Inkjet recording apparatus

Abstract

An inkjet recording device includes a conveyor unit, a carriage, one or more ink head arrays, and a processing head. The processing head includes a pre-processing head disposed upstream of the one or more ink head arrays in the conveying direction and configured to eject a non-colored pre-processing liquid. Assuming that the head disposed closest to one end in the main scanning direction is the one-end head, the head disposed closest to the other end is the other-end head, the distance from the one-end head to the other-end head in the main scanning direction is LC, and the distance from the one-end head to the pre-processing head in the main scanning direction is B1, the relationship |(B1-LC / 2)| / LC ≤ 1 / 4 is satisfied.

Description

Technical Field

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

[0002] Inkjet recording devices such as inkjet printers include an ink head that ejects ink for image formation toward a recording medium. For example, when the recording medium is a fiber sheet such as a woven or knitted fabric, or a plastic sheet, it may be necessary to apply a pre-treatment liquid and a post-treatment liquid to the recording medium before and after the ink is ejected onto the recording medium (e.g., Patent Document 1). The pre-treatment liquid is, for example, a treatment liquid used to improve the fixability of the ink to the recording medium and the cohesion of the ink pigment. The post-treatment liquid is, for example, a treatment liquid used to improve the firmness of the printed image. In this case, the inkjet recording device includes a treatment head for ejecting the pre-treatment liquid and the post-treatment liquid in addition to the ink head.

[0003] When recording media is wide, the ink head and processing heads are mounted on a carriage that reciprocates in the main scanning direction. During recording, the recording medium is intermittently transported in a predetermined transport direction (sub-scanning direction). When the recording medium is stopped, the carriage reciprocates in the main scanning direction. As the carriage moves, ink and processing fluid are ejected from the ink head and processing heads, respectively.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Publication No. 2019-147307 Summary of the Invention

[0007] An inkjet recording device according to one aspect of the present invention includes a conveying unit, a carriage, one or more ink head arrays, and a processing head. The conveying unit conveys the recording medium along a prescribed conveying direction. The carriage reciprocates along a main scanning direction intersecting the conveying direction. The one or more ink head arrays are mounted on the carriage at prescribed positions in the conveying direction. The processing head is mounted on the carriage and is used to eject a non-colored processing liquid. Each of the one or more ink head arrays includes a plurality of ink heads arranged in an array along the main scanning direction for respectively ejecting ink for image formation. As the processing head, a pre-processing head for ejecting a pre-processing liquid serving as the processing liquid is provided, which is arranged upstream in the conveying direction relative to the one or more ink head arrays. Assuming that the head closest to one end side among the multiple ink heads and the processing heads in the main scanning direction is the one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the pre-processing head in the main scanning direction is B1, the pre-processing head is configured in a manner that satisfies the relationship of Formula 1.

[0008] |(B1-LC / 2)| / LC≤1 / 4 (Formula 1)

[0009] In addition, another aspect of the present invention relates to an inkjet recording device that includes a conveying unit, a carriage, one or more ink head arrays, and a processing head. The conveying unit conveys the recording medium along a specified conveying direction. The carriage reciprocates along a main scanning direction that intersects the conveying direction. The one or more ink head arrays are mounted on the carriage at specified positions in the conveying direction. The processing head is mounted on the carriage and is used to eject a non-colored processing liquid. Each of the one or more ink head arrays includes a plurality of ink heads arranged in a manner arranged along the main scanning direction for respectively ejecting ink for image formation. As the processing head, there is a post-processing head for ejecting a post-processing liquid as the processing liquid, which is arranged on the downstream side relative to the one or more ink head arrays in the conveying direction. Assuming that the head closest to one end side among the multiple ink heads and the processing heads in the main scanning direction is the one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the post-processing head in the main scanning direction is B2, the post-processing head is configured in a manner that satisfies the relationship of Formula 2.

[0010] |(B2-LC / 2)| / LC≤1 / 4 (Equation 2) BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a perspective view showing the overall structure of an inkjet printer according to one embodiment of the present invention.

[0012] Figure 2 yes Figure 1 Schematic cross-sectional view along line II-II.

[0013] Figure 3 yes Figure 1 An enlarged perspective view of the carriage is shown.

[0014] Figure 4 It is a schematic diagram showing the serial printing method adopted in this embodiment.

[0015] Figure 5A It is a schematic diagram showing the printing status of the carriage on the forward path and the backward path.

[0016] Figure 5B This is a schematic diagram showing the printing status of the carriage on the forward and return paths.

[0017] Figure 6 This is a top view schematically showing the head configuration of Example 1. Figure 3 The arrangement of the ink head and the processing head in the carriage is shown.

[0018] Figure 7 Schematic diagram for explaining the landing timing of the pre-treatment liquid, ink, and post-treatment liquid at a point P on the recording medium.

[0019] Figure 8 This is a plan view of a carriage showing the head arrangement according to the second embodiment.

[0020] Figure 9 This is a plan view of a carriage showing the head arrangement according to the third embodiment.

[0021] Figure 10 This is a top view of a carriage showing the head arrangement according to the fourth embodiment.

[0022] Figure 11 It is a top view of a carriage showing the head arrangement according to the fifth embodiment.

[0023] Figure 12 It is a top view of a carriage showing the head arrangement according to the sixth embodiment.

[0024] Figure 13 It is a top view of a carriage showing the head arrangement according to the seventh embodiment.

[0025] Figure 14 It is a top view of a carriage showing the head arrangement according to the eighth embodiment.

[0026] Figure 15 It is a top view of a carriage showing the head arrangement and sub-tank arrangement according to the ninth embodiment.

[0027] Figure 16 This is a top view of a carriage showing the head arrangement according to the tenth embodiment.

[0028] Figure 17 This is a top view of a carriage showing the head arrangement according to Example 11.

[0029] Figure 18 It is a plan view of a carriage showing a head arrangement according to Comparative Example 1 for comparison with the present invention.

[0030] Figure 19 It is a plan view of a carriage showing a head arrangement according to Comparative Example 2 for comparison with the present invention. DETAILED DESCRIPTION

[0031] An embodiment of the present invention is described below with reference to the accompanying drawings. In this embodiment, an inkjet printer equipped with an ink head that ejects ink for image formation onto a wide and long recording medium is illustrated as a specific example of an inkjet recording device. The inkjet printer of this embodiment is suitable for digital printing, where images such as text and patterns are printed onto recording media made of materials such as woven and knitted fabrics using an inkjet method. Of course, the inkjet recording device of the present invention can also be used to print various inkjet images onto recording media such as paper and resin sheets.

[0032] [Overall structure of an inkjet printer]

[0033] Figure 1 1 is a perspective view showing the overall structure of an inkjet printer 1 according to an embodiment of the present invention. Figure 2 yes Figure 1 The inkjet printer 1 is a schematic cross-sectional view taken along line II-II. The inkjet printer 1 is a printer that prints images on a wide and long workpiece W (recording medium) using an inkjet method. The printer comprises a device frame 10, a workpiece transport unit 20 (transport unit) assembled to the device frame 10, and a carriage 3. In this embodiment, the left-right direction is the main scanning direction when printing on the workpiece W, and the direction from back to front is the sub-scanning direction (the transport direction F of the workpiece W).

[0034] The device frame 10 forms the framework for mounting the various components of the inkjet printer 1. The workpiece transport unit 20 is a mechanism for intermittently transporting the workpiece W so that it advances along a transport direction F from back to front within the printing area where the inkjet printing process is performed. The carriage 3 carries the ink head 4, pre-processing head 5, post-processing head 6, and auxiliary tank 7, and reciprocates in the left-right direction during the inkjet printing process.

[0035] The device 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 the various components of the inkjet printer 1 and has a width corresponding to the width of the workpiece conveyor 20. The right frame 112 and the left frame 113 are respectively disposed upright on the right and left sides of the central frame 111. Between the right frame 112 and the left frame 113 is the print area 12 where the workpiece W is printed.

[0036] The right frame 112 forms a maintenance area 13. The maintenance area 13 is where the carriage 3 retreats when the printing process is not in progress. The maintenance area 13 is used for cleaning and purging the nozzles (ejection holes) of the ink head 4, pre-processing head 5, and post-processing head 6, and is covered. The left frame 113 forms a turnaround area 14 for the carriage 3. The turnaround area 14 is where the carriage 3 temporarily enters during reverse main scanning, as it performs a main scan from right to left across the print area 12 during the printing process.

[0037] A carriage guide 15 is assembled above the device frame 10 to reciprocate the carriage 3 in the left-right direction. The carriage guide 15 is a flat, horizontally elongated member and is positioned above the workpiece conveyor 20. A timing belt 16 (moving member) is assembled on the carriage guide 15 so that it can rotate in the left-right direction (main scanning direction). The timing belt 16 is an endless belt that is driven by a drive source (not shown) to rotate in the left-right or right-hand direction.

[0038] A pair of upper and lower guide rails 17 are provided on the carriage guide 15, extending parallel to each other in the left-right direction. These guide rails serve as holding members for the carriage 3. The carriage 3 engages with the guide rails 17. Furthermore, the carriage 3 is secured to a timing belt 16. As the timing belt 16 rotates in the left or right direction, the carriage 3 is guided by the guide rails 17 and moves left or right along the carriage guide 15.

[0039] Main reference Figure 2 The workpiece conveying unit 20 includes a feed roller 21 for delivering the pre-printed workpiece W and a take-up roller 22 for taking up the printed workpiece W. The feed roller 21 is located at the lower rear portion of the device frame 10 and serves as the winding axis for the feed roll WA, which is the winding body for the pre-printed workpiece W. The take-up roller 22 is located at the lower front portion of the device frame 10 and serves as the winding axis for the take-up roll WB, which is the winding body for the printed workpiece W. The take-up roller 22 is attached to the first motor M1, which drives the take-up roller 22 to rotate about its axis and take up the workpiece W.

[0040] The path between the delivery roller 21 and the take-up roller 22 and through the print area 12 serves as the conveyance path for the workpiece W. This conveyance path is arranged, in order from the upstream side, with a first tension roller 23, a workpiece guide 24, a conveyance roller 25, a pinch roller 26, a return roller 27, and a second tension roller 28. The first tension roller 23 applies a predetermined tension to the workpiece W upstream of the conveyance roller 25. The workpiece guide 24 changes the conveyance direction of the workpiece W from upward to forward, allowing the workpiece W to enter the print area 12.

[0041] The transport roller 25 generates a conveying force that intermittently transports the workpiece W through the print area 12. Driven by the second motor M2, the transport roller 25 rotates about its axis, intermittently transporting the workpiece W forward (in the predetermined conveying direction F) so that the workpiece W passes through the print area 12 (image forming position) facing the carriage 3. The pinch roller 26 is positioned above the transport roller 25, forming a transport nip with the transport roller 25.

[0042] The folding roller 27 changes the conveyance direction of the workpiece W passing through the print area 12 from the forward direction to the downward direction, and guides the printed workpiece W to the take-up roller 22. The second tension roller 28 applies a predetermined tension to the workpiece W downstream of the conveying roller 25. In the print area 12, a platen 29 is arranged below the conveyance path of the workpiece W.

[0043] The carriage 3 reciprocates in a main scanning direction (in this embodiment, the left-right direction) that intersects (in this embodiment, is perpendicular to) the conveying direction F while being cantilevered by the guide rails 17. The carriage 3 includes a carriage frame 30, an ink head 4, a pre-processing head 5, a post-processing 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 rear frame 32 (engaging portion).

[0044] The head support frame 31 is a horizontal plate that holds the heads 4 to 6 described above. The rear frame 32 is a vertical plate that extends upward from the rear end edge of the head support frame 31. As described above, the timing belt 16 is fixed to the rear frame 32. In addition, the guide rail 17 is engaged with the rear frame 32. That is, in this embodiment, the rear frame 32 is an engaging portion that is held by the guide rail 17 in a cantilevered state. The head support frame 31 is a horizontal plate whose rear end side is supported by the engaging portion in a cantilevered state.

[0045] Furthermore, the cantilevered state indicates a state in which the engaging portion (rear frame 32) of the carriage 3 exists only on one side, upstream or downstream, from the center of the carriage 3 in the conveying direction F, and no other engaging portion exists on the opposite side of the engaging portion. The engaging portion is retained by the guide rail 17, which serves as a retaining member. The engaging portion may also be positioned outside the range where the ink head 4 and the processing head are positioned in the conveying direction F. In other words, the engaging portion may be positioned only upstream or downstream of the range where the ink head 4 and the processing head are positioned in the conveying direction F.

[0046] [Detailed structure of the carriage]

[0047] The carriage 3 will be further described. Figure 3 yes Figure 1 An enlarged perspective view of the carriage 3 is shown. Figure 3 , a conveyance direction F (sub-scanning direction) of the workpiece W and a main scanning direction S which is a moving direction of the carriage 3 are shown. Figure 3 The figure shows an example in which a plurality of ink heads 4 for ejecting ink for image formation onto a workpiece W, a pre-processing head 5 and a post-processing head 6 for ejecting a non-colored processing liquid, and a plurality of subsidiary tanks 7 for supplying the ink and the processing liquid to these heads 4 to 6 are mounted on a carriage 3.

[0048] Each ink head 4 includes: a plurality of nozzles (ink ejection holes) that eject ink droplets in an ejection manner, such as a piezoelectric manner using a piezoelectric element, a thermal manner using a heating element, and an ink channel that guides the ink to the nozzle. As the ink, for example, an aqueous pigment ink containing an aqueous solvent, a pigment, and a binder resin can be used. The plurality of ink heads 4 in this embodiment include first to sixth ink heads 4A to 4F that eject six different colors of ink, respectively. For example, the first ink head 4A ejects orange (second color) ink, the second ink head 4B ejects green (second color) ink, the third ink head 4C ejects yellow (first color) ink, the fourth ink head 4D ejects red (first color) ink, the fifth ink head 4E ejects blue (first color) ink, and the sixth ink head 4F ejects black (second color) ink.

[0049] The ink heads 4A to 4F of each color are mounted on the head support frame 31 of the carriage 3 in a manner arranged in the main scanning direction S. Each of the ink heads 4A to 4F of each color has two heads. For example, the first ink head 4A includes: an upstream head 4A1 arranged on the upstream side of the conveying direction F; and a downstream head 4A2 arranged at a position downstream relative to the upstream head 4A1 and offset to the left of the main scanning direction S. The same is true for the ink heads 4B to 4F of other colors. The upstream heads of these ink heads 4B to 4F are arranged in a row along the main scanning direction S at the same position as the upstream head 4A1 in the conveying direction F, and the downstream heads are arranged in a row along the main scanning direction S at the same position as the downstream head 4A2 in the conveying direction F.

[0050] With this arrangement, the ink heads 4 that eject ink of a single color are concentrated in the main scanning direction S. Specifically, all the ink heads 4 mounted on the carriage 3 that eject ink of a single color are arranged so that no ink heads 4 that eject ink of other colors are sandwiched between them in the main scanning direction S. Alternatively, all the ink heads 4 mounted on the carriage 3 that eject ink of a single color may be arranged within a predetermined range in the main scanning direction S, and no ink heads 4 that eject ink of other colors may be arranged within this range.

[0051] If there are differences in printing conditions such as landing position and ejection volume between the two ink heads 4, there is a higher probability that the difference will be noticeable when the two ink heads 4 eject the same color, compared to when the two ink heads 4 eject different colors. If the ink heads 4 ejecting the same color are arranged together in the main scanning direction S, even if there are differences in printing conditions between the ink heads 4, the quality of the printed image can be minimized.

[0052] The pre-processing head 5 and the post-processing head 6 are each a type of processing head that ejects a non-coloring processing liquid described later. The pre-processing head 5 and the post-processing head 6 are arranged at positions different from the ink head 4 in the conveying direction F. The pre-processing head 5 is arranged on the upstream side of the ink head 4 in the conveying direction F. Figure 3 , an example is shown in which one pre-processing head 5 is arranged near the center of the array of ink heads 4. Similarly, the post-processing head 6 is arranged on the downstream side of the ink head 4 in the conveying direction F. Figure 3 , an example is shown in which two post-processing heads 6A and 6B (a plurality of processing heads) are arranged near the center of the array of ink heads 4 along the main scanning direction S. Various arrangements of the ink heads 4, pre-processing heads 5, and post-processing heads 6 on the carriage 3 will be described in detail in Examples 1 to 17 described below.

[0053] As used in the above description, a series of heads formed by the ink head 4 and the post-processing head 6 along the main scanning direction S is referred to as a head column or simply a column. A head column may also include the pre-processing head 5. Furthermore, a series of heads formed by the ink head 4, the pre-processing head 5, and the post-processing head 6 along the conveying direction F is referred to as a head row or simply a row.

[0054] The pretreatment head 5 is a type of processing head that ejects a pretreatment liquid for performing a predetermined pretreatment on the workpiece W. The pretreatment liquid is ejected from the pretreatment head 5 toward a portion of the workpiece W where ink has not yet been ejected from the ink head 4. The pretreatment liquid is a non-colored treatment liquid that does not exhibit color even when adhered to the workpiece W. For example, it functions to improve the fixability of the ink to the workpiece W and the aggregation of the ink pigment. Examples of such pretreatment liquids include those containing a binder resin mixed in a solvent or those containing a positively charged cationic resin mixed in a solvent.

[0055] The post-processing head 6 is a type of processing head that sprays a post-processing liquid for implementing a prescribed post-processing onto the workpiece W to which ink is attached. The post-processing liquid is sprayed from the post-processing head 6 toward the position of the workpiece W after the ink is sprayed from the ink head 4. The post-processing liquid is also a non-colored processing liquid that does not show color even if it adheres to the workpiece W. It is a processing liquid that plays a role in improving the fixability and firmness (resistance to friction and scratches) of the ink image printed on the workpiece W by the ink head 4. As such a post-processing liquid, a silicone-based processing liquid or the like can be used. In addition, the post-processing liquid and the pre-processing liquid are different processing liquids. Specifically, the components contained in the post-processing liquid and the pre-processing liquid are different.

[0056] Here, a non-colored treatment liquid refers to a treatment liquid whose coloration cannot be discerned by the naked eye when printed on a recording medium alone. The colors here include colors with a chroma of 0, such as black, white, and gray. A non-colored treatment liquid is basically a transparent liquid, but when observing 1L of the treatment liquid in its liquid state, for example, it is not completely transparent and sometimes appears slightly white. This color is very light, and when printed on a recording medium alone, the coloration cannot be discerned by the naked eye. In addition, depending on the type of treatment liquid, when printed on a recording medium alone, the recording medium may sometimes undergo changes such as gloss, but this state does not constitute coloration.

[0057] In this embodiment, the pre-treatment liquid and the post-treatment liquid may be sprayed onto substantially the entire surface of the workpiece W, or may be selectively sprayed like ink according to the image to be printed.

[0058] Next, we'll explain the selective ejection of pre-treatment liquid and post-treatment liquid. As described above, for portions of the workpiece W corresponding to the image's printed color, pre-treatment liquid, ink, and post-treatment liquid are ejected in that order. In this case, the ink can be a single color or multiple colors. For portions not printed, i.e., where ink is not ejected, pre-treatment liquid and post-treatment liquid are generally not ejected. Furthermore, to adjust the quality of the printed image, the texture of the workpiece W, or other factors, the ejection of the pre-treatment liquid and post-treatment liquid may be partially different from the ejection of the ink.

[0059] The head support frame 31 has openings 31H at the head placement location. The ink heads 4A to 4F, the pre-processing head 5, and the post-processing head 6 are assembled to the head support frame 31 so as to fit into the respective openings 31H. The nozzles arranged on the lower end surfaces of the heads 4, 5, and 6 are exposed through the respective openings 31H.

[0060] The sub-tanks 7 are supported by the carriage 3 above the heads 4, 5, and 6 via a holding frame (not shown). The sub-tanks 7 are provided corresponding to the heads 4, 5, and 6, respectively. Ink or processing liquid is supplied to each sub-tank 7 from an ink cartridge or main tank (not shown) containing ink and processing liquid. Each sub-tank 7 supplies the ink or processing liquid to each head 4, 5, and 6. Each sub-tank 7 and the heads 4, 5, and 6 are connected to each other. Figure 3 They are connected through pipelines not shown in the figure (P1, P2, P3 shown in Figure 24).

[0061] As described above, the inkjet printer 1 of this embodiment is a multifunction all-in-one printer equipped with three heads: an ink head 4, a pre-processing head 5, and a post-processing head 6, mounted on a single carriage 3. This inkjet printer 1 can, for example, perform both the pre-processing liquid and post-processing liquid ejection steps in a digital printing process, such as inkjet printing on a material. This simplifies the printing process and reduces the size of the printing apparatus.

[0062] [Print Method]

[0063] Next, a description will be given of a printing method performed by the inkjet printer 1 according to this embodiment. The inkjet printer 1 performs a printing process on the workpiece W using a serial printing method. Figure 4 : is a schematic diagram showing the serial printing method. Figure 4 In FIG, the pre-processing head 5 and the post-processing head 6 are omitted and the carriage 3 is simply drawn.

[0064] If the workpiece W is wide, printing cannot be performed while continuously feeding the workpiece W. The serial printing method is a printing method that repeats the reciprocating movement of the carriage 3 carrying the ink heads 4 of each color in the main scanning direction S and the intermittent feeding of the workpiece W in the feeding direction F. Here, it is assumed that the ink head 4 has a predetermined printing width Pw in the feeding direction F. The printing width Pw is approximately equal to the range of the ink ejection nozzles of the ink head 4.

[0065] In addition, Figure 4 And the following description Figure 5A 、 Figure 5B In FIG, the width of each head in the conveying direction F is drawn to be substantially equal to the printing width Pw. In reality, the width of each head in the conveying direction F is larger than the printing width Pw and the arrangement range of the ejection nozzles.

[0066] Figure 4 The figure shows the state where the carriage 3 moves in the outward direction SA of the main scanning direction S and the printing of the strip image G1 with the printing width Pw is completed. When the main scanning is performed in the outward direction SA, the conveyance of the workpiece W stops. After printing the strip image G1, the workpiece W is sent in the conveying direction F by a spacing equivalent to the printing width Pw. At this time, the carriage 3 waits in the folding area 14 on the left end side. After sending out the workpiece W, the carriage 3 folds back in the return direction SB as the synchronous belt 16 rotates in the reverse direction. The workpiece W is in a stopped state. Then, as shown Figure 4 As shown, the carriage 3 moves in the return path direction SB and prints a band-like image G2 having a print width Pw on the upstream side of the band-like image G1. Thereafter, the same operation is repeated.

[0067] Figure 5A and Figure 5B It is a schematic diagram showing the printing status of the carriage 3 on the forward and return paths. Here, the ink head 4, the pre-processing head 5 and the post-processing head 6 mounted on the carriage 3 are simplified. The ink head 4 includes the first, second, third and fourth ink heads 4A, 4B, 4C and 4D for ejecting inks of the first color, second color, third color and fourth color that are different from each other. These first to fourth ink heads 4A to 4D are arranged in a row along the main scanning direction S. The pre-processing head 5 is arranged on the upstream side of the ink head 4 in the conveying direction F, and the post-processing head 6 is arranged on the downstream side. In addition, Figure 4 Similarly to the situation described in , the workpiece W is fed along the conveying direction F between the forward printing and the return printing. The travel distance in the conveying direction F at this time is the spacing between adjacent heads in the conveying direction F (head pitch). In addition, this travel distance is also the printing width of each head 4, 5, and 6.

[0068] Figure 5AFigure 3 shows a state where the carriage 3 is performing a printing operation (forward main scan) while moving in the forward direction SA of the main scanning direction S. Area A4 on the workpiece W is the area facing the pre-processing head 5 mounted on the upstream side of the carriage 3. During this forward main scan, the pre-processing liquid ejected from the pre-processing head 5 forms a pre-processing layer Lpre on area A4.

[0069] Area A3 is an area with a distance of one head spacing on the downstream side relative to area A4, and is the area faced by the ink head 4. On area A3, a pre-processing layer Lpre has been formed along the entire length in the main scanning direction by the previous return path main scan. In this outward main scan, on the pre-processing layer Lpre of area A3, the first, second, third, and fourth ink layers LCA, LCB, LCC, and LCD are formed by the first to fourth color inks ejected in sequence according to the arrangement order of the first to fourth ink heads 4A to 4D. In addition, for ease of understanding, Figure 5A In the figure, the fourth to first ink layers LCD to LCA are sequentially stacked, but they are not actually stacked. In addition, the aforementioned pre-processing layer Lpre and the post-processing layer Lpos described later are not formed on the workpiece W.

[0070] Area A2 is located downstream of area A3 by a distance of one head pitch and faces the post-processing head 6, mounted on the most downstream side of the carriage 3. Area A2 has already been formed along its entire length in the main scanning direction with the pre-processing layer Lpre formed by the previous outward main scan and the first to fourth ink layers LCA to LCD formed by the previous return main scan. During this outward main scan, the post-processing liquid ejected from the post-processing head 6 forms a post-processing layer Lpos on the first to fourth ink layers LCA to LCD in area A2.

[0071] Area A1 is located downstream of area A2 by a distance of one head pitch and is the area where the carriage 3 passes through and the printing process ends. Specifically, in area 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 in the main scanning direction.

[0072] Figure 5B Indicates the end Figure 5AAfter the outward main scan, the carriage 3 turns back and moves in the return direction SB while performing the return main scan. Before this turnaround, the workpiece W is fed a distance of one head pitch in the conveyance direction F. Area A5 on the workpiece W is located one head pitch upstream of area A4 and is the area that the pretreatment head 5 faces during this return main scan. A pretreatment layer Lpre is formed on area A5 by the pretreatment liquid ejected from the pretreatment head 5.

[0073] In areas 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 area A4, the first to fourth ink layers LCA to LCD are formed on the pre-processing layer Lpre. In area A3, the post-processing layer Lpos is formed on the first to fourth ink layers LCA to LCD. Area A2 is the area where the printing process ends after area A1.

[0074] The reason why printing processing can be performed on both the outward main scan and the return main scan as described above is that the pre-processing head 5 and the post-processing head 6 are arranged in an offset manner relative to the ink head 4 in the conveying direction F. Assuming that the pre-processing head 5, the ink head 4, and the post-processing head 6 are arranged in a row in this order along the main scanning direction S on the slide 3, the printing processing that can eject the pre-processing liquid and the post-processing liquid in a manner that makes them land in the desired order can only be achieved on one side of the outward main scan or the return main scan. In order to be able to perform printing processing in both directions, a pair of pre-processing heads 5 and post-processing heads 6 must be arranged on both sides of the arrangement body of the ink head 4. At this time, the width of the slide 3 in the main scanning direction S becomes large. Since such a configuration is not required in the present embodiment, the width of the slide 3 in the main scanning direction S can be miniaturized.

[0075] Furthermore, providing multiple rows of ink heads 4 can increase the amount of ink deposited on the workpiece W. For example, if there are two rows of ink heads 4, printing can be performed as follows. After the first row of ink heads 4 forms the first through fourth ink layers LCA through LCD as described above, the workpiece W is transported in the transport direction F by a distance equal to one head pitch, and the second row of ink heads 4 forms the first through fourth ink layers LCA through LCD. This allows two layers of each color of ink to be printed on the workpiece W.

[0076] [Various ways to configure the header]

[0077] Hereinafter, various configuration examples of the ink head 4, the pre-processing head 5, and the post-processing head 6 on the carriage 3 will be described as examples 1 to 11. Figures 1 to 5A 、 Figure 5BThis figure is used to explain the basic functions of the pre-processing head 5 and the post-processing head 6. The detailed configuration of the pre-processing head 5 and the post-processing head 6 involved in this embodiment will be described in the following. Figure 6 This will be explained later.

[0078] <Example 1>

[0079] Figure 6 This is a plan view schematically showing the head configuration according to the first embodiment. Figure 6 Or it means Figure 3 FIG. 4 is a diagram showing the arrangement of the ink head 4 and the pre-processing head 5 and the post-processing head 6 (a plurality of processing heads) on the carriage 3. The carriage 3 is supported by the guide rail 17 in a cantilevered state at the rear frame 32 (engaging portion). The rear frame 32 is arranged on the upstream side of the conveying direction F of the head support frame 31. In the conveying direction F, the side of the head support frame 31 on which the rear frame 32 is arranged is referred to as the base end side 311, and the side of the head support frame 31 opposite to the base end side 311 is referred to as the distal end side 312. As already mentioned, the head support frame 31 of the carriage 3 is equipped with the first to sixth ink heads 4A to 4F, the pre-processing head 5, and the post-processing head 6, which respectively eject six different colors of ink. Each of the ink heads 4A to 4F of each color has two (a total of 12) unit heads. There is one pre-processing head 5, and two post-processing heads 6.

[0080] The group of first to sixth ink heads 4A to 4F constituting the ink head 4 is arranged so as to be aligned along the main scanning direction S in the central region of the head support frame 31 in the conveying direction F. The pre-processing head 5 is positioned approximately in the center of the carriage 3 in the main scanning direction S, upstream of the ink heads 4 in the conveying direction F, and on the base end 311 of the head support frame 31. On the other hand, the post-processing head 6 is positioned approximately in the center of the carriage 3 in the main scanning direction S, downstream of the ink heads 4 in the conveying direction F, and on the distal end 312 of the head support frame 31. Both the pre-processing head 5 and the post-processing head 6 are positioned near the center of the head support frame 31 in the main scanning direction S.

[0081] The first ink head 4A includes: an upstream head 4A1; and a downstream head 4A2 arranged on the downstream side relative to the upstream head 4A1. That is, the upstream head 4A1 and the downstream head 4A2 are arranged in the conveying direction F. The upstream head 4A1 is arranged at a position close to the base end side 311 in the central area of the head support frame 31. The downstream head 4A2 is arranged at a position close to the distal end side 312 in the central area of the head support frame 31. Relative to the upstream head 4A1, the downstream head 4A2 is arranged at a position offset toward one side (left side) in the main scanning direction S and partially overlapped in the conveying direction F. Of course, the upstream head 4A1 and the downstream head 4A2 can also be arranged at the same position in the main scanning direction S (positions arranged in a straight line in the conveying direction F). However, the configuration of this embodiment can make the size of the carriage 3 in the conveying direction F smaller.

[0082] The second to sixth ink heads 4B to 4F also include upstream heads 4B1, 4C1, 4D1, 4E1, and 4F1, and downstream heads 4B2, 4C2, 4D2, 4E2, and 4F2, similar to the upstream head 4A1 and downstream head 4A2 described above. The upstream heads 4A1 to 4F1 of the first to sixth ink heads 4A to 4F are arranged in a row at predetermined intervals along the main scanning direction S at the same position in the conveying direction F. Furthermore, the downstream heads 4A2 to 4F2 are also arranged in a row at predetermined intervals along the main scanning direction S at the same position in the conveying direction F. As a result, a zigzag arrangement is formed, with portions of the downstream heads 4A2 to 4F2 intersecting the respective arrangement intervals of the upstream heads 4A1 to 4F1.

[0083] In other words, the structure of the ink head 4 is described. The ink head 4 includes a plurality of ink head arrays mounted on the carriage 3 in an array along the transport direction F. Each of the plurality of ink head arrays includes a plurality of ink heads arranged in an array along the main scanning direction S and each ejecting ink for image formation. Figure 6 In the illustrated example, the plurality of ink head arrays include a first ink head array 41 and a second ink head array 42. The ink heads included in the first ink head array 41 are upstream heads 4A1, 4B1, 4C1, 4D1, 4E1, and 4F1. The ink heads included in the second ink head array 42 are downstream heads 4A2, 4B2, 4C2, 4D2, 4E2, and 4F2.

[0084] The preprocessing head 5 is arranged so that a portion thereof enters between a pair of ink heads adjacent to each other in the main scanning direction S. Specifically, the downstream portion of the preprocessing head 5 enters between the upstream head 4C1 of the third ink head 4C and the upstream head 4D1 of the fourth ink head 4D.

[0085] The post-processing head 6 includes a first post-processing head 6A and a second post-processing head 6B arranged in parallel in the main scanning direction S. Figure 6 ] shows an example in which the first and second post-processing heads 6A and 6B are arranged at the same position in the conveying direction F, spaced apart along the main scanning direction S. The first post-processing head 6A is positioned so that its upstream portion extends between the downstream head 4C2 of the third ink head 4C and the downstream head 4D2 of the fourth ink head 4D. The second post-processing head 6B is positioned so that its upstream portion extends between the downstream head 4D2 and the downstream head 4E2, and is positioned at the same position in the main scanning direction S as the upstream head 4D1. With this arrangement, the first and second post-processing heads 6A and 6B overlap with the downstream heads 4C2, 4D2, and 4E2 in the conveying direction F, with an area fa therebetween.

[0086] In the transport direction F, the width of each head is larger than the printing width Pw and the arrangement range of the ejection nozzles. Therefore, the heads are arranged to have an overlapping area fa so that there is no gap between the printing width Pw of each row of heads and the printing range Pw of the adjacent row of heads.

[0087] In addition, unless otherwise specified, Figure 6 In the figures, the intervals between adjacent heads (the intervals between the centers of the heads) are the same in the main scanning direction S. Similarly, the distances between adjacent heads (the intervals between the centers of the heads) in the conveying direction F are the same.

[0088] As a result of the above-described head arrangement, the pre-processing head 5 and the post-processing head 6 are arranged within the arrangement width H of the ink head 4 in the main scanning direction S. The ink head 4 has an arrangement width H in the main scanning direction S, extending from the downstream head 4A2 of the first ink head 4A to the upstream head 4F1 of the sixth ink head 4F. The pre-processing head 5 is arranged within the arrangement width H on the upstream side of the ink head 4, and the post-processing head 6 is arranged within the arrangement width H on the downstream side of the ink head 4. In particular, in Example 1, the pre-processing head 5 and the post-processing head 6 are positioned approximately in the center of the head array in the main scanning direction S.

[0089] According to the head configuration involved in the embodiment 1 described above, it is possible to achieve both miniaturization of the carriage 3 and increase the necessary amount of ink and treatment liquid ejected. That is, the pre-processing head 5 and the post-processing head 6 are arranged at a different position from the ink head 4 in the conveying direction F. According to this configuration, the ink heads 4A to 4F that can increase the necessary amount of ink ejected are arranged in the main scanning direction S, and can perform printing processing on both the outbound main scanning and the return main scanning, and can shorten the width of the carriage required for carrying the above-mentioned heads 4 to 6 in the main scanning direction. Moreover, the post-processing head 6 is composed of a plurality of first and second post-processing heads 6A and 6B, and they are arranged in the main scanning direction S. Therefore, if the amount of post-processing liquid ejected is insufficient if a single head is used, the necessary amount can be ejected by configuring a plurality of post-processing heads 6A and 6B.

[0090] The first to sixth ink heads 4A to 4F include upstream heads 4A1 to 4F1 (a first ink head row 41) and downstream heads 4A2 to 4F2 (a second ink head row 42), arranged along the transport direction F (a direction intersecting the arrangement direction of the multiple processing heads). Therefore, even if the number of ink heads 4 is increased to increase the amount of ink ejected per color or to achieve multi-color printing, the width of the carriage 3 in the main scanning direction can be prevented from being increased.

[0091] The pre-processing head 5 and the post-processing head 6 are arranged within the arrangement width H of the first to sixth ink heads 4A to 4F in the main scanning direction S. Therefore, even when the carriage 3 carries the pre-processing head 5 and the post-processing head 6 in addition to the ink heads 4, there is no need to increase the width of the carriage 3 in the main scanning direction. In other words, the width of the carriage 3 in the main scanning direction can be reduced.

[0092] The pre-processing heads 5 and post-processing heads 6 are arranged so that portions of them extend between the arrangement intervals of the first to sixth ink heads 4A to 4F. Focusing on the first post-processing head 6A, a portion of the first post-processing head 6A extends between the pair of downstream heads 4C2 and 4D2. This zigzag arrangement allows for high-density arrangement of the ink heads 4 and the processing heads 5 and 6, which are positioned at different locations in the conveying direction F. Consequently, the width of the carriage 3 in the conveying direction F can be reduced.

[0093] In the head arrangement of Example 1, one pre-processing head 5 is positioned upstream of the ink head 4 in the transport direction F, and two post-processing heads 6A and 6B are positioned downstream. This provides a multifunctional, all-in-one inkjet printer 1 in which three heads—those for discharging pre-processing liquid, ink, and post-processing liquid—are mounted on a single carriage 3. Furthermore, because the pre-processing head 5, ink head 4, and post-processing head 6 are sequentially positioned in the transport direction F, the pre-processing liquid, ink, and post-processing liquid can be discharged in a desired landing order during both the forward and return main scanning phases.

[0094] In addition, the carriage 3 has a cantilevered state supported by the guide rail 17 (holding member) ( Figure 1 ) is held by the rear frame 32 (engaging portion). By supporting the carriage 3 in a cantilevered state on the timing belt 16, the structure can be simplified. Furthermore, by supporting the carriage 3 in a cantilevered state, it is easy to configure a structure with the downstream side of the carriage 3 open, making maintenance of the ink head 4 and processing heads 5 and 6 easier.

[0095] In the carriage 3 supported in a cantilevered state, the pre-processing head 5 is positioned on the base end side 311 (the side close to the engaging portion) of the head support frame 31, and the post-processing head 6 is positioned on the distal end side 312 (the side away from the engaging portion). Unlike the base end side 311 of the rear frame 32, which is fixed to the timing belt 16, the distal end side 312, which serves as the free end, is estimated to have a lower positioning accuracy. However, the distal end side 312 is equipped with the post-processing head 6, which does not require relatively high ejection accuracy. Since the post-processing liquid covers the ink image printed on the workpiece W, even if a landing position shift occurs, the relative impact on image quality can be reduced compared to the same degree of landing position shift of the pre-processing liquid. Therefore, even when using a carriage 3 supported in a cantilevered state, image quality can be less likely to degrade.

[0096] <Problems with header configuration>

[0097] As described above, in addition to the ink head 4, the pre-treatment head 5 for ejecting the pre-treatment liquid and the post-treatment head 6 for ejecting the post-treatment liquid are respectively mounted on the slide 3. As the slide 3 moves back and forth in the main scanning direction, the pre-treatment liquid, ink and post-treatment liquid are sprayed onto the workpiece W in sequence. The time from the landing of the pre-treatment liquid to the landing of the ink and the time from the landing of the ink to the landing of the post-treatment liquid will vary depending on the image position in the main scanning direction S. As a result, there is a problem that the image quality on the workpiece W is prone to differences.

[0098] For example, when using a pre-treatment liquid that improves the cohesion of the ink pigment, if the time from the landing of the pre-treatment liquid to the landing of the ink is increased, the coloring will become darker. Furthermore, for example, when using a post-treatment liquid that improves fastness, if the time from the landing of the ink to the landing of the post-treatment liquid is increased, the coloring will become darker. When printing using these, if the time from the landing of the pre-treatment liquid to the landing of the post-treatment liquid is increased, the coloring will become darker. When the same color ink is landed multiple times, for the pre-treatment liquid, the time from the landing of the pre-treatment liquid to the first ink that lands after it lands has a relatively greater impact on the coloring density. For the post-treatment liquid, the time from the landing of the post-treatment liquid to the last ink that lands before it lands has a relatively greater impact on the coloring density.

[0099] To address the aforementioned issues, the inventors have discovered that by appropriately arranging the pre-processing head 5 and the post-processing head 6 on the carriage 3, it is possible to reduce the time difference between the landing of the pre-processing liquid and the landing of the ink, and the time difference between the landing of the ink and the landing of the post-processing liquid, respectively, even between different image positions in the main scanning direction S. The following describes the concept of head arrangement based on this new concept and an example of such arrangement (an embodiment).

[0100] <Header configuration idea>

[0101] Figure 7 Schematic diagram for explaining the landing time of the pre-treatment liquid, ink and post-treatment liquid at point P on the workpiece W. Figure 7 In the figure, the printing area 12 is arranged in the center, and the maintenance area 13 and the return area 14 are arranged on the left and right sides thereof. As described above, the carriage 3 moves between the maintenance area 13 and the return area 14 along the main scanning direction S, thereby ejecting ink, pre-treatment liquid, and post-treatment liquid from the ink head 4, the pre-treatment head 5, and the post-treatment head 6 to the workpiece W. In addition, Figure 7 For ease of explanation, the carriage 3 is shown in both the maintenance area 13 and the return area 14. The following description uses as an example a case where the ink head 4 includes a plurality of ink head arrays and a workpiece W is intermittently conveyed and printed at a head pitch (the spacing between adjacent heads in the conveyance direction F).

[0102] exist Figure 7 In the embodiment, it is defined that among the multiple ink heads and processing heads (pre-processing head 5 and post-processing head 6) included in the multiple ink head arrays 41 and 42, the head closest to one end side in the main scanning direction S is defined as the one end side head, the head closest to the other end side is defined as the other end side head, the distance from the one end side head to the other end side head in the main scanning direction S is defined as LC, the distance from the one end side head to the pre-processing head 5 in the main scanning direction S is defined as B1, and the distance from the one end side head to the specified ink head (in the main scanning direction S) is defined as B2. Figure 7The distance from the upstream head 4D1 of the fourth ink head 4D is K, and the distance from the one end head to the post-processing head 6 in the main scanning direction S is B2. Figure 7 In the example shown, the one-end head is the downstream head 4A2 of the first ink head 4A, and the other-end head is the upstream head 4F1 of the sixth ink head 4F. The distances LC, K, B1, and B2 can be set based on a portion of each head. However, in the following description, the distances are set based on the center of each head in the main scanning direction S. Furthermore, the one-end head and the other-end head may be reversed.

[0103] The center of the head in the main scanning direction S is basically the position of an imaginary line in the main scanning direction S that bisects the area of the planar shape of the head when viewed from above and is perpendicular to the main scanning direction S. In some cases, when the head is viewed from above and an imaginary line that bisects the area of the convex polygon with the smallest area among the convex polygons that include all the ejection nozzles of the head is considered, the position of the imaginary line in the main scanning direction S that bisects the area of the convex polygon with the smallest area can be used as the center of the head in the main scanning direction S.

[0104] First, the timing for each liquid to land on point P on workpiece W within print area 12 will be described. Since the speed of carriage 3 is constant, the following description uses distances. The actual timing can be calculated by dividing each distance by the speed of carriage 3. It is assumed that point P is located at a distance A from the end of print area 12 on the maintenance area 13 side.

[0105] Furthermore, here, liquid is assumed to be ejected from the center of the head in the main scanning direction S. If the nozzles of each head are actually distributed diffusely in the main scanning direction S, this dispersion will also affect the landing time. However, because the positional differences between nozzles in the main scanning direction S within a head are often smaller than the positional differences between nozzles in different heads, the effect of head configuration can be estimated by assuming that the liquid is ejected from the center of the head in the main scanning direction S.

[0106] In addition, for the sake of easy understanding, the ejection time and the landing time are assumed to be simultaneous. In fact, the time of ejection so that the liquid lands at a predetermined position at a predetermined time is earlier than the landing time, which is the flight time of the liquid from the head to the workpiece W.

[0107] Assume that the one-way travel distance of the carriage 3 (the distance from the maintenance area 13 to the turnaround area 14) is the minimum distance LP + LC required for printing, and the carriage 3 is positioned in the maintenance area 13 as its initial position. In this case, during the first movement (leftward movement) of the carriage 3 from the maintenance area 13 to the turnaround area 14, the time T1 for the pretreatment liquid ejected from the pretreatment head 5 to land at point P can be expressed as a distance using the following equation A.

[0108] T1=A+B1 (Formula A)

[0109] After the pretreatment liquid lands on the point P, in the second movement operation (movement in the right direction) of the carriage 3 moving from the turn-back area 14 to the maintenance area 13, ink is ejected from each ink head of the first head row 41 toward the point P. Furthermore, in the third movement operation (movement in the left direction) of the carriage 3 further moving from the maintenance area 13 to the turn-back area 14, ink is ejected from each ink head of the second head row 42 toward the point P.

[0110] In the above description, the time T2 when the red ink (also referred to as the first ink or the initial ink) lands on the point P from the upstream head 4D1 of the fourth ink head 4D can be expressed by the following equation B.

[0111] T2=(LP+LC)+(LP-A)+(LC-K) (Formula B)

[0112] The first bracket of the above formula B is equivalent to the time for the slide 3 to move from the maintenance area 13 to the return area 14 in the first moving action, the second bracket is equivalent to the time for the far end of the slide 3 to reach point P in the second moving action, and the third bracket is equivalent to the time for the slide 3 to move further so that the specified ink head reaches point P.

[0113] Based on the above-mentioned equations A and B, the time AT from the landing of the pre-treatment liquid to the landing of the first ink at the point P can be expressed by the following equation C.

[0114] AT=T2-T1=LP-2A+LC-(B1+K)+LP+LC (Formula C)

[0115] Meanwhile, during printing on a workpiece W, the carriage 3 may first move from the turnaround area 14, i.e., rightward as the first movement. In this case, as described above, the time ΔT from the time the pretreatment liquid lands at point P to the first (initial) landing of red ink can be expressed by the following equation D.

[0116] ΔT=2A-LP-(LC-(B1+K))+(LP+LC) (Formula D)

[0117] Here, all points on the workpiece W in the printing area 12 are studied. Since the distance A can be considered to change from 0 to LP, according to the above-mentioned formulas C and D, the range involved in ΔT can be expressed by the following formulas E, F, and G.

[0118] ΔTmin1≤ΔT≤ΔTmax1 (Formula E)

[0119] ΔTmin1=-LP-|(LC-(B1+K)|+(LP+LC) (Formula F)

[0120] ΔTmax1=LP+|(LC-(B1+K)|+(LP+LC) (Formula G)

[0121] Next, using the same concept as above, the time ΔT from the moment the red ink (also called the second ink or final ink) ejected from the downstream head 4D2 of the fourth ink head 4D lands at point P until the post-treatment liquid lands is described. In the case of a first movement operation in the leftward direction from the maintenance area 13 toward the return area 14, the time ΔT from the moment the red ink from the downstream head 4D2 lands at point P until the post-treatment liquid lands can be expressed by the following equation H.

[0122] ΔT=LP-2A+(LC-(K+B2))+(LP+LC) (Formula H)

[0123] Furthermore, when the number of ink heads 4 arranged in the ink transport direction F is an even number, the first ink landing is followed by the second ink landing as expressed by Formula C. On the other hand, when the number of ink heads 4 arranged in the ink transport direction F is an odd number, the first ink landing is followed by the second ink landing as expressed by Formula D.

[0124] Similarly, when the first movement operation is rightward movement from the turnaround area 14 toward the maintenance area 13 , the time ΔT from the landing of the red ink of the downstream head 4D2 at the point P to the landing of the post-processing liquid can be expressed by the following formula (I).

[0125] ΔT=2A-LP-(LC-(K+B2))+(LP+LC) (Formula I)

[0126] In this case, when the number of ink heads 4 arranged in the ink transport direction F is an even number, the first ink landing is followed by the second ink landing as expressed by Formula D. On the other hand, when the number of ink heads 4 arranged in the ink transport direction F is an odd number, the first ink landing is followed by the second ink landing as expressed by Formula C.

[0127] Similarly, all points on the workpiece W in the printing area 12 are studied. Since the distance A can be considered to vary from 0 to LP, according to the above-mentioned formulas H and I, the range involved in ΔT can be expressed by the following formulas J, K, and L.

[0128] ΔTmin2≤ΔT≤ΔTmax2 (Formula J)

[0129] ΔTmin2=-LP-|(LC-(K+B2)|+(LP+LC) (Formula K)

[0130] ΔTmax2=LP+|(LC-(K+B2)|+(LP+LC) (Formula L)

[0131] In Equations E through G, and J through L, K falls within the range of 0 and below LC to accommodate all ink head configurations. Therefore, when the absolute values of LC-(B1+K) and LC-(K+B2) are small, the occurrence of colors with large time differences in ΔT can be suppressed. In other words, the closer B1 and B2 are to LC / 2, the more the occurrence of colors with large time differences can be suppressed. When considering only the landing time, it is most preferable for both B1 and B2 to be LC / 2.

[0132] Furthermore, the inventors have repeatedly conducted research, experiments, and discussions, and have found that when the following formula 1 is satisfied, regardless of the movement direction of the carriage 3, the difference in time from the landing of the pretreatment liquid to the landing of the ink on the workpiece W can be reduced, and a stable image can be formed.

[0133] |(B1-LC / 2)| / LC≤1 / 4 (Formula 1)

[0134] Similarly, it was found that when the following formula 2 is satisfied, the difference in time from the landing of the ink to the landing of the post-processing liquid on the workpiece W can be reduced, and a stable image can be formed.

[0135] |(B2-LC / 2)| / LC≤1 / 4 (Equation 2)

[0136] Furthermore, when a plurality of pre-treatment heads 5 are provided, it is preferable that at least one pre-treatment head 5 is provided so as to satisfy Formula 1. As described above, by providing at least one pre-treatment head 5 so as to satisfy Formula 1, not only can the time difference from the landing of the pre-treatment liquid to the landing of the ink be reduced, but also, since the pre-treatment liquid can be ejected from other pre-treatment heads 5, the amount of the ejectable pre-treatment liquid can be increased.

[0137] Furthermore, it is more preferable that all of the plurality of pre-processing heads 5 are arranged to satisfy Expression 1. In this case, the time difference from the landing of the pre-processing liquid to the landing of the ink can be further reduced, and the amount of the process liquid that can be ejected can be increased.

[0138] Likewise, when a plurality of post-processing heads 6 are provided, it is preferable that at least one post-processing head 6 be provided to satisfy Formula 2. As described above, by providing at least one post-processing head 6 to satisfy Formula 2, not only can the time difference from ink landing to post-processing liquid landing be reduced, but also, since post-processing liquid can be ejected from other post-processing heads 6, the amount of ejectable post-processing liquid can be increased.

[0139] Furthermore, it is more preferable that all of the plurality of post-processing heads 6 are arranged to satisfy Expression 2. In this case, the time difference from ink landing to post-processing liquid landing can be further reduced, and the amount of dischargeable processing liquid can be increased.

[0140] In addition, in Example 1, the carriage 3 was described as being equipped with both the pre-processing head 5 and the post-processing head 6. However, the carriage 3 may also be equipped with only the pre-processing head 5 or only the post-processing head 6. If equation 1 is satisfied for the ink head 4 and the carriage 3 equipped with only the pre-processing head 5 as a processing head, the time difference between the landing of the pre-processing liquid and the landing of the ink can be reduced. If equation 2 is satisfied for the ink head 4 and the carriage 3 equipped with only the post-processing head 6 as a processing head, the time difference between the landing of the ink and the landing of the pre-processing liquid can be reduced.

[0141] Next, a more preferred configuration of the pre-processing head 5 and the post-processing head 6 defined by the above-mentioned equations 1 and 2 will be described. Considering equations E to G, the range of ΔT varies between the first to sixth ink heads 4A to 4F. That is, the range of ΔT varies depending on the size of K. Figure 7 In the example shown, when B1 > LC / 2, the larger the K value, the greater the range of ΔT variation. In other words, the time difference for the black ink in the sixth ink head 4F is the largest. Furthermore, when the first movement is in the left direction from the maintenance area 13 toward the return area 14, the ΔT time difference is smallest at position A = LP. When the first movement is in the right direction from the return area 14 toward the maintenance area 13, the ΔT time difference is largest at position A = LP.

[0142] In the above example, the time difference between the landing of the pre-treatment liquid and the first landing of the black ink is significant. Therefore, if the time difference between the second landing of the black ink and the landing of the post-treatment liquid is also significant, the image quality of the black image will be more noticeable than that of images of other colors, which can easily affect the image perceived by the naked eye. Therefore, for the sixth ink head 4F that ejects black ink with a high K value, it is preferable to minimize the time difference between the second landing of the black ink and the landing of the post-treatment liquid. Specifically, it is preferable to configure the post-treatment head 6 so that B2 is small.

[0143] The inventors conducted the same research as described above on each ink head 4 and found that: when a plurality of ink head columns including ink heads that eject ink of the same color are mounted on the carriage 3 and the ink heads 4 are concentratedly arranged in the main scanning direction for each color, with respect to the ink of a specified color, in order to suppress the large difference in time from the landing of the pre-treatment liquid to the landing of the first ink and the increase in the difference in time from the landing of the second ink to the landing of the post-treatment liquid, it is effective to set the absolute value of (B1+B2-LC) / LC to a smaller value, preferably satisfying the following formula 3, and more preferably satisfying formula 4.

[0144] |(B1+B2-LC) / LC|≤1 / 2 (Equation 3)

[0145] |(B1+B2-LC) / LC|≤1 / 3 (Equation 4)

[0146] Based on the above ideas, Figure 6In the head configuration with two ink head arrays shown in Example 1, the distance LC from the downstream head 4A2 of the first ink head 4A to the upstream head 4F1 of the sixth ink head 4F in the main scanning direction S is 11, the distance B1 from the downstream head 4A2 to the pre-processing head 5 in the main scanning direction S is 6, and the distance B2 from the downstream head 4A2 to each post-processing head 6 in the main scanning direction S is 5 or 7. In this case, |(B1-LC / 2)| / LC=0.045, satisfying the above-mentioned equation 1. Furthermore, |(B2-LC / 2)| / LC=0.045 or 0.136, both satisfying the above-mentioned equation 2. Therefore, the time difference between the landing of the pre-processing liquid and the landing of the ink ejected from the first ink head array 41 and the time difference between the landing of the ink ejected from the second ink head array 42 and the landing of the post-processing liquid can be reduced. As a result, the pre-treatment liquid, ink, and post-treatment liquid can be stably deposited sequentially on the workpiece W, minimizing variations in image quality on the workpiece W. Furthermore, |(B1+B2-LC) / LC| = 0 or 0.18, both satisfying Equations 3 and 4. Therefore, when multiple head arrays including ink heads that eject ink of the same color are mounted on the carriage 3, significant variations in the time from the deposition of the pre-treatment liquid to the first deposition of ink for a given color of ink can be suppressed, as can variations in the time from the second deposition of ink to the deposition of the post-treatment liquid.

[0147] In addition, as described above, one of the first post-processing head 6A and the second post-processing head 6B of the post-processing head 6 may be arranged at a position that does not satisfy the above-mentioned formulas 1 to 4, but it is most preferably as follows: Figure 6 Any of the post-processing heads 6 shown satisfies the above-mentioned equations 1 to 4.

[0148] <Example 2>

[0149] also, Figure 8This is a top view of the carriage 3A showing the head configuration involved in Example 2. In Example 2, the ink head 4 includes a first ink head array 41 and a second ink head array 42, and the pre-processing head 5 and the post-processing head 6 are located approximately in the center of the array of all the heads in the main scanning direction S. In this head configuration, LC = 11, B1 = 6, and B2 = 5. In this case, |(B1-LC / 2)| / LC = 0.045, which satisfies the above-mentioned formula 1. In addition, |(B2-LC / 2)| / LC = 0.045, which satisfies the above-mentioned formula 2. Therefore, the time difference from the landing of the pre-processing liquid to the landing of the ink ejected from the first ink head array 41 and the time difference from the landing of the ink ejected from the second ink head array 42 to the landing of the post-processing liquid can be reduced. In addition, |(B1+B2-LC) / LC| = 0, which satisfies both the above-mentioned formulas 3 and 4. Therefore, when a plurality of ink head arrays including ink heads that eject ink of the same color are mounted on the carriage 3, with respect to the ink of a specified color, it is possible to suppress the time difference from the landing of the pre-treatment liquid to the landing of the first ink from being large and the time difference from the landing of the second ink to the landing of the post-treatment liquid from becoming large.

[0150] <Example 3>

[0151] also, Figure 9 3B is a top view showing the head arrangement of the embodiment 3. In the embodiment 3, the ink heads are arranged in a row. In addition, in the embodiment 3, the pre-processing head 5 and the post-processing head 6 are located in the approximate center of the array of all the heads in the main scanning direction S. Figure 9 In the head configuration, LC = 6, B1 = 3, and B2 = 3. In this case, |(B1 - LC / 2)I| / LC = 0, satisfying the above-mentioned equation 1. Furthermore, |(B2 - LC / 2)| / LC = 0, satisfying the above-mentioned equation 2. Furthermore, |(B1 + B2 - LC) / LC| = 0, satisfying the above-mentioned equations 3 and 4. Therefore, the same effects as those of the above-mentioned embodiments 1 and 2 can be achieved.

[0152] Hereinafter, preferred head configurations will be further described based on other embodiments.

[0153] <Example 4>

[0154] Figure 101 is a top view schematically showing a carriage 3D having a head configuration according to Example 4. Example 4 differs from Example 1 in that the number of respective unit heads is increased. That is, the ink head 4 is the same as Example 1 in that it includes the first to sixth ink heads 4A to 4F that eject six different colors of ink, respectively. However, each of the ink heads 4A to 4F of each color has three (a total of 18) unit heads. In other words, the ink head 4 has three (an odd number of) ink head columns including a first ink head column 41, a second ink head column 42, and a third ink head column 43. The pre-processing head 5 arranged on the upstream side in the conveying direction F of the ink head 4 includes two unit heads, and the post-processing head 6 arranged on the downstream side includes three unit heads. In addition, the points in which the pre-processing head 5 and the post-processing head 6 are respectively arranged within the range of the configuration width of the ink head 4 in the main scanning direction S are the same as in Example 1.

[0155] The first ink head 4A includes an upstream head 4AA, a center head 4AB, and a downstream head 4AC as the unit heads. The upstream head 4AA is positioned at the most upstream side of the first ink head 4A in the conveying direction F of the carriage 3A. The downstream head 4AC is positioned downstream of the upstream head 4AA at the same position as the upstream head 4AA in the main scanning direction S. The center head 4AB is positioned to the right of the upstream head 4AA and the downstream head 4AC in the main scanning direction S, and is positioned downstream of the upstream head 4AA and upstream of the downstream head 4AC in the conveying direction F. The center head 4AB is positioned so as to partially overlap with the upstream head 4AA and the downstream head 4AC in the conveying direction F.

[0156] The second to sixth ink heads 4B to 4F also include upstream heads 4BA, 4CA, 4DA, 4EA, 4FA, center heads 4BB, 4CB, 4DB, 4EB, 4FB, and downstream heads 4BC, 4CC, 4DC, 4EC, and 4FC, similar to the upstream head 4AA, center head 4AB, and downstream head 4AC described above. The upstream heads 4AA to 4FA, center heads 4BB to 4FB, and downstream heads 4BC to 4FC of the first to sixth ink heads 4A to 4F are arranged in a row along the main scanning direction S at predetermined intervals at the same position in the transport direction F. Furthermore, the ink heads 4 are collectively arranged in the main scanning direction for each color.

[0157] The pre-processing heads 5 include a first pre-processing head 5A and a second pre-processing head 5B, arranged at the same position in the conveying direction F and spaced apart in the main scanning direction S. The first pre-processing head 5A is arranged so that a portion of its downstream side extends between the upstream head 4CA of the third ink head 4C and the upstream head 4DA of the fourth ink head 4D. The second pre-processing head 5B is arranged so that a portion of its downstream side extends between the upstream head 4DA of the fourth ink head 4D and the upstream head 4EA of the fifth ink head 4E.

[0158] The post-processing heads 6 include a first post-processing head 6A, a second post-processing head 6B, and a third post-processing head 6C, which are arranged at intervals in the main scanning direction S at the same position in the conveying direction F. The first post-processing head 6A is arranged so that a portion of its upstream side extends between the downstream head 4BC of the second ink head 4B and the downstream head 4CC of the third ink head 4C. The second post-processing head 6B is arranged so that a portion of its upstream side extends between the downstream head 4CC of the third ink head 4C and the downstream head 4DC of the fourth ink head 4D. The third post-processing head 6C is arranged so that a portion of its upstream side extends between the downstream head 4DC of the fourth ink head 4D and the downstream head 4EC of the fifth ink head 4E.

[0159] exist Figure 10 In the head configuration, the upstream head 4AA or the downstream head 4AC of the first ink head 4A is used as one end head, LC = 11, B1 = 5, 7, and B2 = 3, 5, 7. In this case, |(B1-LC / 2)| / LC = 0.045 and 0.136, both satisfying the above-mentioned formula 1. In addition, |(B2-LC / 2)| / LC = 0.227, 0.045, and 0.136, both satisfying the above-mentioned formula 2. In addition, when B1 = 5, for each value of B2, |(B1+B2-LC) / LC| = 0.273, 0.091, and 0.091, both satisfying the above-mentioned formulas 3 and 4. In addition, when B1 = 7, for each value of B2, |(B1+B2-LC) / LC| = 0.091, 0.091, and 0.272, both satisfying the above-mentioned formulas 3 and 4. Therefore, the same effects as those of the above-mentioned first and second embodiments can be obtained.

[0160] Furthermore, the head configuration of Example 4 achieves the same advantages as Example 1. Specifically, it achieves both miniaturization of the carriage 3D and the necessary increase in the ejection volume of ink and treatment liquid. In particular, in Example 4, both the pre-processing head 5 and the post-processing head 6 are configured with multiple unit heads, thereby significantly increasing the ejection volume of the pre-processing and post-processing liquids. Since the first to sixth ink heads 4A to 4F also comprise unit heads arranged in three rows, the ink ejection volume can also be significantly increased.

[0161] <Example 5>

[0162] Figure 11 1 is a top view schematically showing a carriage 3E having a head configuration according to Example 5. In Example 5, as in Example 1 ( Figure 6 ) Similarly, an example is shown in which the pre-processing head 5 and the post-processing head 6 are arranged in the central area HC of the arrangement width H. However, as will be described later, Example 5 differs from Example 1 in the arrangement of the ink head 4.

[0163] The head support frame 31 of the carriage 3E carries the first to sixth ink heads 4A to 4F, each ejecting six different colors of ink, a pre-processing head 5, and a post-processing head 6. The first to sixth ink heads 4A to 4F are arranged in two rows, similar to those in Example 1. However, in the first ink head 4A, the downstream head 4A2 is positioned to the right of the upstream head 4A1, and the offset direction of the downstream heads of the ink heads 4A to 4F is opposite to that in Example 1. There is one pre-processing head 5, and two post-processing heads 6, a first and a second post-processing head 6A and 6B.

[0164] The pre-processing head 5 and the post-processing head 6 are arranged in the center area HC of the arrangement width H of the first to sixth ink heads 4A to 4F in the main scanning direction S. The pre-processing head 5 is arranged upstream of the arrangement of the first to sixth ink heads 4A to 4F in the conveyance direction F, and the post-processing head 6 is arranged downstream, similar to the first embodiment described above. The pre-processing head 5 is arranged at the same position in the main scanning direction S as the downstream head 4C2 of the third ink head 4C, but upstream in the conveyance direction F. The pre-processing head 5 is arranged so that a portion of its downstream side extends between the upstream heads 4C1 and 4D1 of the third and fourth ink heads 4C and 4D.

[0165] The first and second post-processing heads 6A and 6B are arranged at the same position in the transport direction F, with a predetermined interval in the main scanning direction S. The first post-processing head 6A is positioned so that its upstream portion extends between the downstream head 4B2 of the second ink head 4B and the downstream head 4C2 of the third ink head 4C. The second post-processing head 6B is positioned so that its upstream portion extends between the downstream head 4C2 and the downstream head 4D2 of the fourth ink head 4D.

[0166] In this head arrangement of Example 5, the distance LC from the upstream head 4A1 of the first ink head 4A to the downstream head of the sixth ink head 4F in the main scanning direction S is 11, the distance B1 from the upstream head 4A1 to the pre-processing head 5 in the main scanning direction S is 5, and the distance B2 from the upstream head 4A1 to each post-processing head 6 in the main scanning direction S is 4 or 6. In this case, |(B1-LC / 2)| / LC=0.045, satisfying the above-mentioned equation 1. Furthermore, |(B2-LC / 2)| / LC=0.136 or 0.045, both satisfying the above-mentioned equation 2. Therefore, the time difference between the landing of the pre-processing liquid and the landing of the ink ejected from the first ink head array 41 and the time difference between the landing of the ink ejected from the second ink head array 42 and the landing of the post-processing liquid can be reduced. As a result, the pre-treatment liquid, ink, and post-treatment liquid can be stably deposited sequentially on the workpiece W, minimizing variations in image quality on the workpiece W. Furthermore, |(B1+B2-LC) / LC| = 0.18 or 0, satisfying both Equations 3 and 4. Therefore, when multiple head arrays including ink heads that eject ink of the same color are mounted on the carriage 3, significant variations in the time from the deposition of the pre-treatment liquid to the first deposition of ink for a given color of ink can be suppressed, as can variations in the time from the second deposition of ink to the deposition of the post-treatment liquid.

[0167] Furthermore, the pre-processing heads 5 and the post-processing heads 6 are not only arranged in the central area HC of the arrangement width H, but are also arranged so that the arrangement center of the pre-processing head 5 and the arrangement centers of the first and second post-processing heads 6A and 6B coincide with each other in the main scanning direction S. In this embodiment, since there is only one pre-processing head 5, the center of the pre-processing head 5 in the main scanning direction S serves as the arrangement center C1. For the post-processing heads 6, the midpoint between the first post-processing head 6A and the second post-processing head 6B serves as the arrangement center C2. The pre-processing heads 5 and the post-processing heads 6 are arranged on the head support frame 31 so that their arrangement centers C1 and arrangement centers C2 are located at the same position in the main scanning direction S.

[0168] If based on Figure 4 As described, in this embodiment, the carriage 3 repeatedly performs forward main scanning and return main scanning, causing the pre-treatment liquid, ink, and post-treatment liquid to sequentially land on the workpiece W. By employing the head arrangement of Example 5 while employing such bidirectional main scanning, it is possible to reduce the difference in time from the landing of the pre-treatment liquid on the workpiece W to the landing of the ink, and the difference in time from the landing of the ink to the landing of the post-treatment liquid, at each main scanning position.

[0169] In this case, the central region HC is preferably located in the center of the arrangement width H and has a width of half, and more preferably one-third, of the arrangement width H. Arranging the processing heads in the central region HC means that the arrangement centers of the processing heads are arranged in the central region HC, and more than half of the arrangement centers of the processing heads are arranged in the central region HC. Alternatively, all arrangement centers of the processing heads may be arranged in the central region HC.

[0170] <Example 6>

[0171] In Example 6 and the following Example 7, head configurations are illustrated that take measures to prevent the heating of the processing heads 5 and 6. Typically, a head that ejects liquid using a jetting method generates heat because it uses electricity to pressurize the liquid. The ink head 4 only ejects the liquid when forming the desired color dots. In contrast, the pre-processing head 5 and the post-processing head 6 need to eject the pre-processing liquid and the post-processing liquid corresponding to dots of all colors. Therefore, the pre-processing head 5 and the post-processing head 6 are more likely to heat up than the ink heads 4. Therefore, it is preferable to configure the head configuration in such a way that the pre-processing head 5 and the post-processing head 6 will heat up.

[0172] Figure 12 1 is a top view schematically showing a carriage 3F having a head arrangement according to Example 6. The rear frame 32 (engaging portion) of the carriage 3F is supported in a cantilevered state by the guide rail 17 (holding member) ( Figure 1 ) is held. The ink head 4 having the first to sixth ink heads 4A to 4F, a pre-processing head 5, and a post-processing head 6 having the first and second post-processing heads 6A and 6B are mounted on the head support frame 31. These heads are arranged in the same manner as Figure 6 The embodiment 1 shown is the same, so the description is omitted here.

[0173] In the head configuration of Example 6, LC = 11, B1 = 6, and B2 = 5 or 7. In this case, |(B1 - LC / 2)| / LC = 0.045, satisfying Equation 1 above. Furthermore, |(B2 - LC / 2)| / LC = 0.045 or 0.136, both satisfying Equation 2 above. Furthermore, |(B1 + B2 - LC) / LC| = 0 or 0.18, both satisfying Equations 3 and 4 above.

[0174] In addition, in this embodiment, the pre-processing head 5 is composed of one unit head, and the post-processing head 6 is composed of two unit heads (first and second post-processing heads 6A and 6B). The pre-processing head 5 with fewer unit heads among these pre-processing heads 5 and post-processing heads 6 is arranged on the base end side 311 of the head support frame 31. The post-processing head 6 with more unit heads is arranged on the distal end side 312. In other words, the upstream end edge of the head support frame 31 in the conveying direction F is the side held by the guide rail 17.

[0175] As described above, the processing heads 5 and 6 generate heat due to the ejection operation. Figure 12 As schematically shown in the figure, the heated pre-processing head 5 releases heat ha. The same applies to the first and second post-processing heads 6A and 6B. This heat ha heats the head support frame 31 of the carriage 3F, potentially causing thermal deformation of the head support frame 31, its retaining structure, the rear frame 32, and the mounting brackets between the rear frame 32 and the timing belt 16. This thermal deformation can affect the landing accuracy of ink ejected from the ink head 4 in the cantilevered carriage 3F.

[0176] However, in the carriage 3F of Example 6, the pre-processing head 5, which has a smaller number of unit heads, is positioned on the cantilevered side of the head support frame 31, i.e., the base end side 311. This reduces the effects of thermal deformation (reduced landing accuracy). If the post-processing head 6, which has a larger number of unit heads, is positioned on the base end side 311, the rear frame 32 is exposed to the heat released by the two unit heads, causing it to heat up even more and become more susceptible to thermal deformation.

[0177] Furthermore, in the carriage 3F of Example 6, the pre-processing head 5 is positioned in the head array body HA (head arrangement area) of the ink head 4 and the processing heads 5 and 6, excluding the ends in the main scanning direction S. Of the heads 4, 5, and 6 mounted on the carriage 3F, the pre-processing head 5, serving as the processing head, is positioned closest to the rear frame 32 (engaging portion). This pre-processing head 5 is positioned in a position excluding the end of the head array body HA, i.e., the arrangement end 313.

[0178] Since the carriage 3F cannot be unnecessarily increased in size, if a head is arranged at the configuration end 313 of the head array body in the main scanning direction S, the head becomes the head closest to the corner of the carriage 3F (head support frame 31) in the main scanning direction S. Since the vicinity of the configuration end 313 is also near the cantilever-supported rear frame 32, if thermal deformation occurs in this vicinity, it is possible to cause deformation or positional displacement of the head support frame 31 in the height direction or horizontal direction. This reduces the landing position accuracy of the heads 4, 5, and 6 mounted on the carriage 3F. Therefore, by not arranging high-temperature processing heads (pre-processing head 5 and post-processing head 6) in the area of the configuration end 313, the above-mentioned thermal deformation problem can be made less likely to occur.

[0179] In this embodiment, the row of ink heads 4 arranged on the engaging portion side is arranged in two rows (the first ink head row 41 and the second ink head row 42). Figure 12 The zigzag arrangement is arranged in a position offset to the right. Furthermore, the pre-processing head 5, which has a smaller number of processing heads, is arranged on the engaging portion side, and the pre-processing head 5 is arranged in the center of the zigzag arrangement. This arrangement allows the heads to be arranged in a manner such that the processing heads are not arranged at the arrangement end 313.

[0180] Reference Figure 12 The head configuration of the carriage 3F shown in the figure further illustrates a preferred ink head configuration example. In the carriage 3F, the high-temperature pre-processing head 5 is configured so that a portion of it is adjacent to the ink head 4. Specifically, the pre-processing head 5 is adjacent to the upstream heads 4C1 and 4D1 of the third and fourth ink heads 4C and 4D in the main scanning direction S, and is adjacent to the downstream head 4D2 of the fourth ink head 4D in the conveying direction F. In addition, the first post-processing head 6A is adjacent to the downstream heads 4C2 and 4D2 of the third and fourth ink heads 4C and 4D in the main scanning direction S, and is adjacent to the upstream head 4C1 in the conveying direction F. The second post-processing head 6B is adjacent to the downstream heads 4D2 and 4E2 of the fourth and fifth ink heads 4D and 4E in the main scanning direction S, and is adjacent to the upstream head 4D1 in the conveying direction F. On the other hand, the pre-processing head 5 and the post-processing head 6 are not adjacent to the first, second, and sixth ink heads 4A, 4B, and 4F.

[0181] In the above-described head arrangement, for example, the third, fourth, and fifth ink heads 4C, 4D, and 4E (first ink heads that eject first color ink) that eject yellow, red, and blue ink, respectively, have more unit heads adjacent to the pre-processing head 5 and the post-processing head 6 than the first, second, and sixth ink heads 4A, 4B, and 4F (second ink heads that eject second color ink) that eject orange, green, and black ink, respectively. In other words, the third, fourth, and fifth ink heads 4C, 4D, and 4E are more susceptible to high temperatures than the other ink heads 4A, 4B, and 4F.

[0182] If the viscosity of the ink changes significantly with temperature, the ink ejection characteristics (e.g., ejection volume) from the ink head will also change. The viscosity change characteristics due to temperature vary depending on the type of ink. Therefore, in the case of this embodiment, the ink ejected from the third, fourth, and fifth ink heads 4C, 4D, and 4E, which are susceptible to high temperatures, ejects ink whose viscosity changes less due to temperature than the ink ejected from the first, second, and sixth ink heads 4A, 4B, and 4F. Accordingly, even if the third, fourth, and fifth ink heads 4C, 4D, and 4E are heated by the pre-processing head 5 and the post-processing head 6, the changes in the ejection volume and ejection speed of the ink ejected from these ink heads 4C, 4D, and 4E due to temperature can be reduced.

[0183] At this time, for each ink, the unit number of processing heads adjacent to the ink head 4 can also be used to evaluate the maximum number of unit numbers of processing heads adjacent to the ink head 4 ejecting a certain ink. For the first, second, and sixth ink heads 4A, 4B, and 4F, the maximum number of unit numbers of processing heads adjacent to each other is 0. For the third ink head 4C, the maximum number of unit numbers of processing heads adjacent to each other is 2. For the fourth ink head 4D, the maximum number of unit numbers of processing heads adjacent to each other is 3. For the fifth ink head 4E, the maximum number of unit numbers of processing heads adjacent to each other is 1.

[0184] Furthermore, for each ink, the unit number of processing heads adjacent to the ink head 4 can also be evaluated as the average of the unit number of adjacent processing heads among the ink heads 4 ejecting a particular ink. For the first, second, and sixth ink heads 4A, 4B, and 4F, the average unit number of adjacent processing heads is 0. For the third ink head 4C, the average unit number of adjacent processing heads is 1.5. For the fourth ink head 4D, the average unit number of adjacent processing heads is 2.5. For the fifth ink head 4E, the average unit number of adjacent processing heads is 0.5.

[0185] As a combined evaluation of these, for example, the maximum number of unit heads of adjacent processing heads may be evaluated first, and for inks having no difference in the evaluation, the average number of unit heads of adjacent processing heads may be evaluated.

[0186] Alternatively, the order in which the ink head 4 ejecting each ink is likely to heat up may be evaluated, and the inks having the smallest viscosity change with temperature may be ejected in the order in which the temperature is likely to heat up.

[0187] <Example 7>

[0188] Example 7 shows an embodiment that considers countermeasures for high temperatures of the pre-processing head 5 and post-processing head 6 among multiple ink heads that eject the same color ink. In the above embodiments, the first to sixth ink heads 4A to 4F of each color are each provided with two or three unit heads. If there is a significant difference in the number of adjacent unit heads between these unit heads, the ink ejection characteristics of the unit heads may differ significantly. This embodiment shows an example of a head configuration that reduces this difference in the number of adjacent unit heads.

[0189] Figure 13 This is a top view schematically showing a carriage 3G having a head arrangement according to Example 7. The carriage 3G has a head arrangement such that, when the number of two unit heads (same-color ink heads) included in each of the first to sixth ink heads 4A to 4F adjacent to the pre-processing head 5 or the post-processing head 6 in the main scanning direction S and the transport direction F is counted, the difference between the maximum and minimum count values is 1 or less.

[0190] The arrangement of the ink head 4 in the head arrangement of the carriage 3G is the same as that of the above-mentioned Figure 12 The carriage 3F shown has the same head configuration. Meanwhile, the pre-processing head 5 includes first and second pre-processing heads 5A and 5B arranged side by side in the main scanning direction S, with the upstream head 4C1 of the third ink head 4C sandwiched therebetween. The post-processing head 6 includes first and second post-processing heads 6A and 6B arranged side by side in the main scanning direction S, with the downstream head 4C2 sandwiched therebetween.

[0191] In this head configuration of Example 7, the downstream head of the first ink head 4A serves as the end head, and LC = 11, B1 = 4, 6, and B2 = 3, 5. In this case, |(B1-LC / 2)| / LC = 0.136 or 0.045, respectively, satisfying Equation 1. Furthermore, |(B2-LC / 2)| / LC = 0.227 or 0.045, both satisfying Equation 2. Therefore, the time difference between the landing of the pre-treatment liquid and the landing of the ink ejected from the first ink head array 41, and the time difference between the landing of the ink ejected from the second ink head array 42 and the landing of the post-treatment liquid, can be reduced. As a result, the pre-treatment liquid, ink, and post-treatment liquid can be stably and sequentially landed on the workpiece W, reducing variations in image quality on the workpiece W. Furthermore, when B1 = 4, |(B1 + B2 - LC) / LC| = 0.364 or 0.181, one of which does not satisfy Equations 3 and 4, but the other satisfies them. Furthermore, when B1 = 6, |(B1 + B2 - LC) / LC| = 0.181 or 0, both of which satisfy Equations 3 and 4. Therefore, when multiple head arrays including ink heads that eject ink of the same color are mounted on the carriage 3, it is possible to suppress significant variations in the time from the landing of the pretreatment liquid to the first landing of the ink, and to prevent significant variations in the time from the second landing of the ink to the landing of the post-treatment liquid, for a given color of ink.

[0192] In the second ink head 4B of the carriage 3G, the count values of the processing heads 5 and 6 adjacent to the upstream head 4B1 and the downstream head 4B2 in the main scanning direction S and the conveying direction F are 2 and 1, respectively, with a difference of "1." In the third ink head 4C, the count values of the upstream head 4C1 and the downstream head 4C2 are both 3, with a difference of "0." In the fourth ink head 4D, the count value of the upstream head 4D1 is 1, and the count value of the downstream head 4D2 is 2, with a difference of "1." The count values of the remaining ink heads 4A, 4E, and 4F are all 0. Therefore, for all of the first to sixth ink heads 4A to 4F, the difference between the maximum and minimum values is 1 or less, satisfying the above requirements.

[0193] As described above, in Example 7, the difference between the maximum and minimum count values of the upstream heads 4A1 to 4F1 and the downstream heads 4A2 to 4F2 of the first to sixth ink heads 4A to 4F adjacent to the processing heads 5 and 6, respectively, is 1 or less. This prevents significant variations in ink ejection volume between multiple ink heads of the same color.

[0194] <Example 8>

[0195] Figure 14This is a top view schematically showing a carriage 3H having a head arrangement according to Example 8. Example 8 shows an example in which the pre-processing heads 5 and post-processing heads 6 are arranged as close together as possible on the head support frame 31, rather than being dispersed, thereby reducing contact between the pre-processing liquid and the post-processing liquid and the ink.

[0196] In Example 8, a head arrangement satisfying the following requirements (A) to (C) is exemplified.

[0197] (A) When the number of unit heads of the pre-processing head 5 and the post-processing head 6 is greater, and the number of unit heads of the post-processing head 6 is less, and the condition m=n+odd number is satisfied,

[0198] (B) the arrangement or arrangement center of the one or more pre-processing heads 5 in the main scanning direction S coincides with the arrangement or arrangement center of the one or more post-processing heads 6 in the main scanning direction S, and

[0199] (C) The arrangement or arrangement center of the pre-processing head 5 and the post-processing head 6 coincides with the arrangement position of one of the ink heads 4 in the main scanning direction S.

[0200] Figure 8 The carriage 3H shown includes an ink head 4, a pre-processing head 5, and a post-processing head 6 having a first and a second post-processing head 6A, 6B. Figure 12 The same as others. Therefore, the head configuration in Example 8 also satisfies the relationship between the above-mentioned formulas 1 to 4, and the same effect can be obtained. In addition, in the case of this example, there are m=2 post-processing heads 6 and n=1 pre-processing head 5. Therefore, m=n+odd number that satisfies the above-mentioned requirement (A). In addition, the configuration center of the pre-processing head 5 and the arrangement center of the post-processing head 6 are both the center C in the figure, which also satisfies the above-mentioned requirement (B). Moreover, the center C is consistent with the configuration position of the downstream side head 4D2 of the fourth ink head 4D, which also satisfies the above-mentioned requirement (C).

[0201] According to the head arrangement of Example 8, the pre-processing head 5 and the post-processing head 6 can be mounted on the carriage 3H in a somewhat concentrated state. This reduces the number of ink heads 4A to 4F located near the pre-processing head 5 or the post-processing head 6. Consequently, the likelihood of pre-processing liquid and post-processing liquid coming into contact with ink on the carriage can be reduced.

[0202] <Example 9>

[0203] In Embodiment 9, a preferred arrangement relationship between the heads 4 , 5 , and 6 on the carriage and the sub-tanks that supply ink or processing liquid thereto is exemplified. Figure 15This is a top view showing the carriage 3I and the sub-tank configuration having the head configuration according to Example 9. The carriage 3I includes an ink head 4 having first to sixth ink heads 4A to 4F, a pre-processing head 5, and a post-processing head 6 having first and second post-processing heads 6A and 6B. Figure 12 Therefore, the head configuration in Example 9 also satisfies the relationship between the above-mentioned formulas 1 to 4, and the same effect can be obtained.

[0204] The carriage 3I also carries a sub-tank 7. The sub-tanks 7 include ink sub-tanks 7A to 7F, a pre-treatment liquid sub-tank 71, and a post-treatment liquid sub-tank 72 (all of which are treatment liquid sub-tanks). Ink, pre-treatment liquid, and post-treatment liquid are supplied to these sub-tanks 7 from a main tank (not shown). The ink sub-tanks 7A to 7F supply the ink to the first to sixth ink heads 4A to 4F, respectively. For example, ink of the first color is supplied from the first tank 7A1 of the ink sub-tank 7A via the pipe P1 to the upstream head 4A1 of the first ink head 4A, and from the second tank 7A2 via the pipe P1 to the downstream head 4A2. The second to sixth ink heads 4B to 4F are similarly supplied with ink of the second to sixth colors, respectively.

[0205] The arrangement order of the ink sub-tanks 7 in the main scanning direction S is the same as the arrangement order of the ink heads 4 supplied with ink by each ink sub-tank 7 in the main scanning direction S. Alternatively, ink may be supplied from a single ink sub-tank 7 to multiple ink heads 4 that eject the same color of ink. In this case, the ink heads 4 sharing the ink sub-tank 7 may be arranged in a concentrated position in the main scanning direction S. Furthermore, it is preferable to arrange the ink heads 4 ejecting the same ink in a concentrated position in the main scanning direction S. In the main scanning direction S, the arrangement order of the ink sub-tanks 7 for each color may be the same as the arrangement order of the ink heads 4 for each color.

[0206] The pre-treatment liquid sub-tank 71 supplies the pre-treatment liquid to the pre-treatment head 5 via the pipe P2. The post-treatment liquid sub-tank 72 includes a first tank 72A and a second tank 72B. The first and second tanks 72A and 72B supply the post-treatment liquid to the first and second post-treatment heads 6A and 6B, respectively, via the pipe P3.

[0207] The ink sub-tanks 7A to 7F are mounted on the carriage 31 so as to be aligned along the main scanning direction S. The treatment liquid sub-tanks 71 and 72 are positioned at different locations in the transport direction F than the ink sub-tanks 7A to 7F. Furthermore, the treatment liquid sub-tanks 71 and 72 are aligned in the main scanning direction S. Specifically, the first and second tanks 72A and 72B of the pre-treatment liquid sub-tank 71 and the post-treatment liquid sub-tank 72 are aligned in a row along the main scanning direction S, downstream of the ink sub-tanks 7A to 7F in the transport direction F. Alternatively, only the pre-treatment liquid sub-tank 71 may be positioned upstream of the ink sub-tanks 7A to 7F.

[0208] The liquid in the sub-tank 7, carried on the carriage 3I that reciprocates in the main scanning direction S, is subjected to acceleration in the main scanning direction S. The sub-tank 7 is connected to the heads 4, 5, and 6 via pipes P1, P2, and P3. However, if the sub-tanks 7 are widely distributed on the carriage 3I, the arrangement range of the pipes P1 to P3 in the main scanning direction S also increases. Because these pipes P1 to P3 are also filled with ink or processing liquid, the acceleration may cause meniscus breakdown in the ejection area of the heads 4, 5, and 6.

[0209] However, according to the configuration of Example 9, the ink sub-tanks 7A to 7F, like the first to sixth ink heads 4A to 4F, are mounted on the carriage 3I so as to be aligned along the main scanning direction S. Therefore, the ink sub-tanks 7A to 7F can be arranged in a relatively narrow area on the head support frame 31 of the carriage 3I. Similarly, the pre-treatment liquid sub-tank 71 and the post-treatment liquid sub-tank 72 can also be arranged in a relatively narrow area on the head support frame 31 of the carriage 3I.

[0210] Furthermore, since the pre-treatment liquid sub-tank 71 and the post-treatment liquid sub-tank 72 are positioned differently from the ink sub-tanks 7A to 7F in the transport direction F, the positions of the pre-treatment liquid sub-tank 71 and the post-treatment liquid sub-tank 72 and the treatment heads to which they supply treatment liquid can be arranged so that the positional difference in the main scanning direction S between the pre-treatment liquid sub-tank 71 and the post-treatment liquid sub-tank 72 is minimal. Consequently, the distribution range of the pre-treatment liquid in the interconnected pre-treatment liquid sub-tank 71, the pipeline P, and the pre-treatment head 5 in the main scanning direction S can be reduced, making them less susceptible to the effects of the aforementioned acceleration. Similarly, the distribution range of the interconnected post-treatment liquid in the main scanning direction S can be reduced, making them less susceptible to the effects of the aforementioned acceleration.

[0211] Similarly, the positional differences between the ink sub-tanks 7A to 7F and the ink heads 4 to which they are supplied in the main scanning direction S can be minimized. This reduces the distribution range of the ink in the main scanning direction S, making it less susceptible to the acceleration.

[0212] <Example 10>

[0213] also, Figure 16 : is a top view of the carriage 3J showing the head arrangement according to the tenth embodiment. In the tenth embodiment, the ink head 4 includes a first ink head array 41 and a second ink head array 42. In this embodiment, the post-processing head 6 is located approximately in the center of the array of all the heads in the main scanning direction S, while the pre-processing head 5 is located at one end of the array (at the end of the ink head array). Figure 16In this case, the downstream head of the first ink head 4A and the pre-processing head 5 correspond to one end side head.

[0214] In this head configuration, LC = 11, B1 = 0, and B2 = 5. In this case, |(B1 - LC / 2)| / LC = 0.5, which does not satisfy the above equation 1. On the other hand, |(B2 - LC / 2)| / LC = 0.045, which satisfies the above equation 2. This head configuration is suitable for situations where the pretreatment liquid function has a margin for the required time difference between the landing of the pretreatment liquid and the landing of the ink ejected by the first ink head array 41, but the time difference between the landing of the ink ejected by the second ink head array 42 and the landing of the post-treatment liquid should be reduced.

[0215] <Example 11>

[0216] also, Figure 17 1 is a top view of a carriage 3K showing the head arrangement according to Example 11. In Example 11, the ink head 4 includes a first ink head array 41 and a second ink head array 42. In this embodiment, the post-processing head 6 is located approximately in the center of the array of all heads in the main scanning direction S, while the pre-processing head 5 is located at the other end of the array (at the end of the ink head array). Figure 17 In this case, the downstream side head of the first ink head 4A corresponds to one end side head.

[0217] In this head configuration, LC = 11, B1 = 10, and B2 = 5. In this case, |(B1 - LC / 2)| / LC = 0.409, which does not satisfy the above equation 1. On the other hand, |(B2 - LC / 2)| / LC = 0.045, which satisfies the above equation 2. Similar to Example 10, this head configuration is suitable for situations where the pretreatment liquid function has a margin for the required time difference between the landing of the pretreatment liquid and the landing of the ink ejected from the first ink head array 41, but the time difference between the landing of the ink ejected from the second ink head array 42 and the landing of the post-treatment liquid should be reduced.

[0218] Furthermore, contrary to the above-described embodiments 10 and 11, the arrangement of the pre-processing head 5 may satisfy equation 1, while the arrangement of the post-processing head 6 may not satisfy equation 2. This is suitable for situations where the post-processing liquid function has a margin for the time difference required from the landing of ink ejected from the second ink head array 42 to the landing of the post-processing liquid, but the time difference from the landing of the pre-processing liquid to the landing of ink ejected from the first ink head array 41 should be reduced.

[0219] <About Inkjet Recording Method>

[0220] As described above, the inkjet printer 1 described in each embodiment includes a single ink head array mounted on the carriage 3 at a predetermined position in the transport direction F, or multiple ink head arrays mounted on the carriage 3 aligned in the transport direction F, a pre-processing head, and a post-processing head. Each of the one or more ink head arrays includes multiple ink heads arranged in the main scanning direction S and each ejecting ink for image formation. The pre-processing head 5 is positioned upstream of the one or more ink head arrays in the transport direction F and ejects a non-colored pre-processing liquid. The post-processing head 6 is positioned downstream of the one or more ink head arrays in the transport direction F and ejects a non-colored post-processing liquid.

[0221] Furthermore, an inkjet recording method in the above-mentioned inkjet printer 1 includes: arranging the pre-processing head 5 in a manner satisfying the relationship |(B1-LC / 2)| / LC≤1 / 4 (Formula 1) when, among a plurality of ink heads 4 and processing heads (pre-processing head 5 and post-processing head 6), the head closest to one end side arranged in the main scanning direction S is the one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction S is LC, and the distance from the one end side head to the pre-processing head 5 in the main scanning direction S is B1; while moving the carriage 3 in the main scanning direction S, the pre-processing liquid is ejected from the pre-processing head 5 to a specified recording area on the workpiece W; while conveying the workpiece W along the conveying direction F at a specified conveying interval and moving the carriage 3 along the main scanning direction S, ink is ejected from the ink head 4 to the recording area to which the pre-processing liquid has been ejected.

[0222] This method enables efficient image formation on a workpiece W using an inkjet printer 1 in which the heads for discharging the pretreatment liquid and ink are mounted on a single carriage 3. Furthermore, because the pretreatment head 5 and the ink head 4 are sequentially arranged in the conveyance direction F, the pretreatment liquid and ink can be ejected onto the recording medium in a desired landing order. Furthermore, by appropriately arranging the pretreatment head 5 to satisfy Equation 1, the time difference between the landing of the pretreatment liquid and the landing of the ink can be minimized. As a result, variations in image quality on the workpiece W are minimized.

[0223] In the above method, the processing head mounted on the carriage 3 may be only the pre-processing head 5. Furthermore, in the above method, recording may be completed without applying the post-processing liquid, or the post-processing liquid may be applied after printing by the carriage 3 is completed. In the latter case, the post-processing liquid is applied to substantially the entire surface of the workpiece W by, for example, spraying, transfer using a roller, or immersion in the post-processing liquid.

[0224] In addition, another inkjet recording method in the above-mentioned inkjet printer 1 includes: configuring the post-processing head 6 in a manner that satisfies the relationship |(B2-LC / 2)| / LC≤1 / 4 (Formula 2); while moving the slide 3 in the main scanning direction S, ink is ejected from the ink head 4 to a specified recording area on the workpiece W; while transporting the workpiece W along the transport direction F at the transport spacing and moving the slide 3 along the main scanning direction S, post-processing liquid is ejected from the post-processing head 6 to the recording area to which the ink has been ejected.

[0225] This method enables efficient image formation on a workpiece W using an inkjet printer 1 in which the ink and post-processing liquid ejection heads are mounted on a single carriage. Furthermore, because the ink head 4 and post-processing head 6 are sequentially arranged in the conveyance direction, the ink and post-processing liquid can be ejected onto the workpiece W in a desired landing order. Furthermore, by appropriately arranging the post-processing head 6 to satisfy Equation 2, the time difference between ink landing and post-processing liquid landing can be minimized. As a result, variations in image quality on the workpiece W are minimized.

[0226] In the above method, the processing head mounted on the carriage 3 may be only the post-processing head 6. Furthermore, in the above method, recording may be completed without applying the pre-processing liquid, or the pre-processing liquid may be applied before printing using the carriage 3. In the latter case, the pre-processing liquid is applied to substantially the entire surface of the workpiece W by, for example, spraying, transfer using a roller, or immersion in the pre-processing liquid.

[0227] In addition, another inkjet recording method in the above-mentioned inkjet printer 1 includes: arranging the pre-processing head 5 and the post-processing head 6 on the slide 3 in a manner that satisfies Equations 1 and 2; while moving the slide 3 in the main scanning direction S, spraying the pre-processing liquid from the pre-processing head 5 to the specified recording area on the workpiece W; while conveying the workpiece W along the conveying direction F at a specified conveying spacing and moving the slide 3 along the main scanning direction S, spraying ink from the ink head 4 to the recording area that has been ejected with the pre-processing liquid; spraying ink from the ink head 4 to the recording area that has been ejected with the pre-processing liquid; while further conveying the workpiece W along the conveying direction F at the conveying spacing and moving the slide 3 along the main scanning direction S, spraying the post-processing liquid from the post-processing head 6 to the recording area that has been ejected with the ink.

[0228] According to this method, an image can be effectively formed on a workpiece W using a multifunctional all-in-one inkjet printer 1 in which three heads for discharging a pre-treatment liquid, ink, and post-treatment liquid are mounted on a single carriage 3. Furthermore, because the pre-treatment head 5, ink head 4, and post-treatment head 6 are sequentially arranged in the conveying direction F, the pre-treatment liquid, ink, and post-treatment liquid can be ejected onto the recording medium in a desired landing order. Furthermore, by appropriately arranging the pre-treatment head 5 and post-treatment head 6 to satisfy Equations 1 and 2, the time difference from the landing of the pre-treatment liquid to the landing of the ink, as well as the time difference from the landing of the ink to the landing of the post-treatment liquid, can be reduced. As a result, differences in image quality on the workpiece W are less likely to occur.

[0229] <About Comparative Example>

[0230] Figure 18 This is a top view of carriage 3Z1 showing the head configuration according to Comparative Example 1, which is compared with the present invention. In this head configuration of Comparative Example 1, LC = 13, B1 = 0, and B2 = 13. In this case, |(B1 - LC / 2)| / LC = 0.409, which does not satisfy Equation 1 above. Furthermore, |(B2 - LC / 2)| / LC = 0.682, which does not satisfy Equation 2 above.

[0231] same, Figure 19 This is a top view of carriage 3Z2 showing a head configuration according to Comparative Example 2, which is compared with the present invention. In this head configuration of Comparative Example 2, LC = 7, B1 = 0, and B2 = 7. In this case, |(B1 - LC / 2)| / LC = 0.5, which does not satisfy Equation 1 above. Furthermore, |(B2 - LC / 2)| / LC = 0.5, which does not satisfy Equation 2 above.

[0232] In the head configurations such as those in Comparative Examples 1 and 2, since the time difference from the landing of the pre-treatment liquid to the landing of the ink ejected from the first ink head array 41 becomes larger, and the time difference from the landing of the ink ejected from the second ink head array 42 to the landing of the post-treatment liquid also becomes larger, the image formed on the workpiece W is also likely to have differences.

[0233] [Summary of the Invention]

[0234] An inkjet recording device according to one aspect of the present invention includes a conveying unit, a carriage, one or more ink head arrays, and a processing head. The conveying unit conveys the recording medium along a prescribed conveying direction. The carriage reciprocates along a main scanning direction intersecting the conveying direction. The one or more ink head arrays are mounted on the carriage at prescribed positions in the conveying direction. The processing head is mounted on the carriage and is used to eject a non-colored processing liquid. Each of the one or more ink head arrays includes a plurality of ink heads arranged in an array along the main scanning direction for respectively ejecting ink for image formation. As the processing head, a pre-processing head for ejecting a pre-processing liquid serving as the processing liquid is provided, which is arranged upstream in the conveying direction relative to the one or more ink head arrays. Assuming that the head closest to one end side among the multiple ink heads and the processing heads in the main scanning direction is the one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the pre-processing head in the main scanning direction is B1, the pre-processing head is configured in a manner that satisfies the relationship of Formula 1.

[0235] |(B1-LC / 2)| / LC≤1 / 4 (Formula 1)

[0236] This configuration enables an inkjet recording device to be provided in which the heads for discharging pretreatment liquid and ink are mounted on a single carriage. Furthermore, since the pretreatment head and ink head are sequentially arranged in the conveying direction, the pretreatment liquid and ink can be discharged onto the recording medium in a desired landing order. Furthermore, by appropriately arranging the pretreatment head to satisfy Equation 1, the time difference between the landing of the pretreatment liquid and the landing of the ink can be minimized regardless of the direction of carriage movement. As a result, the pretreatment liquid and ink are sequentially landed on the recording medium, making it less likely that variations in image quality will occur on the recording medium.

[0237] In the above configuration, a plurality of the pre-processing heads may be arranged in the main scanning direction, and at least one of the plurality of pre-processing heads may be arranged so as to satisfy the relationship of Expression 1.

[0238] According to this configuration, even when multiple pre-treatment heads are provided, the time difference between the landing of the pre-treatment liquid and the landing of the ink can be reduced by configuring at least one of the pre-treatment heads to satisfy Formula 1. Furthermore, since the pre-treatment liquid can be ejected from other pre-treatment heads, the amount of ejectable treatment liquid can be increased.

[0239] In the above-described configuration, all of the plurality of pre-processing heads may be arranged so as to satisfy the relationship of Expression 1.

[0240] According to this configuration, by arranging the plurality of pre-processing heads so as to satisfy Expression 1, the time difference from the landing of the pre-processing liquid to the landing of the ink can be further reduced, and the amount of the process liquid that can be discharged can be increased.

[0241] In the above-mentioned structure, it can also be: as the processing head, there is also a post-processing head for ejecting a post-ejection liquid as the processing liquid, which is arranged on the downstream side relative to the one or more ink head columns in the conveying direction, and the ink head columns are arranged in multiple columns along the conveying direction. One of the multiple ink head columns has an ink head for ejecting ink of a specified color, and the other ink head columns in the multiple ink head columns have other ink heads that are arranged adjacent to the one ink head and eject the ink of the specified color. When the distance from the one end side head to the post-processing head in the main scanning direction is B2, the front processing head and the post-processing head are arranged in a manner that satisfies the relationship of the following formula.

[0242] |(B1+B2-LC) / LC|≤1 / 2.

[0243] According to this configuration, a multifunctional, all-in-one inkjet recording device can be provided, in which three heads for discharging a pre-treatment liquid, ink, and a post-treatment liquid are mounted on a single carriage. Furthermore, because the pre-treatment head, ink head, and post-treatment head are sequentially arranged in the conveying direction, the pre-treatment liquid, ink, and post-treatment liquid can be discharged onto the recording medium in a desired landing order. Furthermore, in a configuration in which the ink heads of multiple ink head arrays discharge ink of the same color to a predetermined discharge target area, it is possible to minimize the occurrence of a large difference in the time from the landing of the pre-treatment liquid to the landing of ink ejected from the ink head on the upstream side of the conveying direction, and a large difference in the time from the landing of ink ejected from the ink head on the downstream side of the conveying direction to the landing of the post-treatment liquid.

[0244] In addition, another aspect of the present invention relates to an inkjet recording device that includes a conveying unit, a carriage, one or more ink head arrays, and a processing head. The conveying unit conveys the recording medium along a specified conveying direction. The carriage reciprocates along a main scanning direction that intersects the conveying direction. The one or more ink head arrays are mounted on the carriage at specified positions in the conveying direction. The processing head is mounted on the carriage and is used to eject a non-colored processing liquid. Each of the one or more ink head arrays includes a plurality of ink heads arranged in a manner arranged along the main scanning direction for respectively ejecting ink for image formation. As the processing head, there is a post-processing head for ejecting a post-processing liquid as the processing liquid, which is arranged on the downstream side relative to the one or more ink head arrays in the conveying direction. Assuming that the head closest to one end side among the multiple ink heads and the processing heads in the main scanning direction is the one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the post-processing head in the main scanning direction is B2, the post-processing head is configured in a manner that satisfies the relationship of Formula 2.

[0245] |(B2-LC / 2)| / LC≤1 / 4 (Equation 2)

[0246] This configuration enables an inkjet recording device to be provided in which the ink and post-treatment liquid ejection heads are mounted on a single carriage. Furthermore, because the ink head and post-treatment head are sequentially arranged in the conveyance direction, the ink and post-treatment liquid can be ejected onto the recording medium in a desired landing order. Furthermore, by appropriately arranging the post-treatment heads to satisfy Equation 2, the time difference between ink landing and post-treatment liquid landing can be minimized regardless of the carriage's movement direction. As a result, variations in image quality on the recording medium are minimized.

[0247] In the above configuration, a plurality of the post-processing heads may be arranged in the main scanning direction, and at least one of the plurality of post-processing heads may be arranged so as to satisfy the relationship of Expression 2.

[0248] According to this configuration, even when multiple post-processing heads are provided, the time difference between the ink landing and the post-processing liquid landing can be reduced by configuring at least one of the post-processing heads to satisfy Equation 2. Furthermore, since the post-processing liquid can be ejected from other post-processing heads, the amount of ejectable processing liquid can be increased.

[0249] In the above configuration, all of the plurality of post-processing heads may be arranged so as to satisfy the relationship of Expression 2.

[0250] According to this configuration, by arranging the plurality of post-processing heads so as to satisfy Expression 2, the time difference from ink landing to post-processing liquid landing can be further reduced, and the amount of dischargeable processing liquid can be increased.

[0251] In the above-mentioned configuration, it may also be that: as the processing head, there is also a pre-processing head for ejecting a pre-ejecting liquid as the processing liquid, which is arranged on the upstream side relative to the one or more ink head columns in the conveying direction, and the ink head columns are arranged in a plurality of columns along the conveying direction, and one of the plurality of ink head columns has an ink head that ejects ink of a prescribed color, and the other ink head columns in the plurality of ink head columns have other ink heads that are arranged adjacent to the one ink head and eject ink of the prescribed color, and when the distance from the one end side head to the pre-processing head in the main scanning direction is B1, the pre-processing head and the post-processing head are arranged in a manner that satisfies the relationship of the following formula.

[0252] |(B1+B2-LC) / LC|≤1 / 2

[0253] According to this configuration, in a configuration in which ink of the same color is ejected from ink heads of multiple ink head arrays to a specified ejection target area, it is possible to suppress the increase in the time difference from the landing of the pre-treatment liquid to the landing of the ink ejected from the ink head on the upstream side of the conveying direction, and the time difference from the landing of the ink ejected from the ink head on the downstream side of the conveying direction to the landing of the post-treatment liquid.

[0254] In the above-mentioned configuration, the processing head may further include a pre-processing head for ejecting a pre-ejection liquid serving as the processing liquid and arranged upstream relative to the one or more ink head arrays in the conveying direction, wherein, when the distance from the one end side head to the pre-processing head in the main scanning direction is B1, the pre-processing head may be arranged so as to satisfy the following relationship: 1(B1-LC / 2)| / LC≤1 / 4

[0255] According to this configuration, by appropriately arranging the pre-processing head so as to satisfy the above-mentioned formula, it is possible to further reduce the time difference from the landing of the pre-processing liquid to the landing of the ink.

[0256] In the above configuration, the ink head arrays may be arranged in a plurality of rows along the transport direction, one of the plurality of ink head arrays may include one ink head for ejecting ink of a predetermined color, and the other ink head arrays may include other ink heads arranged adjacent to the one ink head and ejecting ink of the predetermined color, and the pre-processing head and the post-processing head may be arranged so as to satisfy the following relationship: |(B1+B2-LC) / LC|≤1 / 3

[0257] According to this configuration, in a configuration in which ink of the same color is ejected from ink heads of multiple ink head arrays to a specified ejection target area, it is possible to suppress the increase in the time difference from the landing of the pre-treatment liquid to the landing of the ink ejected from the ink head on the upstream side of the conveying direction, and the time difference from the landing of the ink ejected from the ink head on the downstream side of the conveying direction to the landing of the post-treatment liquid.

[0258] In the above configuration, the processing head may be arranged within a range of an arrangement width of the plurality of ink heads in the main scanning direction.

[0259] According to this inkjet recording apparatus, even when the processing head is mounted on the carriage, there is no need to increase the width of the carriage in the main scanning direction.

[0260] In the above configuration, the processing head may be arranged so that a portion thereof enters between a pair of ink heads that are adjacent to each other in the main scanning direction among the plurality of ink heads included in one head row.

[0261] According to this inkjet recording apparatus, ink heads and processing heads arranged at different positions in the transport direction (sub-scanning direction) can be arranged at high density in the transport direction, thereby miniaturizing the width of the carriage in the transport direction.

[0262] In the above-mentioned configuration, the processing head may be arranged in such a manner that a part of the processing head is adjacent to the ink head in the main scanning direction and the conveying direction, and the plurality of ink heads include a plurality of same-color ink heads that eject ink of the same color, and when counting the number of adjacent processing heads in the main scanning direction and the conveying direction for each of the same-color ink heads, the difference between the maximum and minimum values of their count values is less than 1.

[0263] Typically, a head that ejects liquid using a jetting method generates heat because it uses electricity to pressurize the liquid. In particular, unlike an ink head that ejects only when forming dots of a desired color, a processing head that ejects for all colors is more likely to reach high temperatures. Ink heads adjacent to such a processing head are more likely to reach high temperatures, and the amount of ink ejected may differ from that of ink heads not adjacent to the processing head. As described above, by setting the difference between the maximum and minimum counts of each ink head of the same color adjacent to the processing head to less than 1, it is less likely that a large difference in ink ejection volume will occur between multiple ink heads of the same color.

[0264] In the above-mentioned configuration, it may also be that: the processing head is arranged in such a manner that a part of it is adjacent to the ink head in the main scanning direction and the conveying direction, and the multiple ink heads include at least a first ink head that ejects ink of a first color and a second ink head that ejects ink of a second color, and when the number of the processing heads adjacent to the first ink head is greater than the number of the processing heads adjacent to the second ink head, the first ink head ejects ink having a smaller viscosity change due to temperature than the ink of the second color as the ink of the first color.

[0265] According to this inkjet recording device, the first ink head, which has a larger number of adjacent processing heads, ejects ink whose viscosity changes less with temperature. Therefore, even if the first ink head is heated by the processing head, the temperature-related changes in the ejection volume and ejection speed of the first color ink can be reduced.

[0266] In the above configuration, the processing head may be arranged in a central region of an arrangement width of the ink head array in the main scanning direction.

[0267] Alternatively, it may also be: the processing head includes: a pre-processing head, which is arranged on the upstream side of the one or more ink head columns in the conveying direction, and is used to eject the pre-processing liquid as the processing liquid; and a post-processing head, which is arranged on the downstream side of the one or more ink head columns in the conveying direction, and is used to eject the post-processing liquid as the processing liquid, wherein the pre-processing head and the post-processing head are arranged in such a manner that the configuration or arrangement center of one or more of the pre-processing heads in the main scanning direction is consistent with the configuration or arrangement center of one or more of the post-processing heads in the main scanning direction.

[0268] According to these inkjet recording apparatuses, it is possible to reduce, in particular, the difference in time from when the pre-treatment liquid lands on the recording medium to when the ink lands, and the difference in time from when the ink lands to when the post-treatment liquid lands, at each main scanning position.

[0269] In the above-mentioned inkjet recording device, it can also be: when the number of the pre-processing heads and the post-processing heads with more heads is set to m, and the number of the post-processing heads with less heads is set to n, the requirement of m=n+odd number is satisfied, and the configuration or arrangement center of the pre-processing heads and the post-processing heads is consistent with the configuration position of one of the multiple ink heads in the main scanning direction.

[0270] This inkjet recording device allows the pre-processing head and post-processing head to be mounted on the carriage in a somewhat centralized manner. This reduces the number of inkjet heads positioned close to the processing heads. This reduces the likelihood of pre-processing and post-processing liquids coming into contact with the ink on the carriage.

[0271] In the above-mentioned inkjet recording device, it can also be: as the processing head, it includes: a pre-processing head, which is arranged on the upstream side of the one or more ink head columns in the conveying direction, and is used to eject the pre-processing liquid as the processing liquid; and a post-processing head, which is arranged on the downstream side of the one or more ink head columns in the conveying direction, and is used to eject the post-processing liquid as the processing liquid. The inkjet recording device also includes: a holding component, which holds the slide in a state capable of reciprocating along the main scanning direction, wherein the slide includes a locking portion, and the slide is held by the holding component in a cantilever state through the locking portion, and in the conveying direction, the pre-processing head is arranged closer to the locking portion than the post-processing head.

[0272] According to this inkjet recording device, the carriage is supported in a cantilevered configuration by a retaining member, thereby enabling a simple structure. Furthermore, by supporting the carriage in a cantilevered configuration, a single-sided structure with the carriage exposed can be easily configured, facilitating maintenance of the inkjet head and processing head. When the carriage is supported in a cantilevered configuration, height accuracy is likely to decrease on the side of the carriage away from the engaging portion. However, since the post-processing head, which has relatively high requirements for ejection accuracy, is mounted on the side away from the engaging portion, this is unlikely to significantly impact image quality.

[0273] In the above-mentioned inkjet recording device, it can also be: as the processing head, it includes: a pre-processing head, which is arranged on the upstream side of the one or more ink head columns in the conveying direction, and is used to eject the pre-processing liquid as the processing liquid; and a post-processing head, which is arranged on the downstream side of the one or more ink head columns in the conveying direction, and is used to eject the post-processing liquid as the processing liquid. The inkjet recording device also includes: a holding component, which holds the slide in a state capable of reciprocating along the main scanning direction, wherein the slide includes a locking portion, and the slide is held by the holding component in a cantilever state through the locking portion, and the side with fewer heads among the pre-processing head and the post-processing head is arranged on the locking portion side of the slide.

[0274] As described above, the treatment head generates heat during the ejection operation. Consequently, the carriage carrying the treatment head is heated, potentially causing thermal deformation of the carriage and its retaining structure. In a configuration where the carriage is held in a cantilevered position, this thermal deformation can sometimes affect ink placement accuracy. With this configuration, the number of treatment heads positioned near the base end can be reduced, minimizing the impact of thermal deformation.

[0275] The above-mentioned inkjet recording device may also include: a holding component for holding the slide in a state where it can move back and forth along the main scanning direction, wherein the slide includes a locking portion, and the slide is held by the holding component in a cantilever state through the locking portion. In the head arrangement body of the ink head and the processing head, the head arranged on the side of the locking portion closest to the slide is the processing head, and the processing head is arranged at a position in the head arrangement body other than the end of the main scanning direction.

[0276] According to this inkjet recording device, in the head array body (head configuration area), the head arranged on the side closest to the engaging portion is the processing head, and this processing head is not arranged at the end of the head array body in the main scanning direction. Generally speaking, the end in the main scanning direction is closest to the end (corner) of the carriage. If thermal deformation occurs near the end of the carriage, that is, the base end, the positional accuracy of the head mounted on the carriage is reduced. According to the above configuration, this problem is less likely to occur.

[0277] The above-mentioned inkjet recording device may also include: a plurality of ink sub-tanks, which supply the ink to each of the plurality of ink heads; and a treatment liquid sub-tank, which supplies the treatment liquid to the treatment head, wherein the plurality of ink sub-tanks are mounted on the slide in a manner arranged along the main scanning direction, and the treatment liquid sub-tank is mounted on a position of the slide in the conveying direction that is different from the plurality of ink sub-tanks.

[0278] According to the above configuration, the ink sub-tank and the processing head sub-tank are positioned at different locations in the conveying direction. This allows the sub-tanks to be positioned within a relatively narrow range on the carriage. Furthermore, the liquid in the sub-tank, carried on the carriage as it reciprocates in the main scanning direction, is subjected to acceleration in the main scanning direction. The sub-tanks are connected to the head via prescribed conduits. However, if the sub-tanks are widely distributed on the carriage, the conduit placement range in the main scanning direction also increases, increasing the impact of the acceleration and potentially causing meniscus damage in the ejection portion of the head. According to the above configuration, the conduit placement range in the main scanning direction can be relatively narrow.

[0279] Furthermore, another aspect of the present invention relates to an inkjet recording method of an inkjet recording device, wherein the inkjet recording device comprises: a conveying portion for conveying a recording medium along a predetermined conveying direction; a carriage for reciprocating along a main scanning direction intersecting the conveying direction; one or more ink head arrays mounted on the carriage at predetermined positions in the conveying direction; and a processing head mounted on the carriage for ejecting a non-colored processing liquid, wherein each of the one or more ink head arrays includes a plurality of ink heads arranged in an array along the main scanning direction for ejecting ink for image formation, and as the processing head, A pre-treatment head for ejecting a pre-treatment liquid serving as the treatment liquid is provided on the upstream side relative to the one or more ink head arrays in the conveying direction, the inkjet recording method comprising: arranging the pre-treatment head in a manner satisfying the relationship |(B1-LC / 2)| / LC≤1 / 4 (Formula 1) when the head closest to one end side among the multiple ink heads and the treatment heads in the main scanning direction is a one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the pre-treatment head in the main scanning direction is B1; ejecting the pre-treatment liquid from the pre-treatment head toward a specified recording area on the recording medium while moving the carriage toward the main scanning direction; ejecting the ink from the ink head toward the recording area to which the pre-treatment liquid has been ejected while conveying the recording medium along the conveying direction and moving the carriage along the main scanning direction.

[0280] According to this method, an inkjet recording device in which the heads for discharging pretreatment liquid and ink are mounted on a single carriage can be used to efficiently form an image on a recording medium. In particular, because the pretreatment head and ink head are sequentially arranged in the conveyance direction, the pretreatment liquid and ink can be ejected onto the recording medium in a desired landing order. Furthermore, by appropriately arranging the pretreatment heads to satisfy Equation 1, the time difference between the landing of the pretreatment liquid and the landing of the ink can be minimized, regardless of the carriage's direction of movement. As a result, variations in image quality on the recording medium are less likely to occur.

[0281] Furthermore, another aspect of the present invention relates to an inkjet recording method of an inkjet recording device, wherein the inkjet recording device comprises: a conveying portion for conveying a recording medium along a predetermined conveying direction; a carriage for reciprocating along a main scanning direction intersecting the conveying direction; one or more ink head arrays mounted on the carriage at predetermined positions in the conveying direction; and a processing head mounted on the carriage for ejecting a non-colored processing liquid, wherein each of the one or more ink head arrays includes a plurality of ink heads arranged in an array along the main scanning direction for ejecting ink for image formation, and as the processing head, A post-processing head for ejecting a post-processing liquid as the processing liquid is provided on the downstream side relative to the one or more ink head columns in the conveying direction, and the inkjet recording method includes: arranging the post-processing head in a manner satisfying the relationship |(B2-LC / 2)| / LC≤1 / 4 (Formula 2) when the head closest to one end side among the multiple ink heads and the processing heads in the main scanning direction is a one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the post-processing head in the main scanning direction is B2; ejecting the ink from the ink head toward a specified recording area on the recording medium while moving the carriage toward the main scanning direction; and ejecting the post-processing liquid from the post-processing head toward the recording area from which the ink has been ejected while further conveying the recording medium along the conveying direction and moving the carriage toward the main scanning direction.

[0282] This method enables efficient image formation on a recording medium using an inkjet recording device in which the ink and post-treatment liquid ejection heads are mounted on a single carriage. In particular, because the inkjet head and post-treatment liquid ejection heads are sequentially arranged in the conveyance direction, the ink and post-treatment liquid can be ejected onto the recording medium in a desired landing order. Furthermore, by appropriately arranging the post-treatment heads to satisfy Equation 2, the time difference between ink landing and post-treatment liquid landing can be minimized regardless of the carriage's movement direction. As a result, variations in image quality on the recording medium are minimized.

[0283] According to the present invention, an inkjet recording apparatus and an inkjet recording method can be provided that include a carriage that carries an ink head and a processing head and moves in a main scanning direction and can reduce a time difference between ink landing and processing liquid landing.

[0284] Explanation of symbols

[0285] 1 Inkjet printer (ink head recording device)

[0286] 16 Timing belt (moving part)

[0287] 17 Guide rail (holding component)

[0288] 20 Workpiece conveying unit (conveying unit)

[0289] 3. 3A to 3J carriages

[0290] 31 head support frame

[0291] 32 rear frame (locking part)

[0292] 4 ink heads

[0293] 41 First ink head array (ink head array)

[0294] 42 Second ink head row (ink head row)

[0295] 43 Third ink head row (ink head row)

[0296] 4A to 4F: First to sixth ink heads

[0297] 4A1 to 4F1 upstream side head

[0298] 4A2 to 4F2 downstream side head

[0299] 5. Pre-processing head (processing head)

[0300] 6 Post-processing head (processing head)

[0301] 7 secondary containers

[0302] 7A to 7F ink sub-tanks

[0303] 71 Auxiliary container for pretreatment liquid

[0304] 72 Auxiliary container for post-processing liquid

[0305] F Conveying direction

[0306] S Main scanning direction

[0307] W Workpiece (recording medium)

Claims

1. An inkjet recording device, characterized in that include: a conveying portion for conveying the recording medium along a prescribed conveying direction; a carriage reciprocating along a main scanning direction intersecting the conveying direction; One or more ink head arrays are mounted on the carriage at predetermined positions in the transport direction; and The processing head is mounted on the carriage and is used to eject a non-colored processing liquid, wherein Each of the one or more ink head arrays includes a plurality of ink heads arranged in a row along the main scanning direction for ejecting ink for image formation. As the processing head, a pre-processing head for ejecting a pre-processing liquid as the processing liquid is provided, which is arranged upstream of the one or more ink head arrays in the transport direction. Assuming that the head closest to one end side among the plurality of ink heads and the processing heads in the main scanning direction is the one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the pre-processing head in the main scanning direction is B1, the pre-processing head is arranged so as to satisfy the relationship of Formula 1, |(B1−LC / 2)| / LC ≤ 1 / 4 (Equation 1).

2. The inkjet recording device according to claim 1, wherein A plurality of the pre-processing heads are arranged in the main scanning direction, and at least one of the plurality of pre-processing heads is arranged so as to satisfy the relationship of Expression 1.

3. The inkjet recording device according to claim 2, wherein All of the plurality of pre-processing heads are arranged so as to satisfy the relationship of Expression 1.

4. The inkjet recording device according to claim 1, wherein The processing head further includes a post-processing head disposed downstream of the one or more ink head arrays in the transport direction and configured to discharge a post-discharge liquid serving as the processing liquid. The ink head arrays are arranged in a plurality of rows along the transport direction. One of the plurality of ink head arrays includes an ink head for ejecting ink of a predetermined color. The other ink head arrays in the plurality of ink head arrays include other ink heads that are arranged adjacent to the one ink head and eject ink of the predetermined color. When the distance from the one end side head to the post-processing head in the main scanning direction is B2, the pre-processing head and the post-processing head are arranged so as to satisfy the relationship of the following formula: |(B1+B2−LC) / LC| ≤ 1 / 2.

5. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head is arranged within a range of an arrangement width of the plurality of ink heads in the main scanning direction.

6. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head is arranged so that a portion thereof enters between a pair of ink heads that are adjacent to each other in the main scanning direction among the plurality of ink heads included in one head row.

7. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head is arranged so that a portion thereof is adjacent to the ink head in the main scanning direction and the transport direction. The plurality of ink heads include a plurality of ink heads of the same color that eject ink of the same color, When the number of adjacent processing heads in the main scanning direction and the conveying direction is counted for each of the ink heads of the same color, the difference between the maximum and minimum count values is 1 or less.

8. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head is arranged so that a portion thereof is adjacent to the ink head in the main scanning direction and the transport direction. The plurality of ink heads include at least a first ink head for ejecting ink of a first color and a second ink head for ejecting ink of a second color. When the number of processing heads adjacent to the first ink head is greater than the number of processing heads adjacent to the second ink head, the first ink head ejects ink having a viscosity that changes less with temperature than the second color ink as the first color ink.

9. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head is arranged in a central area of the arrangement width of the ink head array in the main scanning direction.

10. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head includes: a pre-processing head arranged upstream of the one or more ink head arrays in the transport direction and configured to eject a pre-processing liquid serving as the processing liquid; and A post-processing head is arranged on the downstream side of the one or more ink head arrays in the conveying direction and is used to eject a post-processing liquid as the processing liquid, wherein The pre-processing heads and the post-processing heads are arranged so that the arrangement or arrangement center of one or more pre-processing heads in the main scanning direction coincides with the arrangement or arrangement center of one or more post-processing heads in the main scanning direction.

11. The inkjet recording device according to claim 10, wherein When the number of the pre-processing heads and the post-processing heads that has a larger number is set to m and the number of the post-processing heads that has a smaller number is set to n, the requirement of m=n+odd number is satisfied. The arrangement or arrangement center of the pre-processing head and the post-processing head coincides with the arrangement position of one of the plurality of ink heads in the main scanning direction.

12. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head includes: a pre-processing head arranged upstream of the one or more ink head arrays in the transport direction and configured to eject a pre-processing liquid serving as the processing liquid; and a post-processing head disposed on a downstream side of the one or more ink head arrays in the transport direction and configured to eject a post-processing liquid serving as the processing liquid; The inkjet recording device further includes a holding member for holding the carriage in a state where the carriage can reciprocate along the main scanning direction. The slide includes an engaging portion, and the slide is held by the holding member in a cantilevered state through the engaging portion. The pre-processing head is arranged closer to the engaging portion than the post-processing head in the conveying direction.

13. The inkjet recording device according to any one of claims 1 to 4, characterized in that The processing head includes: a pre-processing head arranged upstream of the one or more ink head arrays in the transport direction and configured to eject a pre-processing liquid serving as the processing liquid; and a post-processing head disposed on a downstream side of the one or more ink head arrays in the transport direction and configured to eject a post-processing liquid serving as the processing liquid; The inkjet recording device further includes a holding member for holding the carriage in a state where the carriage can reciprocate along the main scanning direction. The slide includes an engaging portion, and the slide is held by the holding member in a cantilevered state through the engaging portion. The pre-processing head or the post-processing head, whichever has a smaller number of heads, is arranged on the engaging portion side of the carriage.

14. The inkjet recording device according to any one of claims 1 to 4, characterized in that Also includes: A holding member holds the carriage in a state where the carriage can reciprocate along the main scanning direction, wherein The slide includes an engaging portion, and the slide is held by the holding member in a cantilevered state through the engaging portion. In the head array of the ink heads and the processing heads, the head disposed closest to the engaging portion of the carriage is the processing head, and the processing head is disposed at a position other than an end in the main scanning direction in the head array.

15. The inkjet recording device according to any one of claims 1 to 4, characterized in that Also includes: a plurality of ink sub-tanks for supplying the ink to each of the plurality of ink heads; and The processing liquid auxiliary tank supplies the processing liquid to the processing head, wherein The plurality of ink sub-tanks are mounted on the carriage so as to be aligned in the main scanning direction, and the processing liquid sub-tank is mounted on the carriage at a position different from the plurality of ink sub-tanks in the transport direction.

16. An inkjet recording device, characterized in that include: a conveying portion for conveying the recording medium along a prescribed conveying direction; a carriage reciprocating along a main scanning direction intersecting the conveying direction; One or more ink head arrays are mounted on the carriage at predetermined positions in the transport direction; and The processing head is mounted on the carriage and is used to eject a non-colored processing liquid, wherein Each of the one or more ink head arrays includes a plurality of ink heads arranged in a row along the main scanning direction for ejecting ink for image formation. As the processing head, a post-processing head for ejecting a post-processing liquid as the processing liquid is provided, which is arranged downstream of the one or more ink head arrays in the transport direction. Assuming that the head closest to one end side among the plurality of ink heads and the processing heads in the main scanning direction is the one end side head, the head closest to the other end side is the other end side head, the distance from the one end side head to the other end side head in the main scanning direction is LC, and the distance from the one end side head to the post-processing head in the main scanning direction is B2, the post-processing head is arranged so as to satisfy the relationship of Formula 2, |(B2−LC / 2)| / LC ≤ 1 / 4 (Formula 2).

17. The inkjet recording device according to claim 16, wherein A plurality of post-processing heads are arranged in the main scanning direction, and at least one of the plurality of post-processing heads is arranged so as to satisfy the relationship of Expression 2.

18. The inkjet recording device according to claim 16, wherein The processing head further includes a pre-processing head disposed upstream of the one or more ink head arrays in the transport direction and configured to discharge a pre-discharge liquid serving as the processing liquid. The ink head arrays are arranged in a plurality of rows along the transport direction. One of the plurality of ink head arrays includes an ink head that ejects ink of a predetermined color. The other ink head arrays in the plurality of ink head arrays include other ink heads that are arranged adjacent to the one ink head and eject ink of the predetermined color. When the distance from the one end side head to the pre-processing head in the main scanning direction is B1, the pre-processing head and the post-processing head are arranged so as to satisfy the relationship of the following formula: |(B1+B2−LC) / LC| ≤ 1 / 2.

19. The inkjet recording device according to claim 16, wherein The processing head further includes a pre-processing head disposed upstream of the one or more ink head arrays in the transport direction and configured to discharge a pre-discharge liquid serving as the processing liquid. When the distance from the one end side head to the pre-processing head in the main scanning direction is B1, the pre-processing head is arranged so as to satisfy the following relationship: |(B1−LC / 2)| / LC ≤ 1 / 4.

20. The inkjet recording device according to claim 19, wherein The ink head arrays are arranged in a plurality of rows along the transport direction. One of the plurality of ink head arrays includes an ink head for ejecting ink of a predetermined color. The other ink head arrays in the plurality of ink head arrays include other ink heads that are arranged adjacent to the one ink head and eject ink of the predetermined color. The pre-processing head and the post-processing head are arranged so as to satisfy the relationship of the following formula: |(B1+B2−LC) / LC| ≤ 1 / 3.

21. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head is arranged within a range of an arrangement width of the plurality of ink heads in the main scanning direction.

22. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head is arranged so that a portion thereof enters between a pair of ink heads that are adjacent to each other in the main scanning direction among the plurality of ink heads included in one head row.

23. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head is arranged so that a portion thereof is adjacent to the ink head in the main scanning direction and the transport direction. The plurality of ink heads include a plurality of ink heads of the same color that eject ink of the same color, When the number of adjacent processing heads in the main scanning direction and the conveying direction is counted for each of the ink heads of the same color, the difference between the maximum and minimum count values is 1 or less.

24. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head is arranged so that a portion thereof is adjacent to the ink head in the main scanning direction and the transport direction. The plurality of ink heads include at least a first ink head for ejecting ink of a first color and a second ink head for ejecting ink of a second color. When the number of the processing heads adjacent to the first ink head is greater than the number of the processing heads adjacent to the second ink head, the first ink head ejects ink having a smaller viscosity change due to temperature than the second color ink as the first color ink.

25. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head is arranged in a central area of the arrangement width of the ink head array in the main scanning direction.

26. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head includes: a pre-processing head arranged upstream of the one or more ink head arrays in the transport direction and configured to eject a pre-processing liquid serving as the processing liquid; and A post-processing head is arranged on the downstream side of the one or more ink head arrays in the conveying direction and is used to eject a post-processing liquid as the processing liquid, wherein The pre-processing heads and the post-processing heads are arranged so that the arrangement or arrangement center of one or more pre-processing heads in the main scanning direction coincides with the arrangement or arrangement center of one or more post-processing heads in the main scanning direction.

27. The inkjet recording device according to claim 26, wherein When the number of the pre-processing heads and the post-processing heads that has a larger number is set to m and the number of the post-processing heads that has a smaller number is set to n, the requirement of m=n+odd number is satisfied. The arrangement or arrangement center of the pre-processing head and the post-processing head coincides with the arrangement position of one of the plurality of ink heads in the main scanning direction.

28. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head includes: a pre-processing head arranged upstream of the one or more ink head arrays in the transport direction and configured to eject a pre-processing liquid serving as the processing liquid; and a post-processing head disposed on a downstream side of the one or more ink head arrays in the transport direction and configured to eject a post-processing liquid serving as the processing liquid; The inkjet recording device further includes a holding member for holding the carriage in a state where the carriage can reciprocate along the main scanning direction. The slide includes an engaging portion, and the slide is held by the holding member in a cantilevered state through the engaging portion. The pre-processing head is arranged closer to the engaging portion than the post-processing head in the conveying direction.

29. The inkjet recording device according to any one of claims 16 to 20, characterized in that The processing head includes: a pre-processing head arranged upstream of the one or more ink head arrays in the transport direction and configured to eject a pre-processing liquid serving as the processing liquid; and a post-processing head disposed on a downstream side of the one or more ink head arrays in the transport direction and configured to eject a post-processing liquid serving as the processing liquid; The inkjet recording device further includes a holding member for holding the carriage in a state where the carriage can reciprocate along the main scanning direction. The slide includes an engaging portion, and the slide is held by the holding member in a cantilevered state through the engaging portion. The pre-processing head and the post-processing head, whichever has a smaller number of heads, is arranged on the engaging portion side of the carriage.

30. The inkjet recording device according to any one of claims 16 to 20, characterized in that Also includes: A holding member holds the carriage in a state where the carriage can reciprocate along the main scanning direction, wherein The slide includes an engaging portion, and the slide is held by the holding member in a cantilevered state through the engaging portion. In the head array of the ink heads and the processing heads, the head disposed closest to the engaging portion of the carriage is the processing head, and the processing head is disposed at a position other than an end in the main scanning direction in the head array.

31. The inkjet recording device according to any one of claims 16 to 20, characterized in that Also includes: a plurality of ink sub-tanks for supplying the ink to each of the plurality of ink heads; and The processing liquid auxiliary tank supplies the processing liquid to the processing head, wherein The plurality of ink sub-tanks are mounted on the carriage so as to be aligned in the main scanning direction, and the processing liquid sub-tank is mounted on the carriage at a position different from the plurality of ink sub-tanks in the transport direction.

Images