simplify the description, the following assumptions will be made: Two nozzles 31 are aligned in the front-to-rear direction in the white head 3. The printing area of ​​the medium M includes eight pixels PX aligned at 1200 dpi in the left-to-right direction, and eight pixels PX aligned at 1200 dpi in the front-to-rear direction. In other words, the printing area of ​​the medium M includes 64 (8 x 8) pixels PX. The lines L21, L22, L23, L24, L25, L26, L27, and L28 of pixels PX aligned in the left-right direction are aligned from front to back in the following order: line L21, line L22, line L23, line L24, line L25, line L26, line L27, and line L28. Under this assumption, the calculated white ink allocation amount of 6 mL for the base B2 corresponds to 32 dots DT in the second printing process in fixed quantity mode.

[0086] As shown in FIG. 11 , the white head 3 is positioned at the leftmost position P21 with its two nozzles 31 aligned on lines L21 and L25 in the front-to-back direction. As indicated by arrow A21, the white head 3 performs an ejection scan from the leftmost position P21 to the rightmost position P22. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L21 and L25. For example, the white head 3 selects not to eject white ink for every other pixel PX on each of lines L21 and L25. As a result, dots DT made of white ink are formed at four of the eight pixels PX on line L21, and dots DT made of white ink are formed at four of the eight pixels PX on line L25.

[0087] As indicated by arrow A22 in FIG. 12 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B2 (1 / 1200 inch in this embodiment). As a result, the white head 3 is positioned at the right end position P22 with the two nozzles 31 positioned on lines L22 and L26 in the front-to-rear direction. As indicated by arrow A23, the white head 3 performs an ejection scan from the right end position P22 to the left end position P21. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L22 and L26. For example, the white head 3 selects not to eject white ink for every other pixel PX on each of lines L22 and L26. As a result, dots DT made of white ink are formed at four of the eight pixels PX on line L22, and dots DT made of white ink are formed at four of the eight pixels PX on line L26.

[0088] As indicated by arrow A24 in FIG. 13 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B2 (1 / 1200 inch in this embodiment). As a result, the white head 3 is positioned at the left end position P21 with the two nozzles 31 positioned on lines L23 and L27 in the front-to-rear direction. As indicated by arrow A25, the white head 3 performs an ejection scan from the left end position P21 to the right end position P22. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L23 and L27. For example, the white head 3 selects not to eject white ink for every other pixel PX on each of lines L23 and L27. As a result, dots DT made of white ink are formed in four of the eight pixels PX on line L23, and dots DT made of white ink are formed in four of the eight pixels PX on line L27.

[0089] As indicated by arrow A26 in FIG. 14 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B2 (1 / 1200 inch in this embodiment). As a result, the white head 3 is positioned at the right end position P22 with the two nozzles 31 positioned on lines L24 and L28 in the front-to-back direction. As indicated by arrow A27, the white head 3 performs an ejection scan from the right end position P22 to the left end position P21. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L24 and L28. For example, the white head 3 selects not to eject white ink for every other pixel PX on each of lines L24 and L28. As a result, dots DT made of white ink are formed in four of the eight pixels PX on line L24, and dots DT made of white ink are formed in four of the eight pixels PX on line L28.

[0090] As a result of the above, a base B12 is formed on the base B11 shown in Figure 10 using 32 dots DT on the medium M. The base B12 is the base B2 formed in the second printing process (S44). In the second printing process (S44), the base B12 is formed in four passes. Note that the color head 4 is disposed downstream (in front of, in this embodiment) of the white head 3 in the sub-scanning direction of the platen 7, and in the second printing process (S44), ejection scans of the color head 4 are repeatedly performed, so that the color layer C1 shown in Figure 4 is layered on the base B12 in parallel with the formation of the base B12.

[0091] 8, after the second printing process (S44), the CPU 91 performs a second transport process (S45). In the second transport process (S45), the CPU 91 transports the platen 7 from the front end position P11 to the rear end position P12.

[0092] After the second conveying process (S45), the CPU 91 performs a first post-processing (S46). In the first post-processing (S46), the CPU 91 repeats the ejection scan of the post-processing head 5 and the sub-scan of the platen 7 from rear to front by a predetermined amount. In the first post-processing (S46), the CPU 91 causes the post-processing head 5 to eject the post-processing liquid in the allocated amount of post-processing liquid for the post-processing layer OC1 calculated in the process of S34.

[0093] In the first post-processing (S46), post-processing liquid is ejected from the post-processing head 5 onto the medium M on the platen 7 onto which white ink and color inks have been ejected in the second printing process (S44). The post-processing liquid ejected from the post-processing head 5 lands on the medium M on the platen 7. The CPU 91 transports the platen 7 from the rear end position P12 to the front end position P11 by repeatedly performing a predetermined amount of sub-scanning of the platen 7 from rear to front. As a result, a post-processing layer OC1 is formed in the area of ​​the medium M where the post-processing layer OC is scheduled to be formed, as shown in state ST6 in FIG.

[0094] In detail, in the first post-processing (S46), the CPU 91 repeats ejection scanning of the post-processing head 5 and sub-scanning of the platen 7 from rear to front by a predetermined amount so that the main scanning resolution of the post-processing layer OC1 is 1200 dpi and the sub-scanning resolution of the post-processing layer OC1 is 600 dpi. The movement of the post-processing head 5 and platen 7 in the first post-processing (S46) differs from the movement of the white head 3 and platen 7 in the first printing process (S42) in that the post-processing head 5 ejects post-processing liquid instead of the white head 3 ejecting white ink, and in that the sub-scanning direction of the platen 7 is reversed. For this reason, a description of the movement of the post-processing head 5 and platen 7 in the first post-processing (S46) will be omitted.

[0095] 8, after the first post-processing (S46), the CPU 91 performs the second post-processing (S47). In the second post-processing (S47), the CPU 91 repeats the ejection scan of the post-processing head 5 and the sub-scan of the platen 7 from front to rear by a predetermined amount. In the second post-processing (S47), the CPU 91 causes the post-processing head 5 to eject the post-processing liquid in the allocated amount of post-processing liquid for the post-processing layer OC2 calculated in the process of S34.

[0096] In the second post-processing (S47), post-processing liquid is ejected from the post-processing head 5 onto the medium M on the platen 7 onto which post-processing liquid was ejected in the first post-processing (S46). The post-processing liquid ejected from the post-processing head 5 lands on the medium M on the platen 7. The CPU 91 transports the platen 7 from the leading end position P11 to the trailing end position P12 by repeatedly sub-scanning the platen 7 from front to rear by a predetermined amount. As a result, a post-processing layer OC2 is formed on the area of ​​the medium M where the post-processing layer OC is scheduled to be formed, as shown in state ST7 in FIG.

[0097] In detail, in the second post-processing (S47), the CPU 91 repeats ejection scanning of the post-processing head 5 and a predetermined amount of sub-scanning of the platen 7 from front to rear so that the main scanning resolution of the post-processing layer OC2 becomes 1200 dpi and the sub-scanning resolution of the post-processing layer OC2 becomes 1200 dpi. The movement of the post-processing head 5 and platen 7 in the second post-processing (S47) differs from the movement of the white head 3 and platen 7 in the second printing process (S44) in that the post-processing head 5 ejects post-processing liquid instead of the white head 3 ejecting white ink. For this reason, a description of the movement of the post-processing head 5 and platen 7 in the second post-processing (S47) will be omitted.

[0098] 8, after the second post-processing (S47), the CPU 91 performs a third transport process (S48). In the third transport process (S48), the CPU 91 transports the platen 7 from rear to front, from the rear end position P12 to the front end position P11. With the platen 7 positioned at the front end position P11, the user removes the printed medium M from the platen 7. This completes the print control in fixed quantity mode (S31 to S48).

[0099] Printing control in fixed rate mode will now be described. The CPU 91, for example, references specified print data and specifies the sub-scan resolution of base B1, the sub-scan resolution of base B2, and the total amount of white ink for base B (S51). The CPU 91 calculates the white ink allocation amount for base B1 and the white ink allocation amount for base B2 based on the specified sub-scan resolution of base B1, the sub-scan resolution of base B2, and the total amount of white ink for base B (S52). The processing of S52 uses simultaneous equations based on the following equations (1) and (2):

[0100] A=A1+A2...(1)

[0101] A1=k×A2...(2)

[0102] The total amount (mL) of white ink of the specified base B is substituted for A. k is a coefficient greater than 0 and less than 1. In this case, A1 / A2 is greater than 0 and less than 1. k is preferably equal to or greater than the ratio of the sub-scanning resolution of base B1 or the post-processing layer OC2 to the sub-scanning resolution of base B2 or the post-processing layer OC2 (sub-scanning resolution of base B1 / sub-scanning resolution of base B2 or sub-scanning resolution of post-processing layer OC1 / sub-scanning resolution of post-processing layer OC2). In other words, A1 / A2 is preferably equal to or greater than the ratio of the sub-scanning resolution of base B1 or the post-processing layer OC2 to the sub-scanning resolution of base B2 or the post-processing layer OC2. In this embodiment, k is equal to the ratio of the sub-scanning resolution of base B1 or the post-processing layer OC1 to the sub-scanning resolution of base B2 or the post-processing layer OC2. In other words, A1 / A2 is equal to the ratio of the sub-scanning resolution of the base B1 or post-processing layer OC1 to the sub-scanning resolution of the base B2 or post-processing layer OC2. Therefore, the ratio of the sub-scanning resolution of the base B1 identified in the process of S51 to the sub-scanning resolution of the base B2 identified in the process of S51 is substituted for k. In the solution (A1, A2) of the simultaneous equations by equations (1) and (2), A1 is the white ink allocation amount (mL) of the base B1 to be calculated, and A2 is the white ink allocation amount (mL) of the base B2 to be calculated.

[0103] For example, suppose the total amount of white ink in base B is 12 mL, the sub-scanning resolution of base B1 is 600 dpi, and the sub-scanning resolution of base B2 is 1200 dpi. In this case, in equations (1) and (2), 12 mL is substituted for A, and 600 dpi / 1200 dpi is substituted for k. Therefore, when the simultaneous equations based on equations (1) and (2) are solved, A1 becomes 4 mL and A2 becomes 8 mL. In other words, the white ink allocation amount for base B1 is 4 mL, and the white ink allocation amount for base B2 is 8 mL.

[0104] The CPU 91, for example, refers to the specified print data and specifies the sub-scanning resolution of the post-processing layer OC1, the sub-scanning resolution of the post-processing layer OC2, and the total amount of post-processing liquid for the post-processing layer OC (S53). The CPU 91 calculates the post-processing liquid allocation amount for the post-processing layer OC1 and the post-processing liquid allocation amount for the post-processing layer OC2 based on the specified sub-scanning resolution of the post-processing layer OC1, the sub-scanning resolution of the post-processing layer OC2, and the total amount of post-processing liquid for the post-processing layer OC (S54). The processing of S54 also uses the simultaneous equations of the above formulas (1) and (2).

[0105] The total amount (mL) of post-processing liquid for the specified post-processing layer OC is substituted for A. The ratio of the sub-scanning resolution of the post-processing layer OC1 specified in the processing of S53 to the sub-scanning resolution of the post-processing layer OC2 specified in the processing of S53 is substituted for k. In this case, in the solution (A1, A2) of the simultaneous equations based on equations (1) and (2), A1 becomes the post-processing liquid allocation amount (mL) for the post-processing layer OC1 to be calculated, and A2 becomes the post-processing liquid allocation amount (mL) for the post-processing layer OC2 to be calculated.

[0106] The CPU 91 performs pre-processing (S61), first printing process (S62), first conveying process (S63), second printing process (S64), second conveying process (S65), first post-processing (S66), second post-processing (S67), and third conveying process (S68) in the following order: pre-processing (S61), first printing process (S62), first conveying process (S63), second printing process (S64), second conveying process (S65), first post-processing (S66), second post-processing (S67), third conveying process (S68).

[0107] The pre-processing (S61) is the same as the pre-processing (S41). That is, in the pre-processing (S61), a pre-processing layer S1 is formed on the medium M, as shown in state ST2 in FIG. 4 . In the first printing process (S62), the white ink allocation amount for the base B1 is different from that in the first printing process (S42). In the first printing process (S62), the CPU 91 causes the white head 3 to eject white ink in the amount of white ink allocated to the base B1 calculated in the process of S52. In the first printing process (S62), the base B1 is formed on the medium M, as shown in state ST3 in FIG.

[0108] In detail, in the first printing process (S62), the CPU 91 repeats the ejection scan of the white head 3 and the sub-scan of the platen 7 from rear to front by a predetermined amount so that the main scanning resolution of the base B1 is 1200 dpi and the sub-scan resolution of the base B1 is 600 dpi.

[0109] 15 and 16, the movement of the white head 3 and platen 7 in the first printing process (S62) in which the main scanning resolution of the base B1 is 1200 dpi and the sub-scanning resolution of the base B1 is 600 dpi will be described. To simplify the explanation, the same assumptions will be made as in the case of the movement of the white head 3 and platen 7 in the first printing process (S42) explained with reference to Figures 9 and 10. Note that the calculated white ink allocation amount of 4 mL for the base B1 corresponds to 22 dots DT in the first printing process in fixed rate mode.

[0110] As shown in FIG. 15 , the white head 3 is positioned at the left end position P21 with its two nozzles 31 aligned on lines L11 and L13 in the front-to-back direction. As indicated by arrow A31, the white head 3 performs an ejection scan from the left end position P21 to the right end position P22. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 onto each pixel PX on lines L11 and L13. For example, the white head 3 alternately ejects white ink onto two consecutive pixels PX on each of lines L11 and L13, and does not eject white ink onto one pixel PX on each of lines L11 and L13. As a result, dots DT made of white ink are formed on six of the eight pixels PX on line L11, and dots DT made of white ink are formed on six of the eight pixels PX on line L13.

[0111] As indicated by arrow A32 in FIG. 16 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B1 (1 / 600 inch in this embodiment). As a result, the white head 3 is positioned at the right end position P22 with its two nozzles 31 positioned on lines L12 and L14 in the front-to-rear direction. As indicated by arrow A33, the white head 3 performs an ejection scan from the right end position P22 to the left end position P21. The white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L11 and L13. For example, for each of lines L11 and L13, the white head 3 alternates between ejecting white ink for two consecutive pixels PX and not ejecting white ink for one pixel PX. As a result, dots DT made of white ink are formed at five of the eight pixels PX on line L12, and dots DT made of white ink are formed at five of the eight pixels PX on line L14.

[0112] As a result of the above, a base B21 is formed by 22 dots DT on the medium M. The base B21 is the base B1 formed by the first printing process (S62). In the first printing process (S62), the base B21 is formed in two passes.

[0113] As shown in FIG. 8 , the first conveying process (S63) is the same as the first conveying process (S43). The second printing process (S64) differs from the second printing process (S44) in the amount of white ink allocated to the base B2. In the second printing process (S64), the CPU 91 causes the white head 3 to eject white ink in the amount of white ink allocated to the base B2 calculated in the process of S52. In the second printing process (S64), as in state ST4 shown in FIG. 4 , the base B2 is formed on the base B1 on the medium M, and as in state ST5 shown in FIG. 4 , the color layer C1 is formed on the base B2 on the medium M.

[0114] More specifically, in the second printing process (S64), the CPU 91 repeats ejection scanning of the white head 3 and a predetermined amount of sub-scanning of the platen 7 from rear to front so that the main scanning resolution of the base B2 becomes 1200 dpi and the sub-scanning resolution of the base B2 becomes 1200 dpi. The CPU 91 repeats ejection scanning of the color head 4 and a predetermined amount of sub-scanning of the platen 7 from rear to front so that the main scanning resolution of the color layer C1 becomes a predetermined resolution (e.g., 1200 dpi) and the sub-scanning resolution of the color layer C1 becomes a predetermined resolution (e.g., 1200 dpi).

[0115] 17 to 20, the movement of the white head 3 and platen 7 in the second printing process (S64) in which the main scanning resolution of the base B2 is 1200 dpi and the sub-scanning resolution of the base B2 is 1200 dpi will be described. To simplify the explanation, the same assumptions will be made as in the case of the movement of the white head 3 and platen 7 in the first printing process (S42) explained with reference to Figures 11 to 14. Note that the calculated white ink allocation amount of 8 mL for the base B2 corresponds to 42 dots DT in the second printing process in fixed rate mode.

[0116] As shown in FIG. 17 , the white head 3 is positioned at the leftmost position P21 with its two nozzles 31 aligned on lines L21 and L25 in the front-to-back direction. As indicated by arrow A41, the white head 3 performs an ejection scan from the leftmost position P21 to the rightmost position P22. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 onto each pixel PX on lines L21 and L25. For example, the white head 3 selects three pixels PX on each of lines L21 and L25 from which to not eject white ink. As a result, dots DT are formed with white ink at five of the eight pixels PX on line L21, and dots DT are formed with white ink at five of the eight pixels PX on line L25.

[0117] As indicated by arrow A42 in FIG. 18 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B2 (1 / 1200 inch in this embodiment). As a result, the white head 3 is positioned at the right end position P22 with the two nozzles 31 positioned on lines L22 and L26 in the front-to-back direction. As indicated by arrow A43, the white head 3 performs an ejection scan from the right end position P22 to the left end position P21. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L22 and L26. For example, the white head 3 selects three pixels PX for which white ink is not to be ejected for each of lines L22 and L26. As a result, dots DT made of white ink are formed at five of the eight pixels PX on line L22, and dots DT made of white ink are formed at five of the eight pixels PX on line L26.

[0118] As indicated by arrow A44 in FIG. 19 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B2 (1 / 1200 inch in this embodiment). As a result, the white head 3 is positioned at the left end position P21 with the two nozzles 31 positioned on lines L23 and L27 in the front-to-back direction. As indicated by arrow A45, the white head 3 performs an ejection scan from the left end position P21 to the right end position P22. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L23 and L27. For example, the white head 3 selects two pixels PX for which white ink is not to be ejected on each of lines L23 and L27. As a result, dots DT made of white ink are formed in each of six of the eight pixels PX on line L23, and dots DT made of white ink are formed in each of six of the eight pixels PX on line L27.

[0119] As indicated by arrow A46 in FIG. 20 , the platen 7 performs a sub-scan forward by an amount equal to the reciprocal of the sub-scan resolution of the base B2 (1 / 1200 inch in this embodiment). As a result, the white head 3 is positioned at the right end position P22 with the two nozzles 31 positioned on lines L24 and L28 in the front-to-rear direction. As indicated by arrow A47, the white head 3 performs an ejection scan from the right end position P22 to the left end position P21. During the ejection scan, the white head 3 selectively ejects or does not eject white ink from each of the two nozzles 31 for each pixel PX on lines L24 and L28. For example, the white head 3 selects three pixels PX for which white ink is not to be ejected on each of lines L24 and L28. As a result, dots DT made of white ink are formed at five of the eight pixels PX on line L24, and dots DT made of white ink are formed at five of the eight pixels PX on line L28.

[0120] As a result of the above, a base B22 is formed on the base B21 shown in FIG. 16 using 42 dots DT on the medium M. The base B22 is the base B2 formed in the second printing process (S64). In the second printing process (S64), the base B22 is formed in four passes. Note that the color head 4 is disposed downstream (in front of, in this embodiment) of the white head 3 in the sub-scanning direction of the platen 7, and in the second printing process (S64), ejection scans of the color head 4 are repeatedly performed, so that the color layer C1 shown in FIG. 4 is layered on the base B22 in parallel with the formation of the base B22.

[0121] As shown in FIG. 8, the second conveying process (S65) is the same as the second conveying process (S45). The first post-processing (S66) differs from the first post-processing (S46) in the amount of post-processing liquid allocated to the post-processing layer OC1. In the first post-processing (S66), the CPU 91 causes the post-processing head 5 to eject the post-processing liquid in the amount of post-processing liquid allocated to the post-processing layer OC1 calculated in the process of S54. In the first post-processing (S66), the post-processing layer OC1 is formed on the medium M, as in state ST6 shown in FIG.

[0122] In detail, in the first post-processing (S66), the CPU 91 repeats ejection scanning of the post-processing head 5 and sub-scanning of the platen 7 from rear to front by a predetermined amount so that the main scanning resolution of the post-processing layer OC1 is 1200 dpi and the sub-scanning resolution of the post-processing layer OC1 is 600 dpi. The movement of the post-processing head 5 and platen 7 in the first post-processing (S66) differs from the movement of the white head 3 and platen 7 in the first printing process (S62) in that the post-processing head 5 ejects post-processing liquid instead of the white head 3 ejecting white ink, and in that the sub-scanning direction of the platen 7 is reversed. For this reason, a description of the movement of the post-processing head 5 and platen 7 in the first post-processing (S66) will be omitted.

[0123] In the second post-processing (S67), the allocated amount of post-processing liquid for the post-processing layer OC2 is different from that in the second post-processing (S47). In the second post-processing (S67), the CPU 91 causes the post-processing head 5 to eject the post-processing liquid in the allocated amount of post-processing liquid for the post-processing layer OC2 calculated in the processing of S54. In the second post-processing (S67), the post-processing layer OC2 is formed on the medium M, as in state ST7 shown in FIG.

[0124] In detail, in the second post-processing (S67), the CPU 91 repeats ejection scanning of the post-processing head 5 and sub-scanning of the platen 7 from front to rear by a predetermined amount so that the main scanning resolution of the post-processing layer OC2 becomes 1200 dpi and the sub-scanning resolution of the post-processing layer OC2 becomes 1200 dpi. The movement of the post-processing head 5 and platen 7 in the second post-processing (S67) differs from the movement of the white head 3 and platen 7 in the second printing process (S64) in that the post-processing head 5 ejects post-processing liquid instead of the white head 3 ejecting white ink. For this reason, a description of the movement of the post-processing head 5 and platen 7 in the second post-processing (S67) will be omitted.

[0125] The third conveying process (S68) is the same as the third conveying process (S48). With the above, printing control in the fixed rate mode (S51 to S68) is completed.

[0126] The main effects of the above embodiment will be described. In the example of forming base B1 in the quantitative mode shown in FIG. 9, the number of dots DT is 32, and the amount of white ink allocated to base B1 is 6 mL. The number of passes required to form base B11 is two. Therefore, as shown in FIG. 21, the duty of base B11 is 6 mL / 2 passes, or 3 mL / pass. In the example of forming base B2 in the quantitative mode shown in FIG. 14, the number of dots is 32, and the amount of white ink allocated to base B2 is 6 mL. The number of passes required to form base B12 is four. Therefore, as shown in FIG. 21, the duty of base B12 is 6 mL / 4 passes, or 1.5 mL / pass.

[0127] On the other hand, in the example of forming base B1 in fixed rate mode shown in FIG. 16 , the number of dots DT is 22, and the white ink allocation amount for base B1 is 4 mL. The number of passes required to form base B21 is two. Therefore, as shown in FIG. 22 , the duty for base B21 is 4 mL / 2 passes, or 2 mL / pass. In the example of forming base B2 in fixed rate mode shown in FIG. 20 , the number of dots is 42, and the white ink allocation amount for base B2 is 8 mL. The number of passes required to form base B22 is four. Therefore, as shown in FIG. 22 , the duty for base B22 is 8 mL / 4 passes, or 2 mL / pass.

[0128] In this embodiment, for example, the duty in the second printing process (S44) has the same meaning as the duty of the background B12. The duty ratio in quantitative mode is the duty in the first printing process (S42) relative to the duty in the second printing process (S44). The duty ratio in quantitative mode is equal to the ratio of the number of passes in the second printing process (S44) relative to the number of passes in the first printing process (S42). In this embodiment, the duty ratio in quantitative mode is equal to the ratio of the sub-scanning resolution in the second printing process (S44) relative to the sub-scanning resolution in the first printing process (S42).

[0129] For example, in the examples shown in FIGS. 10 and 14 , the duty ratio in quantitative mode is "3 / 1.5," which is the ratio of the duty of "1.5" in the second printing process (S44) to the duty of "3" in the first printing process (S42). Therefore, as shown in FIG. 21 , the duty ratio in quantitative mode is "2." The duty ratio in quantitative mode is equal to "4 / 2," which is the ratio of the number of passes of "2" in the first printing process (S42) to the number of passes of "4" in the second printing process (S44). The duty ratio in quantitative mode is equal to "1200 / 600," which is the ratio of the sub-scanning resolution of "600" in the first printing process (S42) to the sub-scanning resolution of "1200" in the second printing process (S44).

[0130] The duty ratio in fixed rate mode is "1." For example, in the examples shown in Figures 16 and 20, the duty ratio in fixed rate mode is "2 / 2," which is the ratio of the duty "2" in the first printing process (S62) to the duty "2" in the second printing process (S64). Therefore, as shown in Figure 22, the duty ratio in fixed rate mode is "1."

[0131] In the above embodiment, the printer 1 includes a white head 3 that ejects white ink onto the medium M, and a CPU 91. The CPU 91 performs a first printing process (S62) in which white ink is ejected from the white head 3 onto the medium M at a sub-scanning resolution of 600 dpi to form a base B21. The CPU 91 performs a second printing process (S64) in which white ink is ejected from the white head 3 onto the medium M at a sub-scanning resolution of 1200 dpi to form a base B22 on the base B21. In the fixed ratio mode, the white ink allocation amount for the base B1 is the total amount of white ink ejected from the white head 3 at the sub-scanning resolution of the base B1, which is the lower of the sub-scanning resolutions of the base B1 and the base B2, in the first printing process (S62) and the second printing process (S64). In the fixed rate mode, the white ink allocation amount for the base B2 is the total amount of white ink ejected from the white head 3 at the higher sub-scanning resolution of the base B2 between the sub-scanning resolution of the base B1 and the sub-scanning resolution of the base B2 in the first printing process (S62) and the second printing process (S64). In the fixed rate mode, the white ink allocation amount for the base B1 is less than the white ink allocation amount for the base B2 in the first printing process (S62) and the second printing process (S64).

[0132] In the fixed-rate mode, the white ink allocation amount for the base B1 is less than the white ink allocation amount for the base B2, resulting in a lower duty for the base B1 and a lower duty ratio. Therefore, in the fixed-rate mode, the ejection flow F is suppressed when the base B1 is formed at a sub-scanning resolution of 600 dpi. As a result, the ejection flow F is suppressed throughout the first printing process (S62) and the second printing process (S64). This prevents the white ink mist stirred up by the ejection flow F from adhering to the underside of the white head 3. Therefore, the printer 1 contributes to suppressing irregularities in the ejection of white ink by the white head 3 when stacking multiple bases B1 and B2 in the fixed-rate mode. Similarly, because the post-treatment allocation amount for the post-treatment layer OC1 is less than the post-treatment liquid allocation amount for the post-treatment layer OC2, the printer 1 contributes to suppressing irregularities in the post-treatment ejection by the post-treatment head 5 when stacking multiple post-treatment layers OC1 and OC2 in the fixed-rate mode.

[0133] In the above embodiment, in the fixed rate mode, the ratio (A1 / A2) of the white ink allocation amount of the base B1 to the white ink allocation amount of the base B2 is equal to or greater than the ratio (600 dpi / 1200 dpi) of the sub-scanning resolution of the base B1 to the sub-scanning resolution, and is less than 1. This allows the printer 1 to suppress an increase in the ejection flow F when the base B2 is formed at a sub-scanning resolution of 1200 dpi in the fixed rate mode, while contributing to suppressing the ejection flow F when the base B1 is formed at a sub-scanning resolution of 600 dpi.

[0134] In the above embodiment, the ratio of the white ink allocation amount of the background B1 to the white ink allocation amount of the background B2 is equal to the ratio of the sub-scanning resolution of the background B1 to the sub-scanning resolution of the background B2. This allows the printer 1 to contribute most to suppressing the ejection flow F overall in the first printing process (S62) and the second printing process (S64) in the fixed ratio mode.

[0135] In the above embodiment, the printer 1 includes a color head 4 that ejects color inks that form a color image onto the medium M. The white head 3 ejects white ink that forms the base B of the color image. In the second printing process (S64), the CPU 91 ejects color inks from the color head 4 onto the medium M to form a color layer C1 that constitutes the color image on the base B2 that constitutes the base B. This allows the printer 1 to contribute to improving the image quality of the base B in the fixed-ratio mode by suppressing irregularities in the ejection of white ink from the white head 3. As a result, the printer 1 contributes to improving the color development of color images in the fixed-ratio mode.

[0136] In the above embodiment, the printer 1 includes a color head 4 that ejects color inks that form a color image onto the medium M. The white head 3 ejects post-treatment liquid that covers the color image. In the second printing process (S64), the CPU 91 ejects color inks from the color head 4 onto the medium M to form a color layer C1 that constitutes the color image. After the second printing process (S64), the CPU 91 performs a first post-processing (S66) in which the post-treatment liquid is ejected from the post-treatment head 5 onto the medium M at a sub-scanning resolution of 600 dpi to form a post-treatment layer OC1 on the color layer C1. The CPU 91 then performs a second post-processing (S67) in which the post-treatment liquid is ejected from the post-treatment head 5 onto the medium M at a sub-scanning resolution of 1200 dpi to form a post-treatment layer OC2 on the post-treatment layer OC1. In the fixed rate mode, the post-treatment liquid allocation amount for the post-treatment layer OC1 is the total amount of post-treatment liquid ejected from the post-treatment head 5 at the lower sub-scanning resolution of the post-treatment layer OC1 in the first post-treatment (S66) and the second post-treatment (S67) at the sub-scanning resolution of the post-treatment layer OC1, whichever is lower. In the fixed rate mode, the post-treatment liquid allocation amount for the post-treatment layer OC2 is the total amount of post-treatment liquid ejected from the post-treatment head 5 at the higher sub-scanning resolution of the post-treatment layer OC2 in the first post-treatment (S66) and the second post-treatment (S67) at the sub-scanning resolution of the post-treatment layer OC2, whichever is higher. In the fixed rate mode, the post-treatment liquid allocation amount for the post-treatment layer OC1 is less than the post-treatment liquid allocation amount for the post-treatment layer OC2. This allows the printer 1 to contribute to reliably covering a color image with post-treatment liquid by suppressing irregularities in the ejection of post-treatment liquid by the post-treatment head 5 in the fixed rate mode.

[0137] In the above embodiment, in the fixed ratio mode, the sub-scanning resolution of base B1 is 600 dpi, which is lower than the sub-scanning resolution of base B2, 1200 dpi. Accordingly, in the fixed ratio mode, the printer 1 forms base B2, which is the layer above base B1, at a sub-scanning resolution of 1200 dpi, thereby contributing to improving the image quality of the layers close to the surface.

[0138] In the above embodiment, the printer 1 includes a pretreatment sprayer 6 that ejects pretreatment liquid onto the medium M. The white head 3 ejects white ink. The CPU 91 performs pretreatment (S61) by ejecting pretreatment liquid from the pretreatment sprayer 6 onto the medium M to form a pretreatment layer S1. After the pretreatment (S61), the CPU 91 ejects white ink from the white head 3 at a sub-scanning resolution of 600 dpi onto the medium M that has been wet with the pretreatment liquid in a first printing process (S62) to form a base B1 on the pretreatment layer S1. According to this, in the fixed-ratio mode, the printer 1 performs wet-on-wet printing in which white ink is ejected onto the medium M that has been wet with the pretreatment liquid in the first printing process (S62), while contributing to ensuring a constant total amount of white ink for the base B in the second printing process (S64).

[0139] Furthermore, because the sub-scanning resolution of the base B1 is 600 dpi, the time required to form the base B1 is shorter than when the sub-scanning resolution of the base B1 is 1200 dpi. This prevents the medium M from drying out before the wet-on-wet printing is complete. Therefore, in the fixed rate mode, the printer 1 contributes to completing the wet-on-wet printing before the medium M dries while suppressing the ejection flow F.

[0140] In the above embodiment, the printer 1 includes an operation unit 98 that accepts a designation of either a fixed rate mode or a fixed rate mode, which are different from each other. When the designation accepted by the operation unit 98 is a designation of the fixed rate mode, the CPU 91 performs a first printing process (S62) and a second printing process (S64). When the designation accepted by the operation unit 98 is a designation of the fixed rate mode, the CPU 91 performs a first printing process (S42) in which white ink is ejected from the white head 3 onto the medium M at a sub-scanning resolution of 600 dpi to form a base B21, and a second printing process (S44) in which white ink is ejected from the white head 3 onto the medium M at a sub-scanning resolution of 1200 dpi to form a base B2 on the base B1. The white ink allocation amount for the base B1 in the fixed rate mode is the total amount of white ink ejected from the white head 3 at the sub-scanning resolution of the base B1, whichever is lower, between the sub-scanning resolution of the base B1 and the sub-scanning resolution of the base B2, in the first printing process (S42) and the second printing process (S44). The white ink allocation amount for the base B2 in the fixed-rate mode is the total amount of white ink ejected from the white head 3 at the higher sub-scan resolution of the base B2 between the sub-scan resolution of the base B1 and the sub-scan resolution of the base B2 in the first printing process (S42) and the second printing process (S44). The white ink allocation amount for the base B1 in the fixed-rate mode and the white ink allocation amount for the base B2 in the fixed-rate mode are equal. This allows the user to specify whether the bases B1 and B2 are formed with different white ink allocation amounts depending on the sub-scan resolutions of the bases B1 and B2, or whether the bases B1 and B2 are formed with the same white ink allocation amount regardless of the sub-scan resolutions of the bases B1 and B2, by specifying either the fixed-rate mode or the fixed-rate mode. Thus, the printer 1 helps the user specify the allocation of white ink amounts to the multiple bases B1 and B2.

[0141] For example, in fixed rate mode, the white ink allocation amount for the base B1 may be so small that it is difficult to fix the white ink to the medium M. Specifically, this may be the case when the total amount of white ink in the base B is relatively small or the sub-scan resolution of the base B1 is relatively low. In this case, by specifying fixed rate mode, the user can set a white ink allocation amount for the base B1 that is greater than the white ink allocation amount for the base B1 in fixed rate mode. This allows the printer 1 to contribute to preventing difficulty in fixing the white ink to the medium M. A difference between the white ink allocation amount for the base B1 and the white ink allocation amount for the base B2 may affect the image quality printed on the medium M. Because the white ink allocation amount for the base B1 and the white ink allocation amount for the base B2 are the same in fixed rate mode, the printer 1 contributes to preventing a difference between the white ink allocation amount for the base B1 and the white ink allocation amount for the base B2 from affecting the image quality printed on the medium M.

[0142] In the above embodiment, the medium M corresponds to the "medium" in this disclosure. The white ink or post-treatment liquid corresponds to the "liquid" in this disclosure. The white head 3 or post-treatment head 5 corresponds to the "target head" in this disclosure. The CPU 91 corresponds to the "controller" and "computer" in this disclosure. The sub-scanning resolution of the base B1 corresponds to the "first resolution" in this disclosure. The base B21 or the post-treatment layer OC1 formed by the first post-treatment (S66) corresponds to the "first layer" in this disclosure. The first printing process (S62) or the first post-treatment (S66) process corresponds to the "first ejection process" in this disclosure. The sub-scanning resolution of the base B2 corresponds to the "second resolution" in this disclosure. The base B22 or the post-treatment layer OC2 formed by the second post-treatment (S67) corresponds to the "second layer" in this disclosure. The second printing process (S64) or the second post-treatment (S67) process corresponds to the "second ejection process" in this disclosure. The white ink allocation amount of the base B1 in the fixed rate mode or the post-treatment liquid allocation amount of the post-treatment layer OC1 in the fixed rate mode corresponds to the “first total amount” in this disclosure. The white ink allocation amount of the base B2 in the fixed rate mode or the post-treatment liquid allocation amount of the post-treatment layer OC2 in the fixed rate mode corresponds to the “second total amount” in this disclosure.

[0143] The color head 4 corresponds to the "color head" in this disclosure. The white ink corresponds to the "base ink" in this disclosure. The color layer C1 corresponds to the "color ink layer" in this disclosure. The second printing process (S64) corresponds to the "color ink ejection process" in this disclosure. The pretreatment spray 6 corresponds to the "pretreatment ejection section" in this disclosure. The pretreatment layer S1 corresponds to the "pretreatment liquid layer" in this disclosure. The pretreatment (S61) corresponds to the "pretreatment liquid ejection process" in this disclosure. The fixed rate mode corresponds to the "first mode" in this disclosure. The fixed quantity mode corresponds to the "second mode" in this disclosure. The operation section 98 corresponds to the "receiving section" in this disclosure. The base B11 or the post-treatment layer OC1 formed by the first post-treatment (S46) corresponds to the "third layer" in this disclosure. The first printing process (S42) or the first post-treatment (S46) corresponds to the "third ejection process" in this disclosure. The base B12 or the post-treatment layer OC1 formed by the second post-treatment (S47) corresponds to the "fourth layer" in this disclosure. The second printing process (S44) or the second post-treatment (S47) corresponds to the "fourth ejection process" in this disclosure. The white ink allocation amount of the base B1 in the quantitative mode or the post-treatment liquid allocation amount of the post-treatment layer OC1 in the quantitative mode corresponds to the "third total amount" in this disclosure. The white ink allocation amount of the base B2 in the quantitative mode or the post-treatment liquid allocation amount of the post-treatment layer OC2 in the quantitative mode corresponds to the "fourth total amount" in this disclosure.

[0144] The present disclosure may be modified from the above embodiment. The modified examples described below may be combined with each other to the extent that no contradictions arise. In the above embodiment, the multiple heads 10 may be line heads. The printer 1 may be equipped with a single head 10 instead of multiple heads 10. The arrangement order of the multiple heads 10 and the type of liquid ejected by each of the multiple heads 10 may be modified from the above embodiment. For example, the white head 3 may eject ink other than white ink as ink for forming the base B.

[0145] In the above embodiment, the sub-scanning resolution of the base B1 is lower than the sub-scanning resolution of the base B2. However, the sub-scanning resolution of the base B2 may be lower than the sub-scanning resolution of the base B1. Similarly, the sub-scanning resolution of the post-processing layer OC2 may be lower than the sub-scanning resolution of the post-processing layer OC1.

[0146] In the above embodiment, k is equal to the ratio of the sub-scan resolution of the base B1 to the sub-scan resolution of the base B2. However, k may be greater than the ratio of the sub-scan resolution of the base B1 to the sub-scan resolution of the base B2. k may be greater than 0 and less than the ratio of the sub-scan resolution of the base B1 to the sub-scan resolution of the base B2. It is sufficient that the white ink allocation amount of the base B1 is less than the white ink allocation amount of the base B2. Note that if the sub-scan resolution of the base B2 is lower than the sub-scan resolution of the base B1, it is sufficient that the white ink allocation amount of the base B2 is less than the white ink allocation amount of the base B1.

[0147] In the above embodiment, divided printing of the base B is performed when the base B is formed, and divided printing of the post-treatment layer OC is performed when the post-treatment layer OC is formed. Alternatively, one of the divided printing of the base B and the divided printing of the post-treatment layer OC may be formed by normal printing. Normal printing is, for example, a printing method in which the base B is formed as a single layer without being divided into bases B1 and B2. In the above embodiment, one or both of the divided printing of the base B and the divided printing of the post-treatment layer OC may be formed by normal printing, and another layer may be divided and printed. The other layer may be, for example, the color layer C1. In this case, it is preferable that the amount of color ink allocated to the color layer C1 with a sub-scanning resolution of 600 dpi be less than the amount of color ink allocated to the color layer C1 with a sub-scanning resolution of 1200 dpi.

[0148] In the above embodiment, the pretreatment layer S1 may be omitted. The base B may be omitted. The color layer C1 may be omitted. The posttreatment layer OC may be omitted. For example, if the pretreatment layer S1 is omitted, the base B1 may be formed on a medium M that is not wet with the pretreatment liquid. The base B1 may be formed on a medium M in a state where the moisture in the pretreatment layer S1 has evaporated after the pretreatment layer S1 has been formed on the medium M. For example, if the medium M contains cotton fibers, a process of evaporating the moisture in the pretreatment layer S1 may be performed after the pretreatment layer S1 is formed.

[0149] In the above embodiment, the pre-treatment liquid is ejected by the pre-treatment spray 6. However, the pre-treatment liquid may be ejected by any one of the plurality of heads 10. In the above embodiment, the post-treatment liquid is ejected by the post-treatment head 5. However, the post-treatment liquid may be ejected by a spray.

[0150] In the above embodiment, in the second printing process, the CPU 91 may perform an ejection scan of the white head 3 instead of parallel scanning of the white head 3 and the color heads 4, and omit the ejection scan of the color heads 4. In this case, the CPU 91 may repeat the ejection scan of the color head 4 and the sub-scan of the platen 7 after the second printing process to form the color layer C1 on the medium M.

[0151] In the above embodiment, in the first post-processing, the CPU 91 may perform a sub-scan of the platen 7 from front to back instead of a sub-scan of the platen 7 from back to front, and may perform an ejection scan of the color head 4 in addition to an ejection scan of the post-processing head 5. In other words, in the first post-processing, the CPU 91 may perform parallel scanning of the color head 4 and the post-processing head 5. This allows the formation of the color layer C1 and the formation of the post-processing layer OC1 on the color layer C1 to be performed in parallel on the medium M. In this case, the CPU 91 may omit the ejection scan of the color head 4 in the second printing process.

[0152] In the above embodiment, the fixed rate mode may be omitted from the fixed rate mode and the fixed rate mode. In this case, when the CPU 91 receives a print instruction (S21: YES), the CPU 91 may proceed to S51 without making the determination in S22.

[0153] The CPU 91 may change the processing order as appropriate in the main processing. For example, the CPU 91 may calculate the white ink allocation amount for the base B1 after the preprocessing (S61) and before the first printing processing (S62). For example, the CPU 91 may calculate the white ink allocation amount for the base B2 after the first conveying processing (S63) and before the second printing processing (S64).

[0154] The sub-scanning direction of the platen 7 may be changed from that in the above embodiment. For example, in the first printing process, the sub-scanning direction of the platen 7 may be from front to rear. In the above embodiment, the CPU 91 references the print data and specifies the sub-scanning resolution of the base B1, the sub-scanning resolution of the base B2, the total amount of white ink for the base B, etc. In contrast, the sub-scanning resolution of the base B1, the sub-scanning resolution of the base B2, the total amount of white ink for the base B, etc. may be specified by the print settings of the printer 1, and the CPU 91 may reference the print settings of the printer 1 and specify the sub-scanning resolution of the base B1, the sub-scanning resolution of the base B2, the total amount of white ink for the base B, etc.

[0155] In the above embodiment, the main scanning resolution of the base B1 is the same as the main scanning resolution of the base B2. Alternatively, the main scanning resolution of the base B1 may be lower than the main scanning resolution of the base B2, or the main scanning resolution of the base B2 may be lower than the main scanning resolution of the base B1. For example, if the main scanning resolution of the base B1 is lower than the main scanning resolution of the base B2, the base B1 is formed by ejecting white ink from the white head 3 at a first frequency during the ejection scan of the white head 3. The base B2 is formed by ejecting white ink from the white head 3 at a second frequency higher than the first frequency during the ejection scan of the white head 3. For example, if the main scanning resolution is 600 dpi, the white ink is ejected from the white head 3 at 10 kHz during the ejection scan of the white head 3. If the main scanning resolution is 1200 dpi, the white ink is ejected from the white head 3 at 20 kHz during the ejection scan of the white head 3. When the main scanning resolution of the base B1 is different from the main scanning resolution of the base B2, the sub-scanning resolution of the base B1 may be the same as the sub-scanning resolution of the base B2. Similarly, for example, the main scanning resolution of the post-processing layer OC1 may be lower than the main scanning resolution of the post-processing layer OC2.

[0156] Instead of the CPU 91, a microcomputer, an ASIC (Application Specific Integrated Circuit), 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 an HDD provided in the server.

[0157] 1: Printer 3: White head 4: Color head 5: Post-treatment head 6: Pre-treatment spray 91: CPU 92: Memory 98: Operation unit

Claims

1. A printer comprising: a target head that ejects liquid onto a medium; and a control unit, wherein the control unit performs a first ejection process in which the liquid is ejected from the target head onto the medium at a first resolution to form a first layer; and a second ejection process in which the liquid is ejected from the target head onto the medium at a second resolution to form a second layer on the first layer, wherein in the first ejection process and the second ejection process, a first total amount, which is the total amount of the liquid ejected from the target head at the lower of the first resolution and the second resolution, is less than a second total amount, which is the total amount of the liquid ejected from the target head at the higher of the first resolution and the second resolution.

2. The printer according to claim 1, wherein the ratio of the first total amount to the second total amount is equal to or greater than the ratio of the low resolution to the high resolution and is less than 1.

3. The printer according to claim 2, wherein the ratio of the first total amount to the second total amount is equal to the ratio of the low resolution to the high resolution.

4. A printer as described in any one of claims 1 to 3, characterized in that it is provided with a color head that ejects color inks that form a color image onto the medium, the target head ejects base ink that forms a base for the color image, and the control unit performs a color ink ejection process that is performed in parallel with or after the second ejection process, in which the color inks are ejected from the color head onto the medium and a color ink layer that forms the color image is formed on the second layer that forms the base.

5. A printer as described in any one of claims 1 to 3, characterized in that it is provided with a color head that ejects color inks that form a color image onto the medium, the target head ejects a post-treatment liquid that covers the color image, and the control unit performs a color ink ejection process that ejects the color inks from the color head onto the medium and forms a color ink layer that constitutes the color image, and a first ejection process that is performed in parallel with or after the color ink ejection process and ejects the post-treatment liquid from the target head onto the medium at the first resolution and forms the first layer on the color ink layer.

6. A printer according to any one of claims 1 to 3, wherein the low resolution is the first resolution, and the high resolution is the second resolution.

7. A printer according to any one of claims 1 to 3, characterized in that it comprises a pretreatment discharge unit that discharges a pretreatment liquid onto the medium, the target head discharges ink, and the control unit performs a pretreatment liquid discharge process in which the pretreatment liquid is discharged from the pretreatment discharge unit onto the medium to form a pretreatment liquid layer, and a first discharge process, which is a process that is performed in parallel with the pretreatment liquid discharge process or after the pretreatment liquid discharge process, in which the ink is discharged from the target head at the first resolution onto the medium wetted with the pretreatment liquid to form the first layer on the pretreatment liquid layer.

8. A printer as described in any one of claims 1 to 3, comprising a reception unit that receives a designation of either a first mode or a second mode that are different from each other, wherein the control unit, when the designation received by the reception unit is a designation of the first mode, performs the first ejection process and the second ejection process, and when the designation received by the reception unit is a designation of the second mode, performs a third ejection process that ejects the liquid from the target head onto the medium at the first resolution to form a third layer, and a fourth ejection process that ejects the liquid from the target head onto the medium at the second resolution to form a fourth layer on the third layer, wherein a third total amount that is the total amount of the liquid ejected from the target head in the third ejection process and a fourth total amount that is the total amount of the liquid ejected from the target head in the fourth ejection process are equal.

9. A control method for a printer equipped with a target head that ejects liquid onto a medium, comprising: a first ejection process in which the liquid is ejected from the target head onto the medium at a first resolution to form a first layer; and a second ejection process in which the liquid is ejected from the target head onto the medium at a second resolution to form a second layer on the first layer, wherein in the first ejection process and the second ejection process, a first total amount, which is the total amount of the liquid ejected from the target head at the lower of the first resolution and the second resolution, is less than a second total amount, which is the total amount of the liquid ejected from the target head at the higher of the first resolution and the second resolution.

10. A control program that causes a computer that controls a printer equipped with a target head that ejects liquid onto a medium to execute a first ejection process that ejects the liquid from the target head onto the medium at a first resolution to form a first layer, and a second ejection process that ejects the liquid from the target head onto the medium at a second resolution to form a second layer on the first layer, wherein in the first ejection process and the second ejection process, a first total amount, which is the total amount of the liquid ejected from the target head at the lower of the first resolution and the second resolution, is less than a second total amount, which is the total amount of the liquid ejected from the target head at the higher of the first resolution and the second resolution.

Images