Printing unit and recording apparatus

Abstract

A printing unit includes a carriage that reciprocates in a main scanning direction, a plurality of inkjet heads that are mounted on the carriage in a manner of being arranged in at least one column along the main scanning direction and that eject ink, and a plurality of tanks that are mounted on the carriage in a manner of being arranged along the main scanning direction and that store ink. The plurality of inkjet heads include a pair of first inkjet heads that are disposed at both end portions in the main scanning direction and that eject ink of the same color, and the plurality of tanks include a first tank that stores ink of a color corresponding to the pair of first inkjet heads. In the carriage, a disposition range in which the plurality of tanks are disposed is set to include the same region as a disposition range in which the plurality of inkjet heads are disposed in the main scanning direction, and the first tank is disposed at a central portion in the main scanning direction among the plurality of tanks.

Description

Technical Field

[0001] This disclosure relates to a printing unit and a recording apparatus having an inkjet head mounted on a carriage that moves in the main scanning direction. Background Technology

[0002] Inkjet printers and other inkjet recording devices include a printing unit for printing on a recording medium. The printing unit has an inkjet head that ejects ink for image formation toward the recording medium. When the recording medium is wide, the inkjet head is mounted on a carriage that reciprocates in the main scanning direction. During printing, the recording medium is intermittently transported in a predetermined direction (sub-scanning direction), and during periods when the recording medium is stationary, the carriage reciprocates in the main scanning direction while ejecting ink from the inkjet head. Furthermore, as in Patent Document 1, there is a known technique where the ink reservoir is mounted on a carriage in the same manner as the inkjet head.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 08-058107 Summary of the Invention

[0006] A printing unit according to one aspect of this disclosure includes: a carriage that reciprocates in a main scanning direction; a plurality of inkjet heads mounted on the carriage in at least one row along the main scanning direction and ejecting ink; and a plurality of ink cans mounted on the carriage in an arrangement along the main scanning direction and containing ink. The plurality of inkjet heads have a pair of first inkjet heads disposed at both ends of the main scanning direction and ejecting ink of the same color, and the plurality of ink cans have a first ink can containing ink of a color corresponding to the pair of first inkjet heads. In the carriage, the arrangement range of the plurality of ink cans is set to include the same region as the arrangement range of the plurality of inkjet heads in the main scanning direction, and the first ink can is disposed at the central portion of the plurality of ink cans in the main scanning direction.

[0007] In addition, another aspect of the recording apparatus disclosed herein includes: the printing unit for recording; and a transport unit that transports the recording medium in a direction intersecting the main scanning direction. Attached Figure Description

[0008] Figure 1 This is a perspective view showing the overall structure of an inkjet recording apparatus according to one embodiment of the present disclosure.

[0009] Figure 2 yes Figure 1 A schematic cross-sectional view of line II-II.

[0010] Figure 3 yes Figure 1 The image shows an enlarged 3D view of the carriage.

[0011] Figure 4 This is a schematic diagram illustrating a serial printing method used in one embodiment of this disclosure.

[0012] Figure 5A This is a schematic diagram showing the printing status in the carriage's path and circuit.

[0013] Figure 5B This is a schematic diagram showing the printing status in the carriage's path and circuit.

[0014] Figure 6 It is a summary representation Figure 3 The diagram shows a top view of the configuration of the inkjet head, processing head, and canister on the carriage, and also illustrates the replenishment path of the ink and processing fluid.

[0015] Figure 7 It is a summary representation Figure 3 The diagram shows a top view of the configuration of the inkjet head, processing head, and canister on the carriage, and also illustrates the replenishment path of the ink and processing fluid.

[0016] Figure 8 This is a schematic top view showing the arrangement of the tanks on the carriage according to a first modified embodiment of the present disclosure.

[0017] Figure 9 This is a schematic top view showing the arrangement of the tank on the carriage according to a second modified embodiment of the present disclosure.

[0018] Figure 10 This is a schematic top view showing the arrangement of the tanks on the carriage according to a third modified embodiment of the present disclosure. Detailed Implementation

[0019] Hereinafter, the printing units of various embodiments of the present disclosure will be described with reference to the accompanying drawings. In these embodiments, as specific examples of an apparatus equipped with a printing unit, an inkjet printer (recording device) equipped with an inkjet head that ejects ink for image formation onto a wide and elongated recording medium is illustrated. Inkjet printers are suitable for digital printing of images such as text or patterns on recording media made of fabrics such as textiles or woven fabrics using inkjet printing. Of course, the printing unit of the present disclosure can also be used for printing various images on recording media such as paper or resin sheets.

[0020] [Overall structure of an inkjet printer]

[0021] Figure 1 This is a perspective view showing the overall structure of the inkjet printer 1 according to the first embodiment of this disclosure. Figure 2 yes Figure 1 A schematic cross-sectional view along line II-II. The inkjet printer 1 (printing unit) is a printer that prints images onto a wide and elongated workpiece W (recording medium) using inkjet technology. It includes a device frame 10, a workpiece transport section 20 (transport section) assembled to the device frame 10, and a carriage 3. It should be noted that in this embodiment, the left-right direction is the main scanning direction S when printing on the workpiece W. Figure 3 The direction from back to front is the secondary scanning direction (the direction that intersects with the main scanning direction S is the conveying direction F of the workpiece W).

[0022] The device frame 10 forms a skeleton for mounting the various components of the inkjet printer 1. The workpiece transport unit 20 is a mechanism that intermittently transports the workpiece W in the printing area where inkjet printing is performed, in a transport direction F from rear to front. The carriage 3, which carries the inkjet head 4, the pre-processing head 5, the post-processing head 6, and the auxiliary canister 7, reciprocates in the main scanning direction S (left-right direction) that intersects with the transport direction F of the workpiece W during the inkjet printing process. This movable unit constitutes the printing unit of this disclosure.

[0023] The device frame 10 includes a central frame 111, a right frame 112, and a left frame 113. The central frame 111 forms the skeleton 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 respectively erected to the right and left of the central frame 111. Between the right frame 112 and the left frame 113 is the printing area 12 for printing the workpiece W.

[0024] The right frame 112 forms a maintenance area 13. Maintenance area 13 is the area where the carriage 3 retracts when the printing process is not being performed. In maintenance area 13, cleaning and purging of the nozzles (ejection holes) of the inkjet head 4, pre-processing head 5, and post-processing head 6 are performed, and the cover is also fitted. The left frame 113 forms a fold-back area 14 for the carriage 3. Fold-back area 14 is the area where the carriage 3, which has performed a main scan of the printing area 12 from right to left during the printing process, temporarily enters when performing a main scan in the opposite direction.

[0025] A carriage guide 15 for reciprocating movement of the carriage 3 in the left-right direction is assembled on the upper side of the device frame 10. The carriage guide 15 is a flat plate-shaped component that is longer in the left-right direction and is disposed above the workpiece transport section 20. A timing belt 16 is assembled to the carriage guide 15 in a manner that allows it to move around in the left-right direction (main scanning direction). The timing belt 16 is a ring belt and is driven to move around in the left or right direction.

[0026] A pair of upper and lower guide rails 17 are provided on the carriage guide 15, extending parallel to the left and right directions, to hold the carriage 3 in a state where it can reciprocate in the main scanning direction S. The carriage 3 engages with the guide rails 17. In addition, the carriage 3 is fixed to the timing belt 16. The carriage 3 is guided by the guide rails 17 as the timing belt 16 moves around in the left or right direction, and moves to the left or right along the carriage guide 15.

[0027] Main reference Figure 2 The workpiece conveying unit 20 includes a delivery roller 21 for conveying the workpiece W before printing and a winding roller 22 for winding the workpiece W after printing. The delivery roller 21 is located at the lower rear of the device frame 10 and serves as the take-up shaft of the delivery roller WA, which is the winding body of the workpiece W before printing. The winding roller 22 is located at the lower front of the device frame 10 and serves as the take-up shaft of the winding roller WB, which is the winding body of the workpiece W after printing. A first motor M1 is attached to the winding roller 22, which drives the winding roller 22 to rotate around its axis to perform the winding action of the workpiece W.

[0028] The path between the feed roller 21 and the winding roller 22, passing through the printing area 12, forms the transport path for the workpiece W. Along this transport path, from upstream, a first tension roller 23, a workpiece guide 24, a transport roller 25, a pinch roller 26, a return roller 27, and a second tension roller 28 are sequentially arranged. 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, causing the workpiece W to be moved into the printing area 12.

[0029] The conveyor roller 25 is a roller that generates a conveying force to intermittently convey the workpiece W in the printing area 12. The conveyor roller 25 is driven to rotate about an axis by a second motor M2, so that the workpiece W is intermittently conveyed in the forward direction (prescribed conveying direction F) through the printing area 12 (image forming position) opposite to the carriage 3. The clamping roller 26 is arranged opposite the conveyor roller 25 from above and forms a conveying clamping part with the conveyor roller 25.

[0030] The return roller 27 changes the transport direction of the workpiece W, which has passed through the printing area 12, from forward to downward, guiding the printed workpiece W toward the winding roller 22. The second tension roller 28 applies a predetermined tension to the workpiece W downstream of the transport roller 25. In the printing area 12, an impression plate 29 is positioned below the transport path of the workpiece W.

[0031] The carriage 3, cantilevered by the guide rail 17, reciprocates in the main scanning direction S (left-right direction in this embodiment) which intersects (orthogonal to) the transport direction F. The carriage 3 includes a carriage frame 30, an inkjet head 4 mounted on the carriage frame 30, a pre-processing head 5, a post-processing head 6, and a secondary canister 7. The carriage frame 30 includes a head support frame 31 and a backrest frame 32.

[0032] The head support frame 31 is a horizontal plate that holds the heads 4 to 6 as described above. The backrest frame 32 is a vertical plate extending upward from the rear end edge of the head support frame 31. As described above, the timing belt 16 is fixed to the backrest frame 32. Furthermore, the guide rail 17 engages with the backrest frame 32. That is, in this embodiment, the backrest frame 32 is held in a cantilevered state at the engagement portion of the guide rail 17. The head support frame 31 is a horizontal plate whose rear end is cantilevered to the guide rail 17 via the engagement portion.

[0033] It should be noted that the so-called cantilever state refers to a state in which the portion held by the guide rail 17, which serves as a holding member, namely the engaging portion (backrest frame 32), exists only on one side of the carriage 3 in the transport direction F, either upstream or downstream, and there are no other engaging portions on the opposite side. The engaging portion can also be positioned outside the area where the inkjet head 4 and processing head are located in the transport direction F. That is, the engaging portion can also be positioned only upstream or only downstream of the area where the inkjet head 4 and processing head are located in the transport direction F.

[0034] [Details about the carriage]

[0035] Further explanation of carriage 3. Figure 3 yes Figure 1 An enlarged perspective view of the carriage 3 shown. Figure 3 The diagram shows the conveying direction F (secondary scanning direction) of workpiece W and the main scanning direction S, which is the moving direction of carriage 3. Figure 3 The image shows an example in which a carriage 3 is equipped with multiple inkjet heads 4 for spraying ink for forming an image onto a workpiece W, a pre-processing head 5 and a post-processing head 6 for spraying a non-color-developing processing liquid, and multiple auxiliary tanks 7 for supplying the ink and processing liquid to these inkjet heads 4-6.

[0036] Each inkjet head 4 has multiple nozzles (ink ejection orifices) that eject ink droplets using, for example, a piezoelectric method using a piezoelectric element or a thermal method using a heating element, and an ink passage that guides the ink to the nozzles. As the ink, for example, an aqueous pigment ink containing a water-based solvent, pigment, and binder resin can be used. In this embodiment, the multiple inkjet heads 4 are capable of ejecting eight different colors of ink. The inkjet heads 4 are mounted on the head support frame 31 of the carriage 3 in two rows arranged in the main scanning direction S. Each color inkjet head 4 has two heads. It should be noted that the detailed configuration of the inkjet heads 4 will be described in detail later.

[0037] The pre-processing head 5 and the post-processing head 6 are positioned differently from the inkjet head 4 in the transport direction F. The pre-processing head 5 is positioned upstream of the inkjet head 4 in the transport direction F. Figure 3 The image shows an example where a pre-processing head 5 is positioned near the right end of the arrangement of inkjet heads 4. Similarly, a post-processing head 6 is positioned downstream of the inkjet head 4 in the transport direction F. Figure 3 The image shows an example where a post-processing head 6 is disposed at the right end of the arrangement of inkjet heads 4. In other embodiments, multiple pre-processing heads 5 or multiple post-processing heads 6 may also be disposed. At least one pre-processing head 5 and at least one post-processing head 6 are respectively provided on the carriage 3. It should be noted that in other embodiments, pre-processing heads 5 and post-processing heads 6 may not be disposed.

[0038] It should be noted that the connection of the heads along the main scanning direction S, consisting of the inkjet head 4, the pre-processing head 5, and the post-processing head 6, is called a column of heads, or simply a column. Furthermore, the connection of the heads along the transport direction F, consisting of the inkjet head 4, the pre-processing head 5, and the post-processing head 6, is called a row of heads, or simply a row.

[0039] The pretreatment head 5 ejects a pretreatment liquid for performing a prescribed pretreatment on the workpiece W. The pretreatment liquid is ejected from the pretreatment head 5 to a position on the workpiece W from the inkjet head 4 where ink has not yet been ejected from the inkjet head 4. The pretreatment liquid is a non-color-developing treatment liquid that does not develop color even when adhering to the workpiece W; for example, it is a treatment liquid that exhibits functions such as improving the fixing properties of the ink on the workpiece W and the cohesiveness of the ink pigment. Such a pretreatment liquid can be a treatment liquid containing a binding resin in a solvent, or a treatment liquid containing a positively charged cationic resin in a solvent.

[0040] The post-processing head 6 ejects a post-processing liquid for performing a prescribed post-processing on the workpiece W to which ink has adhered. The post-processing liquid is ejected from the post-processing head 6 to the position on the workpiece W after ink has been ejected from the inkjet head 4. The post-processing liquid is also a non-color-developing liquid that does not develop color even when adhered to the workpiece W, and it is designed to improve the fixing properties and durability (resistance to friction and scratching) of the ink image printed on the workpiece W by the inkjet head 4. Silicone-based liquids, etc., can be used as such a post-processing liquid. It should be noted that the post-processing liquid and the pre-processing liquid are different liquids. Specifically, the components contained in the post-processing liquid and the pre-processing liquid are different.

[0041] Here, "non-color-developing processing liquid" refers to a processing liquid that, when printed alone on a recording medium, cannot be perceived as developing color by the naked eye. This includes colors with a chroma of 0, such as black, white, and gray. Non-color-developing processing liquids are essentially transparent liquids, but when observing 1 liter of processing liquid as a liquid, it may not be completely transparent, and a slight white tint may be visible. Such colors are very light, and therefore, when printed alone on a recording medium, they cannot be perceived as developing color by the naked eye. It should be noted that, depending on the type of processing liquid, when printed alone on a recording medium, there may sometimes be changes such as a glossy finish on the recording medium, but this is not considered color development.

[0042] In this embodiment, the pretreatment liquid and posttreatment liquid can be sprayed onto approximately the entire surface of the workpiece W, and the pretreatment liquid and posttreatment liquid can also be selectively sprayed in accordance with the image to be printed, similar to ink.

[0043] Next, the case of selectively spraying pretreatment and posttreatment solutions will be explained. As described above, pretreatment solution, ink, and posttreatment solution are sprayed onto the workpiece W, the area corresponding to the printed color of the image, in the order of pretreatment solution, ink, and posttreatment solution. In this case, the ink is one color or multiple colors. In areas where no color is printed, i.e., areas where ink is not sprayed, pretreatment and posttreatment solutions are also generally not sprayed. It should be noted that, in order to adjust the image quality of the printed image, the feel of the workpiece W, etc., the selection of the spraying of pretreatment and posttreatment solutions may differ from the spraying of ink.

[0044] like Figure 3 As shown, an opening 31H is provided at the head mounting position of the head support frame 31. The inkjet head 4, the pre-processing head 5, and the post-processing head 6 are assembled to the head support frame 31 by being embedded in each of the openings 31H. The nozzles disposed on the lower end faces of each of the heads 4, 5, and 6 protrude from each of the openings 31H.

[0045] The auxiliary tank 7 is supported by the carriage 3 above the heads 4, 5, and 6 via a retaining frame (not shown). The auxiliary tank 7 is positioned correspondingly to the heads 4, 5, and 6. Ink or processing fluid is supplied to each auxiliary tank 7 from an ink cartridge or main tank containing ink and processing fluid (not shown), and then supplied to the heads 4, 5, and 6 respectively. Each auxiliary tank 7 is connected to the heads 4, 5, and 6 via... Figure 3 The piping shown in the diagram is omitted from the connection (see reference). Figure 6 Pipeline P).

[0046] As described above, the inkjet printer 1 of this embodiment is an all-in-one printer in which the inkjet head 4, the pretreatment head 5, and the posttreatment head 6 are mounted on a single carriage 3. According to this inkjet printer 1, for example in the inkjet printing process of fabric in digital printing, the pretreatment liquid ejection process and the posttreatment liquid ejection process can be performed simultaneously. Therefore, the printing process can be simplified, and the printing apparatus can be made more compact.

[0047] [Printing Method]

[0048] Next, the printing method performed by the inkjet printer 1 of this embodiment will be described. The inkjet printer 1 prints the workpiece W in a serial printing manner. Figure 4 This is a schematic diagram illustrating the serial printing method. Figure 4 In this text, the preprocessing head 5 and the postprocessing head 6 are omitted, and the carriage 3 is depicted simply.

[0049] When the workpiece W has a wide dimension, it is impossible to continuously transport the workpiece W while printing. The serial printing method involves repeatedly moving the carriage 3, equipped with inkjet heads 4 of various colors, back and forth in the main scanning direction S, and intermittently transporting the workpiece W in the transport direction F. Here, it is assumed that the inkjet 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 area where the ink ejection nozzles of the inkjet head 4 are arranged in the transport direction F. It should be noted that, although in Figure 4 And what follows is an explanation. Figure 5A , Figure 5B In the text, the length of each head in the conveying direction F and the printing width Pw are described as approximately equal. However, in reality, the length of each head in the conveying direction F is larger than the printing width Pw and the length of the area where the nozzles are arranged.

[0050] exist Figure 4The diagram shows the carriage 3 moving in the path direction SA of the main scanning direction S, with the printing of the strip image G1 of printing width Pw completed. During the main scan in the path direction SA, the feeding 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 distance equivalent to the printing width Pw. At this time, the carriage 3 waits in the fold-back area 14 on the left end side. After the workpiece W is fed out, the carriage 3 folds back in the return direction SB as the synchronous belt 16 moves in reverse. The workpiece W is in a stopped state. Then, as... Figure 4 As shown, carriage 3 moves in the loop direction SB and prints a strip image G2 with a printing width Pw on the upstream side of strip image G1. The same operation is repeated below.

[0051] Figure 5A and Figure 5B This is a schematic diagram showing the printing conditions in the path and return of the carriage 3. Here, the inkjet head 4, pre-processing head 5, and post-processing head 6 mounted on the carriage 3 are simplified. The inkjet head 4 has first, second, third, and fourth inkjet heads 4A, 4B, 4C, and 4D for ejecting inks of different first, second, third, and fourth colors, respectively. These first to fourth inkjet heads 4A to 4D are arranged in a row in the main scanning direction S. The pre-processing head 5 is located upstream of the inkjet head 4 in the transport direction F, and the post-processing head 6 is located downstream. Furthermore, with... Figure 4 Similarly, as described above, between the printing on the outgoing path and the printing on the return path, the workpiece W is fed out in the transport direction F. The distance traveled in the transport direction F is the spacing between adjacent heads in the transport direction F (head spacing). Furthermore, this distance is also the printing width Pw of each head (4, 5, 6).

[0052] Figure 5A This shows the state where the carriage 3 moves in the path direction SA in the main scanning direction S while performing a printing operation (path main scan). Region A4 on the workpiece W is the region opposite to the pretreatment head 5 mounted on the upstream side of the carriage 3. In this path main scan, a pretreatment layer Lpre is formed on region A4 using pretreatment liquid ejected from the pretreatment head 5.

[0053] Region A3 is located downstream of Region A4 by one head pitch, and is the region where inkjet heads 4 are opposite each other. In Region A3, a pre-processing layer Lpre has already been formed along the entire length of the main scan direction after the previous main scan. In this next main scan, on the pre-processing layer Lpre in Region A3, inks of the first to fourth colors, sequentially ejected in the order of the first to fourth inkjet heads 4A to 4D, form the first, second, third, and fourth ink layers LCA, LCB, LCC, and LCD. It should be noted that... Figure 5AFor ease of understanding, the illustration shows the sequential stacking of the fourth to the first ink layers (LCD to LCA), but this is not an actual stacking. It should be noted that the aforementioned pre-processing layer Lpre and the subsequent post-processing layer Lpos are not formed on the workpiece W.

[0054] Region A2 is located downstream of Region A3 by one head pitch, and is the region opposite to the post-processing head 6 mounted on the downstream side of the carriage 3. On Region A2, a pre-processing layer Lpre based on the previous outgoing main scan and first to fourth ink layers LCA to LCD based on the previous return main scan have already been formed along the entire length of the main scanning direction in Region A2. In this outgoing main scan, a post-processing layer Lpos is formed on the first to fourth ink layers LCA to LCD in Region A2 using post-processing liquid ejected from the post-processing head 6.

[0055] Region A1 is a region located downstream of region A2 by one head pitch, and is the region where the carriage 3 passes through and the printing process is completed. That is, 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 over the entire length of the main scanning direction.

[0056] Figure 5B Indicates the end Figure 5A After the outgoing main scan, the carriage 3 folds back and moves in the loop direction SB, and performs a loop main scan. Before the folding back movement, the workpiece W is fed out in the transport direction F by a head pitch. Region A5 on the workpiece W is an area one head pitch upstream of region A4, and is the area opposite to the pretreatment head 5 in this loop main scan. On region A5, a pretreatment layer Lpre is formed by the pretreatment liquid sprayed from the pretreatment head 5.

[0057] In regions A4 and A3, the first to fourth ink layers LCA to LCD and the post-processing layer Lpos are formed on the existing layers, respectively. Specifically, in region A4, the first to fourth ink layers LCA to LCD are formed on the pre-processing layer Lpre. In region A3, the post-processing layer Lpos is formed on top of the first to fourth ink layers LCA to LCD. Region A2 is the region where printing processing is completed after region A1.

[0058] Printing can be performed in both the outgoing main scan and the return main scan as described above because the pre-processing head 5 and the post-processing head 6 are offset relative to the inkjet head 4 in the transport direction F. Assuming that the pre-processing head 5, the inkjet head 4, and the post-processing head 6 are arranged in this order in the main scan direction S of the carriage 3, printing that allows the pre-processing liquid and post-processing liquid to land in the desired order can only be achieved in one of the outgoing or return main scans. To enable bidirectional printing, the pre-processing head 5 and the post-processing head 6 must be paired and arranged on opposite sides of the inkjet head 4 array. In this case, the length of the carriage 3 in the main scan direction S is increased. In this embodiment, such a configuration is not required, thus the length of the carriage 3 in the main scan direction S can be reduced.

[0059] It should be noted that having multiple rows of inkjet heads 4 increases the amount of ink applied to the workpiece W. For example, with two rows of inkjet heads 4, printing can be performed as follows: After forming the first to fourth ink layers LCA to LCD using the first row of inkjet heads 4 as described above, the workpiece W is conveyed along the transport direction F by a head pitch amount, and the first to fourth ink layers LCA to LCD are formed using the second row of inkjet heads 4. Thus, two layers of ink can be printed on the workpiece W.

[0060] Figure 6 and Figure 7 It is a summary representation Figure 3 The diagram shows a top view of the arrangement of the inkjet head 4, processing heads 5 and 6, and auxiliary tank 7 on the carriage 3, and is also a diagram showing the replenishment path of ink and processing fluid. As described above, the carriage 3 is positioned against the back frame 32 ( Figure 3 The head support frame 31 is supported in a cantilevered state by the guide rail 17. The backrest frame 32 is positioned 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 with the backrest frame 32 is designated as the base end side, and the opposite side of the base end side is designated as the front end side. As described above, the head support frame 31 of the carriage 3 is equipped with multiple inkjet heads 4 that eject ink of eight colors, a pre-processing head 5, and a post-processing head 6. Each inkjet head 4 of each color has two units (a total of 16). Each pre-processing head 5 and post-processing head 6 has one unit.

[0061] exist Figure 6In this design, letters corresponding to the colors of the ejected ink are displayed on a total of 16 inkjet heads 4. 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. Furthermore, the pre-processing head 5 is labeled "Front," and the post-processing head 6 is labeled "Rear." Similarly, for the multiple auxiliary containers 7, the auxiliary container 7 containing the pre-processing liquid is labeled "Front," the auxiliary container 7 containing the post-processing liquid is labeled "Rear," and the auxiliary containers 7 containing each color of ink are labeled with letters in the same way. It should be noted that, in practice, as... Figure 3 As shown, multiple auxiliary inkjet cans 7 are positioned higher than the inkjet head 4, the pre-processing head 5, and the post-processing head 6. In this case, the arrangement range of the multiple auxiliary inkjet cans 7 in the carriage 3 is set to overlap with the arrangement range of the multiple inkjet heads 4 in a direction orthogonal to the main scanning direction S. In other words, in the main scanning direction S, the arrangement range of the multiple auxiliary inkjet cans 7 is located in the same area as the arrangement range of the multiple inkjet heads 4. Alternatively, one of the comparison ranges can be set to be wider than the other.

[0062] like Figure 6 As shown, in the transport direction F, the pre-processing head 5 is positioned upstream of the plurality of inkjet heads 4, and the post-processing head 6 is positioned downstream of the plurality of inkjet heads 4. Furthermore, the pre-processing head 5 is positioned at the end (left end) of the main scanning direction S of the arrangement range where the plurality of inkjet heads 4 are arranged. On the other hand, the post-processing head 6 is positioned at the end (right end) of the main scanning direction S opposite to the pre-processing head 5 within the arrangement range where the plurality of inkjet heads 4 are arranged. As a result of the above head arrangement, the pre-processing head 5 and the post-processing head 6 are arranged within the arrangement width of the inkjet heads 4 in the main scanning direction S.

[0063] Multiple inkjet heads 4 are arranged in two columns along the main scanning direction S. The first column of inkjet heads 4, located near the pre-processing head 5, contains inkjet heads 4 of colors K, M, O, and Y. A pair of K-color inkjet heads 4 are positioned on the outermost side of the main scanning direction S. Similarly, a pair of M-color inkjet heads 4, a pair of O-color inkjet heads 4, and a pair of Y-color inkjet heads 4 are sequentially positioned on the inner side of the main scanning direction S. In other words, the inkjet heads 4 of the four colors are symmetrically arranged along the main scanning direction S.

[0064] The second row of inkjet heads 4, located near the post-processing head 6, contains inkjet heads 4 for colors C, B, V, and G. A pair of C-color inkjet heads 4 are positioned on the outermost side of the main scanning direction S. Similarly, a pair of B-color inkjet heads 4, a pair of V-color inkjet heads 4, and a pair of G-color inkjet heads 4 are sequentially positioned on the inner side of the main scanning direction S. In other words, the inkjet heads 4 of the four colors are symmetrically arranged in the main scanning direction S.

[0065] In addition, such as Figure 6 As shown, the inkjet heads 4 in the first column and the inkjet heads 4 in the second column are staggered in the main scanning direction S. They are arranged in an alternating pattern by placing inkjet heads 4 from one side between adjacent inkjet heads 4 from the other side. A pre-processing head 5 is positioned behind the C-color inkjet head 4 on the left side of the second column, and a post-processing head 6 is positioned in front of the K-color inkjet head 4 on the right side of the first column.

[0066] Furthermore, in this embodiment, the two inkjet heads 4 that eject ink of the same color are arranged in the same column. As a result, when the carriage 3 reciprocates in the main scanning direction, ink can be ejected from both inkjet heads 4 to the designated pixels during scanning in the same orientation. Therefore, compared to the case where the two inkjet heads 4 are arranged in different columns, the difference in ink landing time to the pixel can be shortened, resulting in a stable image.

[0067] In addition, such as Figure 6 As shown, the two inkjet heads 4, which spray ink of the same color, are symmetrically arranged along the main scanning direction S. Therefore, even when the carriage 3 scans in either the right or left direction, the landing order of each color of ink can be made the same, preventing local color differences on the workpiece W.

[0068] It should be noted that, unless otherwise specified, in the following cases... Figure 6 In each of the diagrams, the spacing between adjacent heads in the main scanning direction S (the spacing between the centers of each head) is the same. Similarly, the spacing between adjacent heads in the transport direction F (the spacing between the centers of each head) is the same.

[0069] Among the multiple auxiliary tanks 7, from left to right, are arranged auxiliary tanks 7 for pretreatment liquid, color G, color V, color B, color C, color K, color M, color O, color Y, and posttreatment liquid. That is, the auxiliary tank 7 for pretreatment liquid (pretreatment liquid tank) is located at the end of the main scanning direction S on the same side as the pretreatment head 5, relative to the arrangement range of the multiple auxiliary tanks 7. Similarly, the auxiliary tank 7 for posttreatment liquid (posttreatment liquid tank) is located at the end of the main scanning direction S on the same side as the posttreatment head 6, relative to the arrangement range of the multiple auxiliary tanks 7.

[0070] An auxiliary tank 7 containing eight colors of ink is arranged between the auxiliary tanks 7 for the pretreatment solution and the posttreatment solution mentioned above. For example... Figure 6 As shown, the four rightmost auxiliary tanks 7 of the eight auxiliary tanks 7 supply ink to the inkjet heads 4 in the first column. Figure 6 Additionally, the four left-hand auxiliary tanks 7 of the aforementioned eight auxiliary tanks 7 supply ink to the inkjet heads 4 in the second column. Figure 7 Then, ink is supplied from one color sub-tank 7 to both inkjet heads 4. Figure 6, Figure 7 In the diagram, the supply lines P for ink, pretreatment solution, and posttreatment solution are each depicted by two straight lines (the line shape differs for each liquid). It should be noted that the actual lines P are constructed of rubber tubing and therefore have some bends.

[0071] The acceleration in the main scanning direction S acts on the liquid in the auxiliary tank 7, which is mounted on the carriage 3 that reciprocates in the main scanning direction S. Additionally, since the tubing P is filled with a liquid consisting of ink or processing fluid, these liquids also experience acceleration in the same way. In particular, the further apart the auxiliary tank 7, which serves as the supply source, and the head, which is the receiving destination, are in the main scanning direction S, and the longer the tubing P extends in the main scanning direction S, the greater the effect of the aforementioned acceleration. Furthermore, when the carriage 3 reverses in the main scanning direction S, if a large pressure is applied from the liquid in the tubing P to the liquid inside the head due to the aforementioned acceleration, pressure fluctuations will occur inside the head. As a result, it becomes difficult to stably eject the liquids from heads 4, 5, and 6, and sometimes it is difficult to form a good ink image on the recording medium.

[0072] The discloser conducted an in-depth study on minimizing the aforementioned effects of acceleration when supplying ink from a secondary tank 7 to two inkjet heads 4 that eject ink of the same color, and as a result discovered... Figure 6 , Figure 7 The inkjet head 4, pre-processing head 5, post-processing head 6, and auxiliary can 7 are arranged as shown. Specifically, among the inkjet heads 4 in the first column, the pair of K-color inkjet heads 4 (a pair of first inkjet heads) located at both ends of the main scanning direction S have the greatest distance from each other, therefore the tubing P inevitably tends to be longer. Therefore, as shown... Figure 6 As shown, the auxiliary container 7 (first container) containing K-color ink is positioned in the center of the main scanning direction S among the multiple auxiliary containers 7.

[0073] It should be noted that the aforementioned central portion refers to the central 1 / 3 of the range within which the multiple sub-canisters 7 are arranged in the main scanning direction S, more preferably 1 / 5. Furthermore, in the case where the multiple sub-canisters 7 are arranged at approximately equal intervals in the main scanning direction S, placing the first canister in the central portion also means the following: When there is an odd number (2n+1) of multiple sub-canisters 7, the first canister is placed at the (n+1)th position from the end of the main scanning direction S. When there is an even number (2n) of multiple sub-canisters 7, the first canister is placed at the nth or (n+1)th position from the end of the main scanning direction S.

[0074] As a result, the length of the tube P relative to the two K-color inkjet heads 4 can be made equal, which can suppress the influence of large acceleration in one tube P and reduce pressure fluctuations.

[0075] Furthermore, in the first column of inkjet head groups 4, the remaining three pairs of inkjet heads 4 (multiple pairs of second inkjet heads) for colors M, O, and Y are also arranged with multiple auxiliary cans 7, such that ink is ejected from the auxiliary cans 7 located relatively inside the main scanning direction S to the inkjet heads 4 located outside the main scanning direction S. In other words, for colors M, O, and Y, the auxiliary cans 7 that contain ink of the color corresponding to the inkjet head 4 located outside the main scanning direction S are positioned at the same position as the auxiliary cans 7 that contain ink of the color corresponding to the inkjet head 4 located inside the main scanning direction S, or closer to the auxiliary can 7 (first can) for color K. Therefore, the difference in the length of the tubing P in the first column of inkjet head groups 4 can be minimized as much as possible.

[0076] Similarly, as Figure 7 As shown, in the second column of inkjet heads 4, the distance between the pair of C-color inkjet heads 4 (a pair of first inkjet heads) located at both ends of the main scanning direction S is also the greatest, therefore the tubing P will inevitably become longer. Therefore, the auxiliary container 7 (first container) containing the C-color ink is positioned in the center of the main scanning direction S among the multiple auxiliary containers 7. It should be noted that when the number of auxiliary containers 7 is even, such as... Figure 6 , Figure 7 As shown, there are two auxiliary tanks 7 located in the central part mentioned above.

[0077] With the configuration described above, the length of the tube P relative to the two C-color inkjet heads 4 can be made equal, which can suppress the influence of large acceleration in one of the tubes P.

[0078] Furthermore, in the second column of inkjet head groups 4, for the remaining three pairs of inkjet heads 4 (multiple pairs of second inkjet heads) for colors B, V, and G, multiple auxiliary cans 7 are also arranged such that ink is ejected from the auxiliary cans 7 located relatively inside the main scanning direction S to the inkjet heads 4 located outside the main scanning direction S. In other words, for the multiple auxiliary cans 7 (second cans) of colors B, V, and G, the auxiliary can 7 that contains ink of the color corresponding to the inkjet head 4 located outside the main scanning direction S of the three pairs of inkjet heads 4 is arranged in the same position as the auxiliary can 7 that contains ink of the color corresponding to the inkjet head 4 located inside the main scanning direction S, or closer to the auxiliary can 7 (first can) of color C.

[0079] Additionally, the secondary tank 7 can also be configured sequentially from the left side of the main scanning direction S as color G, color V, color B, color C, color K, color M, color O, and color Y. This is from... Figure 7The configuration of the secondary canisters replaces the B and M colors. In this configuration, in the arrangement of the secondary canisters 7 relative to the first column of inkjet heads 4, the secondary canisters 7 for the K color (first canister), the secondary canisters 7 for the M and O colors (second canisters) are positioned at the same distance, while the secondary canister 7 for the Y color (second canister) is positioned further away. The second canister can also be configured to be at the same distance from the first canister.

[0080] To further suppress the effects of large acceleration, the auxiliary container 7 containing ink of the color corresponding to the inkjet head 4 located outside the main scanning direction S is positioned closer to the first container than the auxiliary container 7 containing ink of the color corresponding to the inkjet head 4 located inside the main scanning direction S.

[0081] exist Figure 7 In this configuration, the auxiliary ink cans 7 corresponding to multiple pairs of second inkjet heads in the first column are arranged in the order of M, O, and Y colors on the same side (right side) of the main scanning direction S, relative to the auxiliary ink can 7 (first ink can) containing the K-color ink corresponding to a pair of first inkjet heads in the first column. Furthermore, the auxiliary ink cans 7 corresponding to multiple pairs of second inkjet heads in the second column are arranged in the order of B, V, and G colors on the same side (left side, opposite to the first column) of the main scanning direction S, relative to the auxiliary ink can 7 (first ink can) containing the C-color ink corresponding to a pair of first inkjet heads in the second column. This configuration allows the auxiliary ink can 7 containing the color of the inkjet head 4 located on the outer side of the main scanning direction S to be positioned closer to the first ink can than the auxiliary ink can 7 containing the color of the inkjet head 4 located on the inner side of the main scanning direction S.

[0082] Furthermore, with the configuration described above, liquid can be stably supplied from multiple auxiliary tanks 7 arranged in a row along the main scanning direction S to two rows of inkjet heads 4 extending in the main scanning direction S and arranged in the transport direction F. In this case, the length of the tubing P connected to each head can be shortened, thus suppressing the effects of acceleration on the carriage 3 during movement.

[0083] In addition, such as Figure 7 As shown, the arrangement range of the first column of inkjet head groups 4 is offset to the right (one end in the main scanning direction) relative to the arrangement range of the second column of inkjet head groups 4. Furthermore, the sub-cans 7 corresponding to the inkjet head groups 4 in the first column are arranged on the right side of the sub-can configuration range, while the sub-cans 7 corresponding to the inkjet head groups 4 in the second column are arranged on the left side (the opposite end in the main scanning direction). This further shortens the distance between the sub-cans 7 and the inkjet head groups 4 in the main scanning direction, and further suppresses the effects of large accelerations.

[0084] It should be noted that, in Figure 6 , Figure 7The text describes how multiple auxiliary tanks 7 supply ink, pretreatment fluid, and posttreatment fluid to the inkjet head 4, pretreatment head 5, and posttreatment head 6. In this case, the pressure fluctuations in the inkjet head 4, pretreatment head 5, and posttreatment head 6 are reduced due to the acceleration caused by the movement of the carriage 3. It should be noted that all or part of the multiple auxiliary tanks 7 can also be recovery tanks for ink, pretreatment fluid, and posttreatment fluid from the inkjet head 4, pretreatment head 5, and posttreatment head 6. In this case, large accelerations applied to the piping P can be suppressed, similarly reducing pressure fluctuations.

[0085] Furthermore, in this embodiment, the pretreatment head 5 is disposed at the left end of the arrangement range of the plurality of inkjet heads 4, and the auxiliary tank 7 for pretreatment liquid is disposed at the left end of the plurality of auxiliary tanks 7. Therefore, as Figure 6 As shown, the length of the pretreatment fluid supply line P can be shortened, and the line P can be arranged as close as possible to the conveying direction F. Similarly, the post-processing head 6 is positioned at the right end of the arrangement range of the multiple inkjet heads 4, and the auxiliary tank 7 for post-processing fluid is positioned at the right end of the multiple auxiliary tanks 7. Therefore, as Figure 7 As shown, the length of the pipeline P supplying the post-treatment fluid can be shortened, and the pipeline P can be arranged as close as possible to the conveying direction F. This arrangement of the pipeline P prevents excessive acceleration from acting on the internally flowing liquid, reducing pressure fluctuations in each head.

[0086] It should be noted that if the pre-processing head 5 or the post-processing head 6 is arranged between the inkjet heads 4, the arrangement range of the inkjet heads 4 will become longer in the main scanning direction S, and the distance between the inkjet heads 4 and the ink canister 7 in the main scanning direction will also become longer. However, in the above configuration, such a situation can be avoided.

[0087] Similarly, if the pretreatment fluid auxiliary tank 7 or the posttreatment auxiliary tank 7 is arranged between the ink auxiliary tank 7, the arrangement range of the ink auxiliary tank 7 becomes longer in the main scanning direction S, and the distance between the inkjet head 4 and the ink auxiliary tank 7 in the main scanning direction also becomes longer. However, in the above arrangement, such a situation can be avoided.

[0088] Furthermore, in this embodiment, as described above, the post-processing head 6 is positioned opposite to the pre-processing head 5 in the main scanning direction S, and the auxiliary tank 7 for the post-processing liquid is positioned opposite to the auxiliary tank 7 for the pre-processing liquid in the main scanning direction S. Therefore, in addition to shortening the length of the pipeline P as described above, the head and auxiliary tank for the processing liquid are not concentrated at one end of the main scanning direction S, and each pipeline P can be easily configured.

[0089] Figure 8This is a schematic top view showing the arrangement of multiple auxiliary tanks 7 on the carriage 3 according to a first modified embodiment of the present disclosure. In previous embodiments, it was described that the multiple auxiliary tanks 7 were arranged in a row in the main scanning direction S and that each auxiliary tank 7 was a supply tank. In this modified embodiment, as Figure 8 As shown, the multiple auxiliary tanks 7 include: multiple supply tanks ( Figure 8 The second column contains ink of different colors supplied to multiple inkjet heads 4; and multiple recycling tanks ( Figure 8 The first column contains ink of different colors recovered from multiple inkjet heads 4. It should be noted that... Figure 8 The color markings of the ink in the ink and Figure 6 , Figure 7 same.

[0090] Furthermore, the aforementioned plurality of supply tanks and plurality of recovery tanks each consist of multiple sets of tanks, each consisting of a set of supply tanks and a set of recovery tanks arranged at different positions in the transport direction F (orthogonal to the main scanning direction S) and containing ink of the same color. These multiple sets of tanks are arranged in the main scanning direction S, more specifically, in two rows.

[0091] In this structure, the same effect as the previous implementation can be achieved, and liquid can be recovered from each head to the recovery tank during purging operations.

[0092] In addition, such as Figure 8 As shown, the multiple auxiliary tanks 7 also have supply tanks (supply tanks for processing liquids) and recovery tanks (recovery tanks for processing liquids) for the pre-treatment liquid and post-treatment liquid. The supply tanks and recovery tanks are arranged at different positions in the conveying direction F, and are arranged side by side with the multiple sets of tanks of each color in the main scanning direction S.

[0093] Based on this structure, the distances between the supply tank and the recovery tank and the corresponding head can be made close for both pretreatment and posttreatment liquids, thus shortening the pipeline P ( Figure 6 , Figure 7 The length of ).

[0094] Figure 9 This is a schematic top view illustrating the arrangement of tanks on a carriage according to a second modified embodiment of the present disclosure. Regarding the aforementioned multiple sets of tanks, in the first modified embodiment, a supply tank was arranged in the first column and a recovery tank in the second column, but it can also be described as follows... Figure 9As shown, some of the supply tanks are arranged in the first column, and the rest are arranged in the second column. This structure achieves the same effect as the previous embodiment, and increases the flexibility in the layout of the head and auxiliary tanks on the carriage 3. Furthermore, the flexibility in the arrangement of the multiple pipes P is also increased, preventing the pipes P from becoming unnecessarily intertwined.

[0095] Figure 10 This is a schematic top view showing the arrangement of the tank on the carriage according to a third modified embodiment of this disclosure. It should be noted that... Figure 10 In the text, the color markings for the ink are omitted, and the colors are represented sequentially from left to right by numbers. Additionally, in... Figure 10 The diagrams of the pretreatment and posttreatment fluid tanks are omitted. The supply and recovery tanks of each color are not necessarily located at the same position in the main scanning direction S. Figure 10 As shown, the supply tank and the recovery tank can also be arranged in a staggered position in the main scanning direction S and the conveying direction F. In this case, the arrangement area of ​​the multiple auxiliary tanks 7 on the carriage 3 can be reduced in the conveying direction F.

[0096] It should be noted that in the above-described modified embodiments, at least one of the pretreatment liquid and posttreatment liquid may not have a recovery tank.

[0097] Furthermore, this disclosure is not limited to the embodiments described above, and can be implemented in the following ways.

[0098] (1) The inkjet head 4 is not limited to being arranged in two rows in the carriage 3. The inkjet head 4 can be in one row or more than three rows.

[0099] (2) The color of ink is not limited to Figure 6 The colors shown. Ink colors can also include special colors, light shades, white, and other colors.

[0100] Explanation of reference numerals in the attached figures:

[0101] 1. Inkjet printer (recording device)

[0102] 3 carriages

[0103] 4 inkjet heads

[0104] 5 pre-processing heads

[0105] 6 post-processing heads

[0106] 7 auxiliary tanks (canisters)

[0107] 10 Device Frame

[0108] 12 printing areas

[0109] 13 Maintenance Area

[0110] 14 Return Area

[0111] 20 Workpiece Conveying Section

[0112] H-head configuration area

[0113] W workpiece.

Claims

1. A printing unit, wherein, The printing unit includes: The carriage reciprocates in the main scanning direction; Multiple inkjet heads are mounted on the carriage in at least one column along the main scanning direction and eject ink. as well as Multiple ink cans, arranged along the main scanning direction, are mounted on the carriage and contain ink. The plurality of inkjet heads includes a pair of first inkjet heads disposed at both ends of the main scanning direction and ejecting ink of the same color. The plurality of containers includes a first container for holding ink of a color corresponding to the pair of first inkjet heads. In the carriage, the configuration range of the plurality of cans is set to include the same area in the main scanning direction as the configuration range of the plurality of inkjet heads. The first can is disposed at the center of the main scanning direction among the plurality of cans. The plurality of inkjet heads have multiple pairs of second inkjet heads, each pair of second inkjet heads consisting of a pair of inkjet heads that eject ink of the same color and are symmetrically arranged between the pair of first inkjet heads in the main scanning direction. The plurality of tanks have a plurality of second tanks. In the plurality of second canisters, the second canister containing ink of the color corresponding to the second inkjet head located on the outer side of the main scanning direction among the plurality of pairs of second inkjet heads is positioned at the same position as the second canister containing ink of the color corresponding to the second inkjet head located on the inner side of the main scanning direction among the plurality of pairs of second inkjet heads, or is positioned closer to the first canister than the second canister.

2. The printing unit according to claim 1, wherein, The first container is a supply container for containing the ink supplied to the pair of first inkjet heads.

3. The printing unit according to claim 1, wherein, The first container is a recovery container for holding the ink recovered from the pair of first inkjet heads.

4. The printing unit according to claim 1, wherein, The plurality of second canisters are configured on the same side of the main scanning direction relative to the first canister.

5. The printing unit according to claim 1, wherein, The plurality of inkjet heads are arranged in two columns in the main scanning direction, with the configuration range of the inkjet head group in the first column offset from the configuration range of the inkjet head group in the second column towards one end of the main scanning direction. The can corresponding to the inkjet head group in the first column is configured on one end side in the configuration range of the plurality of cans, and the can corresponding to the inkjet head group in the second column is configured on the opposite end side in the configuration range of the plurality of cans.

6. A printing unit, wherein, The printing unit includes: The carriage reciprocates in the main scanning direction; Multiple inkjet heads are mounted on the carriage in at least one column along the main scanning direction and eject ink. as well as Multiple ink cans, arranged along the main scanning direction, are mounted on the carriage and contain ink. The plurality of inkjet heads includes a pair of first inkjet heads disposed at both ends of the main scanning direction and ejecting ink of the same color. The plurality of containers includes a first container for holding ink of a color corresponding to the pair of first inkjet heads. In the carriage, the configuration range of the plurality of cans is set to include the same area in the main scanning direction as the configuration range of the plurality of inkjet heads. The first can is disposed at the center of the main scanning direction among the plurality of cans. The plurality of containers includes: a plurality of supply containers containing inks of different colors supplied to the plurality of inkjet heads; and a plurality of recovery containers containing inks of different colors recovered from the plurality of inkjet heads. The plurality of supply tanks and the plurality of recovery tanks have multiple sets of tanks, each set consisting of a supply tank and a recovery tank arranged at different positions in a direction orthogonal to the main scanning direction and containing ink of the same color, and the multiple sets of tanks are arranged in the main scanning direction.

7. The printing unit according to claim 6, wherein, The multiple tanks are arranged in two columns along the main scanning direction.

8. The printing unit according to claim 6, wherein, The printing unit also includes: A processing head, mounted on the carriage, sprays out a processing liquid; A processing fluid supply tank, mounted on the carriage, contains the processing fluid supplied to the processing head; and A recovery tank for the processing fluid, mounted on the carriage, contains the processing fluid recovered from the processing head. The processing liquid supply tank and the processing liquid recovery tank are arranged at different positions in a direction orthogonal to the main scanning direction, and are arranged with the multiple sets of tanks in the main scanning direction.

9. The printing unit according to claim 1 or 6, wherein, The printing unit also includes: A pretreatment head, mounted on the carriage, sprays a pretreatment liquid; and A pretreatment solution tank, mounted on the carriage, contains the pretreatment solution. The pre-processing head is disposed at the end of the main scanning direction within the configuration range of the plurality of inkjet heads. The pretreatment liquid tank is positioned at the end of the main scanning direction on the same side as the pretreatment head, relative to the configuration range in which the plurality of tanks are configured.

10. The printing unit according to claim 1 or 6, wherein, The printing unit also includes: A post-processing head, mounted on the carriage, sprays post-processing fluid; and A post-treatment fluid tank, mounted on the carriage, contains the post-treatment fluid. The post-processing head is positioned at the end of the main scanning direction within the configuration range where the plurality of inkjet heads are arranged. The post-processing liquid tank is positioned at the end of the main scanning direction on the same side as the post-processing head, relative to the configuration range in which the plurality of tanks are configured.

11. The printing unit according to claim 1 or 6, wherein, The printing unit also includes: A pretreatment head, which is mounted on the carriage, sprays out a pretreatment liquid; A pretreatment liquid tank, which is mounted on the carriage and contains the pretreatment liquid; A post-processing head, mounted on the carriage, sprays post-processing fluid; and A post-treatment fluid tank, mounted on the carriage, contains the post-treatment fluid. The pre-processing head is disposed at the end of the main scanning direction within the configuration range of the plurality of inkjet heads. The pretreatment liquid tank is positioned at the end of the main scanning direction on the same side as the pretreatment head, relative to the configuration range in which the plurality of tanks are configured. The post-processing head is positioned at the end of the main scanning direction on the side opposite to the pre-processing head within the configuration range where the plurality of inkjet heads are arranged. The post-processing liquid tank is positioned at the end of the main scanning direction on the same side as the post-processing head, relative to the configuration range in which the plurality of tanks are configured.

12. A recording device, wherein, The recording device includes: The printing unit according to any one of claims 1 to 11; and The transport unit transports the recording medium in a direction intersecting the main scanning direction.

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