Inkjet recording system and inkjet recording method

Abstract

In the present invention, a computer generates ink dot data indicating pattern data of ink dots used when an ink head ejects ink, and also generates processing solution dot data indicating pattern data of processing solution dots used when a processing solution head ejects a processing solution. The computer performs contraction processing to convert ink dot data with first resolution into primary dot pattern data with second resolution lower than the first resolution, then performs expansion processing to expand each primary dot of a primary dot pattern to be converted into secondary dot pattern data, and thereby generates processing solution dot data.

Description

Inkjet recording system and inkjet recording method

[0001] The present invention relates to an inkjet recording system and an inkjet recording method.

[0002] Patent Literature 1 discloses an inkjet textile printing system that uses an inkjet printer to record an image on a recording material made of a fabric material. In the inkjet textile printing system, ink dot pattern data used to control the ejection of ink by an ink ejection head is created based on image data of an image to be recorded on the recording material, and pretreatment agent dot pattern data used to control the ejection of a pretreatment agent by a pretreatment agent application head is created based on the ink dot pattern data.

[0003] Japanese Patent Application Laid-Open No. 2005-232633

[0004] an inkjet recording system according to one aspect of the present invention, comprising: an inkjet head including an ink head that ejects ink onto a recording material and a treatment liquid head that ejects a treatment liquid that comes into contact with the ink onto the recording material; an ink data creation unit that creates ink dot data indicating data on a pattern of ink dots to be formed on the recording material in response to the ejection of the ink by the ink head based on image data of an image to be recorded on the recording material; a treatment liquid data creation unit that creates treatment liquid dot data indicating data on a pattern of treatment liquid dots to be formed on the recording material in response to the ejection of the treatment liquid by the treatment liquid head; and a control unit that controls the inkjet head to eject the ink from the ink head based on the ink dot data and to eject the treatment liquid from the treatment liquid head based on the treatment liquid dot data. The treatment liquid data creation unit creates the treatment liquid dot data by performing a reduction process to convert the ink dot data of a first resolution into data of a primary dot pattern at a second resolution lower than the first resolution, and then performing an expansion process to expand each dot of the primary dot pattern to convert it into data of a secondary dot pattern. According to the inkjet printing system according to one aspect of the present invention, it is possible to reduce the processing time required to create dot pattern data corresponding to the printing of an image on a printing material.

[0005] An inkjet recording method according to another aspect of the present invention is a method for recording an image on a recording material using an inkjet head including an ink head that ejects ink onto the recording material and a treatment liquid head that ejects a treatment liquid that comes into contact with the ink on the recording material. This inkjet recording method includes an ink data creating step of creating ink dot data indicating data for a pattern of ink dots to be formed on the recording material in response to the ejection of the ink by the ink head, based on image data of the image to be recorded on the recording material; a treatment liquid data creating step of creating treatment liquid dot data indicating data for a pattern of treatment liquid dots to be formed on the recording material in response to the ejection of the treatment liquid by the treatment liquid head; an ink ejecting step of ejecting the ink from the ink head based on the ink dot data; and a treatment liquid ejecting step of ejecting the treatment liquid from the treatment liquid head based on the treatment liquid dot data. In the treatment liquid data creating step, the treatment liquid dot data is created by performing a reduction process to convert the ink dot data at a first resolution into data for a primary dot pattern at a second resolution lower than the first resolution, and then performing an expansion process to expand each dot of the primary dot pattern to convert it into data for a secondary dot pattern. According to the ink jet recording method according to this other aspect of the present invention, it is possible to reduce the processing time required to create data on dot patterns corresponding to the recording of an image on a recording material.

[0006] Fig. 1 is a diagram showing the overall configuration of an inkjet recording system according to an embodiment of the present invention. Fig. 2 is a flowchart showing the processing flow of an inkjet recording method. Fig. 3 is a diagram showing an example of an ink dot pattern represented by data that is the logical sum of ink dot data of each color. Fig. 4 is a diagram showing an example of a primary dot pattern represented by primary dot pattern data. Fig. 5 is a diagram showing an example of a secondary dot pattern represented by secondary dot pattern data. Fig. 6 is a diagram showing an example of a treatment liquid dot pattern represented by treatment liquid dot data.

[0007] In an inkjet textile printing system such as that described above, in order to stably fix ink to a recording material using a treatment agent such as a pretreatment agent, it is necessary to form dots of treatment agent around each ink dot on the recording material. In this case, the technology disclosed in Patent Document 1 has a problem in that when data for a treatment agent dot pattern is created based on data for an ink dot pattern, the amount of processing required for data creation becomes too large. If the amount of processing required for creating data for a dot pattern corresponding to the printing of an image on a recording material becomes too large, a problem arises in that the processing time for data creation becomes long.

[0008] Therefore, there is a demand for an inkjet printing system and an inkjet printing method that can reduce the processing time required to create dot pattern data corresponding to the printing of an image on a printing material.

[0009] An inkjet recording system according to an embodiment of the present invention will be described below with reference to the drawings. In the following embodiment, a specific example of an inkjet recording system will be exemplified, which is a system equipped with an inkjet printer having an ink head that ejects ink for forming an image onto a wide, long recording material. Inkjet printers are suitable for digital textile printing, which uses an inkjet method to print (record) images such as letters and patterns on a recording material that is a fabric material such as a woven or knitted fabric. Of course, the inkjet printer applied to the inkjet recording system according to the present invention can also be used to print various images on recording materials such as paper sheets and resin sheets.

[0010] As shown in FIG. 1 , the inkjet recording system 1 includes an inkjet printer 2 and a computer 6 connected to the inkjet printer 2 so as to enable data communication. FIG. 1 shows a schematic configuration of the inkjet printer 2 as viewed from above. In the inkjet recording system 1, the computer 6 functions as an ink data generator that generates ink dot data DID based on image data DG of an image to be printed on a workpiece W, which is a recording material, and also functions as a treatment liquid data generator that generates treatment liquid dot data DRD. The inkjet printer 2 prints an image on the workpiece W using an inkjet method based on the ink dot data DID and treatment liquid dot data DRD generated by the computer 6. Note that in the inkjet recording system 1, the computer 6 may be incorporated into the inkjet printer 2. That is, the inkjet printer 2 may function as both an ink data generator and a treatment liquid data generator in addition to printing an image on the workpiece W using an inkjet method.

[0011] The inkjet printer 2 is a printer that prints images on a wide and long workpiece W using an inkjet system, and includes an inkjet head 20 including an ink head 3 and a treatment liquid head 4, a workpiece transport unit 21 that transports the workpiece W in a workpiece transport direction F, and a carriage 22 on which the inkjet head 20 is mounted. The inkjet printer 2 is a so-called serial printer that reciprocates the carriage 22 in a main scanning direction H1 that is perpendicular to the workpiece transport direction F on a horizontal plane, and alternates between ejection operations in which ink is ejected from the ink head 3 and treatment liquid is ejected from the treatment liquid head 4, and transport operations for the workpiece W. Another embodiment of the inkjet printer 2 is a so-called line printer in which the positions of the ink head 3 and treatment liquid head 4 included in the inkjet head 20 are fixed relative to the workpiece W transported in the workpiece transport direction F. Note that a sub-scanning direction H2 that is perpendicular to the main scanning direction H1 on a horizontal plane is parallel to the workpiece transport direction F.

[0012] The work transport unit 21 includes a feed roller 211 that pays out the work W before printing, and a take-up roller 212 that takes up the work W after printing. The feed roller 211 is located at the upstream end in the work transport direction F, and is a shaft that supports a roll that is a wound body of the work W before printing. The take-up roller 212 is located at the downstream end in the work transport direction F, and is a shaft that supports a roll that is a wound body of the work W after printing. The take-up roller 212 is provided with a drive source such as a motor that drives the take-up roller 212 to rotate about its axis and perform the winding operation of the work W. The work transport unit 21 transports the work W in the work transport direction F by the feed roller 211 being driven to rotate in accordance with the rotational drive of the take-up roller 212.

[0013] The carriage 22 carries the ink head 3 and the treatment liquid head 4 included in the inkjet head 20, and moves back and forth in a main scanning direction H1 perpendicular to the workpiece transport direction F. The carriage 22 is fixed to a timing belt 24 that is attached to a flat carriage guide 23 extending in the main scanning direction H1 so as to be able to move in circles. The timing belt 24 is an endless belt, and is driven to move in circles in the main scanning direction H1 while attached to the carriage guide 23. The carriage 22 moves back and forth in the main scanning direction H1 along the carriage guide 23 as the timing belt 24 moves in circles in the main scanning direction H1.

[0014] Each of the ink head 3 and processing liquid head 4 mounted on the carriage 22 can move relative to the work W in the main scanning direction H1 and the sub-scanning direction H2 as the work W is transported in the work transport direction F by the work transport unit 21 and the carriage 22 moves back and forth in the main scanning direction H1.

[0015] In this embodiment, the ink head 3 includes multiple individual heads 31 that eject ink of multiple colors, and these multiple individual heads 31 are mounted on the carriage 22. Each of the multiple individual heads 31 includes multiple nozzles that eject ink droplets using an ejection method such as a piezoelectric method using a piezoelectric element or a thermal method using a heating element, an ink flow path that guides the ink to the nozzles, and a wiring board for controlling the ink ejection operation. For example, a water-based pigment ink containing a water-based solvent, pigment, and binder resin can be used as the ink. The multiple individual heads 31 are mounted on the carriage 22 so as to be aligned in two rows in the main scanning direction H1. Each individual head 31 for each color has two heads. Two individual heads 31 that eject ink of the same color are mounted on the carriage 22 so as to be offset from each other in the main scanning direction H1 and the sub-scanning direction H2. In another embodiment, a configuration in which only one ink head 3 is mounted on the carriage 22 is possible.

[0016] In this embodiment, a pre-treatment liquid head 41 and a post-treatment liquid head 42 are respectively mounted on the carriage 22 as the treatment liquid head 4. The pre-treatment liquid head 41 and the post-treatment liquid head 42 are mounted on the carriage 22 so as to be disposed at positions different from the ink head 3 in the workpiece transport direction F parallel to the sub-scanning direction H2. The pre-treatment liquid head 41 is mounted on the carriage 22 so as to be disposed upstream of the ink head 3 in the workpiece transport direction F. FIG. 1 shows an example in which one pre-treatment liquid head 41 is disposed near one end of the array of the plurality of individual heads 31 in the ink head 3 in the main scanning direction H1. The post-treatment liquid head 42 is mounted on the carriage 22 so as to be disposed downstream of the ink head 3 in the workpiece transport direction F. FIG. 1 shows an example in which one post-treatment liquid head 42 is disposed near the other end of the array of the plurality of individual heads 31 in the ink head 3 in the main scanning direction H1. In another embodiment, either the pre-treatment liquid head 41 or the post-treatment liquid head 42 is mounted on the carriage 22 as the treatment liquid head 4 .

[0017] The pretreatment liquid head 41 includes a number of nozzles that eject pretreatment liquid droplets using an ejection method such as a piezoelectric method using a piezoelectric element or a thermal method using a heating element, a pretreatment liquid flow path that guides the pretreatment liquid to the nozzles, and a wiring board for controlling the ejection operation of the pretreatment liquid. The pretreatment liquid head 41 ejects the pretreatment liquid onto a position on the workpiece W before the ink is ejected by the ink head 3. The pretreatment liquid is a treatment liquid that is applied to the workpiece W before the ink. The pretreatment liquid is a treatment liquid that comes into contact with the ink in a wet state on the workpiece W and is a non-coloring treatment liquid that does not develop color even when attached to the workpiece W. The pretreatment liquid has the function of preventing ink bleeding on the workpiece W. Examples of such pretreatment liquid include a treatment liquid in which a binder resin is blended into a solvent, or a treatment liquid in which a positively charged cationic resin is blended into a solvent.

[0018] The post-treatment liquid head 42 includes a number of nozzles that eject post-treatment liquid droplets using an ejection method such as a piezoelectric method using a piezoelectric element or a thermal method using a heating element, a post-treatment liquid flow path that guides the post-treatment liquid to the nozzles, and a wiring board for controlling the ejection operation of the post-treatment liquid. The post-treatment liquid head 42 ejects the post-treatment liquid to a position on the workpiece W after the ink has been ejected by the ink head 3. The post-treatment liquid is a treatment liquid that is applied to the workpiece W after the ink. The post-treatment liquid is a treatment liquid that comes into contact with the ink in a non-dried state on the workpiece W and is a non-color-forming treatment liquid that does not develop color even when attached to the workpiece W. The post-treatment liquid has the function of increasing the fixation of the ink on the workpiece W. A silicone-based treatment liquid or the like can be used as such a post-treatment liquid. Note that the pre-treatment liquid and the post-treatment liquid are different treatment liquids. Specifically, the components contained in the pre-treatment liquid and the post-treatment liquid are different.

[0019] Here, non-colorable processing liquid refers to a liquid that, when printed alone on the workpiece W, is not recognized as colored by the naked eye. Colors here include colors with a saturation of 0 (zero), such as black, white, and gray. Non-colorable processing liquids are basically colorless and transparent liquids, but they are not completely colorless and transparent and may appear slightly white. Such colors are very light, so when printed alone on the workpiece W, they are not recognized as colored by the naked eye. Note that, depending on the type of processing liquid, when printed alone on the workpiece W, changes such as gloss may occur on the workpiece W, but such a state is not colored.

[0020] 1, the inkjet printer 2 further includes a printer control unit 5. The printer control unit 5 is a control unit that controls the ink head 3 and the treatment liquid head 4 included in the inkjet head 20. The printer control unit 5 causes each individual head 31 in the ink head 3 to eject ink, and causes each pre-treatment liquid head 41 and each post-treatment liquid head 42 in the treatment liquid head 4 to eject treatment liquid, based on data created by a computer 6 (described later).

[0021] The computer 6 is a personal computer having a CPU (Central Processing Unit), a storage area such as an HDD (Hard Disk Drive) or flash memory that stores a processing program, a RAM (Random Access Memory) used as a working area for the CPU, etc. The computer 6 functions as an ink data creating unit that creates ink dot data DID by the CPU executing the processing program stored in the HDD or flash memory, and also functions as a treatment liquid data creating unit that creates treatment liquid dot data DRD including pre-treatment liquid dot data DRD1 and post-treatment liquid dot data DRD2.

[0022] The computer 6 creates ink dot data DID as data used by the printer control unit 5 to control the ink ejection from the ink head 3, and creates treatment liquid dot data DRD as data used by the printer control unit 5 to control the treatment liquid ejection from the treatment liquid head 4.

[0023] In the inkjet recording system 1 according to this embodiment, the printer control unit 5 and the computer 6 execute the processes of each step of the inkjet recording method. The processes of each step of the inkjet recording method executed by the printer control unit 5 and the computer 6 will be described in detail with reference to FIGS.

[0024] The computer 6 acquires image data DG of an image to be printed on the workpiece W (image data acquisition step s1). Upon acquiring the image data DG, the computer 6 creates ink dot data DID, based on the image data DG, indicating data on a pattern of ink dots ID to be formed on the workpiece W in response to the ejection of ink by the ink head 3 (ink data creation step s2). If the ink head 3 in the inkjet printer 2 includes multiple individual heads 31 that eject multiple colors of ink, the computer 6 creates ink dot data DID for each color corresponding to each of the multiple individual heads 31. The computer 6 performs halftone processing, such as dithering, on the image data DG to convert the image data DG into halftone image data that can be printed on the workpiece W by the inkjet printer 2. As a result, the computer 6 creates ink dot data DID at a first resolution that can be printed by the inkjet printer 2.

[0025] Once the ink dot data DID for each color has been created, the computer 6 calculates the logical sum data DIDA shown in Figure 3 by taking the logical sum (OR) of the ink dot data DID for each color (logical sum calculation step s3). The logical sum data DIDA represents the data for all ink dot ID patterns in the ink dot data DID for each color. In the logical sum data DIDA shown in Figure 3, ink dot IDs corresponding to ink ejection by the ink head 3 are indicated by solid black dots, and positions where no ink is ejected by the ink head 3 are indicated by solid white dots. Note that if the inkjet printer 2 is equipped with only one ink head 3, the computer 6 omits the logical sum calculation step s3 for calculating the logical sum data DIDA.

[0026] Next, the computer 6 creates first-resolution treatment liquid dot data DRD, as exemplified in Fig. 6, based on the first-resolution ink dot data DID, which indicates data on the pattern of treatment liquid dots RD to be formed on the workpiece W in response to the ejection of treatment liquid by the treatment liquid head 4 (treatment liquid data creation step s4). In the treatment liquid dot data DRD shown in Fig. 6, the treatment liquid dots RD corresponding to the ejection of treatment liquid by the treatment liquid head 4 are indicated by hatched dots, and positions where treatment liquid is not ejected by the treatment liquid head 4 are indicated by white dots. Furthermore, because the treatment liquid dot data DRD is data indicating the pattern of treatment liquid dots RD, it does not include ink dot IDs, but in Fig. 6, the positions of the ink dot IDs are also virtually indicated by black dots.

[0027] The computer 6 creates the treatment liquid dot data DRD at the first resolution so that each treatment liquid dot RD in the treatment liquid dot data DRD includes at least dots that are positioned in the same positions as each ink dot ID in the ink dot data DID. If the ink head 3 in the inkjet printer 2 includes a plurality of individual heads 31 that eject a plurality of colors of ink, the computer 6 creates the treatment liquid dot data DRD at the first resolution based on logical sum data DIDA, which is the logical sum of the ink dot data DID for each color. In this case, the computer 6 creates the treatment liquid dot data DRD at the first resolution so that each treatment liquid dot RD in the treatment liquid dot data DRD includes at least dots that are positioned in the same positions as each ink dot ID in the logical sum data DIDA.

[0028] The computer 6 may create the treatment liquid dot data DRD based on the image data DG. Furthermore, if the number of dots corresponding to the number of nozzles in the ink head 3 and the number of dots corresponding to the number of nozzles in the treatment liquid head 4 match, the computer 6 creates treatment liquid dot data DRD with the same first resolution as the ink dot data DID, as described above. If the number of dots in the ink head 3 and the number of dots in the treatment liquid head 4 do not match, the computer 6 creates treatment liquid dot data DRD with a resolution corresponding to the number of dots in the treatment liquid head 4. For example, if the number of dots in the treatment liquid head 4 is smaller than the number of dots in the ink head 3, the computer 6 creates treatment liquid dot data DRD with a resolution lower than the first resolution of the ink dot data DID.

[0029] The computer 6 creates, as the treatment liquid dot data DRD, pre-treatment liquid dot data DRD1 indicating data on a pattern of pre-treatment liquid dots to be formed on the workpiece W in response to the ejection of the pre-treatment liquid by the pre-treatment liquid head 41. Similarly, the computer 6 creates, as the treatment liquid dot data DRD, post-treatment liquid dot data DRD2 indicating data on a pattern of post-treatment liquid dots to be formed on the workpiece W in response to the ejection of the post-treatment liquid by the post-treatment liquid head 42. In this embodiment, the computer 6 creates treatment liquid dot data DRD that is common to the pre-treatment liquid dot data DRD1 and the post-treatment liquid dot data DRD2. This makes it possible to reduce the amount of processing required for the computer 6 to create the treatment liquid dot data DRD, compared to when the pre-treatment liquid dot data DRD1 and the post-treatment liquid dot data DRD2 are created separately.

[0030] As shown in FIG. 2, when creating the treatment liquid dot data DRD in the treatment liquid data creation step s4, the computer 6 executes a reduction process s41 and an expansion process s42, and executes an enlargement process s43 as needed.

[0031] In the reduction process s41, the computer 6 converts the ink dot data DID at the first resolution, or the logical sum data DIDA obtained by taking the logical sum of the ink dot data DID for each color, into primary dot pattern data DR1, as shown in Figure 4. The primary dot pattern data DR1 is data for a pattern of primary dots R1 at a second resolution lower than the first resolution. In this case, the computer 6 performs reduction process s41 to reduce the pattern of ink dots ID represented by the ink dot data DID or the logical sum data DIDA at a reduction rate of 1 / N (N is an integer greater than or equal to 2) in both the main scanning direction H1 and the sub-scanning direction H2, thereby creating primary dot pattern data DR1 representing a pattern of primary dots R1 at the second resolution that includes the ink dots ID.

[0032] The reduction rate 1 / N in the reduction process s41 is a factor that determines the expansion amount of the treatment liquid dots RD in the treatment liquid dot data DRD. In other words, the reduction rate 1 / N is a factor that determines the range in which the treatment liquid dots RD exist around each ink dot ID included in the ink dot data DID. The reduction rate 1 / N is also a factor that determines the amount of processing required for the expansion process s42 that follows the reduction process s41, and is a factor that determines the amount of processing required to create the treatment liquid dot data DRD. As the value of "N" in the reduction rate 1 / N decreases, treatment liquid dot data DRD in which the treatment liquid dots RD are arranged in a wider area around the ink dot ID is created with a smaller amount of data processing. The reduction rate 1 / N is set to, for example, 1 / 4.

[0033] Although the primary dot pattern data DR1 does not include ink dot IDs, the positions of the ink dot IDs are also virtually shown as black dots in Fig. 4. In addition, in the primary dot pattern data DR1 exemplified in Fig. 4, the primary dots R1 are shown as shaded dots, and positions other than the primary dots R1 are shown as white dots.

[0034] In the expansion process s42 following the reduction process s41, the computer 6 expands each primary dot R1 in the pattern of primary dots R1 in the primary dot pattern data DR1 at the second resolution, converting it into secondary dot pattern data DR2 representing data on the pattern of secondary dots R2 at the second resolution, as shown in Fig. 5. The secondary dot pattern data DR2 does not include ink dot IDs, but in Fig. 5, the positions of the ink dot IDs are also virtually indicated by black dots. Furthermore, in the secondary dot pattern data DR2 illustrated in Fig. 5, the secondary dots R2 are indicated by hatched dots, and positions other than the secondary dots R2 are indicated by white dots.

[0035] Specifically, in the expansion process s42, the computer 6 expands each primary dot R1 by performing a padding process in which each primary dot R1 in the second-resolution primary dot pattern data DR1 is padded to a position surrounding the primary dot R1. That is, the computer 6 expands each primary dot R1 by taking the logical sum (OR) of the position of each primary dot R1 in the second-resolution primary dot pattern data DR1 and the positions surrounding each primary dot R1. In this case, the computer 6 expands each primary dot R1 in the second-resolution primary dot pattern data DR1 to the surrounding positions to create the second-resolution secondary dot pattern data DR2. As a result, the computer 6 creates the second-resolution secondary dot pattern data DR2, which indicates a dot pattern in which secondary dots R2 are arranged at the positions of each primary dot R1 in the second-resolution primary dot pattern data DR1 and at positions surrounding each primary dot R1.

[0036] In the expansion process s42, the computer 6 expands each primary dot R1 of the pattern of primary dots R1 in the primary dot pattern data DR1 at the second resolution in at least one of the main scanning direction H1 and the sub-scanning direction H2 to convert it into secondary dot pattern data DR2 at the second resolution. By expanding each primary dot R1 in the primary dot pattern data DR1 in the main scanning direction H1, the computer 6 can create secondary dot pattern data DR2 that indicates a dot pattern in which secondary dots R2 are arranged at the position of each primary dot R1 and at positions adjacent to each primary dot R1 on both sides of the main scanning direction H1. Similarly, by expanding each primary dot R1 in the primary dot pattern data DR1 in the sub-scanning direction H2, the computer 6 can create secondary dot pattern data DR2 that indicates a dot pattern in which secondary dots R2 are arranged at the position of each primary dot R1 and at positions adjacent to each primary dot R1 on both sides of the sub-scanning direction H2. Furthermore, by expanding each primary dot R1 in the primary dot pattern data DR1 in the main scanning direction H1 and the sub-scanning direction H2, the computer 6 can create secondary dot pattern data DR2 that indicates a dot pattern in which secondary dots R2 are arranged at the position of each primary dot R1, at each position adjacent to each primary dot R1 on both sides in the main scanning direction H1, and at each position adjacent to each primary dot R1 on both sides in the sub-scanning direction H2.

[0037] In the expansion process s42, the computer 6 may expand each primary dot R1 of the pattern of primary dots R1 in the second-resolution primary dot pattern data DR1 in the main scanning direction H1, the sub-scanning direction H2, and first and second diagonal directions H3 and H4 that intersect both the main scanning direction H1 and the sub-scanning direction H2, to convert it into second-resolution secondary dot pattern data DR2. In this way, the computer 6 can create secondary dot pattern data DR2 that indicates a dot pattern in which secondary dots R2 are arranged at the position of each primary dot R1 in the primary dot pattern data DR1, at positions adjacent to each primary dot R1 on both sides in the main scanning direction H1, at positions adjacent to each primary dot R1 on both sides in the sub-scanning direction H2, at positions adjacent to each primary dot R1 on both sides in the first diagonal direction H3, and at positions adjacent to each primary dot R1 on both sides in the second diagonal direction H4. The first diagonal direction H3 and the second diagonal direction H4 are directions that intersect with both the main scanning direction H1 and the sub-scanning direction H2 at an angle of, for example, 45 degrees, and do not overlap with the main scanning direction H1 and the sub-scanning direction H2.

[0038] If the number of dots in the ink head 3 corresponds to the first resolution of the ink dot data DID, while the number of dots in the treatment liquid head 4 corresponds to the second resolution which is lower than the first resolution, the computer 6 recognizes the secondary dot pattern data DR2 of the second resolution created in the expansion process s42 as the treatment liquid dot data DRD.

[0039] On the other hand, if the number of dots in the ink head 3 and the number of dots in the treatment liquid head 4 are the same, then after the expansion process s42, the computer 6 performs an enlargement process s43 on the second-resolution secondary dot pattern data DR2 to create the first-resolution treatment liquid dot data DRD exemplified in Fig. 6. In this case, the computer 6 enlarges the pattern of secondary dots R2 represented by the second-resolution secondary dot pattern data DR2 in both the main scanning direction H1 and the sub-scanning direction H2 by an enlargement rate N (N is an integer of 2 or greater) that is the reciprocal of the reduction rate in the reduction process s41, thereby creating treatment liquid dot data DRD of the first resolution that is the same as the ink dot data DID. In this way, the computer 6 can create first-resolution treatment liquid dot data DRD that indicates a dot pattern in which treatment liquid dots RD are arranged at the positions of each ink dot ID in the ink dot data DID and at positions within a wide range surrounding each ink dot ID.

[0040] As explained above, the computer 6 performs a reduction process s41 on the ink dot data DID of the first resolution, or on the logical sum data DIDA obtained by taking the logical sum of the ink dot data DID of each color, to convert it into primary dot pattern data DR1 of the second resolution, then performs an expansion process s42 on the primary dot pattern data DR1 to convert it into secondary dot pattern data DR2 of the second resolution, and then performs an enlargement process s43 on the secondary dot pattern data DR2 to create treatment liquid dot data DRD of the first resolution. This reduces the amount of processing required for the computer 6 to create the treatment liquid dot data DRD, compared to creating the treatment liquid dot data DRD by directly performing the expansion process s42 on the ink dot data DID without performing the reduction process s41 to lower the resolution of the ink dot data DID. Moreover, it is possible to efficiently create treatment liquid dot data DRD in which treatment liquid dots RD are arranged in a wide area around each ink dot ID in the ink dot data DID.

[0041] As shown in FIG. 2, once the ink dot data DID and treatment liquid dot data DRD for each color have been created, the computer 6 transmits the ink dot data DID and treatment liquid dot data DRD for each color that have been created to the inkjet printer 2 (data transmission step s5).

[0042] When the ink dot data DID and treatment liquid dot data DRD of each color are received in the inkjet printer 2 (data receiving step s6), the printer control unit 5 controls the ink head 3 and treatment liquid head 4 included in the inkjet head 20 to execute each ejection process in the order of pre-treatment liquid ejection step s7, ink ejection step s8 of each color, and post-treatment liquid ejection step s9.

[0043] In the pretreatment liquid ejection step s7, the printer control unit 5 ejects the pretreatment liquid from the pretreatment liquid head 41 based on the treatment liquid dot data DRD as the pretreatment liquid dot data DRD1. As a result, a pattern of dots of the pretreatment liquid is formed on the workpiece W in accordance with the pattern of the treatment liquid dots RD in the treatment liquid dot data DRD.

[0044] In the ink ejection step s8 for each color after the pretreatment liquid ejection step s7, the printer control unit 5 ejects ink from each of the multiple individual heads 31 in the ink head 3 based on the ink dot data DID for each color. As a result, a pattern of ink dots is formed on the workpiece W in accordance with the pattern of the ink dot ID in the ink dot data DID for each color, and an image is printed on the workpiece W.

[0045] At this time, before the ink dot pattern is formed on the workpiece W, a dot pattern of the pretreatment liquid based on the treatment liquid dot data DRD is formed. As described above, the treatment liquid dot data DRD is data that indicates a pattern of the treatment liquid dots RD, in which the treatment liquid dots RD are arranged at the position of each ink dot ID in the ink dot data DID and at each position within a wide area surrounding each ink dot ID. Therefore, before the ink dot pattern is formed on the workpiece W, dots of the pretreatment liquid are formed at the positions where the ink dots are to be formed and within a wide area surrounding them. As a result, when the ink dots are formed on the workpiece W, the dots of the pretreatment liquid that have also been formed within the surrounding area can stably prevent the ink from bleeding on the workpiece W.

[0046] In a post-treatment liquid ejection step s9 following the ink ejection step s8 for each color, the printer control unit 5 ejects the post-treatment liquid from the post-treatment liquid head 42 based on the treatment liquid dot data DRD as the post-treatment liquid dot data DRD2. As a result, a pattern of dots of the post-treatment liquid is formed on the workpiece W in accordance with the pattern of the treatment liquid dots RD in the treatment liquid dot data DRD.

[0047] At this time, after a pattern of ink dots is formed on the workpiece W, a pattern of post-treatment liquid dots is formed based on the treatment liquid dot data DRD. As described above, the treatment liquid dot data DRD is data that indicates a pattern of treatment liquid dots RD, in which treatment liquid dots RD are arranged at the positions of each ink dot ID in the ink dot data DID and at each position within a wide area surrounding each ink dot ID. Therefore, after a pattern of ink dots is formed on the workpiece W, dots of post-treatment liquid are formed at the positions where the ink dots were formed and within a wide area surrounding them. As a result, the fixation of the ink on the workpiece W can be stably improved by the dots of post-treatment liquid that are formed at the positions of the ink dots and at positions within the area surrounding them.

[0048] The mode in which dots of the pre-treatment liquid and the post-treatment liquid are formed at the positions where ink dots are to be formed and within a wide area surrounding them based on the treatment liquid dot data DRD is particularly effective in repeat printing in which the same ink dot pattern is repeated in the main scanning direction H1 and the sub-scanning direction H2.

[0049] In this embodiment, as described above, the computer 6 creates the treatment liquid dot data DRD corresponding to the ink dot data DID by sequentially performing the reduction process s41 and the expansion process s42, and then performing the enlargement process s43 as necessary. This reduces the amount of processing required for the computer 6 to create the treatment liquid dot data DRD corresponding to the ink dot data DID. This makes it possible to shorten the processing time for creating the treatment liquid dot data DRD.

[0050] REFERENCE SIGNS LIST 1 Inkjet recording system 2 Inkjet printer 20 Inkjet head 3 Ink head 31 Individual head 4 Treatment liquid head 41 Pre-treatment liquid head 42 Post-treatment liquid head 5 Printer control unit (control unit) 6 Computer (ink data creation unit, treatment liquid data creation unit) DG Image data DID Ink dot data DRD Treatment liquid dot data DRD1 Pre-treatment liquid dot data DRD2 Post-treatment liquid dot data W Work (recording material)

Claims

1. an inkjet head including an ink head that ejects ink onto a recording material and a treatment liquid head that ejects a treatment liquid that comes into contact with the ink on the recording material; an ink data creating section that creates ink dot data representing data on a pattern of ink dots to be formed on the recording material in response to the ejection of the ink by the ink head, based on image data of an image to be recorded on the recording material; a treatment liquid data creating section that creates treatment liquid dot data indicating data on a pattern of treatment liquid dots to be formed on the recording material in response to ejection of the treatment liquid by the treatment liquid head; a control unit that controls the inkjet head to eject the ink from the ink head based on the ink dot data, and eject the treatment liquid from the treatment liquid head based on the treatment liquid dot data, an inkjet recording system in which the treatment liquid data creation unit creates primary dot pattern data indicating data on each pattern of primary dots at the second resolution that encompasses each of the ink dots in the ink dot data by performing a reduction process to convert the ink dot data of a first resolution into data of a second resolution that is lower than the first resolution, and then creates the treatment liquid dot data by performing an expansion process to expand each of the primary dots in the primary dot pattern data to convert it into secondary dot pattern data indicating data on a pattern of secondary dots.

2. 2. The inkjet recording system according to claim 1, wherein the treatment liquid data creation section creates the treatment liquid dot data of the first resolution by performing an enlargement process on the secondary dot pattern data after the expansion process.

3. the ink head includes a plurality of individual heads each ejecting a respective one of the inks of a plurality of colors; the ink data creation unit creates the ink dot data corresponding to each of the plurality of individual heads; 2. The inkjet recording system according to claim 1, wherein the processing liquid data creation unit converts, in the reduction process, logical sum data obtained by taking a logical sum of the ink dot data corresponding to each of the plurality of individual heads into the primary dot pattern data.

4. the treatment liquid head is provided so as to be movable relative to the recording material in a main scanning direction and in a sub-scanning direction perpendicular to the main scanning direction, 2. The inkjet recording system according to claim 1, wherein, in the expansion process, the treatment liquid data creation unit expands each of the primary dots in the primary dot pattern data in at least one of the main scanning direction and the sub-scanning direction to convert the primary dots into the secondary dot pattern data.

5. the treatment liquid head is provided so as to be movable relative to the recording material in a main scanning direction and in a sub-scanning direction perpendicular to the main scanning direction, 2. The inkjet printing system of claim 1, wherein, in the expansion process, the processing liquid data creation unit expands each of the primary dots in the primary dot pattern data in each of the main scanning direction, the sub-scanning direction, and a first diagonal direction and a second diagonal direction intersecting both the main scanning direction and the sub-scanning direction, to convert the primary dots into the secondary dot pattern data.

6. the treatment liquid head includes a pretreatment liquid head that ejects, as the treatment liquid, a pretreatment liquid that is applied to the recording material before the ink, the treatment liquid data creation unit creates, as the treatment liquid dot data, pretreatment liquid dot data indicating data of a pattern of pretreatment liquid dots to be formed on the recording material in response to ejection of the pretreatment liquid by the pretreatment liquid head, The inkjet recording system according to claim 1 , wherein the control unit causes the pretreatment liquid to be ejected from the pretreatment liquid head based on the pretreatment liquid dot data, and thereafter causes the ink to be ejected from the ink head based on the ink dot data.

7. the treatment liquid head includes a post-treatment liquid head that ejects, as the treatment liquid, a post-treatment liquid that is to be applied to the recording material after the ink, the processing liquid data creation unit creates, as the processing liquid dot data, post-processing liquid dot data indicating data of a pattern of post-processing liquid dots to be formed on the recording material in response to ejection of the post-processing liquid by the post-processing liquid head; The inkjet recording system according to claim 1 , wherein the control unit causes the ink to be ejected from the ink head based on the ink dot data, and thereafter causes the post-treatment liquid to be ejected from the post-treatment liquid head based on the post-treatment liquid dot data.

8. 8. The inkjet recording system according to claim 1, wherein the recording material is a cloth member made of a cloth material.

9. 1. An inkjet recording method for recording an image on a recording material by using an inkjet head including an ink head that ejects ink onto the recording material, and a treatment liquid head that ejects a treatment liquid that comes into contact with the ink on the recording material, comprising: an ink data creating step of creating ink dot data representing data of a pattern of ink dots to be formed on the recording material in response to the ejection of the ink from the ink head, based on image data of the image to be recorded on the recording material; a treatment liquid data creating step of creating treatment liquid dot data indicating data of a pattern of treatment liquid dots to be formed on the recording material in response to ejection of the treatment liquid by the treatment liquid head; an ink ejection step of ejecting the ink from the ink head based on the ink dot data; a treatment liquid discharge step of discharging the treatment liquid from the treatment liquid head based on the treatment liquid dot data, In the treatment liquid data creation process, a reduction process is performed to convert the ink dot data of a first resolution into data of a second resolution which is lower than the first resolution, thereby creating primary dot pattern data which indicates data on each pattern of primary dots of the second resolution which encompasses each of the ink dots in the ink dot data, and then an expansion process is performed to expand each of the primary dots in the primary dot pattern data and convert it into secondary dot pattern data which indicates data on a pattern of secondary dots, thereby creating the treatment liquid dot data.