Inkjet recording device and inkjet recording method

Abstract

Areas with low concentrations of each processing solution and ink, as well as areas with high concentrations of each, occur, resulting in a concentration difference between the two areas. [Solution] The inkjet recording device comprises a transport unit, a carriage, at least one pre-processing head, at least one ink head, and at least one post-processing head. The transport unit transports the recording medium in a predetermined transport direction. The carriage moves back and forth along a main scanning direction intersecting the transport direction. At least one pre-processing head is mounted on the carriage and ejects a non-coloring pre-processing liquid. At least one ink head is mounted on the carriage and ejects ink. At least one post-processing head is mounted on the carriage and ejects a non-coloring post-processing liquid. The at least one pre-processing head, the at least one ink head, and the at least one post-processing head are arranged offset from each other in the transport direction.

Description

Technical Field

[0001] The present disclosure relates to an inkjet recording apparatus including an ink head mounted on a carriage that moves in a main scanning direction.

Background Art

[0002] An inkjet recording apparatus such as an inkjet printer includes an ink head that discharges ink for image formation toward a recording medium.

[0003] When the recording medium is wide, the ink head is mounted on a carriage that reciprocates in the main scanning direction. In the recording process, the recording medium is intermittently fed in a predetermined conveyance direction (sub-scanning direction), and the carriage reciprocates in the main scanning direction while the recording medium is stopped. When the carriage moves, ink (colored ink) is discharged from the ink head.

[0004] Patent Document 1 discloses a technique of applying a pretreatment liquid to the recording medium before discharging colored ink toward the recording medium, and applying a post-treatment liquid to the recording medium after discharging the colored ink toward the recording medium. The pretreatment liquid is, for example, a treatment liquid for improving the fixing property of ink to the recording medium and the aggregation property of ink pigments. The post-treatment liquid is, for example, a treatment liquid for enhancing the fastness of a printed image. The carriage of the inkjet recording apparatus is provided with, in addition to the ink head, a pretreatment head that discharges the pretreatment liquid and a post-treatment head that discharges the post-treatment liquid.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] An inkjet recording apparatus according to one aspect of the present disclosure comprises a transport unit, a carriage, at least one pre-processing head, at least one ink head, and at least one post-processing head. The transport unit transports a recording medium in a predetermined transport direction. The carriage reciprocates along a main scanning direction intersecting the transport direction. At least one pre-processing head is mounted on the carriage and ejects a non-coloring pre-processing liquid. At least one ink head is mounted on the carriage and ejects ink. At least one post-processing head is mounted on the carriage and ejects a non-coloring post-processing liquid. The at least one pre-processing head, the at least one ink head, and the at least one post-processing head are offset from each other in the transport direction. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view showing the overall configuration of an inkjet recording apparatus according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view along line II-II in Figure 1. [Figure 3] Figure 3 is an enlarged perspective view of the carriage shown in Figure 1. [Figure 4] Figure 4 is a schematic diagram showing a serial printing method employed in one embodiment of the present disclosure. [Figure 5A] Figure 5A is a schematic diagram showing the printing status of the carriage during its outbound and return journeys. [Figure 5B] Figure 5B is a schematic diagram showing the printing status of the carriage during its outbound and return journeys. [Figure 6] Figure 6 is a schematic plan view showing the arrangement of the ink head and processing head on the carriage shown in Figure 3. [Figure 7] Figure 7 is a block diagram of an inkjet recording apparatus according to one embodiment of the present disclosure. [Figure 8] Figure 8 is a plan view showing the relationship between a pre-treatment liquid deposition area and an ink deposition area on a recording medium in an inkjet recording apparatus according to one embodiment of the present disclosure. [Figure 9] Figure 9 is a plan view showing the relationship between the pre-treatment liquid deposition area and the ink deposition area on the recording medium in an inkjet recording apparatus according to one embodiment of the present disclosure. [Figure 10] Figure 10 is a schematic diagram showing how ink lands on the surface of the recording medium as the carriage moves. [Modes for carrying out the invention]

[0008] Hereinafter, with reference to the drawings, inkjet recording devices according to each embodiment of the present disclosure will be described. In these embodiments, as a specific example of an inkjet recording device, an inkjet printer equipped with an ink head that ejects image-forming ink onto a wide and long recording medium is exemplified. Inkjet printers are suitable for digital textile printing, which prints images such as characters and patterns onto recording media made of fabrics such as woven or knitted materials using an inkjet method. Of course, the inkjet recording device according to the present disclosure can also be used for printing various inkjet images onto recording media such as paper sheets and resin sheets.

[0009] [Overall configuration of an inkjet printer] Figure 1 is a perspective view showing the overall configuration of an inkjet printer 1 according to the first embodiment of this disclosure, and Figure 2 is a schematic cross-sectional view taken along line II-II in Figure 1. The inkjet printer 1 is a printer that prints images on a wide and long workpiece W (recording medium) using an inkjet method, and includes a device frame 10, a workpiece transport unit 20 (transport unit) and a carriage 3 incorporated into the device frame 10. In this embodiment, the left-right direction is the main scanning direction S (Figure 3) when printing on the workpiece W, and the direction from rear to front is the sub-scanning direction (workpiece W transport direction F).

[0010] The device frame 10 forms the framework for mounting various components of the inkjet printer 1. The workpiece transport unit 20 is a mechanism that intermittently feeds (transports) the workpiece W so that it passes through the printing area (image formation position) where the inkjet printing process is performed in a transport direction F from rear to front. The carriage 3 is equipped with an ink head 4, a pre-processing head 5, a post-processing head 6, and a sub-tank 7, and reciprocates in the main scanning direction S (left-right direction) which intersects with the transport direction F of the workpiece W during the inkjet printing process.

[0011] The apparatus frame 10 includes a central frame 111, a right frame 112, and a left frame 113. The central frame 111 forms the framework for mounting various components of the inkjet printer 1 and has a left-right width corresponding to the workpiece transport section 20. The right frame 112 and the left frame 113 are erected to the right and left of the central frame 111, respectively. The space between the right frame 112 and the left frame 113 is the printing area 12 where the printing process is performed on the workpiece W.

[0012] The right frame 112 forms a maintenance area 13. The maintenance area 13 is an area where the carriage 3 is retracted when the printing process is not being performed. In the maintenance area 13, cleaning and purging processes are performed on the nozzles (ejection holes) of the ink head 4, pre-processing head 5, and post-processing head 6, and caps are fitted. The left frame 113 forms a folding area 14 for the carriage 3. The folding area 14 is an area where the carriage 3, which has primarily scanned the printing area 12 from right to left during the printing process, temporarily enters when it performs a primary scan in the reverse direction.

[0013] A carriage guide 15 is assembled on the upper side of the device frame 10 to allow the carriage 3 to move back and forth in the left-right direction. The carriage guide 15 is a long, flat plate-shaped member and is positioned above the workpiece transport section 20. A timing belt 16 (moving member) is assembled to the carriage guide 15 so as to be able to move around in the left-right direction (main scanning direction). The timing belt 16 is an endless belt and is driven by the carriage drive unit 3S described later to move around in the left or right direction.

[0014] The carriage guide 15 is equipped with a pair of upper and lower guide rails 17 (holding members) that extend parallel to each other in the left-right direction, which hold the carriage 3 in a state that allows it to reciprocate in the main scanning direction S. The carriage 3 is engaged with the guide rails 17. The carriage 3 is also fixed to the timing belt 16. As the timing belt 16 rotates to the left or right, the carriage 3 moves along the carriage guide 15 to the left or right, guided by the guide rails 17.

[0015] Referring mainly to Figure 2, the workpiece transport unit 20 includes a feed roller 21 for feeding out the workpiece W before printing and a take-up roller 22 for winding up the workpiece W after printing. The feed roller 21 is located at the lower rear of the device frame 10 and is the winding shaft of the feed roll WA, which is the winding body of the workpiece W before printing. The take-up roller 22 is located at the lower front of the device frame 10 and is the winding shaft of the take-up roll WB, which is the winding body of the workpiece W after printing. The take-up roller 22 is equipped with a first motor M1 that rotates the take-up roller 22 around its axis and performs the winding operation of the workpiece W.

[0016] The path between the delivery roller 21 and the take-up roller 22 and passing through the printing area 12 serves as the conveyance path for the workpiece W. In this conveyance path, a first tension roller 23, a workpiece guide 24, a conveyance roller 25, a pinch roller 26, a folding roller 27, and a second tension roller 28 are arranged in order from the upstream side. The first tension roller 23 applies a predetermined tension to the workpiece W upstream of the conveyance roller 25. The workpiece guide 24 changes the conveyance direction of the workpiece W from upward to forward and conveys the workpiece W into the printing area 12.

[0017] The conveyance roller 25 is a roller that generates a conveyance force for intermittently feeding the workpiece W in the printing area 12. The conveyance roller 25 is rotationally driven about its axis by a second motor M2, and intermittently conveys the workpiece W in the forward direction (predetermined conveyance direction F) at a predetermined conveyance pitch so that the workpiece W passes through the printing area 12 (image formation position) facing the carriage 3. The pinch roller 26 is arranged to face the conveyance roller 25 from above and forms a conveyance nip portion with the conveyance roller 25.

[0018] The folding roller 27 changes the conveyance direction of the workpiece W that has passed through the printing area 12 from forward to downward and guides the workpiece W after the printing process to the take-up roller 22. The second tension roller 28 applies a predetermined tension to the workpiece W downstream of the conveyance roller 25. A platen 29 is arranged below the conveyance path of the workpiece W in the printing area 12.

[0019] The carriage 3 is supported in a cantilevered manner by the guide rail 17 and reciprocates in the main scanning direction S (in the left-right direction in this embodiment) that intersects (orthogonal in this embodiment) the conveyance direction F in the printing area (image formation position). The carriage 3 includes a carriage frame 30, an ink head 4, a pre-treatment head 5, a post-treatment head 6, and a sub-tank 7 mounted on the carriage frame 30. The carriage frame 30 includes a head support frame 31 and a back frame 32 (engagement portion).

[0020] The head support frame 31 is a horizontal plate that holds the heads 4 to 6 shown above. The back frame 32 is a vertical plate that extends upward from the rear end edge of the head support frame 31. As described above, the timing belt 16 is fixed to the back frame 32. The guide rail 17 is also engaged with the back frame 32. In other words, in this embodiment, the back frame 32 is an engaging portion that holds the guide rail 17 in a cantilevered manner. The head support frame 31 is a horizontal plate whose rear end is cantilevered to the guide rail 17 by the engaging portion.

[0021] The cantilever configuration refers to a state in the carriage 3 where the engaging portion (back frame 32) is located on only one side of the carriage 3 in the transport direction F, either upstream or downstream from the center, and no other engaging portion is present on the opposite side of the engaging portion. The engaging portion is the part held by the guide rail 17, which is a holding member. The engaging portion may also be located outside the area where the ink head 4 and the processing head are located in the transport direction F. That is, the engaging portion may be located only upstream or only downstream of the area where the ink head 4 and the processing head are located in the transport direction F.

[0022] [Carriage Details] Further explanation of carriage 3 is provided. Figure 3 is an enlarged perspective view of carriage 3 shown in Figure 1. Figure 3 shows the transport direction F (sub-scanning direction) of the workpiece W and the main scanning direction S, which is the direction of movement of carriage 3. Figure 3 shows an example in which multiple ink heads 4 that eject image-forming ink onto the workpiece W, pre-processing heads 5 and post-processing heads 6 that eject non-coloring processing liquid, and multiple sub-tanks 7 that supply the ink and processing liquid to these heads 4 to 6 are mounted on carriage 3.

[0023] Each of the ink heads 4 includes a number of nozzles (ink ejection holes) 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, and an ink passage that guides the ink to these nozzles. As the ink, for example, an aqueous pigment ink containing an aqueous solvent, a pigment, and a binder resin can be used. Note that the ink may also contain a dye instead of a pigment. Therefore, hereafter, the concept including pigments and dyes may be expressed as a colorant. The plurality of ink heads 4 in this embodiment include first to sixth ink heads 4A to 4F, each ejecting six different colors of ink. For example, the first ink head 4A ejects orange ink, the second ink head 4B ejects green ink, the third ink head 4C ejects yellow ink, the fourth ink head 4D ejects red ink, the fifth ink head 4E ejects blue ink, and the sixth ink head 4F ejects black ink.

[0024] Each of the ink heads 4A to 4F for each color is mounted on the head support frame 31 of the carriage 3 so as to be aligned in the main scanning direction S. Each of the ink heads 4A to 4F for each color has one head.

[0025] The pre-processing head 5 and post-processing head 6 are positioned differently from the ink head 4 in the transport direction F. The pre-processing head 5 is positioned upstream of the ink head 4 in the transport direction F. Figure 3 shows an example where one pre-processing head 5 is positioned near the right end of the ink head 4 array. Similarly, the post-processing head 6 is positioned downstream of the ink head 4 in the transport direction F. Figure 3 shows an example where one post-processing head 6 is positioned at the right end of the ink head 4 array. In other embodiments, multiple pre-processing heads 5 or multiple post-processing heads 6 may be provided. That is, the carriage 3 is provided with at least one pre-processing head 5 and at least one post-processing head 6.

[0026] The pre-treatment head 5 discharges a pre-treatment liquid to perform a predetermined pre-treatment on the workpiece W. The pre-treatment liquid is discharged from the pre-treatment head 5 to a position on the workpiece W where ink has not yet been discharged from the inkhead 4. The pre-treatment liquid is a non-coloring treatment liquid that does not develop color even when it adheres to the workpiece W, and is a treatment liquid that exhibits functions such as improving the ink's fixation to the workpiece W and the aggregation of the ink pigment (dye). As such a pre-treatment liquid, a treatment liquid containing a binder resin in the solvent, or a treatment liquid containing a positively charged cationic resin in the solvent can be used.

[0027] The post-processing head 6 discharges a post-processing solution to perform a predetermined post-processing on the workpiece W to which ink has adhered. The post-processing solution is discharged from the post-processing head 6 to the position on the workpiece W after the ink has been discharged from the ink head 4. The post-processing solution is a non-coloring solution that does not develop color even when it adheres to the workpiece W, and it is a solution that enhances the fixation and robustness (resistance to rubbing and abrasion) of the ink image printed on the workpiece W by the ink head 4. Silicone-based solutions can be used as such post-processing solutions. Note that the post-processing solution and the pre-processing solution are different solutions. Specifically, the components contained in the post-processing solution and the pre-processing solution are different.

[0028] Here, a non-coloring processing solution refers to a solution that, when printed on a recording medium alone, is not perceived as color by the naked eye. Here, "color" includes colors with zero saturation, such as black, white, and gray. A non-coloring processing solution is basically a transparent liquid; however, for example, a liter of the solution may not be completely transparent when viewed in liquid form, and may appear slightly white. Such colors are very faint, and therefore, when printed on a recording medium alone, they are not perceived as color by the naked eye. Note that depending on the type of processing solution, when printed on a recording medium alone, changes such as glossiness may occur on the recording medium; however, such a state is not considered color development.

[0029] In this embodiment, the pre-treatment liquid and post-treatment liquid may be dispensed over substantially the entire surface of the workpiece W, or they may be dispensed selectively according to the image to be printed, similar to ink.

[0030] Next, we will explain the case where pre-treatment and post-treatment solutions are selectively dispensed. As mentioned above, the pre-treatment solution, ink, and post-treatment solution are dispensed in the order of the workpiece W where the color is printed according to the image. In this case, the ink may be one color or multiple colors. In general, the pre-treatment solution and post-treatment solution are not dispensed in the areas where no color is printed, i.e., in the areas where ink is not dispensed. In addition, the selection of the dispensing of the pre-treatment solution and post-treatment solution may be made different from the dispensing of the ink in order to adjust the image quality to be printed or the texture of the workpiece W.

[0031] Each head support frame 31 has an opening 31H (Figure 3) at the location where each head is positioned. The ink heads 4A to 4F, the pre-processing head 5, and the post-processing head 6 are assembled to the head support frame 31 so that they fit into their respective openings 31H. The nozzles located on the lower end faces of each head 4, 5, and 6 are exposed through each opening 31H.

[0032] The sub-tanks 7 are supported by the carriage 3 above the heads 4, 5, and 6 via a retaining frame (not shown). Each sub-tank 7 is provided corresponding to each of the heads 4, 5, and 6. Each sub-tank 7 is supplied with ink or processing fluid from a cartridge or main tank containing the ink and processing fluid (not shown). Each sub-tank 7 supplies the ink or processing fluid to each of the heads 4, 5, and 6. Each sub-tank 7 and the heads 4, 5, and 6 are connected by a conduit (not shown in Figure 3).

[0033] As described above, the inkjet printer 1 according to this embodiment is an all-in-one type printer in which three types of heads, an ink head 4, a pre-treatment head 5, and a post-treatment head 6, are mounted on a single carriage 3. With this inkjet printer 1, for example, in the printing process of performing inkjet printing on fabric in digital textile printing, the pre-treatment liquid discharge process and the post-treatment liquid discharge process can be performed integrally. Therefore, the printing process can be simplified and the printing equipment can be made more compact.

[0034] [Print method] Next, the printing method performed by the inkjet printer 1 according to this embodiment will be described. The inkjet printer 1 performs printing on the workpiece W using a serial printing method. Figure 4 is a schematic diagram showing the serial printing method. In Figure 4, the pre-processing head 5 and post-processing head 6 are omitted, and the carriage 3 is depicted in a simplified manner.

[0035] If the workpiece W has a wide size, it is not possible to print while continuously feeding the workpiece W. The serial printing method is a printing method that repeats the reciprocal movement of the carriage 3 equipped with each color ink head 4 in the main scanning direction S and the intermittent feeding of the workpiece W in the transport direction F. Here, it is assumed that the ink head 4 has a predetermined printing width Pw in the transport direction F. The printing width Pw is approximately equal to the arrangement range of the ink ejection nozzles of the ink head 4. Note that in Figure 4 and Figures 5A and 5B described below, the width of the transport direction F for each head and the printing width Pw are depicted as approximately equal. In reality, the width of the transport direction F for each head is larger than the printing width Pw and the arrangement range of the ejection nozzles.

[0036] Figure 4 shows the state where carriage 3 has moved in the forward direction SA in the main scanning direction S, and printing of a strip image G1 with a print width Pw has been completed. During this main scanning in the forward direction SA, the feed of the workpiece W is stopped. After printing the strip image G1, the workpiece W is fed out in the transport direction F by a pitch corresponding to the print width Pw. At this time, carriage 3 waits in the turnaround area 14 on the left end. After the workpiece W has been fed out, carriage 3 turns back in the return direction SB as the timing belt 16 reverses direction. The workpiece W is in a stopped state. Then, as shown in Figure 4, carriage 3 moves in the return direction SB and prints a strip image G2 with a print width Pw upstream of the strip image G1. The same operation is repeated thereafter.

[0037] Figures 5A and 5B are schematic diagrams showing the printing process on the forward and return journeys of carriage 3. Here, the ink head 4, pre-processing head 5, and post-processing head 6 mounted on carriage 3 are shown in a simplified manner. Ink head 4 is equipped with first, second, third, and fourth ink heads 4A, 4B, 4C, and 4D for ejecting different first, second, third, and fourth color inks, respectively. These first to fourth ink heads 4A to 4D are arranged in a line in the main scanning direction S. The pre-processing head 5 is located upstream of the ink head 4 in the transport direction F, and the post-processing head 6 is located downstream. Also, as explained in Figure 4, the workpiece W is sent in the transport direction F between the forward and return printing journeys. The travel distance in the transport direction F is the distance pitch (head pitch) between adjacent heads in the transport direction F. This travel distance is also the printing width Pw of each head 4, 5, and 6.

[0038] Figure 5A shows the state in which the carriage 3 is performing a printing operation while moving in the forward path SA in the main scanning direction S (forward main scan). Region A4 on the workpiece W is the region in which the pre-processing head 5, mounted on the uppermost side of the carriage 3, faces. In this forward main scan, a pre-processing layer Lpre is formed on region A4 by the pre-processing liquid ejected from the pre-processing head 5.

[0039] Region A3 is located one head pitch downstream of region A4 and is the region where the ink heads 4 face each other. On region A3, the pre-processing layer Lpre has already been formed along the entire length in the main scanning direction by the previous return main scan. In this forward main scan, the first, second, third, and fourth ink layers LCA, LCB, LCC, and LCD are formed on the pre-processing layer Lpre in region A3 by the first to fourth color inks ejected sequentially in the order of the first to fourth ink heads 4A to 4D. Note that in Figure 5A, the fourth to first ink layers LCD to LCA are shown as being stacked sequentially for ease of understanding, but they are not actually stacked. Also, the aforementioned pre-processing layer Lpre and the post-processing layer Lpos described later are not formed on the workpiece W.

[0040] Region A2 is located one head pitch downstream of region A3 and is the region where the post-processing head 6, mounted at the downstream end of carriage 3, faces. On region A2, the pre-processing layer Lpre from the previous forward main scan and the first to fourth ink layers LCA to LCD from the previous return main scan have already been formed along the entire length in the main scan direction. In the current forward main scan, a post-processing layer Lpos is formed on the first to fourth ink layers LCA to LCD in region A2 by the post-processing liquid discharged from the post-processing head 6.

[0041] Region A1 is the region located one head pitch downstream of region A2, through which carriage 3 has passed and where the printing process is completed. Specifically, in region A1, the pre-processing layer Lpre, the first to fourth ink layers LCA to LCD, and the post-processing layer Lpos are formed along the entire length in the main scanning direction.

[0042] Figure 5B shows the state after the forward main scan in Figure 5A has been completed, with the carriage 3 turning around and moving in the return direction SB while performing the return main scan. Before the aforementioned turning around movement, the workpiece W has been fed forward by one head pitch in the transport direction F. Region A5 on the workpiece W is one head pitch upstream of region A4, and in this return main scan, it is the region where the pre-processing head 5 faces. A pre-processing layer Lpre is formed on region A5 by the pre-processing liquid discharged from the pre-processing head 5.

[0043] In areas A4 and A3, the first to fourth ink layers LCA to LCD and the post-processing layer Lpos are formed on top of the existing layers, respectively. Specifically, in area A4, the first to fourth ink layers LCA to LCD are formed on top of the pre-processing layer Lpre. In area A3, the post-processing layer Lpos is formed on top of the first to fourth ink layers LCA to LCD. Area A2 is the area where the printing process is completed, following area A1.

[0044] The reason why printing is possible in both the forward and return main scans, as described above, is that the pre-processing head 5 and post-processing head 6 are positioned shifted in the transport direction F relative to the ink head 4. If, for example, the pre-processing head 5, ink head 4, and post-processing head 6 were arranged in a line in the main scan direction S in this order on the carriage 3, then printing that allows the pre-processing liquid and post-processing liquid to land in the desired order could only be achieved in either the forward or return main scan. To enable bidirectional printing, the pre-processing head 5 and post-processing head 6 pair would have to be positioned on both sides of the ink head 4 array. In this case, the width of the carriage 3 in the main scan direction S would increase. Since such an arrangement is unnecessary in this embodiment, the width of the carriage 3 in the main scan direction S can be reduced.

[0045] Furthermore, by using multiple rows of ink heads 4, the amount of ink deposited on the workpiece W can be increased. For example, if there are two rows of ink heads 4, printing can be performed as follows: The first row of ink heads 4 forms the first to fourth ink layers LCA to LCD as described above. Then, the workpiece W is transported in the transport direction F by one head pitch, and the second row of ink heads 4 forms the first to fourth ink layers LCA to LCD. In this way, two layers' worth of ink can be printed on the workpiece W.

[0046] Figure 6 is a schematic plan view showing the head arrangement on the carriage 3 according to this embodiment, and also shows the arrangement of the ink head 4, pre-processing head 5, and post-processing head 6 (multiple processing heads) on the carriage 3 shown in Figure 3. As previously described, the carriage 3 is equipped with first to sixth ink heads 4A to 4F, a pre-processing head 5, and a post-processing head 6, each ejecting six different colored inks. There is one of each color ink head 4A to 4F, pre-processing head 5, and post-processing head 6. The group of first to sixth ink heads 4A to 4F that constitute the ink head 4 are arranged in the central region of the transport direction F of the carriage 3 so as to be aligned in the main scanning direction S. Also, when viewed along the main scanning direction S, the downstream end of the pre-processing head 5 in the transport direction F is positioned to overlap with the upstream end of the ink head 4 in the transport direction F. Similarly, when viewed along the main scanning direction S, the downstream end of the ink head 4 in the transport direction F is positioned to overlap with the upstream end of the post-processing head 6 in the transport direction F.

[0047] Unless otherwise specified, in all figures, including Figure 6, the distance between adjacent heads (the distance between the centers of each head) is the same in the main scanning direction S. Similarly, the distance between adjacent heads (the distance between the centers of each head) is the same in the transport direction F.

[0048] In Figure 6, the nozzle region located on the underside of each head is schematically illustrated with dashed lines within the external shape of each head. The nozzle region is an area defined by nozzles located on the underside of each head that discharge liquid during printing. In each head, multiple nozzles are formed in this nozzle region, arranged along the main scanning direction S and the transport direction F.

[0049] Furthermore, the upstream and downstream ends of the nozzle regions of the first ink heads 4A to the sixth ink heads 4F are positioned at the same location in the transport direction F. In addition, the upstream ends of the nozzle regions of the first ink heads 4A to the sixth ink heads 4F are positioned continuously with respect to the downstream end of the nozzle region of the pre-processing head 5 in the transport direction F (they are touching, adjacent). Similarly, the upstream end of the nozzle region of the post-processing head 6 is positioned continuously with respect to the downstream end of the nozzle region of the first ink heads 4A to the sixth ink heads 4F in the transport direction F.

[0050] The placement area of ​​each nozzle is arranged so that the ink and each processing liquid land adjacent to each other in units of resolution. Therefore, the landing area of ​​the pre-processing liquid and the landing area of ​​the ink of the first ink head 4A to the sixth ink head 4F are continuous (adjacent) at the pre-processing / ink head boundary line L1, and the landing area of ​​the ink in the nozzle area of ​​the first ink head 4A to the sixth ink head 4F and the landing area of ​​the post-processing liquid are continuous at the ink / post-processing head boundary line L2.

[0051] Figure 7 is a block diagram of the inkjet printer 1 according to this embodiment. The inkjet printer 1 further comprises a control unit 90 that comprehensively controls the operation of each part of the inkjet printer 1, a carriage drive unit 3S, an I / F 91, and an image memory 92. The control unit 90 consists of a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores the control program, a RAM (Random Access Memory) used as the CPU's work area, etc. In addition to the aforementioned first motor M1 and second motor M2, ink head 4, pre-processing head 5 and post-processing head 6, the control unit 90 is electrically connected to the carriage drive unit 3S, I / F 91, image memory 92, etc. The carriage drive unit 3S includes a motor (not shown) that rotates a timing belt 16 to move the carriage 3 back and forth along the main scanning direction S.

[0052] The image memory 92 temporarily stores print image data provided by an external device, such as a personal computer.

[0053] I / F91 is an interface circuit for enabling data communication with external devices. For example, it creates communication signals according to the communication protocol of a network connecting the inkjet printer 1 and the external device, and converts the communication signals from the network into data in a format that the inkjet printer 1 can process. Print instruction signals transmitted from a personal computer or the like are provided to the control unit 90 via I / F91, and image data is stored in the image memory 92 via I / F91.

[0054] The control unit 90 functions by having the CPU execute a control program stored in ROM, thereby comprising a drive control unit 901, a discharge control unit 902, a discharge pattern specification unit 903, and a storage unit 904.

[0055] The drive control unit 901 controls the transport operation of the workpiece W by controlling the first motor M1 and the second motor M2 of the workpiece transport unit 20. The drive control unit 901 also controls the reciprocating movement of the carriage 3 along the main scanning direction S by controlling the carriage drive unit 3S.

[0056] The ejection control unit 902 inputs predetermined command signals to the ink head 4, pre-treatment head 5, and post-treatment head 6, and controls the ejection operation of each color of ink, pre-treatment liquid, and post-treatment liquid.

[0057] The ejection pattern specification unit 903 specifies the ejection pattern for each head in order to land ink at a predetermined position on the workpiece W, according to the image information received from the I / F 91 or the image memory 92. More specifically, the ejection pattern specification unit 903 specifies the amount of ink ejected (ejection pattern) for each color ink head 4 and inputs a signal corresponding to the ejection amount and ejection timing to the ejection control unit 902. The ejection pattern specification unit 903 also performs the same control as described above for the pre-treatment head 5 that ejects pre-treatment liquid and the post-treatment head 6 that ejects post-treatment liquid.

[0058] The memory unit 904 pre-stores various thresholds, parameters, etc., that are referenced by the drive control unit 901, the discharge control unit 902, and the discharge pattern specification unit 903 of the control unit 90.

[0059] The structure of the control unit 90 is not limited to the above-described embodiment, and may be in a different form depending on the structure of the device and program. In other words, the functions of the drive control unit 901, the discharge control unit 902, the discharge pattern specification unit 903, and the storage unit 904 can be said to be performed by the control unit 90.

[0060] <Regarding the dispensing of each processing solution and ink> As shown in Figure 6, in this embodiment, one pre-treatment head 5 is positioned upstream of the ink head 4 and one post-treatment head 6 is positioned downstream of the ink head 4 in the transport direction F. In other words, an all-in-one inkjet printer 1 can be provided that has three types of heads—a head for ejecting pre-treatment liquid, ink, and post-treatment liquid—mounted on a single carriage 3. Furthermore, since the pre-treatment head 5, ink head 4, and post-treatment head 6 are sequentially positioned in the transport direction F, the pre-treatment liquid, ink, and post-treatment liquid can be ejected in a desired landing order during both the forward and return main scans.

[0061] As described above, in this embodiment, the inkjet printer 1 includes a workpiece transport unit 20 that transports the workpiece W in a predetermined transport direction F, a carriage 3 that reciprocates along a main scanning direction S intersecting the transport direction F, a pre-treatment head 5 mounted on the carriage 3 that ejects a non-coloring pre-treatment liquid, an ink head 4 mounted on the carriage 3 that ejects ink, and a post-treatment head 6 mounted on the carriage 3 that ejects a non-coloring post-treatment liquid. When the ejection control unit 902 controls the ejection of each head in response to the movement of the carriage 3 in the main scanning direction S, the pre-processing head 5 ejects pre-processing liquid to a predetermined recording area (pixel) on the workpiece W as the carriage 3 moves first along the main scanning direction S. Then, the workpiece transport unit 20 transports the workpiece W in the transport direction F (Figure 6) at a predetermined pitch. Furthermore, as the carriage 3 moves second along the main scanning direction S, the ink head 4 ejects ink to the recording area. Then, the workpiece transport unit 20 further transports the workpiece W in the transport direction F. As the carriage 3 moves third along the main scanning direction S, the post-processing head 6 ejects post-processing liquid to the recording area, thereby forming an ink image containing pre-processing liquid, ink, and post-processing liquid in the recording area. For this reason, in this embodiment, the pre-processing head 5, ink head 4, and post-processing head 6 are offset from each other in the transport direction F (Figure 6). Therefore, the pre-processing liquid, ink, and post-processing liquid can be reliably and stably applied to the workpiece W in this order. As a result, high-quality printing can be reliably achieved on the workpiece W. For example, the first movement of the carriage 3 is in one direction in the main scanning direction S (from right to left in Figure 6), the second movement is in the other direction in the main scanning direction S (from left to right in Figure 6), and the third movement is in the aforementioned one direction in the main scanning direction S.

[0062] In other words, in this embodiment, if the movement of the carriage 3 when the pre-treatment head 5 moves along the main scanning direction S to eject the pre-treatment liquid over a predetermined area on the workpiece W is called the first scan, the movement of the carriage 3 when the ink head 4 moves along the main scanning direction S to eject ink over the predetermined area is called the second scan, and the movement of the carriage 3 when the post-treatment head 6 moves along the main scanning direction S to eject the post-treatment liquid over the predetermined area is called the third scan, then the first scan, the second scan, and the third scan are all different scans, and each of the first scan, the second scan, and the third scan is performed at least once in this order. As a result, the pre-treatment liquid, ink, and post-treatment liquid can be applied to the workpiece W more reliably in this order. The predetermined area on the workpiece W is an area equivalent to or smaller than the area printed in one scan.

[0063] Furthermore, this disclosure is not limited to the configuration in which a single row of ink heads 4 is arranged along the main scanning direction S, as in this embodiment. Alternatively, two or more rows of ink heads 4 may be arranged in the transport direction F, with each row of ink heads 4 positioned along the main scanning direction S. Also, the ink heads 4 are not limited to those that form images of multiple colors. A single ink head 4 that ejects a single color of ink may be mounted on the carriage 3. In this case as well, the pre-processing head 5, ink heads 4, and post-processing head 6 should be arranged in this order, offset in the transport direction.

[0064] Furthermore, in this embodiment, the carriage 3 has a back frame 32 (engaging portion) that is cantilevered by a guide rail 17 (holding member). By cantilevering the carriage 3 to the timing belt 16, the structure can be simplified. In addition, by cantilevering, the downstream side of the carriage 3 can be easily opened, making it easier to perform maintenance on the ink head 4 and processing heads 5 and 6.

[0065] In this cantilevered carriage 3, the pre-processing head 5 is positioned at the base end 311 (the side closer to the engagement portion) of the head support frame 31, and the post-processing head 6 is positioned at the tip end 312 (the side further from the engagement portion). Unlike the base end 311, which is close to the back frame 32 fixed to the timing belt 16, the tip end 312, which is a free end, is expected to have reduced positional accuracy. However, the tip end 312 is equipped with a post-processing head 6, which does not require a high degree of precision in ejection accuracy. Since the post-processing liquid coats the ink image printed on the workpiece W, even if there is a misalignment in the point of impact, the relative impact on image quality can be reduced compared to if a similar misalignment occurs in the pre-processing liquid. Therefore, even when using a cantilevered carriage 3, it is possible to make it less likely for image quality to deteriorate.

[0066] <Challenges in carriage scanning> Figure 10 is a schematic diagram showing how ink 4M lands on the surface of the workpiece W as the carriage 3 moves. When the workpiece W is made of fabric such as woven or knitted material, or paper made of paper fibers, various irregularities exist on its surface. In the case of fabric, surface undulations caused by the weaving or knitting process, and irregularities between adjacent threads depending on the thickness and twist of the threads, exist. Generally, these irregularities are larger than the ink dot diameter of several tens of microns, or at least not negligible in relation to the ink dot diameter. In the case of paper, minute irregularities exist due to the random distribution of paper fibers on the surface, and depending on the type of paper, the irregularities may be of a size that is not negligible in relation to the ink dot diameter. In other words, recording media such as fabrics and certain types of paper may have irregularities on their surface with a periodicity that is not negligible in relation to the dot diameter of the ejected ink.

[0067] In Figure 10, when the ink head 4 moves in the main scanning direction S1 from right to left on the paper surface due to the movement of a carriage (not shown), and ejects ink 4M, the movement speed of the ink head 4 and the ejection speed of the ink 4M combine, causing each ink 4M to land on the workpiece W at an angle along the direction indicated by the arrows in Figure 10. In this case, if the workpiece W has an uneven shape with alternating inclined first surfaces K1 and second surfaces K2, then as shown in Figure 10, the amount of ink 4M that lands per unit area (coated amount) is relatively small on the first surface K1, which is nearly parallel to the ejection direction of the ink 4M, while the amount of ink 4M that lands per unit area is relatively large on the second surface K2, which is nearly perpendicular to the ejection direction of the ink 4M. This phenomenon occurs because the area on which the same amount of ink 4M lands is larger on the first surface K1 than on the second surface K2.

[0068] Furthermore, when the pre-treatment head 5 ejects the pre-treatment liquid while moving in the main scanning direction S1 in Figure 10 prior to the impact of the ink 4M as described above, the amount of pre-treatment liquid impacted per unit area becomes relatively small on the first surface K1, while the amount of pre-treatment liquid impacted per unit area becomes relatively large on the second surface K2. As a result, on the first surface K1, a small amount of ink impacts a small amount of pre-treatment liquid, while on the second surface K2, a large amount of ink impacts a large amount of pre-treatment liquid.

[0069] As mentioned above, the pretreatment solution has the function of improving the adhesion of ink to the surface of the workpiece W. For example, if the ink used has high permeability, the pretreatment solution acts to suppress that penetration and solidify it on the surface (increasing the amount of ink that adheres). Also, if the ink used has low permeability, the pretreatment solution acts to retain the ink on the surface. Thus, the properties of the pretreatment solution differ depending on the properties of the ink used, but in either case, the pretreatment solution exhibits the function of improving the adhesion of ink to the surface of the workpiece W.

[0070] Furthermore, because the pretreatment solution has this function, when both the pretreatment solution and ink are in small amounts on the first surface K1 in Figure 10, the amount of ink fixed to the surface decreases, resulting in a relatively lower density on the workpiece W. As a result, a significant relative density difference is observed between the first surface K1 and the second surface K2, where both the pretreatment solution and ink are in large amounts, causing density unevenness on the workpiece W.

[0071] Similarly, when the post-processing head 6 ejects post-processing liquid while moving in the main scanning direction S1 in Figure 10 after the ink 4M has landed as shown in Figure 10, the amount of post-processing liquid landed per unit area is relatively small on the first surface K1, while the amount of post-processing liquid landed per unit area is relatively large on the second surface K2. As a result, a small amount of post-processing liquid lands on a small amount of ink on the first surface K1, while a large amount of post-processing liquid lands on a large amount of ink on the second surface K2.

[0072] If the post-processing solution has the function of improving the fixation and robustness (resistance to rubbing and abrasion, abrasion resistance) of the ink image printed on the workpiece W, then if both the ink and post-processing solution are insufficient on the first surface K1, the amount of ink applied will be small and the abrasion resistance will be low. As a result, after a long time has passed since printing on the workpiece W, the density will be relatively lower than other parts such as the second surface K2, causing density unevenness on the workpiece W. Such a decrease in density can be exacerbated by washing, rubbing, wind and rain, etc.

[0073] In this embodiment, in order to eliminate the concentration difference that occurs between areas with low and high concentrations of each processing liquid and ink due to the scanning direction of each head, as described above, the ink head 4, pre-processing head 5, and post-processing head 6 are suitably arranged on the carriage 3, and the control unit 90 suitably controls the timing of liquid discharge from each ink head.

[0074] In other words, in this embodiment, as described above, when the movement of the carriage 3 when the pre-treatment head 5 moves along the main scanning direction S and ejects the pre-treatment liquid is called the first scan, when the ink head 4 moves along the main scanning direction S and ejects ink is called the second scan, and when the post-treatment head 6 moves along the main scanning direction S and ejects post-treatment liquid is called the third scan, the movement of the carriage 3 is different in the first scan and the second scan, which are consecutive. As a result, for example, a small amount of pre-treatment liquid and a large amount of ink are applied to the first surface K1 in Figure 6, while a large amount of pre-treatment liquid and a small amount of ink are applied to the second surface K2. Therefore, as described above, areas with little and a large amount of pre-treatment liquid and ink do not occur on the workpiece W due to the scanning direction of the pre-treatment head 5 and the ink head 4, and density differences between the two can be prevented. In particular, by reducing the occurrence of areas with extremely little ink on the surface of the workpiece W, the amount of ink on the workpiece W can be made uniform, and density unevenness can be reduced. As a result, the image quality of the workpiece W can be improved. Note that if there are two or more rows of ink heads 4, it is sufficient that the ink head 4 located directly downstream (immediately after) the pre-processing head 5 and the pre-processing head 5 satisfy the above relationship. The same applies when there are two or more rows of pre-processing heads 5. In other words, it is sufficient that the movement direction of the carriage 3 is different between one scan of the first scan and one scan of the second scan, which are consecutive.

[0075] Similarly, in this embodiment, the movement direction of the carriage 3 is different for the second scan and the third scan, which are consecutive. In this case as well, a small amount of ink and a large amount of post-processing fluid are applied to the first surface K1 in Figure 6, while a large amount of ink and a small amount of post-processing fluid are applied to the second surface K2. Therefore, as described above, areas with little and a large amount of ink and post-processing fluid do not occur due to the scanning direction of the ink head 4 and the post-processing head 6, and density differences between the two can be prevented. In particular, the occurrence of areas with a small amount of ink and low scratch resistance is reduced, so the occurrence of areas where the density drops drastically compared to other areas after a long period of time can be reduced. As a result, density unevenness after a long period of time has passed since printing is reduced, and a stable image can be maintained over a long period of time, improving the quality of the printed material. Note that if there are two or more rows of ink heads 4, it is sufficient that the ink head 4 located directly upstream (immediately before) the post-processing head 6 and the post-processing head 6 satisfy the above relationship. The same applies when there are two or more rows of post-processing heads 6. In other words, the direction of movement of the carriage 3 must be different between one of the second scans and one of the third scans, which are consecutive.

[0076] In the example shown in Figure 10, the amount of liquid impacted varies depending on the direction of the main scan due to the inclination of the impact surface of the workpiece W. In the case of fabrics and other materials, the amount of liquid impacted may vary depending on the direction of the main scan not only when the impact surface is simply inclined, but also due to the irregular shape of convex and concave parts. In such cases as well, the problem can be improved as described above by reversing the scanning direction of the carriage 3 in the first movement (first scan) and the scanning direction of the carriage 3 in the second movement (second scan). Similarly, the problem can be improved as described above by reversing the scanning direction of the carriage 3 in the second movement and the scanning direction of the carriage 3 in the third movement (third scan).

[0077] Furthermore, as shown in Figure 6, in this embodiment, the pre-processing head 5 has a pre-processing nozzle region 5Z, each ink head 4 has an ink nozzle region 4Z, and the post-processing head 6 has a post-processing nozzle region 6Z. The pre-processing nozzle region 5Z is a region defined by a plurality of pre-processing nozzles that are positioned facing the workpiece W at the image formation position and each discharges pre-processing liquid as the carriage 3 moves in the first direction. Similarly, the ink nozzle region 4Z is a region defined by a plurality of ink nozzles that are positioned facing the workpiece W at the image formation position and each discharges ink as the carriage 3 moves in the second direction. Furthermore, the post-processing nozzle region 6Z is a region defined by a plurality of post-processing nozzles that are positioned facing the workpiece W at the image formation position and each discharges post-processing liquid as the carriage 3 moves in the third direction. Furthermore, in Figure 6, when viewed along the main scanning direction S, the pre-processing nozzle area 5Z, the ink nozzle area 4Z, and the post-processing nozzle area 6Z are arranged so as not to overlap with each other, and are arranged continuously (adjacent to each other) along the transport direction F.

[0078] Furthermore, in this embodiment, the lengths of the pre-processing nozzle area 5Z, the ink nozzle area 4Z, and the post-processing nozzle area 6Z in the transport direction F are set to be greater than or equal to the maximum transport pitch (maximum feed pitch) of the workpiece W.

[0079] With this configuration, even when the workpiece transport unit 20 intermittently transports the workpiece W at the maximum transport pitch, no gaps are formed in the image on the workpiece W, making it possible to form a high-quality image in a short time.

[0080] Furthermore, it is desirable that the distance in the transport direction F from the downstream end of the ink nozzle area 4Z in the transport direction F to the downstream end of the post-processing nozzle area 6Z in the transport direction F be set to be greater than or equal to the length of the ink nozzle area 4Z in the transport direction F.

[0081] With this configuration, it becomes possible to reliably print the post-treatment liquid at a printable pitch, so that high-quality printing can be performed in a short time without leakage of the post-treatment liquid. In this case, the post-treatment nozzle area 6Z may extend further upstream or downstream in the transport direction F than the range shown in Figure 6. Also, if there are multiple rows of ink heads 4, the distance in the transport direction F from the downstream end of the ink nozzle area 4Z of the downstreammost ink head 4 in the transport direction F to the downstream end of the post-treatment nozzle area 6Z in the transport direction F should be set to be greater than or equal to the length of the ink nozzle area 4Z in the transport direction F. In other words, the distance in the transport direction F from the downstream end of the ink nozzle area 4Z of multiple rows of ink heads 4, considered as a single ink nozzle area, to the downstream end of the post-treatment nozzle area 6Z in the transport direction F should be set to be greater than or equal to the length of the ink nozzle area 4Z in the transport direction F.

[0082] In Figure 6, the pre-treatment head 4 and the post-treatment head 6 are positioned at the same location in the main scanning direction S. This arrangement shortens the length of the carriage 3 in the main scanning direction S. The positions of the pre-treatment head 4 and the post-treatment head 6 in the main scanning direction S can be any position relative to the first to sixth ink heads 4A to 4F. In Figure 6, the pre-treatment head 4 and the post-treatment head 6 are positioned at the right end of the first to sixth ink heads 4A to 4F, which are aligned in the main scanning direction S. By positioning them at the right end, or conversely at the left end, it becomes less likely that mist adhering to the carriage 3 will react and solidify when using pre-treatment or post-treatment solutions that react with the ink.

[0083] Figures 8 and 9 are plan views showing the relationship between the pre-treatment liquid landing area and the ink landing area on the workpiece W in the inkjet printer 1 according to this embodiment. In this embodiment, the ejection pattern designation unit 903 (control unit 90) designates the ejection timing of the pre-treatment head 5 and the ink head 4 according to the image information so that the area where the pre-treatment liquid lands is wider than the area where the ink lands, corresponding to predetermined image information.

[0084] As shown in Figure 8, when an ink image is formed over a wide area on the workpiece W, a pre-treatment liquid impact area 5H is set in advance to be wider than the ink image, and the pre-treatment liquid ejected from the pre-treatment head 5 is impacted there. Then, the ink ejected from the ink head 4 is impacted in the ink impact area 4H corresponding to the ink image. On the other hand, as shown in Figure 9, even when an ink image is formed only partially on the workpiece W, it is sufficient that the pre-treatment liquid impact area 5H is set to be wider than the ink impact area 4H. This type of control makes it possible to reliably apply the pre-treatment liquid to the entire area where the ink will be applied, thereby improving print quality by stably exhibiting the interaction between the pre-treatment liquid and the ink.

[0085] In particular, in this embodiment, the ejection pattern designation unit 903 (control unit 90) specifies the ejection timing of the pre-treatment head 5 and the ink head 4 so that the area 5H where the pre-treatment liquid lands encompasses the area 4H where the ink lands from the surrounding area, as shown in Figures 8 and 9. As a result, it becomes possible to more reliably apply the pre-treatment liquid to the entire area where the ink is applied.

[0086] Furthermore, the configuration in which the pre-treatment liquid impact area 5H is set to be relatively wider than the ink impact area 4H is not limited to the configuration in which it encloses from the periphery as described above. The pre-treatment liquid impact area 5H may be wider than the ink impact area 4H only in the transport direction F and equivalent in the main scanning direction S, or the pre-treatment liquid impact area 5H may be wider than the ink impact area 4H only in the main scanning direction S and equivalent in the transport direction F. Moreover, if the ink impact area 4H is ring-shaped, the pre-treatment liquid impact area 5H may be a wider ring shape. In addition, the ink impact area 4H and the pre-treatment liquid impact area 5H, which are formed by the ejection of ink and pre-treatment liquid from the ink head 4 and the pre-treatment head 5, may be set in advance by editing the print pattern (print image information), or the ejection timing of each head may be set to be earlier or later in accordance with the print pattern.

[0087] Furthermore, as described above, in a configuration where the pretreatment solution is printed over a wider area than the ink, regardless of the size of the ink image, it is possible to reduce the amount of pretreatment solution used compared to the case where the entire workpiece W is immersed in the pretreatment solution beforehand.

[0088] Furthermore, as mentioned above, in the case where the pretreatment solution is selectively printed, the pretreatment solution may be printed over a wider area than the ink to correspond to ink printing patterns where further suppression of bleeding is necessary. In this case, if the ink impact area 4H and the pretreatment solution impact area 5H are set to the same range, printing may not be possible in the necessary areas, so it is desirable to expand the printing range of the pretreatment solution as described above.

[0089] Furthermore, in this embodiment, the transport speed of the workpiece W and the scanning speed of the carriage 3 are set so that the time from the impact of the pre-treatment liquid to the impact of the post-treatment liquid on a predetermined pixel on the workpiece W falls within the range of 0.5 seconds to 10 seconds for the entire workpiece W.

[0090] With this configuration, high print quality can be ensured across the entire printing area of ​​the workpiece W. In particular, if the time from the impact of the pre-treatment solution to the impact of the post-treatment solution is less than 0.5 seconds, image quality such as color development, texture, and durability tends to deteriorate. Also, if the time from the impact of the pre-treatment solution to the impact of the post-treatment solution exceeds 10 seconds, the difference in image quality between the lower and upper limits of that time, i.e., the variation in image quality, tends to increase.

[0091] Although an inkjet printer 1 according to one embodiment of the present disclosure has been described above, the present disclosure is not limited thereto, and for example, the following modified embodiments can be taken.

[0092] In the above embodiment, the pre-processing head 5 has a pre-processing nozzle area 5Z, each ink head 4 has an ink nozzle area 4Z, and the post-processing head 6 has a post-processing nozzle area 6Z. As shown in Figure 6, the pre-processing nozzle area 5Z, the ink nozzle area 4Z, and the post-processing nozzle area 6Z are arranged so that they do not overlap when viewed along the main scanning direction S. On the other hand, the areas where the nozzles of each head are arranged may be arranged so that their ends partially overlap when viewed along the main scanning direction S. In this case, it is desirable that the nozzles (actual discharge nozzles) that the discharge control unit 902 controls to discharge ink or each processing liquid during printing are controlled so that they do not overlap when viewed along the main scanning direction S. That is, in this disclosure, the multiple nozzles (pre-processing nozzles, ink nozzles, post-processing nozzles) that discharge liquids (pre-processing liquid, ink, post-processing liquid) in conjunction with the movement of the carriage 3 (first movement, second movement, third movement) refer to the nozzles that actually discharge each liquid during printing.

[0093] In other words, the nozzles of each head are not limited to discharging liquid from all pre-arranged nozzles, but may be controlled to discharge liquid from only some of the nozzles. Furthermore, among the pre-processing nozzle area, the ink nozzle area, and the post-processing nozzle area, it is desirable that the length of the shortest nozzle in the transport direction F is longer than half the length of the longest nozzle. Such control allows for high-quality printing to be achieved in a short time. Note that in each head, multiple nozzles only need to be arranged in line in the transport direction F, and the number of nozzles arranged in the main scanning direction S is not limited.

[0094] Furthermore, part or all of the control unit 90 of the inkjet printer 1 may be a personal computer or the like that transmits print image information to the inkjet printer 1. [Explanation of symbols]

[0095] 1. Inkjet printer 3 carriages 4 Ink Heads 4H Ink Impact Area 4M Ink 5 Pre-processing head 5H Pre-treatment liquid impact area 6. Post-processing head 7 Sub-tank 10. Device frame 12 Print Area 13 Maintenance Area 14 Turning Point Area 20 Workpiece transport section 90 Control Unit 901 Drive Control Unit 902 Discharge Control Unit 903 Discharge pattern specification unit (discharge condition specification unit) 904 Storage section 91 I / F 92 Image memory F Conveying direction K1 1st page K2 2nd side L1 Pre-processing / Inkhead boundary L2 Ink / Post-processing Head Boundary M1 First Motor M2 Second Motor S Main scanning direction Double job

Claims

1. A transport unit that transports the recording medium in a predetermined transport direction, A carriage that moves back and forth along a main scanning direction intersecting the transport direction, Mounted on the carriage is at least one processing head having a processing nozzle region for discharging a non-coloring processing liquid, Mounted on the carriage, at least one ink head having an ink nozzle area for ejecting ink, Equipped with, When viewed along the main scanning direction, The end of one of the at least one processing heads on one side in the transport direction is arranged to overlap with the end of one of the at least one ink heads on the other side in the transport direction. An inkjet recording apparatus in which the end of the processing nozzle area of ​​one processing head on one side in the transport direction and the end of the ink nozzle area of ​​one ink head on the other side in the transport direction are arranged in a continuous manner.

2. An inkjet recording apparatus according to Claim 1, The at least one ink head comprises a plurality of ink heads, including the one ink head. The carriage has a plurality of openings, Each of the plurality of ink heads has the ink nozzle area, An inkjet recording device in which the plurality of ink heads and the one processing head are fitted into the plurality of openings and fixed to the carriage.

3. An inkjet recording apparatus according to claim 1, If the movement of the carriage when the processing head moves along the main scanning direction to eject the processing liquid over a predetermined area on the recording medium is defined as the first scan, and the movement of the carriage when the ink head moves along the main scanning direction to eject the ink over the predetermined area is defined as the second scan, An inkjet recording apparatus in which the first scan and the second scan are different scans from each other.

4. An inkjet recording apparatus according to claim 3, An inkjet recording apparatus in which the movement direction of the carriage is different in the first scan and the second scan, which are consecutive.

5. An inkjet recording apparatus according to claim 1, The transport unit intermittently transports the recording medium at a predetermined transport pitch. An inkjet recording device in which the length of each of the ink nozzle region and the processing nozzle region in the transport direction is set to be greater than or equal to the maximum value of the transport pitch.

6. An inkjet recording apparatus according to claim 1, An inkjet recording apparatus in which, among the ink nozzle area and the processing nozzle area, the length of the shortest one in the transport direction is longer than half the length of the longest one.

7. A transport unit that transports a recording medium in a predetermined transport direction, A carriage that moves back and forth along a main scanning direction intersecting the transport direction, Mounted on the carriage is at least one processing head having a processing nozzle region for discharging a non-coloring processing liquid, Mounted on the carriage, at least one ink head having an ink nozzle area for ejecting ink, An inkjet recording method for an inkjet recording apparatus comprising, When viewed along the main scanning direction, one end of one of the at least one processing heads in the transport direction overlaps with the other end of one of the at least one ink heads in the transport direction, and the one end of the processing nozzle area of ​​the processing head in the transport direction and the other end of the ink nozzle area of ​​the ink head in the transport direction are arranged to be continuous. The non-coloring processing solution is deposited from at least one of the processing heads, The ink is to be deposited from at least one of the aforementioned ink heads. An inkjet recording method comprising the following features.

8. The inkjet recording method according to claim 7, The recording medium is fabric, and the method is an inkjet recording method.

Images