Printing unit and recording device

Abstract

This printing unit comprises: a carriage which reciprocates in a main scanning direction; a plurality of ink heads which are mounted in the carriage so as to be arranged side-by-side in at least one row in the main scanning direction, and which eject ink; and a plurality of tanks which are mounted in the carriage so as to be arranged side-by-side in the main scanning direction, and which store the ink. The plurality of ink heads include a pair of first ink heads which are disposed at both ends in the main scanning direction and which eject ink of the same color, and the plurality of tanks include a first tank for storing ink of a color corresponding to the pair of first ink heads. In the carriage, a disposition range in which the plurality of tanks are disposed is set so as to include the same region in the main scanning direction as a disposition range in which the plurality of ink heads are disposed, and the first tank is disposed in the center in the main scanning direction among the plurality of tanks.

Description

Technical Field

[0001] The present disclosure relates to a printing unit and a 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 a printing unit that performs printing on a recording medium. The printing unit has an ink head that discharges ink for image formation toward the recording medium. When the recording medium is wide, the ink head is mounted on a carriage that reciprocates in the main scanning direction. At the time of printing, the recording medium is intermittently fed in a predetermined direction (sub-scanning direction), and ink is discharged from the ink head while the carriage reciprocates in the main scanning direction during the stop of the recording medium. Also, as in Patent Document 1, a technique is known in which a tank for storing ink is mounted on the carriage in the same manner as the ink head.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] A printing unit according to one aspect of the present disclosure comprises a carriage that reciprocates in a main scanning direction, a plurality of ink heads mounted on the carriage so as to be arranged in at least one row along the main scanning direction and for ejecting ink, and a plurality of tanks mounted on the carriage so as to be arranged along the main scanning direction and for containing ink. The plurality of ink heads have a pair of first ink heads arranged at both ends of the main scanning direction and for ejecting ink of the same color, and the plurality of tanks have a first tank for containing ink of the color corresponding to the pair of first ink heads. In the carriage, the arrangement range in which the plurality of tanks are arranged is set to include the same area in the main scanning direction as the arrangement range in which the plurality of ink heads are arranged, and the first tank is located in the center of the plurality of tanks in the main scanning direction.

[0005] Furthermore, a recording device relating to another aspect of this disclosure comprises the printing unit described above and a transport unit that transports the recording medium in a direction intersecting the main scanning direction. [Brief explanation of the drawing]

[0006] [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, processing head, and tank on the carriage shown in Figure 3, and illustrates the replenishment routes for ink and processing fluid. [Figure 7] Figure 7 is a schematic plan view showing the arrangement of the ink head, processing head, and tank on the carriage shown in Figure 3, and illustrates the replenishment routes for ink and processing fluid. [Figure 8] Figure 8 is a schematic plan view showing the arrangement of tanks on a carriage according to the first modified embodiment of the present disclosure. [Figure 9] Figure 9 is a schematic plan view showing the arrangement of tanks on a carriage according to a second modified embodiment of the present disclosure. [Figure 10] Figure 10 is a schematic plan view showing the arrangement of tanks on a carriage according to a third modified embodiment of the present disclosure. [Modes for carrying out the invention]

[0007] The printing units according to each embodiment of this disclosure will be described below with reference to the drawings. In these embodiments, as a specific example of a device equipped with a printing unit, an inkjet printer (recording device) equipped with an ink head that ejects image-forming ink onto a wide and long recording medium will be 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 printing units according to this disclosure can also be used for printing various images onto recording media such as paper sheets and resin sheets.

[0008] [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 (printing unit) 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 (the transport direction F of the workpiece W, which intersects the main scanning direction S).

[0009] The device frame 10 forms a 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 moves in a transport direction F from rear to front within the printing area where the inkjet printing process is performed. 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 the transport direction F of the workpiece W during the inkjet printing process. This movable unit constitutes the printing unit of this disclosure.

[0010] 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.

[0011] 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.

[0012] 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 is mounted on 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 to move around in the left or right direction.

[0013] The carriage guide 15 is equipped with a pair of upper and lower guide rails 17 that extend parallel to each other in the left-right direction, holding the carriage 3 in a state where it can 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.

[0014] 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.

[0015] The path between the feed roller 21 and the take-up roller 22, passing through the printing area 12, serves as the transport path for the workpiece W. Along this transport path, the first tension roller 23, workpiece guide 24, transport roller 25 and pinch roller 26, return roller 27, and second tension roller 28 are arranged in order from upstream. The first tension roller 23 applies a predetermined tension to the workpiece W upstream of the transport roller 25. The workpiece guide 24 changes the transport direction of the workpiece W from upward to forward, bringing the workpiece W into the printing area 12.

[0016] The transport roller 25 is a roller that generates a transport force to intermittently feed the workpiece W in the printing area 12. The transport roller 25 is rotationally driven around its axis by the second motor M2 and intermittently transports the workpiece W forward (in a predetermined transport direction F) so that the workpiece W passes through the printing area 12 (image formation position) facing the carriage 3. The pinch roller 26 is positioned to face the transport roller 25 from above and forms a transport nip section with the transport roller 25.

[0017] The folding roller 27 changes the conveyance direction of the workpiece W that has passed through the printing area 12 from the forward direction to the downward direction, 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 on the downstream side of the conveyance roller 25. A platen 29 is disposed below the conveyance path of the workpiece W in the printing area 12.

[0018] The carriage 3 is supported in a cantilevered manner on the guide rail 17 and reciprocates in the main scanning direction S (the left-right direction in this embodiment) that intersects (orthogonal in this embodiment) the conveyance direction F. 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.

[0019] The head support frame 31 is a horizontal plate that holds the above-described heads 4 to 6. The back frame 32 is a vertical plate that extends upward from the rear edge of the head support frame 31. As described above, the timing belt 16 is fixed to the back frame 32. Also, the guide rail 17 is engaged with the back frame 32. That is, in this embodiment, the back frame 32 is an engaging portion that is held in a cantilevered manner by the guide rail 17. The head support frame 31 is a horizontal plate whose rear end side is supported in a cantilevered manner by the guide rail 17 by the engaging portion.

[0020] Note that the cantilevered state means that, in the carriage 3, the engaging portion (back frame 32), which is the portion held by the guide rail 17 as the holding member, exists only on one side, upstream or downstream, from the center of the carriage 3 in the conveyance direction F, and there is no other engaging portion on the opposite side of the side where the engaging portion exists. The engaging portion may be further disposed outside the range where the ink head 4 and the processing heads are disposed in the conveyance direction F. That is, the engaging portion may be disposed only on the upstream side or only on the downstream side with respect to the range where the ink head 4 and the processing heads are disposed in the conveyance direction F.

[0021] [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.

[0022] Each of the ink heads 4 is equipped with numerous 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, pigment, and binder resin can be used. The multiple ink heads 4 in this embodiment are each capable of ejecting eight colors of ink. The ink heads 4 are mounted on the head support frame 31 of the carriage 3 so as to be arranged in two rows in the main scanning direction S. Each ink head 4 of each color has two heads. The detailed arrangement of the ink heads 4 will be described in detail later.

[0023] 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. The carriage 3 is provided with at least one pre-processing head 5 and at least one post-processing head 6. In other embodiments, the pre-processing head 5 and post-processing head 6 may not be provided.

[0024] Furthermore, a sequence of heads along the main scanning direction S, consisting of the ink head 4, pre-processing head 5, and post-processing head 6, is referred to as a row of heads, or simply a row. Similarly, a sequence of heads along the transport direction F, consisting of the ink head 4, pre-processing head 5, and post-processing head 6, is referred to as a line of heads, or simply a line.

[0025] The pretreatment head 5 discharges a pretreatment solution to perform a predetermined pretreatment on the workpiece W. The pretreatment solution is discharged from the pretreatment head 5 to a position on the workpiece W where ink has not yet been discharged from the inkhead 4. The pretreatment solution is a non-coloring solution that does not develop color even when it adheres to the workpiece W, and is a solution that exhibits functions such as improving the ink's fixation to the workpiece W and the aggregation of the ink pigment. As such a pretreatment solution, a solution containing a binder resin in the solvent, or a solution containing a positively charged cationic resin in the solvent can be used.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] As shown in Figure 3, an opening 31H is provided in the head support frame 31 where the print head is positioned. The ink head 4, pre-processing head 5, and 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 of the print heads 4, 5, and 6 are exposed through each opening 31H.

[0031] 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 ink and processing fluid (not shown), and these are supplied 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) (see conduit P in Figure 6).

[0032] 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.

[0033] [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.

[0034] 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 length of the transport direction F of the area where the ink ejection nozzles of the ink head 4 are located. Note that in Figure 4 and Figures 5A and 5B described below, the length of the transport direction F of each head and the printing width Pw are depicted as approximately equal, but in reality, the length of the transport direction F of each head is greater than the printing width Pw and the length of the transport direction F of the area where the ejection nozzles are located.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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 complete. 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.

[0041] 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.

[0042] 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.

[0043] 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 length of the carriage 3 in the main scan direction S would increase. Since such an arrangement is unnecessary in this embodiment, the length of the carriage 3 in the main scan direction S can be reduced.

[0044] 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.

[0045] Figures 6 and 7 are schematic plan views showing the arrangement of the ink heads 4, processing heads 5 and 6, and sub-tanks 7 on the carriage 3 shown in Figure 3, and illustrate the replenishment routes for ink and processing fluid. As mentioned above, the carriage 3 is cantilevered by guide rails 17 on the back frame 32 (Figure 3). The back frame 32 is located upstream of the head support frame 31 in the transport direction F. In the transport direction F, the side of the head support frame 31 where the back frame 32 is located is considered the base end, and the side of the head support frame 31 opposite the base end is considered the front end. As previously described, the head support frame 31 of the carriage 3 is equipped with multiple ink heads 4 that eject eight colors of ink, a pre-processing head 5, and a post-processing head 6. Each color ink head 4 has two unit heads (16 in total). There is one pre-processing head 5 and one post-processing head 6.

[0046] In Figure 6, each of the 16 ink heads 4 is marked with an alphabet corresponding to the color of ink it ejects. Specifically, K represents black, Y represents yellow, M represents magenta, C represents cyan, B represents blue, V represents violet, O represents orange, and G represents green. The pre-treatment head 5 is labeled "pre," and the post-treatment head 6 is labeled "post." Similarly, the sub-tanks 7 are also labeled as follows: the sub-tank 7 containing the pre-treatment solution is labeled "pre," the sub-tank 7 containing the post-treatment solution is labeled "post," and the sub-tanks 7 containing each color of ink are labeled with an alphabet in the same manner as above. In reality, the sub-tanks 7 are positioned higher than the ink heads 4, pre-treatment heads 5, and post-treatment heads 6, as shown in Figure 3. In this case, the arrangement range of the multiple sub-tanks 7 in the carriage 3 is set to overlap with the arrangement range of the multiple ink heads 4 in a direction perpendicular to the main scanning direction S. In other words, in the main scanning direction S, the arrangement range of the multiple sub-tanks 7 is located in the same area as the arrangement range of the multiple ink heads 4. In this case, one of the arrangement ranges being compared may be set to be wider than the other.

[0047] As shown in Figure 6, in the transport direction F, the pre-processing head 5 is positioned upstream of the multiple ink heads 4, and the post-processing head 6 is positioned downstream of the multiple ink heads 4. Furthermore, the pre-processing head 5 is positioned at the left end of the arrangement range in the main scanning direction S where the multiple ink heads 4 are positioned. On the other hand, the post-processing head 6 is positioned at the right end of the arrangement range where the multiple ink heads 4 are positioned, opposite to the pre-processing head 5 in the main scanning direction S. As a result of the above head arrangement, the pre-processing head 5 and the post-processing head 6 are positioned within the arrangement width range of the ink heads 4 in the main scanning direction S.

[0048] Multiple ink heads 4 are arranged in two rows in the main scanning direction S. The first row of ink heads 4, closer to the pre-processing head 5, contains the K, M, O, and Y color ink heads 4. A pair of K color ink heads 4 are positioned on the outermost side in the main scanning direction S, while a pair of M color ink heads 4, a pair of O color ink heads 4, and a pair of Y color ink heads 4 are positioned sequentially towards the inside of the main scanning direction S. In other words, the above four color ink heads 4 are arranged symmetrically in the main scanning direction S.

[0049] The second row of ink heads 4, closer to the post-processing head 6, contains the C, B, V, and G color ink heads 4. A pair of C color ink heads 4 are positioned on the outermost side in the main scanning direction S, while a pair of B color ink heads 4, a pair of V color ink heads 4, and a pair of G color ink heads 4 are positioned sequentially towards the inside of the main scanning direction S. In other words, the above four color ink heads 4 are also arranged symmetrically in the main scanning direction S.

[0050] Furthermore, as shown in Figure 6, the first row of ink heads 4 and the second row of ink heads 4 are offset in the main scanning direction S, and the ink heads 4 of one row are positioned between adjacent ink heads 4 of the other, resulting in an overall staggered arrangement. A pre-processing head 5 is positioned behind the left C-color ink head 4 of the second row, and a post-processing head 6 is positioned in front of the right K-color ink head 4 of the first row.

[0051] Furthermore, in this embodiment, the two ink heads 4 that eject ink of the same color are arranged in the same row. As a result, when the carriage 3 moves back and forth in the main scanning direction, ink can be ejected from the two ink heads 4 to a predetermined pixel during scanning in the same direction. Therefore, compared to the case where the two ink heads 4 are arranged in different rows, it is possible to shorten the difference in ink landing time to the pixel and form a stable image.

[0052] Furthermore, as shown in Figure 6, the two ink heads 4 that eject ink of the same color are arranged symmetrically in the main scanning direction S. Therefore, regardless of whether the carriage 3 scans to the right or to the left, the order in which the inks of each color land can be made the same, preventing the occurrence of partial color differences on the workpiece W.

[0053] 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.

[0054] In the multiple sub-tanks 7, the sub-tanks 7 for pre-treatment solution, G color, V color, B color, C color, K color, M color, O color, Y color, and post-treatment solution are arranged from left to right. That is, the pre-treatment solution sub-tank 7 (tank for pre-treatment solution) is located at the end of the main scanning direction S on the same side as the pre-treatment head 5 in the arrangement range where the multiple sub-tanks 7 are located. Similarly, the post-treatment solution sub-tank 7 (tank for post-treatment solution) is located at the end of the main scanning direction S on the same side as the post-treatment head 6 in the arrangement range where the multiple sub-tanks 7 are located.

[0055] Between the sub-tanks 7 for the pre-treatment and post-treatment solutions, eight sub-tanks 7 for different colors of ink are positioned. As shown in Figure 6, of these eight sub-tanks 7, the four on the right supply their respective inks to the first row of ink heads 4 (Figure 6). The four on the left supply their respective inks to the second row of ink heads 4 (Figure 7). Thus, ink is supplied from one color sub-tank 7 to two ink heads 4. In Figures 6 and 7, the pipelines P for supplying the ink, pre-treatment solution, and post-treatment solution are depicted as two straight lines, respectively (different line types for each solution). Note that the actual pipelines P are made of rubber tubing and therefore have some curves.

[0056] The liquid in the sub-tank 7 mounted on the carriage 3, which moves back and forth in the main scanning direction S, is subjected to the acceleration in that direction. Similarly, since the conduit P is filled with ink or processing fluid, these liquids are also subjected to acceleration. In particular, the greater the distance between the supplying sub-tank 7 and the receiving head in the main scanning direction S, the longer the conduit P extends in that direction, and the greater the effect of the acceleration. Furthermore, when the carriage 3 reverses direction in the main scanning direction S, the acceleration creates a large pressure that is applied from the liquid in the conduit P to the liquid inside the head, causing pressure fluctuations within the head. As a result, it may become difficult to stably eject the respective liquids from the heads 4, 5, and 6, making it challenging to form a good ink image on the recording medium.

[0057] The discloser of this disclosure has diligently studied how to minimize the effects of acceleration when supplying ink from a single sub-tank 7 to two ink heads 4 that eject ink of the same color. As a result, they have arrived at the arrangement of the ink heads 4, pre-processing head 5, post-processing head 6, and sub-tank 7 shown in Figures 6 and 7. Specifically, in the first row of ink heads 4, the pair of K-color ink heads 4 (a pair of first ink heads) located at both ends of the main scanning direction S have the greatest distance from each other, and therefore the pipeline P is inevitably long. For this reason, as shown in Figure 6, the sub-tank 7 (first tank) that contains the K-color ink is located in the center of the main scanning direction S among multiple sub-tanks 7.

[0058] The above-mentioned central area refers to the central 1 / 3 of the range in which the multiple sub-tanks 7 are arranged in the main scanning direction S, and more preferably, the central 1 / 5 of the range. Furthermore, in an embodiment in which the multiple sub-tanks 7 are arranged at approximately equal intervals in the main scanning direction S, placing the first tank in the central area also means the following: If there is an odd number of sub-tanks 7 (2n+1), the first tank is placed as the (n+1)th tank from the end of the main scanning direction S. If there is an even number of sub-tanks 7 (2n), the first tank is placed as the nth or (n+1)th tank from the end of the main scanning direction S.

[0059] As a result, it becomes possible to make the length of the pipeline P equal for the two K-color ink heads 4, thereby suppressing the influence of large accelerations on one of the pipelines P and reducing pressure fluctuations.

[0060] Furthermore, in the first row of ink heads (4 groups), for the remaining three pairs of ink heads (multiple pairs of second ink heads) for M, O, and Y colors, multiple sub-tanks 7 are arranged so that ink is discharged from sub-tanks 7 located relatively inside the main scanning direction S for the ink heads 4 located outside the main scanning direction S. In other words, for the multiple sub-tanks 7 (multiple second tanks) for M, O, and Y colors, the sub-tanks 7 containing the ink of the color corresponding to the ink heads 4 located outside the main scanning direction S are located at the same position as, or closer to, the sub-tanks 7 containing the ink of the color corresponding to the ink heads 4 located inside the main scanning direction S, or even closer to the K color sub-tank 7 (first tank). This makes it possible to minimize the difference in the length of the pipeline P in the first row of ink heads (4 groups).

[0061] Similarly, as shown in Figure 7, in the second row of ink heads 4, the pair of C-color ink heads 4 (a pair of first ink heads) located at both ends of the main scanning direction S are the closest to each other, and therefore the pipeline P is inevitably longer. For this reason, the sub-tank 7 (first tank) containing the C-color ink is located in the center of the main scanning direction S among multiple sub-tanks 7. Note that when the number of sub-tanks 7 is even, there are two sub-tanks 7 located in the center, as shown in Figures 6 and 7.

[0062] The above arrangement makes it possible to make the length of the conduit P equal for the two C-color ink heads 4, thereby suppressing the effect of large accelerations on one of the conduits P.

[0063] Furthermore, in the second row of ink heads 4, for the remaining three pairs of ink heads 4 (multiple pairs of second ink heads) for colors B, V, and G, multiple sub-tanks 7 are arranged so that ink is discharged from sub-tanks 7 located relatively inside the main scanning direction S for the ink heads 4 located outside the main scanning direction S. In other words, for the multiple sub-tanks 7 (second tanks) for colors B, V, and G, the sub-tanks 7 that contain the ink of the color corresponding to the ink head 4 located outside the main scanning direction S are located at the same position as, or closer to, the sub-tank 7 (first tank) for color C, corresponding to the ink of the ink head 4 located inside the main scanning direction S.

[0064] Alternatively, the sub-tanks 7 may be arranged from left to right in the main scanning direction S as G, V, B, C, K, M, O, and Y. This is the same as the sub-tank arrangement in Figure 7, but with B and M swapped. In this arrangement, relative to the first row of ink heads 4, the M and O sub-tanks 7 (second tanks) are at the same distance from the K sub-tank 7 (first tank), while the Y sub-tank 7 (second tank) is located further away. The second tank may be positioned at the same distance from the first tank in this manner.

[0065] To further suppress the effects of large accelerations, the sub-tank 7 containing the ink of the color corresponding to the ink head 4 located outside the main scanning direction S should be positioned closer to the first tank than the sub-tank 7 containing the ink of the color corresponding to the ink head 4 located inside the main scanning direction S.

[0066] In the arrangement shown in Figure 7, the sub-tanks 7 corresponding to the multiple pairs of second ink heads in the first row are arranged in the order of M, O, and Y colors on the same side (right) of the main scanning direction S as the sub-tank 7 (first tank) that contains K color ink corresponding to the pair of first ink heads in the first row. Similarly, the sub-tanks 7 corresponding to the multiple pairs of second ink heads in the second row are arranged in the order of B, V, and G colors on the same side (left, opposite to the first row) of the main scanning direction S as the sub-tank 7 (first tank) that contains C color ink corresponding to the pair of first ink heads in the second row. With this arrangement, the sub-tanks 7 containing the ink of the colors corresponding to the ink heads 4 located outside the main scanning direction S can be positioned closer to the first tank than the sub-tanks 7 containing the ink of the colors corresponding to the ink heads 4 located inside the main scanning direction S.

[0067] With the above arrangement, liquid can be stably supplied from multiple sub-tanks 7, which are arranged in a single line along the main scanning direction S, to two rows of ink heads 4, each extending in the main scanning direction S and aligned in the transport direction F. In this case, the length of the conduit P connected to each head can be shortened, thereby reducing the effect of acceleration received when the carriage 3 moves.

[0068] Furthermore, as shown in Figure 7, the arrangement range of the first row of ink heads 4 is shifted to the right (towards one end in the main scanning direction) relative to the arrangement range of the second row of ink heads 4. The sub-tank 7 corresponding to the first row of ink heads 4 is positioned on the right side within the arrangement range of the sub-tank 7, while the sub-tank 7 corresponding to the second row of ink heads 4 is positioned on the left side within the arrangement range of the sub-tank 7 (towards the other end opposite to the aforementioned end in the main scanning direction). By doing so, the distance between the sub-tank 7 and the ink heads 4 in the main scanning direction can be shortened, and the effects of large accelerations can be further suppressed.

[0069] In Figures 6 and 7, the configuration is described in which the multiple sub-tanks 7 are supply tanks that supply ink, pre-treatment liquid, and post-treatment to the ink head 4, pre-treatment head 5, and post-treatment head 6. In this case, the pressure fluctuations in the ink head 4, pre-treatment head 5, and post-treatment head 6 can be reduced due to the influence of the acceleration acting as the carriage 3 moves. In addition, all or some of the multiple sub-tanks 7 may be recovery tanks that recover ink, pre-treatment liquid, and post-treatment from the ink head 4, pre-treatment head 5, and post-treatment head 6. In this case, the large acceleration acting on the pipeline P can be suppressed, and pressure fluctuations can be reduced in a similar manner.

[0070] Furthermore, in this embodiment, the pre-treatment head 5 is positioned at the left end of the arrangement range of the multiple ink heads 4, and the sub-tank 7 for the pre-treatment liquid is positioned at the left end of the multiple sub-tanks 7. As a result, as shown in Figure 6, the length of the pipeline P for supplying the pre-treatment liquid can be shortened, and the pipeline P can be arranged as much as possible along the transport direction F. Similarly, the post-treatment head 6 is positioned at the right end of the arrangement range of the multiple ink heads 4, and the sub-tank 7 for the post-treatment liquid is positioned at the right end of the multiple sub-tanks 7. As a result, as shown in Figure 7, the length of the pipeline P for supplying the post-treatment liquid can be shortened, and the pipeline P can be arranged as much as possible along the transport direction F. The above arrangement of pipeline P prevents large accelerations from acting on the liquid flowing inside, and reduces pressure fluctuations at each head.

[0071] If the pre-processing head 5 or post-processing head 6 is placed between the ink heads 4, the placement range of the ink heads 4 will be extended in the main scanning direction S, and the distance between the ink heads 4 and the ink sub-tank 7 in the main scanning direction will also be extended. However, with the above-described arrangement, this cannot be prevented.

[0072] Similarly, if a sub-tank 7 for pre-treatment solution or a sub-tank 7 for post-treatment is placed between the sub-tanks 7 for ink, the placement range of the sub-tanks 7 for ink becomes longer in the main scanning direction S, and the distance between the ink head 4 and the sub-tanks 7 for ink in the main scanning direction also becomes longer. However, with the above-described arrangement, this does not occur.

[0073] Furthermore, in this embodiment, as described above, the post-processing head 6 is positioned on the opposite side of the pre-processing head 5 in the main scanning direction S, and the sub-tank 7 for the post-processing liquid is positioned on the opposite side of the sub-tank 7 for the pre-processing liquid in the main scanning direction S. Therefore, in addition to being able to shorten the length of the pipeline P as described above, the processing liquid heads and sub-tanks are not concentrated at one end of the main scanning direction S, and each pipeline P can be easily arranged.

[0074] Figure 8 is a schematic plan view showing the arrangement of a plurality of sub-tanks 7 on a carriage 3 according to the first modified embodiment of the present disclosure. In the previous embodiment, the plurality of sub-tanks 7 were arranged in a row in the main scanning direction S, and each sub-tank 7 was described as a supply tank. In this modified embodiment, as shown in Figure 8, the plurality of sub-tanks 7 include a plurality of supply tanks (second row in Figure 8) that contain inks of different colors supplied to a plurality of ink heads 4, and a plurality of recovery tanks (first row in Figure 8) that contain inks of different colors recovered from the plurality of ink heads 4. The notation for ink colors in Figure 8 is the same as in Figures 6 and 7.

[0075] Furthermore, the above-mentioned multiple supply tanks and multiple recovery tanks are arranged at different positions in the transport direction F (a direction perpendicular to the main scanning direction S), and each set of tanks consists of a set of supply tanks and a set of recovery tanks that contain ink of the same color. These sets of tanks are arranged side by side in the main scanning direction S, and more specifically, they are arranged in two rows.

[0076] Even with this configuration, the same effects as in the previous embodiment can be achieved, and liquid can be recovered from each head into the recovery tank during purging operations, etc.

[0077] Furthermore, as shown in Figure 8, the multiple sub-tanks 7 also have supply tanks (supply tanks for processing liquids) and recovery tanks (recovery tanks for processing liquids) for pre-treatment liquids and post-treatment liquids. These supply tanks and recovery tanks are arranged at different positions in the transport direction F and are arranged in parallel with the multiple sets of tanks of each color in the main scanning direction S.

[0078] With this configuration, the supply tank and recovery tank for the pre-treatment liquid and post-treatment liquid can be brought closer to the corresponding head, thus shortening the length of the pipeline P (Figures 6 and 7).

[0079] Figure 9 is a schematic plan view showing the arrangement of tanks on a carriage according to a second modified embodiment of the present disclosure. In the first modified embodiment, the multiple sets of tanks described above were arranged with supply tanks in the first row and recovery tanks in the second row. However, as shown in Figure 9, some supply tanks may be arranged in the first row and the other supply tanks in the second row. This configuration also provides the same effects as the previous embodiment and increases the degree of freedom in the layout of the head and sub-tanks on the carriage 3. Furthermore, it increases the degree of freedom in the routing of multiple pipelines P and suppresses complex intersections between pipelines P.

[0080] Figure 10 is a schematic plan view showing the arrangement of tanks on a carriage according to a third modified embodiment of the present disclosure. In Figure 10, the ink colors are not indicated and are shown in order from left to right by numbers. Also, Figure 10 omits the illustration of the pre-treatment liquid and post-treatment liquid tanks. The supply tanks and recovery tanks for each color are not limited to being arranged at the same position in the main scanning direction S. As shown in Figure 10, the supply tanks and recovery tanks may be arranged at offset positions (staggered) in the main scanning direction S and the transport direction F. In this case, the arrangement area of ​​the multiple sub-tanks 7 on the carriage 3 can be reduced in the transport direction F.

[0081] In addition, in each of the above modified embodiments, at least one of the pre-treatment liquid and the post-treatment liquid may be configured without a recovery tank.

[0082] Furthermore, this disclosure is not limited to the embodiments described above, and can take the following forms.

[0083] (1) The ink heads 4 are not limited to being arranged in two rows on the carriage 3. The ink heads 4 may be arranged in one row or in three or more rows.

[0084] (2) The ink colors are not limited to those shown in Figure 6. The ink colors may include spot colors, light colors, white, and other colors. [Explanation of Symbols]

[0085] 1. Inkjet printer (recording device) 3 carriages 4 Ink Heads 5 Pre-processing head 6. Post-processing head 7 Sub-tank (tank) 10. Device frame 12 Print Area 13 Maintenance Area 14 Turning Point Area 20 Workpiece transport section H Head placement area Double job

Claims

1. A carriage that moves back and forth in the main scanning direction, Multiple ink heads are mounted on the carriage so as to be aligned in at least one row along the main scanning direction, and eject ink. Multiple tanks for containing ink are mounted on the carriage so as to be aligned along the main scanning direction, Equipped with, The plurality of ink heads are arranged at both ends of the main scanning direction and each has a pair of first ink heads that eject ink of the same color. The plurality of tanks each have a first tank that contains ink of a color corresponding to the pair of first ink heads. In the carriage, the central part of the arrangement range in the main scanning direction where the plurality of tanks are arranged and the central part of the arrangement range in the main scanning direction where the plurality of ink heads are arranged are set to overlap in a transport direction that intersects the main scanning direction. The first tank is positioned in the center of the main scanning direction among the plurality of tanks, The aforementioned multiple ink heads are A pair of second ink heads, each consisting of a pair of ink heads that eject ink of the same color and are arranged symmetrically between the pair of first ink heads in the main scanning direction, A pair of third ink heads, each consisting of a pair of ink heads that eject ink of the same color and are arranged symmetrically between the pair of second ink heads in the main scanning direction, It further possesses, The plurality of tanks further comprises a second tank for containing ink of a color corresponding to the pair of second ink heads, and a third tank for containing ink of a color corresponding to the pair of third ink heads. The first tank is positioned closer to the center in the main scanning direction among the plurality of tanks than the second tank, A printing unit in which the second tank is located at the same position as the third tank or closer to the first tank than the third tank.

2. A carriage that moves back and forth in the main scanning direction, Multiple ink heads are mounted on the carriage so as to be aligned in at least one row along the main scanning direction, and eject ink. Multiple tanks for containing ink are mounted on the carriage so as to be aligned along the main scanning direction, Equipped with, The plurality of ink heads are arranged at both ends of the main scanning direction and each has a pair of first ink heads that eject ink of the same color. The plurality of tanks each have a first tank that contains ink of a color corresponding to the pair of first ink heads. In the carriage, the central part of the arrangement range in the main scanning direction where the plurality of tanks are arranged and the central part of the arrangement range in the main scanning direction where the plurality of ink heads are arranged are set to overlap in a transport direction that intersects the main scanning direction. The first tank is positioned in the center of the main scanning direction among the plurality of tanks, The plurality of ink heads are arranged in two rows in the main scanning direction, and the arrangement range of the first row of ink heads is shifted to one end of the main scanning direction relative to the arrangement range of the second row of ink heads. A printing unit in which, of the plurality of tanks, the tank corresponding to the first row of ink heads is located at one end within the arrangement range of the plurality of tanks, and the tank corresponding to the second row of ink heads is located at the other end of the arrangement range of the plurality of tanks, opposite to the one end.

3. A printing unit according to claim 1 or 2, A printing unit in which the first tank is a supply tank that contains ink supplied to the pair of first ink heads.

4. A printing unit according to claim 1 or 2, The first tank is a recovery tank for storing ink recovered from the pair of first ink heads, in a printing unit.

5. A printing unit according to claim 1, A printing unit in which the second tank and the third tank are located on the same side of the main scanning direction relative to the first tank.

6. A carriage that moves back and forth in the main scanning direction, Multiple ink heads are mounted on the carriage so as to be aligned in at least one row along the main scanning direction, and eject ink. Multiple tanks for containing ink are mounted on the carriage so as to be aligned along the main scanning direction, Equipped with, The plurality of ink heads are arranged at both ends of the main scanning direction and each has a pair of first ink heads that eject ink of the same color. The plurality of tanks each have a first tank that contains ink of a color corresponding to the pair of first ink heads. In the carriage, the central part of the arrangement range in the main scanning direction where the plurality of tanks are arranged and the central part of the arrangement range in the main scanning direction where the plurality of ink heads are arranged are set to overlap in a transport direction that intersects the main scanning direction. The first tank is positioned in the center of the main scanning direction among the plurality of tanks, The plurality of tanks include a plurality of supply tanks that contain ink of different colors to be supplied to the plurality of ink heads, and a plurality of recovery tanks that contain ink of different colors to be recovered from the plurality of ink heads. A printing unit comprising multiple sets of tanks, each consisting of a set of supply tanks and a set of recovery tanks, which are arranged at different positions in a direction perpendicular to the main scanning direction and contain ink of the same color, and the multiple sets of tanks are arranged in line in the main scanning direction.

7. A printing unit according to claim 6, The aforementioned multiple sets of tanks are arranged in two rows in the main scanning direction, forming a printing unit.

8. A printing unit according to claim 6, Mounted on the carriage is a processing head that discharges processing liquid, A processing liquid supply tank mounted on the carriage and containing the processing liquid to be supplied to the processing head, A recovery tank for processing liquid, mounted on the carriage and containing the processing liquid recovered from the processing head, Furthermore, A printing unit in which the processing liquid supply tank and the processing liquid recovery tank are arranged at different positions in a direction perpendicular to the main scanning direction, and are arranged in line with the multiple sets of tanks in the main scanning direction.

9. A printing unit according to claim 1 or 2, Mounted on the carriage is a pre-treatment head that discharges a pre-treatment liquid, A pretreatment liquid tank mounted on the carriage and containing the pretreatment liquid, Furthermore, The pre-processing head is positioned at the end of the main scanning direction of the arrangement range in which the plurality of ink heads are arranged. The printing unit is configured such that the pre-treatment liquid tank is located at the end of the main scanning direction on the same side as the pre-treatment head, relative to the arrangement range in which the multiple tanks are located.

10. A printing unit according to claim 1 or 2, Mounted on the carriage is a post-treatment head that discharges post-treatment liquid, A tank for post-treatment liquid, mounted on the carriage and containing the post-treatment liquid, Furthermore, The post-processing head is positioned at the end of the main scanning direction of the arrangement range in which the plurality of ink heads are arranged. The post-processing liquid tank is located at the end of the main scanning direction on the same side as the post-processing head with respect to the arrangement range in which the plurality of tanks are arranged in the printing unit.

11. A printing unit according to claim 1 or 2, Mounted on the carriage is a pre-treatment head that discharges a pre-treatment liquid, A pretreatment liquid tank mounted on the carriage and containing the pretreatment liquid, Mounted on the carriage is a post-treatment head that discharges post-treatment liquid, A tank for post-treatment liquid, mounted on the carriage and containing the post-treatment liquid, Furthermore, The pre-processing head is positioned at the end of the main scanning direction of the arrangement range in which the plurality of ink heads are arranged. The pre-treatment liquid tank is positioned at the end of the main scanning direction on the same side as the pre-treatment head with respect to the arrangement range in which the plurality of tanks are arranged. The post-processing head is positioned at the end of the main scanning direction opposite to the pre-processing head in the arrangement range where the plurality of ink heads are arranged, The post-processing liquid tank is located at the end of the main scanning direction on the same side as the post-processing head with respect to the arrangement range in which the plurality of tanks are arranged in the printing unit.

12. A printing unit according to any one of claims 1, 2, and 6, A transport unit that transports the recording medium in a direction intersecting the main scanning direction, A recording device equipped with the following features.

Images